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Author SHA1 Message Date
Dominique Quatravaux
83a559f7b9 Remove unused variable un darwin_nat_target::resume 
gdb/ChangeLog:

	* darwin-nat.c (darwin_nat_target::resume): Remove status
	variable.

Change-Id: Ibcbdd6641a12252840c7dea9f388f4f8ce265e3d
 2021-04-08 15:22:49 -04:00
Felix Willgerodt
16e311ab6d gdb: Allow prologue detection via symbols for Intel compilers. 
The next-gen Intel Fortran compiler isn't flang-based, but emits
prologue_end in the same manner.  As do the newer Intel C/C++ compilers.
This allows prologue detection based on dwarf for all newer Intel compilers.
The cut-off version was not chosen for any specific reason other than the
effort to test this.

gdb/Changelog:
2021-04-08  Felix Willgerodt  <felix.willgerodt@intel.com>

    	* i386-tdep.c (i386_skip_prologue): Use symbol table to find the
    	prologue end for Intel compilers.
    	* amd64-tdep.c (amd64_skip_prologue): Likewise.
    	* producer.c (producer_is_icc_ge_19): New function.
    	* producer.h (producer_is_icc_ge_19): New declaration.
 2021-04-08 09:19:57 +02:00
Felix Willgerodt
fbb3bcfcd8 gdb: Update producer check for Intel compilers. 
The main goal of this patch is to get rid of a warning for the new Fortran
compiler:

(gdb) b 9
warning: Could not recognize version of Intel Compiler in: "Intel(R) Fortran 21.0-2087b"
Breakpoint 1 at 0x4048cf: file comp.f90, line 9.

While trying to fix this I analyzed DW_AT_producer of all latest Intel
compilers for C, C++ and Fortran.  They do no longer necessarily start with
"Intel (R)" nor do they follow the internal and external version number
scheme that the original patch for this check assumed.  Some newer compilers
even contradict the "intermediate" digit in the old version scheme and have
the MINOR number as the second digit, even when having 3 or 4 digits overall.

Therefore I rewrote the check to consider the first MAJOR.MINOR string found
as the version number.  This might not be 100% correct for some older
internal compilers, but the only current user of this function is only
checking for the major version anyway.  Hence this should be reliable enough
and extendable enough going forward.

gdb/ChangeLog:
2021-04-08  Felix Willgerodt  <felix.willgerodt@intel.com>

    	* producer.c: (producer_is_icc): Update for new version scheme.
    	(producer_parsing_tests): Update names and expected results.
    	* producer.h: (producer_is_icc): Update comment accordingly.
 2021-04-08 09:18:55 +02:00
Simon Marchi
e97007b64a gdb: make target_ops::follow_fork return void 
I noticed that all implementations return false, so
target_ops::follow_fork doesn't really need to return a value.  Change
it to return void.

gdb/ChangeLog:

	* target.h (struct target_ops) <follow_fork>: Return void.
	(target_follow_fork): Likewise.
	* target.c (default_follow_fork): Likewise.
	(target_follow_fork): Likewise.
	* infrun.c (follow_fork_inferior): Adjust.
	* fbsd-nat.h (class fbsd_nat_target) <follow_fork>: Return void.
	* fbsd-nat.c (fbsd_nat_target:::follow_fork): Likewise.
	* linux-nat.h (class linux_nat_target) <follow_fork>: Likewise.
	* linux-nat.c (linux_nat_target::follow_fork): Return void.
	* obsd-nat.h (class obsd_nat_target) <follow_fork>: Return void.
	* obsd-nat.c (obsd_nat_target::follow_fork): Likewise.
	* remote.c (class remote_target) <follow_fork>: Likewise.
	(remote_target::follow_fork): Likewise.
	* target-delegates.c: Re-generate.

Change-Id: If908c2f68b29fa275be2b0b9deb41e4c6a1b7879
 2021-04-07 16:57:29 -04:00
Weimin Pan
dc2b480f3d CTF: handle forward reference type 
Added function fetch_tid_type which calls get_tid_type and will set up
the type, associated with a tid, if it is not read in yet. Also implement
function read_forward_type which handles the CTF_K_FORWARD kind.

Expanded gdb.base/ctf-ptype.exp to add cases with forward references.

gdb/ChangeLog:
       * ctfread.c (fetch_tid_type): New function, use throughout file.
       (read_forward_type): New function.
       (read_type_record): Call read_forward_type.

gdb/testsuite/ChangeLog:
       * gdb.base/ctf-ptype.c: Add struct link containing a forward
       reference type.
       * gdb.base/ctf-ptype.exp: Add "ptype struct link".
 2021-04-07 14:07:48 -04:00
Andrew Burgess
0a703a4ced gdb/fortran: handle dynamic types within arrays and structures 
This commit replaces this patch:

  https://sourceware.org/pipermail/gdb-patches/2021-January/174933.html

which was itself a replacement for this patch:

  https://sourceware.org/pipermail/gdb-patches/2020-July/170335.html

The motivation behind the original patch can be seen in the new test,
which currently gives a GDB session like this:

  (gdb) ptype var8
  type = Type type6
      PTR TO -> ( Type type2 :: ptr_1 )
      PTR TO -> ( Type type2 :: ptr_2 )
  End Type type6
  (gdb) ptype var8%ptr_2
  type = PTR TO -> ( Type type2
      integer(kind=4) :: spacer
      Type type1, allocatable :: t2_array(:)	<------ Issue #1
  End Type type2 )
  (gdb) ptype var8%ptr_2%t2_array
  Cannot access memory at address 0x38		<------ Issue #2
  (gdb)

Issue #1: Here we see the abstract dynamic type, rather than the
resolved concrete type.  Though in some cases the user might be
interested in the abstract dynamic type, I think that in most cases
showing the resolved concrete type will be of more use.  Plus, the
user can always figure out the dynamic type (by source code inspection
if nothing else) given the concrete type, but it is much harder to
figure out the concrete type given only the dynamic type.

Issue #2: In this example, GDB evaluates the expression in
EVAL_AVOID_SIDE_EFFECTS mode (due to ptype).  The value returned for
var8%ptr_2 will be a non-lazy, zero value of the correct dynamic
type.  However, when GDB asks about the type of t2_array this requires
GDB to access the value of var8%ptr_2 in order to read the dynamic
properties.  As this value was forced to zero (thanks to the use of
EVAL_AVOID_SIDE_EFFECTS) then GDB ends up accessing memory at a base
of zero plus some offset.

Both this patch, and my previous two attempts, have all tried to
resolve this problem by stopping EVAL_AVOID_SIDE_EFFECTS replacing the
result value with a zero value in some cases.

This new patch is influenced by how Ada handles its tagged typed.
There are plenty of examples in ada-lang.c, but one specific case is
ada_structop_operation::evaluate.  When GDB spots that we are dealing
with a tagged (dynamic) type, and we're in EVAL_AVOID_SIDE_EFFECTS
mode, then GDB re-evaluates the child operation in EVAL_NORMAL mode.

This commit handles two cases like this specifically for Fortran, a
new fortran_structop_operation, and the already existing
fortran_undetermined, which is where we handle array accesses.

In these two locations we spot when we are dealing with a dynamic type
and re-evaluate the child operation in EVAL_NORMAL mode so that we
are able to access the dynamic properties of the type.

The rest of this commit message is my attempt to record why my
previous patches failed.

To understand my second patch, and why it failed lets consider two
expressions, this Fortran expression:

  (gdb) ptype var8%ptr_2%t2_array	--<A>
  Operation: STRUCTOP_STRUCT		--(1)
   Operation: STRUCTOP_STRUCT		--(2)
    Operation: OP_VAR_VALUE		--(3)
     Symbol: var8
     Block: 0x3980ac0
    String: ptr_2
   String: t2_array

And this C expression:

  (gdb) ptype ptr && ptr->a == 3	--<B>
  Operation: BINOP_LOGICAL_AND		--(4)
   Operation: OP_VAR_VALUE		--(5)
    Symbol: ptr
    Block: 0x45a2a00
   Operation: BINOP_EQUAL		--(6)
    Operation: STRUCTOP_PTR		--(7)
     Operation: OP_VAR_VALUE		--(8)
      Symbol: ptr
      Block: 0x45a2a00
     String: a
    Operation: OP_LONG			--(9)
     Type: int
     Constant: 0x0000000000000003

In expression <A> we should assume that t2_array is of dynamic type.
Nothing has dynamic type in expression <B>.

This is how GDB currently handles expression <A>, in all cases,
EVAL_AVOID_SIDE_EFFECTS or EVAL_NORMAL, an OP_VAR_VALUE operation
always returns the real value of the symbol, this is not forced to a
zero value even in EVAL_AVOID_SIDE_EFFECTS mode.  This means that (3),
(5), and (8) will always return a real lazy value for the symbol.

However a STRUCTOP_STRUCT will always replace its result with a
non-lazy, zero value with the same type as its result.  So (2) will
lookup the field ptr_2 and create a zero value with that type.  In
this case the type is a pointer to a dynamic type.

Then, when we evaluate (1) to figure out the resolved type of
t2_array, we need to read the types dynamic properties.  These
properties are stored in memory relative to the objects base address,
and the base address is in var8%ptr_2, which we already figured out
has the value zero.  GDB then evaluates the DWARF expressions that
take the base address, add an offset and dereference.  GDB then ends
up trying to access addresses like 0x16, 0x8, etc.

To fix this, I proposed changing STRUCTOP_STRUCT so that instead of
returning a zero value we instead returned the actual value
representing the structure's field in the target.  My thinking was
that GDB would not try to access the value's contents unless it needed
it to resolve a dynamic type.  This belief was incorrect.

Consider expression <B>.  We already know that (5) and (8) will return
real values for the symbols being referenced.  The BINOP_LOGICAL_AND,
operation (4) will evaluate both of its children in
EVAL_AVOID_SIDE_EFFECTS in order to get the types, this is required
for C++ operator lookup.  This means that even if the value of (5)
would result in the BINOP_LOGICAL_AND returning false (say, ptr is
NULL), we still evaluate (6) in EVAL_AVOID_SIDE_EFFECTS mode.

Operation (6) will evaluate both children in EVAL_AVOID_SIDE_EFFECTS
mode, operation (9) is easy, it just returns a value with the constant
packed into it, but (7) is where the problem lies.  Currently in GDB
this STRUCTOP_STRUCT will always return a non-lazy zero value of the
correct type.

When the results of (7) and (9) are back in the BINOP_LOGICAL_AND
operation (6), the two values are passed to value_equal which performs
the comparison and returns a result.  Note, the two things compared
here are the immediate value (9), and a non-lazy zero value from (7).

However, with my proposed patch operation (7) no longer returns a zero
value, instead it returns a lazy value representing the actual value
in target memory.  When we call value_equal in (6) this code causes
GDB to try and fetch the actual value from target memory.  If `ptr` is
NULL then this will cause GDB to access some invalid address at an
offset from zero, this will most likely fail, and cause GDB to throw
an error instead of returning the expected type.

And so, we can now describe the problem that we're facing.  The way
GDB's expression evaluator is currently written we assume, when in
EVAL_AVOID_SIDE_EFFECTS mode, that any value returned from a child
operation can safely have its content read without throwing an
error.  If child operations start returning real values (instead of
the fake zero values), then this is simply not true.

If we wanted to work around this then we would need to rewrite almost
all operations (I would guess) so that EVAL_AVOID_SIDE_EFFECTS mode
does not cause evaluation of an operation to try and read the value of
a child operation.  As an example, consider this current GDB code from
eval.c:

  struct value *
  eval_op_equal (struct type *expect_type, struct expression *exp,
  	       enum noside noside, enum exp_opcode op,
  	       struct value *arg1, struct value *arg2)
  {
    if (binop_user_defined_p (op, arg1, arg2))
      {
        return value_x_binop (arg1, arg2, op, OP_NULL, noside);
      }
    else
      {
        binop_promote (exp->language_defn, exp->gdbarch, &arg1, &arg2);
        int tem = value_equal (arg1, arg2);
        struct type *type = language_bool_type (exp->language_defn,
  					      exp->gdbarch);
        return value_from_longest (type, (LONGEST) tem);
      }
  }

We could change this function to be this:

  struct value *
  eval_op_equal (struct type *expect_type, struct expression *exp,
  	       enum noside noside, enum exp_opcode op,
  	       struct value *arg1, struct value *arg2)
  {
    if (binop_user_defined_p (op, arg1, arg2))
      {
        return value_x_binop (arg1, arg2, op, OP_NULL, noside);
      }
    else
      {
        struct type *type = language_bool_type (exp->language_defn,
  					      exp->gdbarch);
        if (noside == EVAL_AVOID_SIDE_EFFECTS)
  	  return value_zero (type, VALUE_LVAL (arg1));
        else
  	{
  	  binop_promote (exp->language_defn, exp->gdbarch, &arg1, &arg2);
  	  int tem = value_equal (arg1, arg2);
  	  return value_from_longest (type, (LONGEST) tem);
  	}
      }
  }

Now we don't call value_equal unless we really need to.  However, we
would need to make the same, or similar change to almost all
operations, which would be a big task, and might not be a direction we
wanted to take GDB in.

So, for now, I'm proposing we go with the more targeted, Fortran
specific solution, that does the minimal required in order to
correctly resolve the dynamic types.

gdb/ChangeLog:

	* f-exp.h (class fortran_structop_operation): New class.
	* f-exp.y (exp): Create fortran_structop_operation instead of the
	generic structop_operation.
	* f-lang.c (fortran_undetermined::evaluate): Re-evaluate
	expression as EVAL_NORMAL if the result type was dynamic so we can
	extract the actual array bounds.
	(fortran_structop_operation::evaluate): New function.

gdb/testsuite/ChangeLog:

	* gdb.fortran/dynamic-ptype-whatis.exp: New file.
	* gdb.fortran/dynamic-ptype-whatis.f90: New file.
 2021-04-07 17:19:46 +01:00
Andrew Burgess
30ab358668 gdb: allow casting to rvalue reference in more cases 
It is not currently possible to cast some values to an rvaule
reference.  This happens when simple scalar values are cast to an
rvalue reference of the same type, e.g.:

  int global_var;

Then in GDB:

  (gdb) p static_cast<int&&> (global_var)
  Attempt to take address of value not located in memory.

Which is clearly silly.

The problem is that as part of the cast an intermediate value is
created within GDB that becomes an lval_none rather than the original
lval_memory.  The casting logic basically goes like this:

The call tree that leads to the error looks like this:

  value_cast
    value_cast
    value_ref
      value_addr
        error

The first value_cast call is casting the value for 'global_var' to
type 'int&&'.  GDB spots that the target type is a reference, and so
calls value_cast again, this time casting 'global_var' to type 'int'.
We then call value_ref to convert the result of the second value_cast
into a reference.

Unfortunately, the second cast results in the value (for global_var)
changing from an lval_memory to an lval_none.  This is because int to
int casting calls extract_unsigned_integer and then
value_from_longest.

In theory value_cast has a check at its head that should help in this
case, the code is:

  if (value_type (arg2) == type)
    return arg2;

However, this only works in some cases.  In our case
'value_type (arg2)' will be an objfile owned type, while the type from
the expression parser 'int&&' will be gdbarch owned.  The pointers
will not be equal, but the meaning of the type will be equal.

I did consider making the int to int casting case smarter, but this
obviously is only one example.  We must also consider things like
float to float, or pointer to pointer....

So, I instead decided to try and make the initial check smarter.
Instead of a straight pointer comparison, I now propose that we use
types_deeply_equal.  If this is true then we are casting something
back to its current type, in which case we can preserve the lval
setting by using value_copy.

gdb/ChangeLog:

	* valops.c (value_cast): Call value_deeply_equal before performing
	any cast.

gdb/testsuite/ChangeLog:

	* gdb.cp/rvalue-ref-params.cc (f3): New function.
	(f4): New function.
	(global_int): New global variable.
	(global_float): Likeiwse.
	(main): Call both new functions.
	* gdb.cp/rvalue-ref-params.exp: Add new tests.
 2021-04-07 12:49:12 +01:00
Andrew Burgess
5e18990f1f gdb: move cheap pointer equality check earlier in types_equal 
I noticed that in types equal we start with a cheap pointer equality
check, then resolve typedefs, then do a series of (semi-)expensive
checks, including checking type names, before, finally performing
another pointer equality check.

We should hoist the second pointer equality check to immediately after
we have resolved typedefs.  This would save performing the more
expensive checks.

This isn't going to give any noticable performance improvement, I just
spotted this in passing and figured I might as well commit the fix.

There should be no user visible changes after this commit.

gdb/ChangeLog:

	* gdbtypes.c (types_equal): Move pointer equality check earlier in
	the function.
 2021-04-07 12:49:12 +01:00
Caroline Tice
56d467f4ee gdb: handle relative paths to DWO files 
DWARF allows .dwo file paths to be relative rather than absolute.

When they are relative, DWARF uses DW_AT_comp_dir to find the .dwo
file.  DW_AT_comp_dir can also be relative, making the entire search
patch for the .dwo file relative.

In this case, GDB currently searches relative to its current working
directory, i.e. the directory from which the debugger was launched,
but not relative to the directory containing the built binary.  This
cannot be right, as the compiler, when generating the relative paths,
knows where it's building the binary but can have no idea where the
debugger will be launched.

The correct thing is to add the directory containing the binary to the
search paths used for resolving relative locations of dwo files. That
is what this patch does.

gdb/ChangeLog:

	* dwarf2/read.c (try_open_dwop_file): Add path for the binary to
	the search paths used resolve relative location of .dwo file.

gdb/testsuite/ChangeLog:

	* gdb.dwarf2/fission-relative-dwo.c: New file.
	* gdb.dwarf2/fission-relative-dwo.exp: New file.
 2021-04-07 11:41:50 +01:00
Andrew Burgess
1fd999d909 gdb: Handle missing .debug_str section 
While messing with the Dwarf assembler (gdb/testsuite/lib/dwarf.exp) I
managed to create an ELF which made use of DW_FORM_strp, but didn't
include a .debug_str section.

When I started GDB on this ELF, GDB crashed.  I would have expected to
get an error instead.

I tracked this down to an unfortunate design choice in
dwarf2_section_info, a class which wraps around a bfd section, and is
used for reading in debug information.  GBB creates many
dwarf2_section_info objects, one for each debug section that might
need to be read, then as we find the input bfd sections we associate
them with the corresponding dwarf2_section_info.

If no matching input bfd section is found then the dwarf2_section_info
is left in an unassociated state, its internal bfd section pointer is
null.

If later GDB tries to read content from the dwarf2_section_info, for
example, which trying to read the string associated with DW_FORM_strp,
we spot that there is no associated bfd section and issue an error
message.

To make the users life easier, the error message includes the section
name being looked for, and the bfd from which the section was
obtained.

However, we get the section name by calling bfd_section_name on the
associated section, and we get the bfd filename by calling
bfd_get_filename on the owner of the associated section.

Of course, if there is no associated section then both the calls
bfd_section_name and dwarf2_section_info::get_bfd_owner will result in
undefined behaviour (e.g. a crash).

The solution I propose in this patch is, I know, not ideal.  I simply
spot the case where there is no associated section, and print a
simpler error message, leaving out the section name and filename.

A better solution would involve redesigning dwarf2_section_info, we
could associate each dwarf2_section_info with the initial bfd being
parsed.  We would then display this filename if there's nothing better
to display (e.g. if we find a section in a dwo/dwp split dwarf file
then we would probably use that filename in preference).

Each dwarf2_section_info could also have the concept of the default
section name that would be read for that section, for example, string
data might appear in ".debug_str" or ".zdebug_str", but if neither is
found, then it would probably be OK to just say ".debug_str" is
missing.

Anyway, I didn't do any of that redesign, I just wanted to stop GDB
crashing for now, so instead we get this:

  Dwarf Error: DW_FORM_strp used without required section

Which isn't the best, but in context, isn't too bad:

  Reading symbols from /path/to/executable...
  Dwarf Error: DW_FORM_strp used without required section
  (No debugging symbols found in /path/to/executable)

I also added some asserts into dwarf2_section_info which should
trigger before GDB crashes in future, if we trigger any other bad
paths through this code.

And there's a test for the specific issue I hit.

gdb/ChangeLog:

	* dwarf2/section.c (dwarf2_section_info::get_bfd_owner): Add an
	assert.
	(dwarf2_section_info::get_file_name): Add an assert.
	(dwarf2_section_info::read_string): Display a minimal, sane error
	when the dwarf2_section_info is not associated with a bfd section.

gdb/testsuite/ChangeLog:

	* gdb.dwarf2/dw2-using-debug-str.exp: Add an additional test.
 2021-04-07 11:31:30 +01:00
Andrew Burgess
79c024436b gdb/py: fix gdb.parameter('data-directory') 
It was reported on IRC that using gdb.parameter('data-directory')
doesn't work correctly.

The problem is that the data directory is stored in 'gdb_datadir',
however the set/show command is associated with a temporary
'staged_gdb_datadir'.

When the user does 'set data-directory VALUE', the VALUE is stored in
'staged_gdb_datadir' by GDB, then set_gdb_datadir is called.  This in
turn calls set_gdb_data_directory to copy the value from
staged_gdb_datadir into gdb_datadir.

However, set_gdb_data_directory will resolve relative paths, so the
value stored in gdb_datadir might not match the value in
staged_gdb_datadir.

The Python gdb.parameter API fetches the parameter values by accessing
the variable associated with the show command, so in this case
staged_gdb_datadir.  This causes two problems:

1. Initially staged_gdb_datadir is NULL, and remains as such until the
user does 'set data-directory VALUE' (which might never happen), but
gdb_datadir starts with GDB's default data-directory value.  So
initially from Python gdb.parameter('data-directory') will return the
empty string, even though at GDB's CLI 'show data-directory' prints a
real path.

2. If the user does 'set data-directory ./some/relative/path', GDB
will resolve the relative path, thus, 'show data-directory' at the CLI
will print an absolute path.  However, the value is staged_gdb_datadir
will still be the relative path, and gdb.parameter('data-directory')
from Python will return the relative path.

In this commit I fix both of these issues by:

1. Initialising the value in staged_gdb_datadir based on the initial
value in gdb_datadir, and

2. In set_gdb_datadir, after calling set_gdb_data_directory, I copy
the value in gdb_datadir back into staged_gdb_datadir.

With these two changes in place the value in staged_gdb_datadir should
always match the value in gdb_datadir, and accessing data-directory
from Python should now work correctly.

gdb/ChangeLog:

	* top.c (staged_gdb_datadir): Update comment.
	(set_gdb_datadir): Copy the value of gdb_datadir back into
	staged_datadir.
	(init_main): Initialise staged_gdb_datadir.

gdb/testsuite/ChangeLog:

	* gdb.python/py-parameter.exp: Add test for reading data-directory
	using gdb.parameter API.
 2021-04-07 11:14:26 +01:00
Tom de Vries
340d00fb78 [gdb/breakpoints] Workaround missing line-table entry 
When running test-case gdb.opt/inline-cmds.exp, we run into this KFAIL with
gcc:
...
Breakpoint 7, main () at gdb.opt/inline-cmds.c:71^M
71        result = 0; /* set breakpoint 3 here */^M
(gdb) PASS: gdb.opt/inline-cmds.exp: continue to breakpoint: consecutive func1
next^M
73        func1 (); /* first call */^M
(gdb) PASS: gdb.opt/inline-cmds.exp: next to first func1
next^M
75        marker ();^M
(gdb) KFAIL: gdb.opt/inline-cmds.exp: next to second func1 (PRMS: gdb/25884)
...
while with clang we have instead:
...
next^M
74        func1 (); /* second call */^M
(gdb) PASS: gdb.opt/inline-cmds.exp: next to second func1
...

The relevant bit of the test source is here in inline-cmds.c:
...
    71    result = 0; /* set breakpoint 3 here */
    72
    73    func1 (); /* first call */
    74    func1 (); /* second call */
    75    marker ();
...
with func1 defined as:
...
    33  inline __attribute__((always_inline)) int func1(void)
    34  {
    35    bar ();
    36    return x * y;
    37  }
...

The corresponding insns are:
...
  40050b:       movl   $0x0,0x200b1f(%rip)        # 601034 <result>
  400515:       callq  40057b <bar>
  40051a:       callq  40057b <bar>
  40051f:       callq  400596 <marker>
...
and the line number info is:
...
Line number    Starting address    View    Stmt
         71            0x40050b               x
         35            0x400515               x
         75            0x40051f               x
...

The line number info is missing an entry for the insn at 40051a, and that is
causing the FAIL.  This is a gcc issue, filed as PR gcc/98780 -" Missing line
table entry for inlined stmt at -g -O0".

[ For contrast, with clang we have an extra entry:
...
Line number    Starting address    View    Stmt
         71            0x40050b               x
         35            0x400515               x
         35            0x40051a
         75            0x40051f               x
...
though it appears to be missing the start-of-statement marker. ]

However, there is debug info that indicates that the insn at 40051a is not
part of the line table entry for the insn at 400515:
...
<2><1c4>: Abbrev Number: 8 (DW_TAG_inlined_subroutine)
    <1c5>   DW_AT_abstract_origin: <0x2a2>
    <1c9>   DW_AT_low_pc      : 0x400515
    <1d1>   DW_AT_high_pc     : 0x5
    <1d9>   DW_AT_call_file   : 1
    <1da>   DW_AT_call_line   : 73
 <2><1db>: Abbrev Number: 8 (DW_TAG_inlined_subroutine)
    <1dc>   DW_AT_abstract_origin: <0x2a2>
    <1e0>   DW_AT_low_pc      : 0x40051a
    <1e8>   DW_AT_high_pc     : 0x5
    <1f0>   DW_AT_call_file   : 1
    <1f1>   DW_AT_call_line   : 74
...
and indeed lldb manages to "next" from line 73 to line 74.

Work around the missing line table entry, by using the inline frame info to
narrow the stepping range in prepare_one_step.

Tested on x86_64-linux.

gdb/ChangeLog:

2021-04-06  Tom de Vries  <tdevries@suse.de>

	PR breakpoints/25884
	* infcmd.c (prepare_one_step): Using inline frame info to narrow
	stepping range.

gdb/testsuite/ChangeLog:

2021-04-06  Tom de Vries  <tdevries@suse.de>

	PR breakpoints/25884
	* gdb.opt/inline-cmds.exp: Remove kfail.
 2021-04-06 15:12:38 +02:00
Tom de Vries
d811a7cf74 [gdb/tui] Fix len_without_escapes in tui-disasm.c 
On openSUSE Tumbleweed I run into:
...
FAIL: gdb.tui/basic.exp: asm window shows main
ERROR: invalid command name "_csi_L"
...

Using a minimal example, we get:
...
$ gdb -q outputs/gdb.tui/basic/basic -ex "tui enable" -ex "layout asm"
<TUI output>
src/gdb/ui-style.c:243: internal-error: bool \
  ui_file_style::parse(const char*, size_t*): Assertion `match == 0' failed.
...

The problem is in len_without_escapes, where we detect the start of an escape
sequence, but then pass ptr to style.parse while ptr no longer points to the
escape due to the ptr++ in the while condition:
...
  while ((c = *ptr++) != '\0')
     {
      if (c == '\033')
        {
          ui_file_style style;
          size_t n_read;
          if (style.parse (ptr, &n_read))
...

Fix this by removing the ++ in the while condition, and adding ptr++ in the
loop body where appropriate.

Tested on x86_64-linux.

gdb/ChangeLog:

2021-04-06  Tom de Vries  <tdevries@suse.de>

	PR tui/27680
	* tui/tui-disasm.c (len_without_escapes): Pass ptr pointing at escape
	to style.parse.
 2021-04-06 10:40:11 +02:00
Simon Marchi
306b445a6d gdb: fix internal error in avr_frame_unwind_cache 
When trying to do pretty much anything that requires unwinding a frame
on AVR, we get

    /home/simark/src/wt/avr/gdb/trad-frame.h:143: internal-error: LONGEST trad_frame_saved_reg::addr() const: Assertion `m_kind == trad_frame_saved_reg_kind::ADDR' failed.

This is likely coming from the trad-frame refactor in 098caef485
("Refactor struct trad_frame_saved_regs").  Here's an example of how to
reproduce it:

In one terminal:

    $ cat test.c
    int foo(int x)
    {
      return x * 7;
    }

    int main() {
        return foo(2);
    }
    $ avr-gcc -gdwarf-4 -mmcu=atmega2560 test.c
    $ /tmp/simavr/bin/simavr --mcu atmega2560 -g a.out
    Loaded 330 .text at address 0x0
    Loaded 0 .data

And in another one:

    $ ./gdb -q -nx --data-directory=data-directory a.out -ex "tar rem :1234" -ex "b foo" -ex c -ex bt
    Reading symbols from a.out...
    Remote debugging using :1234
    0x00000000 in __vectors ()
    Breakpoint 1 at 0x110: file test.c, line 3.
    Note: automatically using hardware breakpoints for read-only addresses.
    Continuing.

    Breakpoint 1, foo (x=2) at test.c:3
    3         return x * 7;
    #0  foo (x=2) at test.c:3
    /home/simark/src/wt/avr/gdb/trad-frame.h:143: internal-error: LONGEST trad_frame_saved_reg::addr() const: Assertion `m_kind == trad_frame_saved_reg_kind::ADDR' failed.

What the AVR code does is:

1. In avr_scan_prologue, in the block that says "First stage of the
   prologue scanning.", look for "push rX" instructions and note that rX
   is saved on the stack.  But instead of putting the actual stack
   address directly, it puts an offset (from the previous frame's sp).
2. Back in avr_frame_unwind_cache, in the block that says "Adjust all
   the saved registers", adjust all these values to be real stack
   addresses.

To check whether a register was assigned an address (and therefore if it
needs adjustment), the code does:

    if (info->saved_regs[i].addr () > 0)

Since commit 098caef485, it's invalid to call the `addr` getter of
trad_frame_saved_reg if the register hasn't been assigned an address.
Instead, the code could use the `is_addr` getter to verify if the
register has been assigned an address.  This is what this patch does.

gdb/ChangeLog:

	* avr-tdep.c (avr_frame_unwind_cache): Use
	trad_frame_saved_reg::is_addr.

Change-Id: I5803089160b829400178746c5e3bca0c1cd11c00
 2021-04-04 22:29:34 -04:00
Simon Marchi
9161c89ad8 gdb: remove objfile parameter from get_objfile_bfd_data 
I noticed it was unused.  I think that makes sense, as it shows that
objfile_per_bfd_storage is not specific to one objfile (it can be shared
by multiple objfiles that have the same bfd).

There is one thing I wonder though, maybe I'm missing something.  If
the BFD doesn't require relocation, get_objfile_bfd_data stores the
newly allocated object in objfiles_bfd_data, so we can assume that
objfiles_bfd_data is the owner of the object.  When the bfd's refcount
drops to 0, the corresponding objfile_per_bfd_storage object in
objfiles_bfd_data is deleted.

But if the BFD requires relocation, get_objfile_bfd_data returns a newly
allocated object that isn't kept anywhere else (and isn't shared).  So
the objfile becomes the owner of the objfile_per_bfd_storage object.  In
objfile::~objfile, we have this:

    if (obfd)
      gdb_bfd_unref (obfd);
    else
      delete per_bfd;

I'm thinking that obfd could be non-nullptr, and it could require
relocation.  In that case, it would never be freed.  Anyway, that's not
really connected to this patch.

gdb/ChangeLog:

	* objfiles.c (get_objfile_bfd_data): Remove objfile parameter,
	adjust callers.

Change-Id: Ifa3158074ea6b42686780ba09d0c964b0cf14cf1
 2021-04-02 11:51:45 -04:00
Simon Marchi
0072c87379 gdb: pass objfile_per_bfd_storage instead of objfile to partial_symtab 
Since partial_symtab is supposed to be objfile-independent (since series
[1]), I think it would make sense for partial_symtab to not take an
objfile as a parameter in its constructor.

This patch replaces that parameter with an objfile_per_bfd_storage
parameter.

The objfile is used for two things:

 - to get the objfile_name, for debug messages.  We can get that name
   from the bfd instead.
 - to intern the partial symtab filename.  Even though it goes through
   an objfile method, the request is actually forwarded to the
   underlying objfile_per_bfd_storage.  So we can ask the new
   objfile_per_bfd_storage instead.

In order to get a reference to the BFD from the objfile_per_bfd_storage,
the BFD is saved in the objfile_per_bfd_storage object.

[1] https://sourceware.org/pipermail/gdb-patches/2021-February/176625.html

gdb/ChangeLog:

	* psympriv.h (struct partial_symtab) <partial_symtab>: Change
	objfile parameter for objfile_per_bfd_storage, adjust callers.
	(struct standard_psymtab) <standard_psymtab>: Likewise.
	(struct legacy_psymtab) <legacy_psymtab>: Likewise.
	* psymtab.c (partial_symtab::partial_symtab): Likewise.
	* ctfread.c (struct ctf_psymtab): Likewise.
	* dwarf2/read.h (struct dwarf2_psymtab): Likewise.
	* dwarf2/read.c (struct dwarf2_include_psymtab): Likewise.
	(dwarf2_create_include_psymtab): Likewise.
	* objfiles.h (struct objfile_per_bfd_storage)
	<objfile_per_bfd_storage>: Add bfd parameter, adjust callers.
	<get_bfd>: New method.
	<m_bfd>: New field.
	* objfiles.c (get_objfile_bfd_data): Adjust.

Change-Id: I2ed3ab5d2e6f27d034bd4dc26ae2fae7b0b8a2b9
 2021-04-02 11:45:37 -04:00
Simon Marchi
9984dd9994 gdb: use std::string in partial_symtab::partial_symtab / allocate_symtab 
This simplifies the code a bit.

gdb/ChangeLog:

	* psymtab.c (partial_symtab::partial_symtab): Change
	last_objfile_name to be an std::string.
	* symfile.c (allocate_symtab): Likewise.

Change-Id: I3dfe217233ed9346c2abc04a9b1be0df69a90af8
 2021-04-02 11:39:55 -04:00
Simon Marchi
4a4f97c129 gdb: add intern methods to objfile_per_bfd_storage 
This allows keeping the objfile_per_bfd_storage implementation details
into objfile_per_bfd_storage, instead of into objfile.  And this makes
the intern methods usable for code that only has an
objfile_per_bfd_storage to work with.

gdb/ChangeLog:

	* objfiles.h (struct objfile_per_bfd_storage) <intern>: New
	methods.
	(struct objfile) <intern>: Use
	objfile::objfile_per_bfd_storage::intern.

Change-Id: Ifd54026c5efaeffafac9b84ff84c199acc7ce78a
 2021-04-02 11:35:29 -04:00
Simon Marchi
0672875f3c gdb: remove TYPE_FLAG_ENUM 
gdb/ChangeLog:

	* gdbtypes.h (TYPE_FLAG_ENUM): Remove, replace all uses
	with type::is_flag_enum.

Change-Id: I74e23893066eecd6df641045b859a6d6ebb13dd0
 2021-04-01 21:10:09 -04:00
Simon Marchi
9902b32793 gdb: add type::is_flag_enum / type::set_is_flag_enum 
Add the `is_flag_enum` and `set_is_flag_enum` methods on `struct type`,
in order to remove the `TYPE_FLAG_ENUM` macro.  In this patch, the macro
is changed to use the getter, so all the call sites of the macro that
are used as a setter are changed to use the setter method directly.  The
next patch will remove the macro completely.

gdb/ChangeLog:

	* gdbtypes.h (struct type) <is_flag_enum,
	set_is_flag_enum>: New methods.
	(TYPE_FLAG_ENUM): Use type::is_flag_enum, change all
	write call sites to use type::set_is_flag_enum.

Change-Id: I9c56c91626c8d784947ba94fcb97818526b81d1c
 2021-04-01 21:10:09 -04:00
Simon Marchi
3bc440a2c4 gdb: remove TYPE_DECLARED_CLASS 
gdb/ChangeLog:

	* gdbtypes.h (TYPE_DECLARED_CLASS): Remove, replace all uses
	with type::is_declared_class.

Change-Id: Ifecb2342417ecd7bf570c3205344b09d706daab2
 2021-04-01 21:10:09 -04:00
Simon Marchi
aa70e35c71 gdb: add type::is_declared_class / type::set_is_declared_class 
Add the `is_declared_class` and `set_is_declared_class` methods on
`struct type`, in order to remove the `TYPE_DECLARED_CLASS` macro.  In
this patch, the macro is changed to use the getter, so all the call
sites of the macro that are used as a setter are changed to use the
setter method directly.  The next patch will remove the macro
completely.

gdb/ChangeLog:

	* gdbtypes.h (struct type) <is_declared_class,
	set_is_declared_class>: New methods.
	(TYPE_DECLARED_CLASS): Use type::is_declared_class, change all
	write call sites to use type::set_is_declared_class.

Change-Id: Idf08d32e137c885a0aba0a18f556a899c1cbfd68
 2021-04-01 21:10:08 -04:00
Boris Staletic
bfb9f5dcfe Use importlib instead of imp module on python 3.4+ 
Python 3.4 has deprecated the imp module in favour of importlib. This
patch avoids the DeprecationWarning. This warning is visible to users
whose libpython.so has been compiled with --with-pydebug.

Considering that even python 3.5 has reached end of life, would it be
better to just use importlib and drop support for python 3.0 to 3.3?

2021-02-28  Boris Staletic  <boris.staletic@gmail.com>

	* gdb/python/lib/gdb/__init__.py: Use importlib on python 3.4+
	to avoid deprecation warnings.
 2021-04-01 12:26:52 -06:00
Martin Liska
733f5eea6b Use startswith in gdb subfolder. 
gdb/ChangeLog:

	* cp-name-parser.y: Use startswith instead of strncmp.
	* m2-exp.y: Likewise.
	* macroexp.c (substitute_args): Likewise.
	* mi/mi-main.c (command_notifies_uscc_observer): Likewise.
	* rust-exp.y: Likewise.
 2021-04-01 06:29:59 +02:00
Tom Tromey
af82f89db0 Remove two trivial functions from dwarf2/read.c 
This removes dw2_map_matching_symbols and dw2_expand_symtabs_matching,
merging them with their sole trivial callers.

gdb/ChangeLog
2021-03-31  Tom Tromey  <tom@tromey.com>

	* dwarf2/read.c (dwarf2_gdb_index::map_matching_symbols): Merge
	with dw2_map_matching_symbols.
	(dwarf2_gdb_index::expand_symtabs_matching): Merge with
	dw2_expand_symtabs_matching.
 2021-03-31 18:28:30 -06:00
Tom Tromey
3570682a2c Fix typo in dwarf2/stringify.h 
Pedro pointed out a typo in a comment in dwarf2/stringify.h.  This
fixes it.

gdb/ChangeLog
2021-03-31  Tom Tromey  <tromey@adacore.com>

	* dwarf2/stringify.h: Fix typo.
 2021-03-31 09:48:56 -06:00
Simon Marchi
8a91fbdf3b gdb/dwarf: disable per-BFD resource sharing for -readnow objfiles 
New in v2:

  - Disable sharing only for -readnow objfiles, not all objfiles.

As described in PR 27541, we hit an internal error when loading a binary
the standard way and then loading it with the -readnow option:

    $ ./gdb -nx -q --data-directory=data-directory ~/a.out -ex "set confirm off" -ex "file -readnow ~/a.out"
    Reading symbols from /home/simark/a.out...
    Reading symbols from ~/a.out...
    /home/simark/src/binutils-gdb/gdb/dwarf2/read.c:8098: internal-error: void create_all_comp_units(dwarf2_per_objfile*): Assertion `per_objfile->per_bfd->all_comp_units.empty ()' failed.

This is a recurring problem that exposes a design issue in the DWARF
per-BFD sharing feature.  Things work well when loading a binary with
the same method (with/without index, with/without readnow) twice in a
row.  But they don't work so well when loading a binary with different
methods.  See this previous fix, for example:

    efb763a5ea ("gdb: check for partial symtab presence in dwarf2_initialize_objfile")

That one handled the case where the first load is normal (uses partial
symbols) and the second load uses an index.

The problem is that when loading an objfile with a method A, we create a
dwarf2_per_bfd and some dwarf2_per_cu_data and initialize them with the
data belonging to that method.  When loading another obfile sharing the
same BFD but with a different method B, it's not clear how to re-use the
dwarf2_per_bfd/dwarf2_per_cu_data previously created, because they
contain the data specific to method A.

I think the most sensible fix would be to not share a dwarf2_per_bfd
between two objfiles loaded with different methods.  That means that two
objfiles sharing the same BFD and loaded the same way would share a
dwarf2_per_bfd.  Two objfiles sharing the same BFD but loaded with
different methods would use two different dwarf2_per_bfd structures.

However, this isn't a trivial change.  So to fix the known issue quickly
(including in the gdb 10 branch), this patch just disables all
dwarf2_per_bfd sharing for objfiles using READNOW.

Generalize the gdb.base/index-cache-load-twice.exp test to test all
the possible combinations of loading a file with partial symtabs, index
and readnow.  Move it to gdb.dwarf2, since it really exercises features
of the DWARF reader.

gdb/ChangeLog:

	PR gdb/27541
	* dwarf2/read.c (dwarf2_has_info): Don't share dwarf2_per_bfd
	with objfiles using READNOW.

gdb/testsuite/ChangeLog:

	PR gdb/27541
	* gdb.base/index-cache-load-twice.exp: Remove.
	* gdb.base/index-cache-load-twice.c: Remove.
	* gdb.dwarf2/per-bfd-sharing.exp: New.
	* gdb.dwarf2/per-bfd-sharing.c: New.

Change-Id: I9ffcf1e136f3e75242f70e4e58e4ba1fd3083389
 2021-03-30 13:37:11 -04:00
Tom Tromey
9f67fc596b Remove parameter from language_info 
I noticed that language_info is only ever called with a value of '1'.
This patch removes the parameter.

2021-03-29  Tom Tromey  <tromey@adacore.com>

	* top.c (check_frame_language_change): Update.
	* language.c (language_info): Remove parameter.
	* language.h (language_info): Remove parameter.
 2021-03-29 09:36:11 -06:00
Luis Machado
9b8ffbf410 Don't pass empty options to GCC 
On aarch64-linux, I noticed the compile command didn't work at all.  It
always gave the following error:

aarch64-linux-gnu-g++: error: : No such file or directory

Turns out we're passing an empty argv entry to GCC (because aarch64 doesn't
have a -m64 option), and GCC's behavior is to think that is a file it needs
to open.  One can reproduce it like so:

gcc "" "" "" ""
gcc: error: : No such file or directory
gcc: error: : No such file or directory
gcc: error: : No such file or directory
gcc: error: : No such file or directory
gcc: fatal error: no input files
compilation terminated.

The solution is to check for an empty string and skip adding that to argv.

Regression tested on aarch64-linux/Ubuntu 18.04/20.04.

gdb/ChangeLog:

2021-03-29  Luis Machado  <luis.machado@linaro.org>

	* compile/compile.c (get_args): Don't add empty argv entries.
 2021-03-29 11:59:50 -03:00
Rainer Orth
25b48839b3 Restore procfs.c compilation 
Since c8fbd44a01 (gdb: remove
target_is_pushed free function), procfs.c compilation is broken, which
went unnoticed for lack of functioning buildbots:

/vol/src/gnu/gdb/hg/master/dist/gdb/procfs.c: In member function 'virtual void procfs_target::attach(const char*, int)':
/vol/src/gnu/gdb/hg/master/dist/gdb/procfs.c:1772:8: error: 'inf' was not declared in this scope; did you mean 'info'?
 1772 |   if (!inf->target_is_pushed (this))
      |        ^~~
      |        info
/vol/src/gnu/gdb/hg/master/dist/gdb/procfs.c: In member function 'virtual void procfs_target::create_inferior(const char*, const string&, char**, int)':
/vol/src/gnu/gdb/hg/master/dist/gdb/procfs.c:2865:8: error: 'inf' was not declared in this scope; did you mean 'info'?
 2865 |   if (!inf->target_is_pushed (this))
      |        ^~~
      |        info

Fixed by defining inf.  Tested on amd64-pc-solaris2.11 and
sparcv9-sun-solaris2.11.

2021-03-29  Rainer Orth  <ro@CeBiTec.Uni-Bielefeld.DE>

	gdb:
	* procfs.c (procfs_target::attach): Define inf.
	Use it.
	(procfs_target::create_inferior): Likewise.
 2021-03-29 13:26:35 +02:00
Tom Tromey
edc02ceb97 Simplify DWARF reader initialization 
Now that the quick functions are separate from the object file format,
there's no need to have elfread.c push a new entry on the objfile 'qf'
list.  Instead, this detail can be pushed into the DWARF reader.  That
is what this patch implements.

I wasn't sure whether lazy reading still makes sense or not.  It's
still only used by ELF, and only in certain situations (like vfork, I
think).  It may not be carrying its weight, so we may want to consider
removing this in the future.

Also, I'm unclear on why the various indices are only used for ELF.
This seems sub-optimal.  However, I haven't tried to address that
here.

gdb/ChangeLog
2021-03-28  Tom Tromey  <tom@tromey.com>

	* elfread.c (can_lazily_read_symbols): Move to dwarf2/read.c.
	(elf_symfile_read): Simplify.
	* dwarf2/read.c (struct lazy_dwarf_reader): Move from elfread.c.
	(make_lazy_dwarf_reader): New function.
	(make_dwarf_gdb_index, make_dwarf_debug_names): Now static.
	(dwarf2_initialize_objfile): Return void.  Remove index_kind
	parameter.  Push on 'qf' list.
	* dwarf2/public.h (dwarf2_initialize_objfile): Change return
	type.  Remove 'index_kind' parameter.
	(make_dwarf_gdb_index, make_dwarf_debug_names): Don't declare.
 2021-03-28 10:43:15 -06:00
Tom Tromey
6e23d91aa7 Don't declare elf_sym_fns_lazy_psyms 
An earlier patch neglected to delete a forward declaration of
elf_sym_fns_lazy_psyms.  This is no longer defined.  This patch
removes it.

gdb/ChangeLog
2021-03-27  Tom Tromey  <tom@tromey.com>

	* elfread.c (elf_sym_fns_lazy_psyms): Don't declare.
 2021-03-27 16:48:36 -06:00
Tom Tromey
594b8948eb Don't clear 'qf' in elf_symfile_read 
I noticed that I forgot to make a change in my series to make it
possible to attach multiple debug readers to an objfile.  In one spot,
elf_symfile_read still clears the 'qf' list.  However, this should
have been removed toward the end of that series.

This patch fixes the offending spot.  Tested on x86-64 Fedora 32.

gdb/ChangeLog
2021-03-27  Tom Tromey  <tom@tromey.com>

	* elfread.c (elf_symfile_read): Don't clear 'qf'.
 2021-03-27 16:41:53 -06:00
Lancelot SIX
efe1ecd834 gdb-add-index.sh: Remove use of non posix 'local' 
While working on gdb-add-index.sh, it appeared that it uses the non
POSIX 'local' keyword.  Instead of using local to allow variable
shadowing, I rename the local one to avoid name conflicts altogether.

This commit gets rid of the following shellcheck warning:

    In gdb-add-index.sh line 63:
        local file="$1"
        ^--------^ SC2039: In POSIX sh, 'local' is undefined.

gdb/ChangeLog:

	* contrib/gdb-add-index.sh: Avoid variable shadowing and get
	rid of 'local'.
 2021-03-26 23:42:33 +00:00
Tom Tromey
f4655dee77 Use function view in quick_symbol_functions::map_symbol_filenames 
This changes quick_symbol_functions::map_symbol_filenames to use a
function_view, and updates all the uses.  It also changes the final
parameter to 'bool'.  A couple of spots are further updated to use
operator() rather than a lambda.

gdb/ChangeLog
2021-03-26  Tom Tromey  <tom@tromey.com>

	* symtab.c (struct output_source_filename_data): Add 'output'
	method and operator().
	(output_source_filename_data::output): Rename from
	output_source_filename.
	(output_partial_symbol_filename): Remove.
	(info_sources_command): Update.
	(struct add_partial_filename_data): Add operator().
	(add_partial_filename_data::operator()): Rename from
	maybe_add_partial_symtab_filename.
	(make_source_files_completion_list): Update.
	* symfile.c (quick_symbol_functions): Update.
	* symfile-debug.c (objfile::map_symbol_filenames): Update.
	* quick-symbol.h (symbol_filename_ftype): Change type of 'fun' and
	'need_fullname'.  Remove 'data' parameter.
	(struct quick_symbol_functions) <map_symbol_filenames>: Likewise.
	* psymtab.c (psymbol_functions::map_symbol_filenames): Update.
	* psympriv.h (struct psymbol_functions) <map_symbol_filenames>:
	Change type of 'fun' and 'need_fullname'.  Remove 'data'
	parameter.
	* objfiles.h (struct objfile) <map_symbol_filenames>: Change type
	of 'fun' and 'need_fullname'.  Remove 'data' parameter.
	* mi/mi-cmd-file.c (print_partial_file_name): Remove 'ignore'
	parameter.
	(mi_cmd_file_list_exec_source_files): Update.
	* dwarf2/read.c
	(dwarf2_base_index_functions::map_symbol_filenames): Update.
 2021-03-26 13:44:24 -06:00
Tom Tromey
2315bb2d57 Simplify use of map_matching_symbols in ada-lang.c 
I noticed that ada-lang.c creates a lambda to call
aux_add_nonlocal_symbols.  However, this code can be simplified a bit
by changing match_data to implement operator(), and then simply
passing the object as the callback.  That is what this patch
implements.

gdb/ChangeLog
2021-03-26  Tom Tromey  <tom@tromey.com>

	* ada-lang.c (struct match_data): Add operator().
	(match_data::operator()): Rename from aux_add_nonlocal_symbols.
	(callback): Remove 'callback'.
 2021-03-26 13:44:24 -06:00
Tom Tromey
e2cd5ca40c Simplify psymbol_functions::expand_symtabs_matching 
I noticed that psymbol_functions::expand_symtabs_matching calls
make_ignore_params once per psymtab that is matched.  This seems
possibly expensive, so this patch hoists the call out of the loop.

gdb/ChangeLog
2021-03-26  Tom Tromey  <tom@tromey.com>

	* psymtab.c (psymbol_functions::expand_symtabs_matching): Only
	call make_ignore_params once.
 2021-03-26 13:28:03 -06:00
Tom Tromey
cd43f63e00 Allow expand_symtabs_matching to examine imported psymtabs 
Currently the psymtab variant of expand_symtabs_matching has this
check:

      /* We skip shared psymtabs because file-matching doesn't apply
	 to them; but we search them later in the loop.  */
      if (ps->user != NULL)
	continue;

In a larger series I'm working on, it's convenient to remove this
check.  And, I noticed that a similar check is not done for
expand_symtabs_with_fullname.  So, it made sense to me to remove the
check here as well.

gdb/ChangeLog
2021-03-26  Tom Tromey  <tom@tromey.com>

	* psymtab.c (psymbol_functions::expand_symtabs_matching): Remove
	"user" check.
 2021-03-26 13:28:03 -06:00
Simon Marchi
b4b1a226df gdb: defer commit resume until all available events are consumed 
Rationale
---------

Let's say you have multiple threads hitting a conditional breakpoint
at the same time, and all of these are going to evaluate to false.
All these threads will need to be resumed.

Currently, GDB fetches one target event (one SIGTRAP representing the
breakpoint hit) and decides that the thread should be resumed.  It
calls resume and commit_resume immediately.  It then fetches the
second target event, and does the same, until it went through all
threads.

The result is therefore something like:

  - consume event for thread A
  - resume thread A
  - commit resume (affects thread A)
  - consume event for thread B
  - resume thread B
  - commit resume (affects thread B)
  - consume event for thread C
  - resume thread C
  - commit resume (affects thread C)

For targets where it's beneficial to group resumptions requests (most
likely those that implement target_ops::commit_resume), it would be
much better to have:

  - consume event for thread A
  - resume thread A
  - consume event for thread B
  - resume thread B
  - consume event for thread C
  - resume thread C
  - commit resume (affects threads A, B and C)

Implementation details
----------------------

To achieve this, this patch adds another check in
maybe_set_commit_resumed_all_targets to avoid setting the
commit-resumed flag of targets that readily have events to provide to
infrun.

To determine if a target has events readily available to report, this
patch adds an `has_pending_events` target_ops method.  The method
returns a simple bool to say whether or not it has pending events to
report.

Testing
=======

To test this, I start GDBserver with a program that spawns multiple
threads:

 $ ../gdbserver/gdbserver --once :1234 ~/src/many-threads-stepping-over-breakpoints/many-threads-stepping-over-breakpoints

I then connect with GDB and install a conditional breakpoint that always
evaluates to false (and force the evaluation to be done by GDB):

 $ ./gdb -nx --data-directory=data-directory \
     /home/simark/src/many-threads-stepping-over-breakpoints/many-threads-stepping-over-breakpoints \
     -ex "set breakpoint condition-evaluation host" \
     -ex "set pag off" \
     -ex "set confirm off" \
     -ex "maint set target-non-stop on" \
     -ex "tar rem :1234" \
     -ex "tb main" \
     -ex "b 13 if 0" \
     -ex c \
     -ex "set debug infrun" \
     -ex "set debug remote 1" \
     -ex "set debug displaced"

I then do "continue" and look at the log.

The remote target receives a bunch of stop notifications for all
threads that have hit the breakpoint.  infrun consumes and processes
one event, decides it should not cause a stop, prepares a displaced
step, after which we should see:

 [infrun] maybe_set_commit_resumed_all_process_targets: not requesting commit-resumed for target remote, target has pending events

Same for a second thread (since we have 2 displaced step buffers).
For the following threads, their displaced step is deferred since
there are no more buffers available.

After consuming the last event the remote target has to offer, we get:

 [infrun] maybe_set_commit_resumed_all_process_targets: enabling commit-resumed for target remote
 [infrun] maybe_call_commit_resumed_all_process_targets: calling commit_resumed for target remote
 [remote] Sending packet: $vCont;s:p14d16b.14d1b1;s:p14d16b.14d1b2#55
 [remote] Packet received: OK

Without the patch, there would have been one vCont;s just after each
prepared displaced step.

gdb/ChangeLog:
yyyy-mm-dd  Simon Marchi  <simon.marchi@efficios.com>
	    Pedro Alves  <pedro@palves.net>

	* async-event.c (async_event_handler_marked): New.
	* async-event.h (async_event_handler_marked): Declare.
	* infrun.c (maybe_set_commit_resumed_all_targets): Switch to
	inferior before calling target method.  Don't commit-resumed if
	target_has_pending_events is true.
	* remote.c (remote_target::has_pending_events): New.
	* target-delegates.c: Regenerate.
	* target.c (target_has_pending_events): New.
	* target.h (target_ops::has_pending_events): New target method.
	(target_has_pending_events): New.

Change-Id: I18112ba19a1ff4986530c660f530d847bb4a1f1d
 2021-03-26 16:02:11 +00:00
Simon Marchi
1192f124a3 gdb: generalize commit_resume, avoid commit-resuming when threads have pending statuses 
The rationale for this patch comes from the ROCm port [1], the goal
being to reduce the number of back and forths between GDB and the
target when doing successive operations.  I'll start with explaining
the rationale and then go over the implementation.  In the ROCm / GPU
world, the term "wave" is somewhat equivalent to a "thread" in GDB.
So if you read if from a GPU stand point, just s/thread/wave/.

ROCdbgapi, the library used by GDB [2] to communicate with the GPU
target, gives the illusion that it's possible for the debugger to
control (start and stop) individual threads.  But in reality, this is
not how it works.  Under the hood, all threads of a queue are
controlled as a group.  To stop one thread in a group of running ones,
the state of all threads is retrieved from the GPU, all threads are
destroyed, and all threads but the one we want to stop are re-created
from the saved state.  The net result, from the point of view of GDB,
is that the library stopped one thread.  The same thing goes if we
want to resume one thread while others are running: the state of all
running threads is retrieved from the GPU, they are all destroyed, and
they are all re-created, including the thread we want to resume.

This leads to some inefficiencies when combined with how GDB works,
here are two examples:

 - Stopping all threads: because the target operates in non-stop mode,
   when the user interface mode is all-stop, GDB must stop all threads
   individually when presenting a stop.  Let's suppose we have 1000
   threads and the user does ^C.  GDB asks the target to stop one
   thread.  Behind the scenes, the library retrieves 1000 thread
   states and restores the 999 others still running ones.  GDB asks
   the target to stop another one.  The target retrieves 999 thread
   states and restores the 998 remaining ones.  That means that to
   stop 1000 threads, we did 1000 back and forths with the GPU.  It
   would have been much better to just retrieve the states once and
   stop there.

 - Resuming with pending events: suppose the 1000 threads hit a
   breakpoint at the same time.  The breakpoint is conditional and
   evaluates to true for the first thread, to false for all others.
   GDB pulls one event (for the first thread) from the target, decides
   that it should present a stop, so stops all threads using
   stop_all_threads.  All these other threads have a breakpoint event
   to report, which is saved in `thread_info::suspend::waitstatus` for
   later.  When the user does "continue", GDB resumes that one thread
   that did hit the breakpoint.  It then processes the pending events
   one by one as if they just arrived.  It picks one, evaluates the
   condition to false, and resumes the thread.  It picks another one,
   evaluates the condition to false, and resumes the thread.  And so
   on.  In between each resumption, there is a full state retrieval
   and re-creation.  It would be much nicer if we could wait a little
   bit before sending those threads on the GPU, until it processed all
   those pending events.

To address this kind of performance issue, ROCdbgapi has a concept
called "forward progress required", which is a boolean state that
allows its user (i.e. GDB) to say "I'm doing a bunch of operations,
you can hold off putting the threads on the GPU until I'm done" (the
"forward progress not required" state).  Turning forward progress back
on indicates to the library that all threads that are supposed to be
running should now be really running on the GPU.

It turns out that GDB has a similar concept, though not as general,
commit_resume.  One difference is that commit_resume is not stateful:
the target can't look up "does the core need me to schedule resumed
threads for execution right now".  It is also specifically linked to
the resume method, it is not used in other contexts.  The target
accumulates resumption requests through target_ops::resume calls, and
then commits those resumptions when target_ops::commit_resume is
called.  The target has no way to check if it's ok to leave resumed
threads stopped in other target methods.

To bridge the gap, this patch generalizes the commit_resume concept in
GDB to match the forward progress concept of ROCdbgapi.  The current
name (commit_resume) can be interpreted as "commit the previous resume
calls".  I renamed the concept to "commit_resumed", as in "commit the
threads that are resumed".

In the new version, we have two things:

 - the commit_resumed_state field in process_stratum_target: indicates
   whether GDB requires target stacks using this target to have
   resumed threads committed to the execution target/device.  If
   false, an execution target is allowed to leave resumed threads
   un-committed at the end of whatever method it is executing.

 - the commit_resumed target method: called when commit_resumed_state
   transitions from false to true.  While commit_resumed_state was
   false, the target may have left some resumed threads un-committed.
   This method being called tells it that it should commit them back
   to the execution device.

Let's take the "Stopping all threads" scenario from above and see how
it would work with the ROCm target with this change.  Before stopping
all threads, GDB would set the target's commit_resumed_state field to
false.  It would then ask the target to stop the first thread.  The
target would retrieve all threads' state from the GPU and mark that
one as stopped.  Since commit_resumed_state is false, it leaves all
the other threads (still resumed) stopped.  GDB would then proceed to
call target_stop for all the other threads.  Since resumed threads are
not committed, this doesn't do any back and forth with the GPU.

To simplify the implementation of targets, this patch makes it so that
when calling certain target methods, the contract between the core and
the targets guarantees that commit_resumed_state is false.  This way,
the target doesn't need two paths, one for commit_resumed_state ==
true and one for commit_resumed_state == false.  It can just assert
that commit_resumed_state is false and work with that assumption.
This also helps catch places where we forgot to disable
commit_resumed_state before calling the method, which represents a
probable optimization opportunity.  The commit adds assertions in the
target method wrappers (target_resume and friends) to have some
confidence that this contract between the core and the targets is
respected.

The scoped_disable_commit_resumed type is used to disable the commit
resumed state of all process targets on construction, and selectively
re-enable it on destruction (see below for criteria).  Note that it
only sets the process_stratum_target::commit_resumed_state flag.  A
subsequent call to maybe_call_commit_resumed_all_targets is necessary
to call the commit_resumed method on all target stacks with process
targets that got their commit_resumed_state flag turned back on.  This
separation is because we don't want to call the commit_resumed methods
in scoped_disable_commit_resumed's destructor, as they may throw.

On destruction, commit-resumed is not re-enabled for a given target
if:

 1. this target has no threads resumed, or

 2. this target has at least one resumed thread with a pending status
    known to the core (saved in thread_info::suspend::waitstatus).

The first point is not technically necessary, because a proper
commit_resumed implementation would be a no-op if the target has no
resumed threads.  But since we have a flag do to a quick check, it
shouldn't hurt.

The second point is more important: together with the
scoped_disable_commit_resumed instance added in fetch_inferior_event,
it makes it so the "Resuming with pending events" described above is
handled efficiently.  Here's what happens in that case:

 1. The user types "continue".

 2. Upon destruction, the scoped_disable_commit_resumed in the
    `proceed` function does not enable commit-resumed, as it sees some
    threads have pending statuses.

 3. fetch_inferior_event is called to handle another event, the
    breakpoint hit evaluates to false, and that thread is resumed.
    Because there are still more threads with pending statuses, the
    destructor of scoped_disable_commit_resumed in
    fetch_inferior_event still doesn't enable commit-resumed.

 4. Rinse and repeat step 3, until the last pending status is handled
    by fetch_inferior_event.  In that case,
    scoped_disable_commit_resumed's destructor sees there are no more
    threads with pending statues, so it asks the target to commit
    resumed threads.

This allows us to avoid all unnecessary back and forths, there is a
single commit_resumed call once all pending statuses are processed.

This change required remote_target::remote_stop_ns to learn how to
handle stopping threads that were resumed but pending vCont.  The
simplest example where that happens is when using the remote target in
all-stop, but with "maint set target-non-stop on", to force it to
operate in non-stop mode under the hood.  If two threads hit a
breakpoint at the same time, GDB will receive two stop replies.  It
will present the stop for one thread and save the other one in
thread_info::suspend::waitstatus.

Before this patch, when doing "continue", GDB first resumes the thread
without a pending status:

    Sending packet: $vCont;c:p172651.172676#f3

It then consumes the pending status in the next fetch_inferior_event
call:

    [infrun] do_target_wait_1: Using pending wait status status->kind = stopped, signal = GDB_SIGNAL_TRAP for Thread 1517137.1517137.
    [infrun] target_wait (-1.0.0, status) =
    [infrun]   1517137.1517137.0 [Thread 1517137.1517137],
    [infrun]   status->kind = stopped, signal = GDB_SIGNAL_TRAP

It then realizes it needs to stop all threads to present the stop, so
stops the thread it just resumed:

    [infrun] stop_all_threads:   Thread 1517137.1517137 not executing
    [infrun] stop_all_threads:   Thread 1517137.1517174 executing, need stop
    remote_stop called
    Sending packet: $vCont;t:p172651.172676#04

This is an unnecessary resume/stop.  With this patch, we don't commit
resumed threads after proceeding, because of the pending status:

    [infrun] maybe_commit_resumed_all_process_targets: not requesting commit-resumed for target extended-remote, a thread has a pending waitstatus

When GDB handles the pending status and stop_all_threads runs, we stop a
resumed but pending vCont thread:

    remote_stop_ns: Enqueueing phony stop reply for thread pending vCont-resume (1520940, 1520976, 0)

That thread was never actually resumed on the remote stub / gdbserver,
so we shouldn't send a packet to the remote side asking to stop the
thread.

Note that there are paths that resume the target and then do a
synchronous blocking wait, in sort of nested event loop, via
wait_sync_command_done.  For example, inferior function calls, or any
run control command issued from a breakpoint command list.  We handle
that making wait_sync_command_one a "sync" point -- force forward
progress, or IOW, force-enable commit-resumed state.

gdb/ChangeLog:
yyyy-mm-dd  Simon Marchi  <simon.marchi@efficios.com>
	    Pedro Alves  <pedro@palves.net>

	* infcmd.c (run_command_1, attach_command, detach_command)
	(interrupt_target_1): Use scoped_disable_commit_resumed.
	* infrun.c (do_target_resume): Remove
	target_commit_resume call.
	(commit_resume_all_targets): Remove.
	(maybe_set_commit_resumed_all_targets): New.
	(maybe_call_commit_resumed_all_targets): New.
	(enable_commit_resumed): New.
	(scoped_disable_commit_resumed::scoped_disable_commit_resumed)
	(scoped_disable_commit_resumed::~scoped_disable_commit_resumed)
	(scoped_disable_commit_resumed::reset)
	(scoped_disable_commit_resumed::reset_and_commit)
	(scoped_enable_commit_resumed::scoped_enable_commit_resumed)
	(scoped_enable_commit_resumed::~scoped_enable_commit_resumed):
	New.
	(proceed): Use scoped_disable_commit_resumed and
	maybe_call_commit_resumed_all_targets.
	(fetch_inferior_event): Use scoped_disable_commit_resumed.
	* infrun.h (struct scoped_disable_commit_resumed): New.
	(maybe_call_commit_resumed_all_process_targets): New.
	(struct scoped_enable_commit_resumed): New.
	* mi/mi-main.c (exec_continue): Use scoped_disable_commit_resumed.
	* process-stratum-target.h (class process_stratum_target):
	<commit_resumed_state>: New.
	* record-full.c (record_full_wait_1): Change commit_resumed_state
	around calling commit_resumed.
	* remote.c (class remote_target) <commit_resume>: Rename to...
	<commit_resumed>: ... this.
	(struct stop_reply): Move up.
	(remote_target::commit_resume): Rename to...
	(remote_target::commit_resumed): ... this.  Check if there is any
	thread pending vCont resume.
	(remote_target::remote_stop_ns): Generate stop replies for resumed
	but pending vCont threads.
	(remote_target::wait_ns): Add gdb_assert.
	* target-delegates.c: Regenerate.
	* target.c (target_wait, target_resume): Assert that the current
	process_stratum target isn't in commit-resumed state.
	(defer_target_commit_resume): Remove.
	(target_commit_resume): Remove.
	(target_commit_resumed): New.
	(make_scoped_defer_target_commit_resume): Remove.
	(target_stop): Assert that the current process_stratum target
	isn't in commit-resumed state.
	* target.h (struct target_ops) <commit_resume>: Rename to ...
	 <commit_resumed>: ... this.
	(target_commit_resume): Remove.
	(target_commit_resumed): New.
	(make_scoped_defer_target_commit_resume): Remove.
	* top.c (wait_sync_command_done): Use
	scoped_enable_commit_resumed.

[1] https://github.com/ROCm-Developer-Tools/ROCgdb/
[2] https://github.com/ROCm-Developer-Tools/ROCdbgapi

Change-Id: I836135531a29214b21695736deb0a81acf8cf566
 2021-03-26 15:58:47 +00:00
Pedro Alves
e5b9b39f88 target_is_non_stop_p and sync targets 
gdb.base/maint-target-async-off.exp fails if you test against
gdbserver with "maint set target-non-stop on" forced.

  (gdb) run
  Starting program: build/gdb/testsuite/outputs/gdb.base/maint-target-async-off/maint-target-async-off

  Breakpoint 1, main () at src/gdb/testsuite/gdb.base/maint-target-async-off.c:21
  21        return 0;
  (gdb) FAIL: gdb.base/maint-target-async-off.exp: continue until exit (timeout)

Above, GDB just stopped listening to stdin.

Basically, GDB assumes that a target working in non-stop mode
operation also supports async mode; it's a requirement.  GDB
misbehaves badly otherwise, and even hits failed assertions.

Fix this by making target_is_non_stop_p return false if async is off.

gdb/ChangeLog:

	* target.c (target_always_non_stop_p): Also check whether the
	target can async.

Change-Id: I7e52e1061396a5b9b02ada462f68a14b76d68974
 2021-03-26 15:57:25 +00:00
Tom Tromey
bab287cdcf Avoid some pointer chasing in DWARF reader 
I noticed a spot in the DWARF reader using "per_objfile->per_bfd",
where a local per_bfd variable had already been created.  Looking
through the file, I found a number of such spots.  This patch changes
them to use the already-existing local, avoiding a bit of excess
pointer chasing.

gdb/ChangeLog
2021-03-26  Tom Tromey  <tom@tromey.com>

	* dwarf2/read.c (dwarf2_read_debug_names)
	(dwarf2_build_psymtabs_hard, create_addrmap_from_aranges)
	(dw2_debug_names_iterator::next, create_type_unit_group):
	Simplify.
 2021-03-26 09:37:22 -06:00
Pedro Alves
eff4f69db4 Fix bkpt-other-inferior.exp race 
When testing with "maint set target-non-stop on",
gdb.server/bkpt-other-inferior.exp sometimes fails like so:

 (gdb) inferior 2
 [Switching to inferior 2 [process 368191] (<noexec>)]
 [Switching to thread 2.1 (Thread 368191.368191)]
 [remote] Sending packet: $m7ffff7fd0100,1#5b
 [remote] Packet received: 48
 [remote] Sending packet: $m7ffff7fd0100,1#5b
 [remote] Packet received: 48
 [remote] Sending packet: $m7ffff7fd0100,9#63
 [remote] Packet received: 4889e7e8e80c000049
 #0  0x00007ffff7fd0100 in ?? ()
 (gdb) PASS: gdb.server/bkpt-other-inferior.exp: inf 2: switch to inferior
 break -q main
 Breakpoint 2 at 0x1138: file /home/pedro/gdb/binutils-gdb/src/gdb/testsuite/gdb.server/server.c, line 21.
 (gdb) PASS: gdb.server/bkpt-other-inferior.exp: inf 2: set breakpoint
 delete breakpoints
 Delete all breakpoints? (y or n) y
 (gdb) [remote] wait: enter
 [remote] wait: exit
 FAIL: gdb.server/bkpt-other-inferior.exp: inf 2: delete all breakpoints in delete_breakpoints (timeout)
 ERROR: breakpoints not deleted
 Remote debugging from host ::1, port 55876
 monitor exit

The problem is here:

 (gdb) [remote] wait: enter

The testcase isn't expecting any output after the prompt.

Why is that "[remote] wait" output?  What happens is that "delete
breakpoints" queries the user, and `query` disables/reenables target
async, which results in the remote target's async event handler ending
up marked:

 (top-gdb) bt
 #0  mark_async_event_handler (async_handler_ptr=0x556bffffffff) at ../../src/gdb/async-event.c:295
 #1  0x0000556bf71b711f in infrun_async (enable=1) at ../../src/gdb/infrun.c:119
 #2  0x0000556bf7471387 in target_async (enable=1) at ../../src/gdb/target.c:3684
 #3  0x0000556bf748a0bd in gdb_readline_wrapper_cleanup::~gdb_readline_wrapper_cleanup (this=0x7ffe3cf30eb0, __in_chrg=<optimized out>) at ../../src/gdb/top.c:1074
 #4  0x0000556bf74874e2 in gdb_readline_wrapper (prompt=0x556bfa17da60 "Delete all breakpoints? (y or n) ") at ../../src/gdb/top.c:1096
 #5  0x0000556bf75111c5 in defaulted_query(const char *, char, typedef __va_list_tag __va_list_tag *) (ctlstr=0x556bf7717f34 "Delete all breakpoints? ", defchar=0 '\000', args=0x7ffe3cf31020) at ../../src/gdb/utils.c:893
 #6  0x0000556bf751166f in query (ctlstr=0x556bf7717f34 "Delete all breakpoints? ") at ../../src/gdb/utils.c:985
 #7  0x0000556bf6f11404 in delete_command (arg=0x0, from_tty=1) at ../../src/gdb/breakpoint.c:13500
 ...

... which then later results in a target_wait call:

 (top-gdb) bt
 #0  remote_target::wait_ns (this=0x7ffe3cf30f80, ptid=..., status=0xde530314f0802800, options=...) at ../../src/gdb/remote.c:7937
 #1  0x0000556bf7369dcb in remote_target::wait (this=0x556bfa0b2180, ptid=..., status=0x7ffe3cf31568, options=...) at ../../src/gdb/remote.c:8173
 #2  0x0000556bf745e527 in target_wait (ptid=..., status=0x7ffe3cf31568, options=...) at ../../src/gdb/target.c:2000
 #3  0x0000556bf71be686 in do_target_wait_1 (inf=0x556bfa1573d0, ptid=..., status=0x7ffe3cf31568, options=...) at ../../src/gdb/infrun.c:3463
 #4  0x0000556bf71be88b in <lambda(inferior*)>::operator()(inferior *) const (__closure=0x7ffe3cf31320, inf=0x556bfa1573d0) at ../../src/gdb/infrun.c:3526
 #5  0x0000556bf71bebcd in do_target_wait (wait_ptid=..., ecs=0x7ffe3cf31540, options=...) at ../../src/gdb/infrun.c:3539
 #6  0x0000556bf71bf97b in fetch_inferior_event () at ../../src/gdb/infrun.c:3879
 #7  0x0000556bf71a27f8 in inferior_event_handler (event_type=INF_REG_EVENT) at ../../src/gdb/inf-loop.c:42
 #8  0x0000556bf71cc8b7 in infrun_async_inferior_event_handler (data=0x0) at ../../src/gdb/infrun.c:9220
 #9  0x0000556bf6ecb80f in check_async_event_handlers () at ../../src/gdb/async-event.c:327
 #10 0x0000556bf76b011a in gdb_do_one_event () at ../../src/gdbsupport/event-loop.cc:216
 ...

... which returns TARGET_WAITKIND_IGNORE.

Fix this by only enabling remote output around setting the breakpoint.

gdb/testsuite/ChangeLog:

	* gdb.server/bkpt-other-inferior.exp: Only enable remote output
	around setting the breakpoint.

Change-Id: I2fd152fd9c46b1c5e7fa678cc4d4054dac0b2bd4
 2021-03-25 22:10:36 +00:00
Pedro Alves
323fd5b9f9 Fix problem exposed by gdb.server/stop-reply-no-thread-multi.exp 
Running gdb.server/stop-reply-no-thread-multi.exp with "maint set
target-non-stop on" occasionally hit an internal error like this:

  ...
  continue
  Continuing.
  warning: multi-threaded target stopped without sending a thread-id, using first non-exited thread
  /home/pedro/gdb/binutils-gdb/src/gdb/inferior.c:291: internal-error: inferior* find_inferior_pid(process_stratum_target*, int): Assertion `pid != 0' failed.
  A problem internal to GDB has been detected,
  further debugging may prove unreliable.

  This is a bug, please report it.
  FAIL: gdb.server/stop-reply-no-thread-multi.exp: to_disable=Tthread: continue until exit (GDB internal error)

The backtrace looks like this:

 ...
 #5  0x0000560357b0879c in internal_error (file=0x560357be6c18 "/home/pedro/gdb/binutils-gdb/src/gdb/inferior.c", line=291, fmt=0x560357be6b21 "%s: Assertion `%s' failed.") at /home/pedro/gdb/binutils-gdb/src/gdbsupport/errors.cc:55
 #6  0x000056035762061b in find_inferior_pid (targ=0x5603596e9560, pid=0) at /home/pedro/gdb/binutils-gdb/src/gdb/inferior.c:291
 #7  0x00005603576206e6 in find_inferior_ptid (targ=0x5603596e9560, ptid=...) at /home/pedro/gdb/binutils-gdb/src/gdb/inferior.c:305
 #8  0x00005603577d43ed in remote_target::check_pending_events_prevent_wildcard_vcont (this=0x5603596e9560, may_global_wildcard=0x7fff84fb05f0) at /home/pedro/gdb/binutils-gdb/src/gdb/remote.c:7215
 #9  0x00005603577d2a9c in remote_target::commit_resumed (this=0x5603596e9560) at /home/pedro/gdb/binutils-gdb/src/gdb/remote.c:6680
 ...

pid is 0 in this case because the queued event is a process exit event
with no pid associated:

 (top-gdb) p event->ws
 During symbol reading: .debug_line address at offset 0x563c9a is 0 [in module /home/pedro/gdb/binutils-gdb/build/gdb/gdb]
 $1 = {kind = TARGET_WAITKIND_EXITED, value = {integer = 0, sig = GDB_SIGNAL_0, related_pid = {m_pid = 0, m_lwp = 0, m_tid = 0}, execd_pathname = 0x0, syscall_number = 0}}
 (top-gdb)

This fixes it, and adds a "maint set target-non-stop on/off" axis to the testcase.

gdb/ChangeLog:

	* remote.c
	(remote_target::check_pending_events_prevent_wildcard_vcont):
	Check whether the event's ptid is not null_ptid before looking up
	the corresponding inferior.

gdb/testsuite/ChangeLog:

	* gdb.server/stop-reply-no-thread-multi.exp (run_test): Add
	"target_non_stop" parameter and use it.
	(top level): Add "maint set target-non-stop on/off" testing axis.

Change-Id: Ia30cf275305ee4dcbbd33f731534cd71d1550eaa
 2021-03-25 22:09:54 +00:00
Changbin Du
d3cbca38df gdb/riscv: fix creating breakpoints at invalid addresses 
To allow breakpoints to be created at invalid addresses,
target_read_code is used instead of read_code.  This was fixed in
commit:

  commit c01660c625
  Date:   Wed Apr 17 00:31:43 2019 +0100

      gdb/riscv: Allow breakpoints to be created at invalid addresses

Unfortunately, the call to read_code was left in by mistake.  The
result is that GDB will fail when trying to create the breakpoint,
rather than when trying to install the breakpoint (as is the case with
other targets).

This commit fixes this mistake and removes the offending call to
read_code.

gdb/ChangeLog:

	* riscv-tdep.c (riscv_breakpoint_kind_from_pc): Remove call to
	read_code.
 2021-03-25 11:10:02 +00:00
Simon Marchi
328d42d87e gdb: remove current_top_target function 
The current_top_target function is a hidden dependency on the current
inferior.  Since I'd like to slowly move towards reducing our dependency
on the global current state, remove this function and make callers use

  current_inferior ()->top_target ()

There is no expected change in behavior, but this one step towards
making those callers use the inferior from their context, rather than
refer to the global current inferior.

gdb/ChangeLog:

	* target.h (current_top_target): Remove, make callers use the
	current inferior instead.
	* target.c (current_top_target): Remove.

Change-Id: Iccd457036f84466cdaa3865aa3f9339a24ea001d
 2021-03-24 18:08:24 -04:00
Simon Marchi
d777bf0df2 gdb: move all "current target" wrapper implementations to target.c 
The following patch removes the current_top_target function, replacing
uses with `current_inferior ()->top_target ()`.  This is a problem for
uses in target.h, because they don't have access to the current_inferior
function and the inferior structure: target.h can't include inferior.h,
otherwise that would make a cyclic inclusion.

Avoid this by moving all implementations of the wrappers that call
target methods with the current target to target.c.  Many of them are
changed from a macro to a function, which is an improvement for
readability and debuggability, IMO.

target_shortname and target_longname were not function-like macros, so a
few adjustments are needed.

gdb/ChangeLog:

	* target.h (target_shortname): Change to function declaration.
	(target_longname): Likewise.
	(target_attach_no_wait): Likewise.
	(target_post_attach): Likewise.
	(target_prepare_to_store): Likewise.
	(target_supports_enable_disable_tracepoint): Likewise.
	(target_supports_string_tracing): Likewise.
	(target_supports_evaluation_of_breakpoint_conditions): Likewise.
	(target_supports_dumpcore): Likewise.
	(target_dumpcore): Likewise.
	(target_can_run_breakpoint_commands): Likewise.
	(target_files_info): Likewise.
	(target_post_startup_inferior): Likewise.
	(target_insert_fork_catchpoint): Likewise.
	(target_remove_fork_catchpoint): Likewise.
	(target_insert_vfork_catchpoint): Likewise.
	(target_remove_vfork_catchpoint): Likewise.
	(target_insert_exec_catchpoint): Likewise.
	(target_remove_exec_catchpoint): Likewise.
	(target_set_syscall_catchpoint): Likewise.
	(target_rcmd): Likewise.
	(target_can_lock_scheduler): Likewise.
	(target_can_async_p): Likewise.
	(target_is_async_p): Likewise.
	(target_execution_direction): Likewise.
	(target_extra_thread_info): Likewise.
	(target_pid_to_exec_file): Likewise.
	(target_thread_architecture): Likewise.
	(target_find_memory_regions): Likewise.
	(target_make_corefile_notes): Likewise.
	(target_get_bookmark): Likewise.
	(target_goto_bookmark): Likewise.
	(target_stopped_by_watchpoint): Likewise.
	(target_stopped_by_sw_breakpoint): Likewise.
	(target_supports_stopped_by_sw_breakpoint): Likewise.
	(target_stopped_by_hw_breakpoint): Likewise.
	(target_supports_stopped_by_hw_breakpoint): Likewise.
	(target_have_steppable_watchpoint): Likewise.
	(target_can_use_hardware_watchpoint): Likewise.
	(target_region_ok_for_hw_watchpoint): Likewise.
	(target_can_do_single_step): Likewise.
	(target_insert_watchpoint): Likewise.
	(target_remove_watchpoint): Likewise.
	(target_insert_hw_breakpoint): Likewise.
	(target_remove_hw_breakpoint): Likewise.
	(target_can_accel_watchpoint_condition): Likewise.
	(target_can_execute_reverse): Likewise.
	(target_get_ada_task_ptid): Likewise.
	(target_filesystem_is_local): Likewise.
	(target_trace_init): Likewise.
	(target_download_tracepoint): Likewise.
	(target_can_download_tracepoint): Likewise.
	(target_download_trace_state_variable): Likewise.
	(target_enable_tracepoint): Likewise.
	(target_disable_tracepoint): Likewise.
	(target_trace_start): Likewise.
	(target_trace_set_readonly_regions): Likewise.
	(target_get_trace_status): Likewise.
	(target_get_tracepoint_status): Likewise.
	(target_trace_stop): Likewise.
	(target_trace_find): Likewise.
	(target_get_trace_state_variable_value): Likewise.
	(target_save_trace_data): Likewise.
	(target_upload_tracepoints): Likewise.
	(target_upload_trace_state_variables): Likewise.
	(target_get_raw_trace_data): Likewise.
	(target_get_min_fast_tracepoint_insn_len): Likewise.
	(target_set_disconnected_tracing): Likewise.
	(target_set_circular_trace_buffer): Likewise.
	(target_set_trace_buffer_size): Likewise.
	(target_set_trace_notes): Likewise.
	(target_get_tib_address): Likewise.
	(target_set_permissions): Likewise.
	(target_static_tracepoint_marker_at): Likewise.
	(target_static_tracepoint_markers_by_strid): Likewise.
	(target_traceframe_info): Likewise.
	(target_use_agent): Likewise.
	(target_can_use_agent): Likewise.
	(target_augmented_libraries_svr4_read): Likewise.
	(target_log_command): Likewise.
	* target.c (target_shortname): New.
	(target_longname): New.
	(target_attach_no_wait): New.
	(target_post_attach): New.
	(target_prepare_to_store): New.
	(target_supports_enable_disable_tracepoint): New.
	(target_supports_string_tracing): New.
	(target_supports_evaluation_of_breakpoint_conditions): New.
	(target_supports_dumpcore): New.
	(target_dumpcore): New.
	(target_can_run_breakpoint_commands): New.
	(target_files_info): New.
	(target_post_startup_inferior): New.
	(target_insert_fork_catchpoint): New.
	(target_remove_fork_catchpoint): New.
	(target_insert_vfork_catchpoint): New.
	(target_remove_vfork_catchpoint): New.
	(target_insert_exec_catchpoint): New.
	(target_remove_exec_catchpoint): New.
	(target_set_syscall_catchpoint): New.
	(target_rcmd): New.
	(target_can_lock_scheduler): New.
	(target_can_async_p): New.
	(target_is_async_p): New.
	(target_execution_direction): New.
	(target_extra_thread_info): New.
	(target_pid_to_exec_file): New.
	(target_thread_architecture): New.
	(target_find_memory_regions): New.
	(target_make_corefile_notes): New.
	(target_get_bookmark): New.
	(target_goto_bookmark): New.
	(target_stopped_by_watchpoint): New.
	(target_stopped_by_sw_breakpoint): New.
	(target_supports_stopped_by_sw_breakpoint): New.
	(target_stopped_by_hw_breakpoint): New.
	(target_supports_stopped_by_hw_breakpoint): New.
	(target_have_steppable_watchpoint): New.
	(target_can_use_hardware_watchpoint): New.
	(target_region_ok_for_hw_watchpoint): New.
	(target_can_do_single_step): New.
	(target_insert_watchpoint): New.
	(target_remove_watchpoint): New.
	(target_insert_hw_breakpoint): New.
	(target_remove_hw_breakpoint): New.
	(target_can_accel_watchpoint_condition): New.
	(target_can_execute_reverse): New.
	(target_get_ada_task_ptid): New.
	(target_filesystem_is_local): New.
	(target_trace_init): New.
	(target_download_tracepoint): New.
	(target_can_download_tracepoint): New.
	(target_download_trace_state_variable): New.
	(target_enable_tracepoint): New.
	(target_disable_tracepoint): New.
	(target_trace_start): New.
	(target_trace_set_readonly_regions): New.
	(target_get_trace_status): New.
	(target_get_tracepoint_status): New.
	(target_trace_stop): New.
	(target_trace_find): New.
	(target_get_trace_state_variable_value): New.
	(target_save_trace_data): New.
	(target_upload_tracepoints): New.
	(target_upload_trace_state_variables): New.
	(target_get_raw_trace_data): New.
	(target_get_min_fast_tracepoint_insn_len): New.
	(target_set_disconnected_tracing): New.
	(target_set_circular_trace_buffer): New.
	(target_set_trace_buffer_size): New.
	(target_set_trace_notes): New.
	(target_get_tib_address): New.
	(target_set_permissions): New.
	(target_static_tracepoint_marker_at): New.
	(target_static_tracepoint_markers_by_strid): New.
	(target_traceframe_info): New.
	(target_use_agent): New.
	(target_can_use_agent): New.
	(target_augmented_libraries_svr4_read): New.
	(target_log_command): New.
	* bfin-tdep.c (bfin_sw_breakpoint_from_kind): Adjust.
	* infrun.c (set_schedlock_func): Adjust.
	* mi/mi-main.c (exec_reverse_continue): Adjust.
	* reverse.c (exec_reverse_once): Adjust.
	* sh-tdep.c (sh_sw_breakpoint_from_kind): Adjust.
	* tui/tui-stack.c (tui_locator_window::make_status_line): Adjust.
	* remote-sim.c (gdbsim_target::detach): Adjust.
	(gdbsim_target::files_info): Adjust.

Change-Id: I72ef56e9a25adeb0b91f1ad05e34c89f77ebeaa8
 2021-03-24 18:07:30 -04:00
Tom Tromey
b64f703b51 Remove 'kind' parameter from dw2_map_matching_symbols 
I noticed that dw2_map_matching_symbols does not use its 'kind'
parameter.  This patch removes it.  Tested by rebuilding.

2021-03-24  Tom Tromey  <tom@tromey.com>

	* dwarf2/read.c (dw2_map_matching_symbols): Update.
	(dw2_expand_symtabs_matching_symbol): Remove 'kind' parameter.
	(check_match, dw2_expand_symtabs_matching)
	(dwarf2_debug_names_index::map_matching_symbols)
	(dwarf2_debug_names_index::expand_symtabs_matching): Update.
 2021-03-24 14:50:25 -06:00
Keith Seitz
68f115f8c0 Fix TYPE_DECLARED_CLASS thinko 
Simon pointed out an error that I made in
compile_cplus_conver_struct_or_union in my original C++ compile submission:

  if (type->code () == TYPE_CODE_STRUCT)
    {
      const char *what = TYPE_DECLARED_CLASS (type) ? "struct" : "class";

      resuld = instance->plugin ().build_decl
        (what, name.get (), (GCC_CP_SYMBOL_CLASS | nested_access
                             | (TYPE_DECLARED_CLASS (type)
                                ? GCC_CP_FLAG_CLASS_NOFLAG
                                : GCC_CP_FLAG_CLASS_IS_STRUCT)),
         0, nullptr, 0, filename, line);
    }

Notice that WHAT will contain "struct" for TYPE_DECLARED_CLASS. Whoops.

Fortunately this first parameter of build_decl is only used for
debugging.

gdb/ChangeLog
2021-03-24  Keith Seitz  <keiths@redhat.com>

	* compile/compile-cplus-types.c
	(compile_cplus_convert_struct_or_union): Fix TYPE_DECLARED_CLASS
	thinko.
 2021-03-24 13:44:17 -07:00
Simon Marchi
41c0087ba5 gdb: make gdbarch_data_registry static 
This variable was made static in:

  6bd434d6ca ("gdb: make some variables static")

But I modified gdbarch.c instead of gdbarch.sh, so the change was
later reverted when gdbarch.c was re-generated.

Do it right this time.

gdb/ChangeLog:

	* gdbarch.sh (gdbarch_data_registry): Make static.
	* gdbarch.c: Re-generate.

Change-Id: I4048ba99a0cf47acd9da050934965db222fbd159
 2021-03-24 15:39:11 -04:00