Currently, gdb.gdb/selftest.exp fails if you build GDB with
optimization (-O2, etc.).
The reason is that after setting a breakpoint in captured_main, we
stop at:
...
Breakpoint 1, captured_main_1 (context=<optimized out>) at src/gdb/main.c:492
...
while selftest_setup expects a stop at captured_main.
Here, captured_main_1 has been inlined into captured_main, and
captured_main has been inlined into gdb_main:
...
$ nm ./build/gdb/gdb | egrep ' [tT] .*captured_main|gdb_main' | c++filt
000000000061b950 T gdb_main(captured_main_args*)
...
Indeed, the two inlined functions show up in the backtrace:
...
(gdb) bt
#0 captured_main_1 (context=<optimized out>) at main.c:492
#1 captured_main (data=<optimized out>) at main.c:1147
#2 gdb_main (args=args@entry=0x7fffffffdb80) at main.c:1173
#3 0x000000000040fea5 in main (argc=<optimized out>, argv=<optimized out>)
at gdb.c:32
...
We're now stopping at captured_main_1 because commit ddfe970e6b
("Don't elide all inlined frames") makes GDB present a stop at the
innermost inlined frame if the program stopped by a user breakpoint.
Now, the selftest.exp testcase explicitly asks to stop at
"captured_main", not "captured_main_1", so I'm thinking that it's
GDB'S behavior that should be improved. That is what this commit
does, by only showing a stop at an inline frame if the user breakpoint
was set in that frame's block.
Before this commit:
(top-gdb) b captured_main
Breakpoint 1 at 0x792f99: file src/gdb/main.c, line 492.
(top-gdb) r
Starting program: build/gdb/gdb
Breakpoint 1, captured_main_1 (context=<optimized out>) at src/gdb/main.c:492
492 lim_at_start = (char *) sbrk (0);
(top-gdb)
After this commit, we now instead get:
(top-gdb) b captured_main
Breakpoint 1 at 0x791339: file src/gdb/main.c, line 492.
(top-gdb) r
Starting program: build/gdb/gdb
Breakpoint 1, captured_main (data=<optimized out>) at src/gdb/main.c:1147
1147 captured_main_1 (context);
(top-gdb)
and:
(top-gdb) b captured_main_1
Breakpoint 2 at 0x791339: file src/gdb/main.c, line 492.
(top-gdb) r
Starting program: build/gdb/gdb
Breakpoint 2, captured_main_1 (context=<optimized out>) at src/gdb/main.c:492
492 lim_at_start = (char *) sbrk (0);
(top-gdb)
Note that both captured_main and captured_main_1 resolved to the same
address, 0x791339. That is necessary to trigger the issue in
question. The gdb.base/inline-break.exp testcase currently does not
exercise that, but the new test added by this commit does. That new
test fails without the GDB fix and passes with the fix. No
regressions on x86-64 GNU/Linux.
While at it, the THIS_PC comparison in stopped_by_user_bp_inline_frame
is basically a nop, so just remove it -- if a software or hardware
breakpoint explains the stop, then it must be that it was installed at
the current PC.
gdb/ChangeLog:
2018-06-19 Pedro Alves <palves@redhat.com>
* inline-frame.c (stopped_by_user_bp_inline_frame): Replace PC
parameter with a block parameter. Compare location's block symbol
with the frame's block instead of addresses.
(skip_inline_frames): Pass the current block instead of the
frame's address. Break out as soon as we determine the frame
should not be skipped.
gdb/testsuite/ChangeLog:
2018-06-19 Pedro Alves <palves@redhat.com>
* gdb.opt/inline-break.c (func_inline_callee, func_inline_caller)
(func_extern_caller): New.
(main): Call func_extern_caller.
* gdb.opt/inline-break.exp: Add tests for inline frame skipping
logic change.
244 lines
4.4 KiB
C
244 lines
4.4 KiB
C
/* This testcase is part of GDB, the GNU debugger.
|
|
|
|
Copyright (C) 2012-2018 Free Software Foundation, Inc.
|
|
|
|
This program is free software; you can redistribute it and/or modify
|
|
it under the terms of the GNU General Public License as published by
|
|
the Free Software Foundation; either version 3 of the License, or
|
|
(at your option) any later version.
|
|
|
|
This program is distributed in the hope that it will be useful,
|
|
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
GNU General Public License for more details.
|
|
|
|
You should have received a copy of the GNU General Public License
|
|
along with this program. If not, see <http://www.gnu.org/licenses/>. */
|
|
|
|
/* The file ../gdb.dwarf2/inline-break.S was generated manually from
|
|
this file, and should be regenerated if this file is modified. */
|
|
|
|
#ifdef __GNUC__
|
|
# define ATTR __attribute__((gnu_inline)) __attribute__((always_inline))
|
|
#else
|
|
# define ATTR
|
|
#endif
|
|
|
|
/* A static inlined function that is called once. */
|
|
|
|
static inline ATTR int
|
|
func1 (int x)
|
|
{
|
|
return x * 23;
|
|
}
|
|
|
|
/* A non-static inlined function that is called once. */
|
|
|
|
inline ATTR int
|
|
func2 (int x)
|
|
{
|
|
return x * 17;
|
|
}
|
|
|
|
/* A static inlined function that calls another static inlined
|
|
function. */
|
|
|
|
static inline ATTR int
|
|
func3b (int x)
|
|
{
|
|
return x < 14 ? 1 : 2;
|
|
}
|
|
|
|
static inline ATTR int
|
|
func3a (int x)
|
|
{
|
|
return func3b (x * 23);
|
|
}
|
|
|
|
/* A non-static inlined function that calls a static inlined
|
|
function. */
|
|
|
|
static inline ATTR int
|
|
func4b (int x)
|
|
{
|
|
return x < 13 ? 1 : 2;
|
|
}
|
|
|
|
inline ATTR int
|
|
func4a (int x)
|
|
{
|
|
return func4b (x * 17);
|
|
}
|
|
|
|
/* A static inlined function that calls a non-static inlined
|
|
function. */
|
|
|
|
inline ATTR int
|
|
func5b (int x)
|
|
{
|
|
return x < 12 ? 1 : 2;
|
|
}
|
|
|
|
static inline ATTR int
|
|
func5a (int x)
|
|
{
|
|
return func5b (x * 23);
|
|
}
|
|
|
|
/* A non-static inlined function that calls another non-static inlined
|
|
function. */
|
|
|
|
inline ATTR int
|
|
func6b (int x)
|
|
{
|
|
return x < 14 ? 3 : 2;
|
|
}
|
|
|
|
inline ATTR int
|
|
func6a (int x)
|
|
{
|
|
return func6b (x * 17);
|
|
}
|
|
|
|
/* A static inlined function that is called more than once. */
|
|
|
|
static inline ATTR int
|
|
func7b (int x)
|
|
{
|
|
return x < 23 ? 1 : 4;
|
|
}
|
|
|
|
static inline ATTR int
|
|
func7a (int x)
|
|
{
|
|
return func7b (x * 29);
|
|
}
|
|
|
|
/* A non-static inlined function that is called more than once. */
|
|
|
|
inline ATTR int
|
|
func8b (int x)
|
|
{
|
|
return x < 7 ? 11 : 9;
|
|
}
|
|
|
|
static inline ATTR int
|
|
func8a (int x)
|
|
{
|
|
return func8b (x * 31);
|
|
}
|
|
|
|
static inline ATTR int
|
|
inline_func1 (int x)
|
|
{
|
|
int y = 1; /* inline_func1 */
|
|
|
|
return y + x;
|
|
}
|
|
|
|
static int
|
|
not_inline_func1 (int x)
|
|
{
|
|
int y = 2; /* not_inline_func1 */
|
|
|
|
return y + inline_func1 (x);
|
|
}
|
|
|
|
inline ATTR int
|
|
inline_func2 (int x)
|
|
{
|
|
int y = 3; /* inline_func2 */
|
|
|
|
return y + not_inline_func1 (x);
|
|
}
|
|
|
|
int
|
|
not_inline_func2 (int x)
|
|
{
|
|
int y = 4; /* not_inline_func2 */
|
|
|
|
return y + inline_func2 (x);
|
|
}
|
|
|
|
static inline ATTR int
|
|
inline_func3 (int x)
|
|
{
|
|
int y = 5; /* inline_func3 */
|
|
|
|
return y + not_inline_func2 (x);
|
|
}
|
|
|
|
static int
|
|
not_inline_func3 (int x)
|
|
{
|
|
int y = 6; /* not_inline_func3 */
|
|
|
|
return y + inline_func3 (x);
|
|
}
|
|
|
|
/* The following three functions serve to exercise GDB's inline frame
|
|
skipping logic when setting a user breakpoint on an inline function
|
|
by name. */
|
|
|
|
/* A static inlined function that is called by another static inlined
|
|
function. */
|
|
|
|
static inline ATTR int
|
|
func_inline_callee (int x)
|
|
{
|
|
return x * 23;
|
|
}
|
|
|
|
/* A static inlined function that calls another static inlined
|
|
function. The body of the function is as simple as possible so
|
|
that both functions are inlined to the same PC address. */
|
|
|
|
static inline ATTR int
|
|
func_inline_caller (int x)
|
|
{
|
|
return func_inline_callee (x);
|
|
}
|
|
|
|
/* An extern not-inline function that calls a static inlined
|
|
function. */
|
|
|
|
int
|
|
func_extern_caller (int x)
|
|
{
|
|
return func_inline_caller (x);
|
|
}
|
|
|
|
/* Entry point. */
|
|
|
|
int
|
|
main (int argc, char *argv[])
|
|
{
|
|
/* Declaring x as volatile here prevents GCC from combining calls.
|
|
If GCC is allowed to combine calls then some of them end up with
|
|
no instructions at all, so there is no specific address for GDB
|
|
to set a breakpoint at. */
|
|
volatile int x = argc;
|
|
|
|
x = func1 (x);
|
|
|
|
x = func2 (x);
|
|
|
|
x = func3a (x);
|
|
|
|
x = func4a (x);
|
|
|
|
x = func5a (x);
|
|
|
|
x = func6a (x);
|
|
|
|
x = func7a (x) + func7b (x);
|
|
|
|
x = func8a (x) + func8b (x);
|
|
|
|
x = not_inline_func3 (-21);
|
|
|
|
func_extern_caller (1);
|
|
|
|
return x;
|
|
}
|