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c-family: Macro support in -Wmisleading-indentation [PR80076]

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Currently the -Wmisleading-indentation warning doesn't do any analysis
when the guarded statement or the statement after it is produced by a
macro.  This means we warn for:

  if (flag)
    foo ();
    bar ();

but not for:

  #define BAR bar
  if (flag)
    foo ();
    BAR ();

This patch extends the -Wmisleading-indentation implementation to
support analyzing such statements and their tokens.  This is done in the
"natural" way by resolving the location of each of the three tokens to
the token's macro expansion point.  (Additionally, if the tokens all
resolve to the same macro expansion point then we instead use their
locations within the macro definition.)  When these resolved locations
are all different, then we can proceed with applying the warning
heuristics to them as if no macros were involved.

gcc/c-family/ChangeLog:

	PR c/80076
	* c-indentation.c (should_warn_for_misleading_indentation): Move
	declarations of local variables closer to their first use.
	Handle virtual token locations by resolving them to their
	respective macro expansion points.  If all three tokens are
	produced from the same macro expansion, then instead use their
	loci within the macro definition.

gcc/objc/ChangeLog:

	PR c/80076
	* objc-gnu-runtime-abi-01.c
	(gnu_runtime_abi_01_get_class_super_ref): Reduce indentation of
	misleadingly indented return statements.
	* objc-next-runtime-abi-01.c
	(next_runtime_abi_01_get_class_super_ref): Likewise.

gcc/ChangeLog:

	PR c/80076
	* gensupport.c (alter_attrs_for_subst_insn) <case SET_ATTR>:
	Reduce indentation of misleadingly indented code fragment.
	* lra-constraints.c (multi_block_pseudo_p): Likewise.
	* sel-sched-ir.c (merge_fences): Likewise.

libcpp/ChangeLog:

	PR c/80076
	* include/line-map.h (first_map_in_common): Declare.
	* line-map.c (first_map_in_common): Remove static.

gcc/testsuite/ChangeLog:

	PR c/80076
	* c-c++-common/Wmisleading-indentation-5.c: New test.
This commit is contained in:
Patrick Palka 2020-09-17 14:27:22 -04:00
parent 71e3d1970c
commit 4839de55e2
9 changed files with 177 additions and 80 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

61
gcc/c-family/c-indentation.c
View File

@ -213,19 +213,6 @@ should_warn_for_misleading_indentation (const token_indent_info &guard_tinfo,
const token_indent_info &body_tinfo,
const token_indent_info &next_tinfo)
{
location_t guard_loc = guard_tinfo.location;
location_t body_loc = body_tinfo.location;
location_t next_stmt_loc = next_tinfo.location;
enum cpp_ttype body_type = body_tinfo.type;
enum cpp_ttype next_tok_type = next_tinfo.type;
/* Don't attempt to compare the indentation of BODY_LOC and NEXT_STMT_LOC
if either are within macros. */
if (linemap_location_from_macro_expansion_p (line_table, body_loc)
|| linemap_location_from_macro_expansion_p (line_table, next_stmt_loc))
return false;
/* Don't attempt to compare indentation if #line or # 44 "file"-style
directives are present, suggesting generated code.
@ -266,6 +253,7 @@ should_warn_for_misleading_indentation (const token_indent_info &guard_tinfo,
} <- NEXT
baz ();
*/
enum cpp_ttype next_tok_type = next_tinfo.type;
if (next_tok_type == CPP_CLOSE_BRACE
|| next_tinfo.keyword == RID_ELSE)
return false;
@ -287,6 +275,7 @@ should_warn_for_misleading_indentation (const token_indent_info &guard_tinfo,
bar (); <- BODY
baz (); <- NEXT
*/
enum cpp_ttype body_type = body_tinfo.type;
if (body_type == CPP_OPEN_BRACE)
return false;
@ -294,6 +283,52 @@ should_warn_for_misleading_indentation (const token_indent_info &guard_tinfo,
if (next_tok_type == CPP_SEMICOLON)
return false;
location_t guard_loc = guard_tinfo.location;
location_t body_loc = body_tinfo.location;
location_t next_stmt_loc = next_tinfo.location;
/* Resolve each token location to the respective macro expansion
point that produced the token. */
if (linemap_location_from_macro_expansion_p (line_table, guard_loc))
guard_loc = linemap_resolve_location (line_table, guard_loc,
LRK_MACRO_EXPANSION_POINT, NULL);
if (linemap_location_from_macro_expansion_p (line_table, body_loc))
body_loc = linemap_resolve_location (line_table, body_loc,
LRK_MACRO_EXPANSION_POINT, NULL);
if (linemap_location_from_macro_expansion_p (line_table, next_stmt_loc))
next_stmt_loc = linemap_resolve_location (line_table, next_stmt_loc,
LRK_MACRO_EXPANSION_POINT, NULL);
/* When all three tokens are produced from a single macro expansion, we
instead consider their loci inside that macro's definition. */
if (guard_loc == body_loc && body_loc == next_stmt_loc)
{
const line_map *guard_body_common_map
= first_map_in_common (line_table,
guard_tinfo.location, body_tinfo.location,
&guard_loc, &body_loc);
const line_map *body_next_common_map
= first_map_in_common (line_table,
body_tinfo.location, next_tinfo.location,
&body_loc, &next_stmt_loc);
/* Punt on complicated nesting of macros. */
if (guard_body_common_map != body_next_common_map)
return false;
guard_loc = linemap_resolve_location (line_table, guard_loc,
LRK_MACRO_DEFINITION_LOCATION, NULL);
body_loc = linemap_resolve_location (line_table, body_loc,
LRK_MACRO_DEFINITION_LOCATION, NULL);
next_stmt_loc = linemap_resolve_location (line_table, next_stmt_loc,
LRK_MACRO_DEFINITION_LOCATION,
NULL);
}
/* Give up if the loci are not all distinct. */
if (guard_loc == body_loc || body_loc == next_stmt_loc)
return false;
expanded_location body_exploc = expand_location (body_loc);
expanded_location next_stmt_exploc = expand_location (next_stmt_loc);
expanded_location guard_exploc = expand_location (guard_loc);

2
gcc/gensupport.c
View File

@ -1501,7 +1501,7 @@ alter_attrs_for_subst_insn (class queue_elem * elem, int n_dup)
case SET_ATTR:
if (strchr (XSTR (sub, 1), ',') != NULL)
XSTR (sub, 1) = duplicate_alternatives (XSTR (sub, 1), n_dup);
break;
break;
case SET_ATTR_ALTERNATIVE:
case SET:

12
gcc/lra-constraints.c
View File

@ -4776,12 +4776,12 @@ multi_block_pseudo_p (int regno)
if (regno < FIRST_PSEUDO_REGISTER)
return false;
EXECUTE_IF_SET_IN_BITMAP (&lra_reg_info[regno].insn_bitmap, 0, uid, bi)
if (bb == NULL)
bb = BLOCK_FOR_INSN (lra_insn_recog_data[uid]->insn);
else if (BLOCK_FOR_INSN (lra_insn_recog_data[uid]->insn) != bb)
return true;
return false;
EXECUTE_IF_SET_IN_BITMAP (&lra_reg_info[regno].insn_bitmap, 0, uid, bi)
if (bb == NULL)
bb = BLOCK_FOR_INSN (lra_insn_recog_data[uid]->insn);
else if (BLOCK_FOR_INSN (lra_insn_recog_data[uid]->insn) != bb)
return true;
return false;
}
/* Return true if LIST contains a deleted insn. */

4
gcc/objc/objc-gnu-runtime-abi-01.c
View File

@ -821,7 +821,7 @@ gnu_runtime_abi_01_get_class_super_ref (location_t loc ATTRIBUTE_UNUSED,
ucls_super_ref =
objc_build_component_ref (imp->class_decl,
get_identifier ("super_class"));
return ucls_super_ref;
return ucls_super_ref;
}
else
{
@ -829,7 +829,7 @@ gnu_runtime_abi_01_get_class_super_ref (location_t loc ATTRIBUTE_UNUSED,
uucls_super_ref =
objc_build_component_ref (imp->meta_decl,
get_identifier ("super_class"));
return uucls_super_ref;
return uucls_super_ref;
}
}

4
gcc/objc/objc-next-runtime-abi-01.c
View File

@ -938,7 +938,7 @@ next_runtime_abi_01_get_class_super_ref (location_t loc ATTRIBUTE_UNUSED,
ucls_super_ref =
objc_build_component_ref (imp->class_decl,
get_identifier ("super_class"));
return ucls_super_ref;
return ucls_super_ref;
}
else
{
@ -946,7 +946,7 @@ next_runtime_abi_01_get_class_super_ref (location_t loc ATTRIBUTE_UNUSED,
uucls_super_ref =
objc_build_component_ref (imp->meta_decl,
get_identifier ("super_class"));
return uucls_super_ref;
return uucls_super_ref;
}
}

110
gcc/sel-sched-ir.c
View File

@ -722,63 +722,63 @@ merge_fences (fence_t f, insn_t insn,
!= BLOCK_FOR_INSN (last_scheduled_insn));
}
/* Find edge of first predecessor (last_scheduled_insn_old->insn). */
FOR_EACH_SUCC_1 (succ, si, last_scheduled_insn_old,
SUCCS_NORMAL | SUCCS_SKIP_TO_LOOP_EXITS)
{
if (succ == insn)
{
/* No same successor allowed from several edges. */
gcc_assert (!edge_old);
edge_old = si.e1;
}
}
/* Find edge of second predecessor (last_scheduled_insn->insn). */
FOR_EACH_SUCC_1 (succ, si, last_scheduled_insn,
SUCCS_NORMAL | SUCCS_SKIP_TO_LOOP_EXITS)
{
if (succ == insn)
{
/* No same successor allowed from several edges. */
gcc_assert (!edge_new);
edge_new = si.e1;
}
}
/* Find edge of first predecessor (last_scheduled_insn_old->insn). */
FOR_EACH_SUCC_1 (succ, si, last_scheduled_insn_old,
SUCCS_NORMAL | SUCCS_SKIP_TO_LOOP_EXITS)
{
if (succ == insn)
{
/* No same successor allowed from several edges. */
gcc_assert (!edge_old);
edge_old = si.e1;
}
}
/* Find edge of second predecessor (last_scheduled_insn->insn). */
FOR_EACH_SUCC_1 (succ, si, last_scheduled_insn,
SUCCS_NORMAL | SUCCS_SKIP_TO_LOOP_EXITS)
{
if (succ == insn)
{
/* No same successor allowed from several edges. */
gcc_assert (!edge_new);
edge_new = si.e1;
}
}
/* Check if we can choose most probable predecessor. */
if (edge_old == NULL || edge_new == NULL)
{
reset_deps_context (FENCE_DC (f));
delete_deps_context (dc);
vec_free (executing_insns);
free (ready_ticks);
/* Check if we can choose most probable predecessor. */
if (edge_old == NULL || edge_new == NULL)
{
reset_deps_context (FENCE_DC (f));
delete_deps_context (dc);
vec_free (executing_insns);
free (ready_ticks);
FENCE_CYCLE (f) = MAX (FENCE_CYCLE (f), cycle);
if (FENCE_EXECUTING_INSNS (f))
FENCE_EXECUTING_INSNS (f)->block_remove (0,
FENCE_EXECUTING_INSNS (f)->length ());
if (FENCE_READY_TICKS (f))
memset (FENCE_READY_TICKS (f), 0, FENCE_READY_TICKS_SIZE (f));
}
else
if (edge_new->probability > edge_old->probability)
{
delete_deps_context (FENCE_DC (f));
FENCE_DC (f) = dc;
vec_free (FENCE_EXECUTING_INSNS (f));
FENCE_EXECUTING_INSNS (f) = executing_insns;
free (FENCE_READY_TICKS (f));
FENCE_READY_TICKS (f) = ready_ticks;
FENCE_READY_TICKS_SIZE (f) = ready_ticks_size;
FENCE_CYCLE (f) = cycle;
}
else
{
/* Leave DC and CYCLE untouched. */
delete_deps_context (dc);
vec_free (executing_insns);
free (ready_ticks);
}
FENCE_CYCLE (f) = MAX (FENCE_CYCLE (f), cycle);
if (FENCE_EXECUTING_INSNS (f))
FENCE_EXECUTING_INSNS (f)->block_remove (0,
FENCE_EXECUTING_INSNS (f)->length ());
if (FENCE_READY_TICKS (f))
memset (FENCE_READY_TICKS (f), 0, FENCE_READY_TICKS_SIZE (f));
}
else
if (edge_new->probability > edge_old->probability)
{
delete_deps_context (FENCE_DC (f));
FENCE_DC (f) = dc;
vec_free (FENCE_EXECUTING_INSNS (f));
FENCE_EXECUTING_INSNS (f) = executing_insns;
free (FENCE_READY_TICKS (f));
FENCE_READY_TICKS (f) = ready_ticks;
FENCE_READY_TICKS_SIZE (f) = ready_ticks_size;
FENCE_CYCLE (f) = cycle;
}
else
{
/* Leave DC and CYCLE untouched. */
delete_deps_context (dc);
vec_free (executing_insns);
free (ready_ticks);
}
}
/* Fill remaining invariant fields. */

56
gcc/testsuite/c-c++-common/Wmisleading-indentation-5.c Normal file
View File

@ -0,0 +1,56 @@
/* PR c/80076 */
/* { dg-options "-Wmisleading-indentation" } */
void foo(void);
void test01(int flag) {
#define bar() foo() /* { dg-message "this statement" } */
if (flag) /* { dg-warning "does not guard" } */
foo();
bar(); /* { dg-message "in expansion of macro" } */
#undef bar
}
void test02(int flag) {
#define bar() foo()
if (flag) /* { dg-warning "does not guard" } */
bar();
foo(); /* { dg-message "this statement" } */
#undef bar
}
void test03(int flag) {
#define bar() foo() /* { dg-message "this statement" } */
if (flag) /* { dg-warning "does not guard" } */
bar();
bar(); /* { dg-message "in expansion of macro" } */
#undef bar
}
void test04(int flag, int num) {
#define bar() \
{ \
if (flag) \
num = 0; \
num = 1; \
}
bar();
/* { dg-warning "does not guard" "" { target *-*-* } .-5 } */
/* { dg-message "this statement" "" { target *-*-* } .-4 } */
#undef bar
}
void test05(int flag, int num) {
#define baz() (num = 1)
#define bar() \
{ \
if (flag) \
num = 0; \
baz(); \
}
#define wrapper bar
wrapper();
/* { dg-warning "does not guard" "" { target *-*-* } .-6 } */
/* { dg-message "this statement" "" { target *-*-* } .-10 } */
#undef bar
}

6
libcpp/include/line-map.h
View File

@ -1225,6 +1225,12 @@ LINEMAP_SYSP (const line_map_ordinary *ord_map)
return ord_map->sysp;
}
const struct line_map *first_map_in_common (line_maps *set,
location_t loc0,
location_t loc1,
location_t *res_loc0,
location_t *res_loc1);
/* Return a positive value if PRE denotes the location of a token that
comes before the token of POST, 0 if PRE denotes the location of
the same token as the token for POST, and a negative value

2
libcpp/line-map.c
View File

@ -1289,7 +1289,7 @@ first_map_in_common_1 (line_maps *set,
virtual location of the token inside the resulting macro, upon
return of a non-NULL result. */
static const struct line_map*
const struct line_map*
first_map_in_common (line_maps *set,
location_t loc0,
location_t loc1,