From 65791f426fc950b0af4e6e2ef675c213e623b16f Mon Sep 17 00:00:00 2001
From: Jakub Jelinek <jakub@redhat.com>
Date: Fri, 1 Dec 2017 09:17:06 +0100
Subject: [PATCH] re PR c/79153 (-Wimplicit-fallthrough missed warning)
PR c/79153
* tree.h (SWITCH_BREAK_LABEL_P): Define.
* gimplify.c (collect_fallthrough_labels): Handle GIMPLE_BIND
starting with a GIMPLE_SWITCH and ending with GIMPLE_LABEL with
SWITCH_BREAK_LABEL_P set on the label.
(gimplify_switch_expr): Set SWITCH_BREAK_LABEL_P on the label
added for default case if it was missing and not all cases covered.
Wrap GIMPLE_SWITCH and the switch_body_seq into a GIMPLE_BIND if
switch_body_seq ends with a GIMPLE_LABEL with SWITCH_BREAK_LABEL_P
set on the label.
* tree-chrec.c (evolution_function_is_univariate_p): Add return true;
to avoid -Wimplicit-fallthrough warning.
* config/i386/i386.c (ix86_expand_special_args_builtin): Add
FALLTHRU comment to avoid -Wimplicit-fallthrough warning.
c/
* c-parser.c: Include tree-iterator.h.
(c_parser_switch_statement): Emit LABEL_EXPR for the break label
into SWITCH_BODY instead of after it and set SWITCH_BREAK_LABEL_P
on it.
cp/
* cp-gimplify.c (genericize_switch_stmt): Emit LABEL_EXPR for the
break label into SWITCH_BODY instead of after it and set
SWITCH_BREAK_LABEL_P on it.
* parser.c (cp_parser_objc_expression): Add FALLTHRU comment to avoid
-Wimplicit-fallthrough warning.
fortran/
* match.c (gfc_match): Add FALLTHRU comment to avoid
-Wimplicit-fallthrough warning.
testsuite/
* c-c++-common/Wimplicit-fallthrough-7.c: Adjust expected warning
line.
* c-c++-common/Wimplicit-fallthrough-36.c: New test.
From-SVN: r255298
---
gcc/ChangeLog | 15 ++++
gcc/c/ChangeLog | 6 ++
gcc/c/c-parser.c | 6 +-
gcc/config/i386/i386.c | 1 +
gcc/cp/ChangeLog | 9 +++
gcc/cp/cp-gimplify.c | 4 +-
gcc/cp/parser.c | 1 +
gcc/fortran/ChangeLog | 6 ++
gcc/fortran/match.c | 1 +
gcc/gimplify.c | 60 +++++++++++++++-
gcc/testsuite/ChangeLog | 5 ++
.../c-c++-common/Wimplicit-fallthrough-36.c | 72 +++++++++++++++++++
.../c-c++-common/Wimplicit-fallthrough-7.c | 4 +-
gcc/tree-chrec.c | 1 +
gcc/tree.h | 5 ++
15 files changed, 188 insertions(+), 8 deletions(-)
create mode 100644 gcc/testsuite/c-c++-common/Wimplicit-fallthrough-36.c
diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 46c4545efbe3..bd2626e0213d 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,5 +1,20 @@
2017-12-01 Jakub Jelinek <jakub@redhat.com>
+ PR c/79153
+ * tree.h (SWITCH_BREAK_LABEL_P): Define.
+ * gimplify.c (collect_fallthrough_labels): Handle GIMPLE_BIND
+ starting with a GIMPLE_SWITCH and ending with GIMPLE_LABEL with
+ SWITCH_BREAK_LABEL_P set on the label.
+ (gimplify_switch_expr): Set SWITCH_BREAK_LABEL_P on the label
+ added for default case if it was missing and not all cases covered.
+ Wrap GIMPLE_SWITCH and the switch_body_seq into a GIMPLE_BIND if
+ switch_body_seq ends with a GIMPLE_LABEL with SWITCH_BREAK_LABEL_P
+ set on the label.
+ * tree-chrec.c (evolution_function_is_univariate_p): Add return true;
+ to avoid -Wimplicit-fallthrough warning.
+ * config/i386/i386.c (ix86_expand_special_args_builtin): Add
+ FALLTHRU comment to avoid -Wimplicit-fallthrough warning.
+
PR tree-optimization/83221
* tree-ssa-reassoc.c (sort_by_operand_rank): Shift bb_rank
down by 16.
diff --git a/gcc/c/ChangeLog b/gcc/c/ChangeLog
index 90db38a0419e..1fb0c3d0b7ff 100644
--- a/gcc/c/ChangeLog
+++ b/gcc/c/ChangeLog
@@ -1,5 +1,11 @@
2017-12-01 Jakub Jelinek <jakub@redhat.com>
+ PR c/79153
+ * c-parser.c: Include tree-iterator.h.
+ (c_parser_switch_statement): Emit LABEL_EXPR for the break label
+ into SWITCH_BODY instead of after it and set SWITCH_BREAK_LABEL_P
+ on it.
+
PR c/83222
* c-tree.h (decl_constant_value_1): Declare.
* c-typeck.c (decl_constant_value_1): New function.
diff --git a/gcc/c/c-parser.c b/gcc/c/c-parser.c
index 755cd2b43419..e9267fe9cc10 100644
--- a/gcc/c/c-parser.c
+++ b/gcc/c/c-parser.c
@@ -67,6 +67,7 @@ along with GCC; see the file COPYING3. If not see
#include "run-rtl-passes.h"
#include "intl.h"
#include "c-family/name-hint.h"
+#include "tree-iterator.h"
/* We need to walk over decls with incomplete struct/union/enum types
after parsing the whole translation unit.
@@ -5846,14 +5847,15 @@ c_parser_switch_statement (c_parser *parser, bool *if_p)
if (!open_brace_p && c_parser_peek_token (parser)->type != CPP_SEMICOLON)
warn_for_multistatement_macros (loc_after_labels, next_loc, switch_loc,
RID_SWITCH);
- c_finish_case (body, ce.original_type);
if (c_break_label)
{
location_t here = c_parser_peek_token (parser)->location;
tree t = build1 (LABEL_EXPR, void_type_node, c_break_label);
SET_EXPR_LOCATION (t, here);
- add_stmt (t);
+ SWITCH_BREAK_LABEL_P (c_break_label) = 1;
+ append_to_statement_list_force (t, &body);
}
+ c_finish_case (body, ce.original_type);
c_break_label = save_break;
add_stmt (c_end_compound_stmt (switch_loc, block, flag_isoc99));
c_parser_maybe_reclassify_token (parser);
diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c
index 145b1c6043b3..9f9db38c4b8f 100644
--- a/gcc/config/i386/i386.c
+++ b/gcc/config/i386/i386.c
@@ -34987,6 +34987,7 @@ ix86_expand_special_args_builtin (const struct builtin_description *d,
default:
break;
}
+ /* FALLTHRU */
case V64QI_FTYPE_PCCHAR_V64QI_UDI:
case V32QI_FTYPE_PCCHAR_V32QI_USI:
case V16QI_FTYPE_PCCHAR_V16QI_UHI:
diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index bb0e2bbb7bf7..31b69bf72553 100644
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,3 +1,12 @@
+2017-12-01 Jakub Jelinek <jakub@redhat.com>
+
+ PR c/79153
+ * cp-gimplify.c (genericize_switch_stmt): Emit LABEL_EXPR for the
+ break label into SWITCH_BODY instead of after it and set
+ SWITCH_BREAK_LABEL_P on it.
+ * parser.c (cp_parser_objc_expression): Add FALLTHRU comment to avoid
+ -Wimplicit-fallthrough warning.
+
2017-11-30 Jason Merrill <jason@redhat.com>
PR c++/82219 - bogus -Wignored-qualifiers with template
diff --git a/gcc/cp/cp-gimplify.c b/gcc/cp/cp-gimplify.c
index 3187a64a7254..68a253a02db7 100644
--- a/gcc/cp/cp-gimplify.c
+++ b/gcc/cp/cp-gimplify.c
@@ -330,11 +330,13 @@ genericize_switch_stmt (tree *stmt_p, int *walk_subtrees, void *data)
cp_walk_tree (&type, cp_genericize_r, data, NULL);
*walk_subtrees = 0;
+ if (TREE_USED (break_block))
+ SWITCH_BREAK_LABEL_P (break_block) = 1;
+ finish_bc_block (&body, bc_break, break_block);
*stmt_p = build2_loc (stmt_locus, SWITCH_EXPR, type, cond, body);
SWITCH_ALL_CASES_P (*stmt_p) = SWITCH_STMT_ALL_CASES_P (stmt);
gcc_checking_assert (!SWITCH_STMT_NO_BREAK_P (stmt)
|| !TREE_USED (break_block));
- finish_bc_block (stmt_p, bc_break, break_block);
}
/* Genericize a CONTINUE_STMT node *STMT_P. */
diff --git a/gcc/cp/parser.c b/gcc/cp/parser.c
index 03aeaea7597f..707c6f55605c 100644
--- a/gcc/cp/parser.c
+++ b/gcc/cp/parser.c
@@ -29003,6 +29003,7 @@ cp_parser_objc_expression (cp_parser* parser)
default:
break;
}
+ /* FALLTHRU */
default:
error_at (kwd->location,
"misplaced %<@%D%> Objective-C++ construct",
diff --git a/gcc/fortran/ChangeLog b/gcc/fortran/ChangeLog
index e6c048090ec4..7154ac3c1efe 100644
--- a/gcc/fortran/ChangeLog
+++ b/gcc/fortran/ChangeLog
@@ -1,3 +1,9 @@
+2017-12-01 Jakub Jelinek <jakub@redhat.com>
+
+ PR c/79153
+ * match.c (gfc_match): Add FALLTHRU comment to avoid
+ -Wimplicit-fallthrough warning.
+
2017-12-01 Thomas Koenig <tkoenig@gcc.gnu.org>
PR fortran/83224
diff --git a/gcc/fortran/match.c b/gcc/fortran/match.c
index dcabe269e61a..c437c853f71b 100644
--- a/gcc/fortran/match.c
+++ b/gcc/fortran/match.c
@@ -1240,6 +1240,7 @@ loop:
default:
gfc_internal_error ("gfc_match(): Bad match code %c", c);
}
+ /* FALLTHRU */
default:
diff --git a/gcc/gimplify.c b/gcc/gimplify.c
index 2c2abd76c089..16a86ce70f04 100644
--- a/gcc/gimplify.c
+++ b/gcc/gimplify.c
@@ -1897,6 +1897,27 @@ collect_fallthrough_labels (gimple_stmt_iterator *gsi_p,
do
{
+ if (gimple_code (gsi_stmt (*gsi_p)) == GIMPLE_BIND)
+ {
+ /* Recognize the special GIMPLE_BIND added by gimplify_switch_expr,
+ which starts on a GIMPLE_SWITCH and ends with a break label.
+ Handle that as a single statement that can fall through. */
+ gbind *bind = as_a <gbind *> (gsi_stmt (*gsi_p));
+ gimple *first = gimple_seq_first_stmt (gimple_bind_body (bind));
+ gimple *last = gimple_seq_last_stmt (gimple_bind_body (bind));
+ if (last
+ && gimple_code (first) == GIMPLE_SWITCH
+ && gimple_code (last) == GIMPLE_LABEL)
+ {
+ tree label = gimple_label_label (as_a <glabel *> (last));
+ if (SWITCH_BREAK_LABEL_P (label))
+ {
+ prev = bind;
+ gsi_next (gsi_p);
+ continue;
+ }
+ }
+ }
if (gimple_code (gsi_stmt (*gsi_p)) == GIMPLE_BIND
|| gimple_code (gsi_stmt (*gsi_p)) == GIMPLE_TRY)
{
@@ -2315,6 +2336,7 @@ gimplify_switch_expr (tree *expr_p, gimple_seq *pre_p)
preprocess_case_label_vec_for_gimple (labels, index_type,
&default_case);
+ bool add_bind = false;
if (!default_case)
{
glabel *new_default;
@@ -2322,14 +2344,46 @@ gimplify_switch_expr (tree *expr_p, gimple_seq *pre_p)
default_case
= build_case_label (NULL_TREE, NULL_TREE,
create_artificial_label (UNKNOWN_LOCATION));
+ if (old_in_switch_expr)
+ {
+ SWITCH_BREAK_LABEL_P (CASE_LABEL (default_case)) = 1;
+ add_bind = true;
+ }
new_default = gimple_build_label (CASE_LABEL (default_case));
gimplify_seq_add_stmt (&switch_body_seq, new_default);
}
+ else if (old_in_switch_expr)
+ {
+ gimple *last = gimple_seq_last_stmt (switch_body_seq);
+ if (last && gimple_code (last) == GIMPLE_LABEL)
+ {
+ tree label = gimple_label_label (as_a <glabel *> (last));
+ if (SWITCH_BREAK_LABEL_P (label))
+ add_bind = true;
+ }
+ }
switch_stmt = gimple_build_switch (SWITCH_COND (switch_expr),
- default_case, labels);
- gimplify_seq_add_stmt (pre_p, switch_stmt);
- gimplify_seq_add_seq (pre_p, switch_body_seq);
+ default_case, labels);
+ /* For the benefit of -Wimplicit-fallthrough, if switch_body_seq
+ ends with a GIMPLE_LABEL holding SWITCH_BREAK_LABEL_P LABEL_DECL,
+ wrap the GIMPLE_SWITCH up to that GIMPLE_LABEL into a GIMPLE_BIND,
+ so that we can easily find the start and end of the switch
+ statement. */
+ if (add_bind)
+ {
+ gimple_seq bind_body = NULL;
+ gimplify_seq_add_stmt (&bind_body, switch_stmt);
+ gimple_seq_add_seq (&bind_body, switch_body_seq);
+ gbind *bind = gimple_build_bind (NULL_TREE, bind_body, NULL_TREE);
+ gimple_set_location (bind, EXPR_LOCATION (switch_expr));
+ gimplify_seq_add_stmt (pre_p, bind);
+ }
+ else
+ {
+ gimplify_seq_add_stmt (pre_p, switch_stmt);
+ gimplify_seq_add_seq (pre_p, switch_body_seq);
+ }
labels.release ();
}
else
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index e41a29ddb8fd..ea2f2c7764b6 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,5 +1,10 @@
2017-12-01 Jakub Jelinek <jakub@redhat.com>
+ PR c/79153
+ * c-c++-common/Wimplicit-fallthrough-7.c: Adjust expected warning
+ line.
+ * c-c++-common/Wimplicit-fallthrough-36.c: New test.
+
PR sanitizer/81275
* c-c++-common/tsan/pr81275.c: Remove dg-skip-if.
diff --git a/gcc/testsuite/c-c++-common/Wimplicit-fallthrough-36.c b/gcc/testsuite/c-c++-common/Wimplicit-fallthrough-36.c
new file mode 100644
index 000000000000..1821e48b9286
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/Wimplicit-fallthrough-36.c
@@ -0,0 +1,72 @@
+/* PR c/79153 */
+/* { dg-do compile } */
+/* { dg-options "-Wimplicit-fallthrough" } */
+
+int
+test (int v1, int v2)
+{
+ switch (v1)
+ {
+ case 3:
+ switch (v2) /* { dg-warning "this statement may fall through" } */
+ {
+ case 1:
+ return 28;
+ case 2:
+ return 38;
+ case 3:
+ return 88;
+ default:
+ break;
+ }
+ case 4: /* { dg-message "here" } */
+ return 168;
+ case 5:
+ switch (v2) /* { dg-warning "this statement may fall through" } */
+ {
+ case 4:
+ break;
+ case 5:
+ return 38;
+ case 6:
+ return 88;
+ }
+ case 6: /* { dg-message "here" } */
+ return 169;
+ case 7:
+ switch (v2) /* { dg-warning "this statement may fall through" } */
+ {
+ case 7:
+ return 38;
+ case 8:
+ return 88;
+ }
+ case 8: /* { dg-message "here" } */
+ return 170;
+ case 9:
+ switch (v2) /* { dg-bogus "this statement may fall through" } */
+ {
+ case 9:
+ return 38;
+ case 10:
+ return 88;
+ default:
+ return 89;
+ }
+ case 10:
+ return 171;
+ case 11:
+ switch (v2) /* { dg-bogus "this statement may fall through" } */
+ {
+ case -__INT_MAX__ - 1 ... 31:
+ return 38;
+ case 32:
+ return 88;
+ case 33 ... __INT_MAX__:
+ return 89;
+ }
+ case 12:
+ return 172;
+ }
+ return -1;
+}
diff --git a/gcc/testsuite/c-c++-common/Wimplicit-fallthrough-7.c b/gcc/testsuite/c-c++-common/Wimplicit-fallthrough-7.c
index 24a573b4d195..a602216fa730 100644
--- a/gcc/testsuite/c-c++-common/Wimplicit-fallthrough-7.c
+++ b/gcc/testsuite/c-c++-common/Wimplicit-fallthrough-7.c
@@ -51,9 +51,9 @@ f (int i)
{
case 1:
{
- switch (i + 2)
+ switch (i + 2) /* { dg-warning "statement may fall through" } */
case 4:
- bar (1); /* { dg-warning "statement may fall through" } */
+ bar (1);
case 5:
bar (5);
return;
diff --git a/gcc/tree-chrec.c b/gcc/tree-chrec.c
index beddf108104b..9c14374e93a9 100644
--- a/gcc/tree-chrec.c
+++ b/gcc/tree-chrec.c
@@ -1161,6 +1161,7 @@ evolution_function_is_univariate_p (const_tree chrec)
return false;
break;
}
+ return true;
default:
return true;
diff --git a/gcc/tree.h b/gcc/tree.h
index db6785820b0e..e5a37afcce84 100644
--- a/gcc/tree.h
+++ b/gcc/tree.h
@@ -766,6 +766,11 @@ extern void omp_clause_range_check_failed (const_tree, const char *, int,
#define FALLTHROUGH_LABEL_P(NODE) \
(LABEL_DECL_CHECK (NODE)->base.private_flag)
+/* Set on the artificial label created for break; stmt from a switch.
+ This is used to implement -Wimplicit-fallthrough. */
+#define SWITCH_BREAK_LABEL_P(NODE) \
+ (LABEL_DECL_CHECK (NODE)->base.protected_flag)
+
/* Nonzero means this expression is volatile in the C sense:
its address should be of type `volatile WHATEVER *'.
In other words, the declared item is volatile qualified.
--
GitLab