[gcc r12-9287] c, c++, cgraphunit: Prevent duplicated -Wunused-value warnings [PR108079]
Jakub Jelinek
jakub@gcc.gnu.org
Sun Mar 19 05:30:43 GMT 2023
https://gcc.gnu.org/g:e4984838f6af868399ef9d885377199c38907ee1
commit r12-9287-ge4984838f6af868399ef9d885377199c38907ee1
Author: Jakub Jelinek <jakub@redhat.com>
Date: Fri Mar 10 10:10:24 2023 +0100
c, c++, cgraphunit: Prevent duplicated -Wunused-value warnings [PR108079]
On the following testcase, we warn with -Wunused-value twice, once
in the FEs and later on cgraphunit again with slightly different
wording.
The following patch fixes that by registering a warning suppression in the
FEs when we warn and not warning in cgraphunit anymore if that happened.
2023-03-10 Jakub Jelinek <jakub@redhat.com>
PR c/108079
gcc/
* cgraphunit.cc (check_global_declaration): Don't warn for unused
variables which have OPT_Wunused_variable warning suppressed.
gcc/c/
* c-decl.cc (pop_scope): Suppress OPT_Wunused_variable warning
after diagnosing it.
gcc/cp/
* decl.cc (poplevel): Suppress OPT_Wunused_variable warning
after diagnosing it.
gcc/testsuite/
* c-c++-common/Wunused-var-18.c: New test.
(cherry picked from commit 2c63cc7268fd5615997989f153e9405d0f5aaa50)
Diff:
---
gcc/c/c-decl.cc | 5 ++++-
gcc/cgraphunit.cc | 1 +
gcc/cp/decl.cc | 1 +
gcc/testsuite/c-c++-common/Wunused-var-18.c | 10 ++++++++++
4 files changed, 16 insertions(+), 1 deletion(-)
diff --git a/gcc/c/c-decl.cc b/gcc/c/c-decl.cc
index c701f07befe..619a2090937 100644
--- a/gcc/c/c-decl.cc
+++ b/gcc/c/c-decl.cc
@@ -1306,7 +1306,10 @@ pop_scope (void)
&& scope != external_scope)
{
if (!TREE_USED (p))
- warning (OPT_Wunused_variable, "unused variable %q+D", p);
+ {
+ warning (OPT_Wunused_variable, "unused variable %q+D", p);
+ suppress_warning (p, OPT_Wunused_variable);
+ }
else if (DECL_CONTEXT (p) == current_function_decl)
warning_at (DECL_SOURCE_LOCATION (p),
OPT_Wunused_but_set_variable,
diff --git a/gcc/cgraphunit.cc b/gcc/cgraphunit.cc
index 76d541755b8..5aa7b57c9e1 100644
--- a/gcc/cgraphunit.cc
+++ b/gcc/cgraphunit.cc
@@ -1123,6 +1123,7 @@ check_global_declaration (symtab_node *snode)
&& (TREE_CODE (decl) != FUNCTION_DECL
|| (!DECL_STATIC_CONSTRUCTOR (decl)
&& !DECL_STATIC_DESTRUCTOR (decl)))
+ && (! VAR_P (decl) || !warning_suppressed_p (decl, OPT_Wunused_variable))
/* Otherwise, ask the language. */
&& lang_hooks.decls.warn_unused_global (decl))
warning_at (DECL_SOURCE_LOCATION (decl),
diff --git a/gcc/cp/decl.cc b/gcc/cp/decl.cc
index 012eac5096d..0f25bb57946 100644
--- a/gcc/cp/decl.cc
+++ b/gcc/cp/decl.cc
@@ -691,6 +691,7 @@ poplevel (int keep, int reverse, int functionbody)
else
warning_at (DECL_SOURCE_LOCATION (decl),
OPT_Wunused_variable, "unused variable %qD", decl);
+ suppress_warning (decl, OPT_Wunused_variable);
}
else if (DECL_CONTEXT (decl) == current_function_decl
// For -Wunused-but-set-variable leave references alone.
diff --git a/gcc/testsuite/c-c++-common/Wunused-var-18.c b/gcc/testsuite/c-c++-common/Wunused-var-18.c
new file mode 100644
index 00000000000..5ff772b74c1
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/Wunused-var-18.c
@@ -0,0 +1,10 @@
+/* PR c/108079 */
+/* { dg-do compile } */
+/* { dg-options "-Wunused-variable" } */
+
+int
+main ()
+{
+ static int x; /* { dg-warning "unused variable 'x'" } */
+ /* { dg-bogus "'x' defined but not used" "" { target *-*-* } .-1 } */
+}
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