public inbox for gcc-cvs@sourceware.org
help / color / mirror / Atom feed
* [gcc r13-5314] c++: Quash bogus -Wunused-value with new [PR107797]
@ 2023-01-23 21:42 Marek Polacek
0 siblings, 0 replies; only message in thread
From: Marek Polacek @ 2023-01-23 21:42 UTC (permalink / raw)
To: gcc-cvs
https://gcc.gnu.org/g:e3585e6acdfd5c1793f877476647d2521620c95c
commit r13-5314-ge3585e6acdfd5c1793f877476647d2521620c95c
Author: Marek Polacek <polacek@redhat.com>
Date: Thu Jan 19 17:12:34 2023 -0500
c++: Quash bogus -Wunused-value with new [PR107797]
We shouldn't emit "right operand of comma operator has no effect"
when that comma operator was created by the compiler for "new int{}".
convert_to_void/COMPOUND_EXPR already checks warning_suppressed_p so
we can just suppress -Wunused-value.
PR c++/107797
gcc/cp/ChangeLog:
* cvt.cc (ocp_convert): copy_warning when creating a new
COMPOUND_EXPR.
* init.cc (build_new_1): Suppress -Wunused-value on
compiler-generated COMPOUND_EXPRs.
gcc/testsuite/ChangeLog:
* g++.dg/warn/Wunused-value-1.C: New test.
Diff:
---
gcc/cp/cvt.cc | 6 ++++--
gcc/cp/init.cc | 2 ++
gcc/testsuite/g++.dg/warn/Wunused-value-1.C | 12 ++++++++++++
3 files changed, 18 insertions(+), 2 deletions(-)
diff --git a/gcc/cp/cvt.cc b/gcc/cp/cvt.cc
index 0cbfd8060cb..17827d06a4a 100644
--- a/gcc/cp/cvt.cc
+++ b/gcc/cp/cvt.cc
@@ -711,8 +711,10 @@ ocp_convert (tree type, tree expr, int convtype, int flags,
return error_mark_node;
if (e == TREE_OPERAND (expr, 1))
return expr;
- return build2_loc (EXPR_LOCATION (expr), COMPOUND_EXPR, TREE_TYPE (e),
- TREE_OPERAND (expr, 0), e);
+ e = build2_loc (EXPR_LOCATION (expr), COMPOUND_EXPR, TREE_TYPE (e),
+ TREE_OPERAND (expr, 0), e);
+ copy_warning (e, expr);
+ return e;
}
complete_type (type);
diff --git a/gcc/cp/init.cc b/gcc/cp/init.cc
index f816c474cef..52e96fbe590 100644
--- a/gcc/cp/init.cc
+++ b/gcc/cp/init.cc
@@ -3800,6 +3800,8 @@ build_new_1 (vec<tree, va_gc> **placement, tree type, tree nelts,
if (cookie_expr)
rval = build2 (COMPOUND_EXPR, TREE_TYPE (rval), cookie_expr, rval);
+ suppress_warning (rval, OPT_Wunused_value);
+
if (rval == data_addr && TREE_CODE (alloc_expr) == TARGET_EXPR)
/* If we don't have an initializer or a cookie, strip the TARGET_EXPR
and return the call (which doesn't need to be adjusted). */
diff --git a/gcc/testsuite/g++.dg/warn/Wunused-value-1.C b/gcc/testsuite/g++.dg/warn/Wunused-value-1.C
new file mode 100644
index 00000000000..2ba5587fce0
--- /dev/null
+++ b/gcc/testsuite/g++.dg/warn/Wunused-value-1.C
@@ -0,0 +1,12 @@
+// PR c++/107797
+// { dg-do compile { target c++11 } }
+// { dg-options "-Wunused" }
+
+void
+g ()
+{
+ (long) new int{};
+ long(new int{});
+ (long) new int();
+ long(new int());
+}
^ permalink raw reply [flat|nested] only message in thread
only message in thread, other threads:[~2023-01-23 21:42 UTC | newest]
Thread overview: (only message) (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2023-01-23 21:42 [gcc r13-5314] c++: Quash bogus -Wunused-value with new [PR107797] Marek Polacek
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).