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author | Marek Polacek <polacek@redhat.com> | 2023-01-19 17:12:34 -0500 |
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committer | Marek Polacek <polacek@redhat.com> | 2023-01-23 16:41:48 -0500 |
commit | e3585e6acdfd5c1793f877476647d2521620c95c (patch) | |
tree | be03840369b1fc4e087b3b97fed693bce71e861d /gcc | |
parent | 72e46b3c7ad5e3d2c69868a510c00707c356106a (diff) | |
download | gcc-e3585e6acdfd5c1793f877476647d2521620c95c.zip gcc-e3585e6acdfd5c1793f877476647d2521620c95c.tar.gz gcc-e3585e6acdfd5c1793f877476647d2521620c95c.tar.bz2 |
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.
Diffstat (limited to 'gcc')
-rw-r--r-- | gcc/cp/cvt.cc | 6 | ||||
-rw-r--r-- | gcc/cp/init.cc | 2 | ||||
-rw-r--r-- | 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 0cbfd80..17827d0 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 f816c47..52e96fb 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 0000000..2ba5587f --- /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()); +} |