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| author | Patrick Palka <ppalka@gcc.gnu.org> | 2015-06-13 16:11:15 +0000 |
|---|---|---|
| committer | Patrick Palka <ppalka@gcc.gnu.org> | 2015-06-13 16:11:15 +0000 |
| commit | 076fecad0db4fb76524af6785b146491d4060dd4 (patch) | |
| tree | e76304d58d1deaf94d7fd2dc50a09d6c2979c651 /gcc/c-family | |
| parent | 313d38e359bfcd8b56c946233294061c66ae21dc (diff) | |
| download | gcc-076fecad0db4fb76524af6785b146491d4060dd4.zip gcc-076fecad0db4fb76524af6785b146491d4060dd4.tar.gz gcc-076fecad0db4fb76524af6785b146491d4060dd4.tar.bz2 | |
Emit -Waddress warnings for comparing address of reference against NULL
gcc/c-family/ChangeLog:
PR c++/65168
* c-common.c (c_common_truthvalue_conversion): Warn when
converting an address of a reference to a truth value.
gcc/cp/ChangeLog:
PR c++/65168
* typeck.c (cp_build_binary_op): Warn when comparing an address
of a reference against NULL.
gcc/testsuite/ChangeLog:
PR c++/65168
g++.dg/warn/Walways-true-3.C: New test.
From-SVN: r224455
Diffstat (limited to 'gcc/c-family')
| -rw-r--r-- | gcc/c-family/ChangeLog | 6 | ||||
| -rw-r--r-- | gcc/c-family/c-common.c | 14 |
2 files changed, 20 insertions, 0 deletions
diff --git a/gcc/c-family/ChangeLog b/gcc/c-family/ChangeLog index a2324a4..80c3e48 100644 --- a/gcc/c-family/ChangeLog +++ b/gcc/c-family/ChangeLog @@ -1,3 +1,9 @@ +2015-06-13 Patrick Palka <ppalka@gcc.gnu.org> + + PR c++/65168 + * c-common.c (c_common_truthvalue_conversion): Warn when + converting an address of a reference to a truth value. + 2015-06-08 Andrew MacLeod <amacleod@redhat.com> * array-notation-common.c : Adjust include files. diff --git a/gcc/c-family/c-common.c b/gcc/c-family/c-common.c index 5b76567..b1af682 100644 --- a/gcc/c-family/c-common.c +++ b/gcc/c-family/c-common.c @@ -4973,6 +4973,20 @@ c_common_truthvalue_conversion (location_t location, tree expr) tree totype = TREE_TYPE (expr); tree fromtype = TREE_TYPE (TREE_OPERAND (expr, 0)); + if (POINTER_TYPE_P (totype) + && TREE_CODE (fromtype) == REFERENCE_TYPE) + { + tree inner = expr; + STRIP_NOPS (inner); + + if (DECL_P (inner)) + warning_at (location, + OPT_Waddress, + "the compiler can assume that the address of " + "%qD will always evaluate to %<true%>", + inner); + } + /* Don't cancel the effect of a CONVERT_EXPR from a REFERENCE_TYPE, since that affects how `default_conversion' will behave. */ if (TREE_CODE (totype) == REFERENCE_TYPE |