diff options
| author | mpolacek <mpolacek@138bc75d-0d04-0410-961f-82ee72b054a4> | 2016-09-24 09:39:23 +0000 |
|---|---|---|
| committer | mpolacek <mpolacek@138bc75d-0d04-0410-961f-82ee72b054a4> | 2016-09-24 09:39:23 +0000 |
| commit | 481ce48135cce519b0a63fa3ea03426513a5dc44 (patch) | |
| tree | 2202f7c8afd097fcf4c53d3a4cbe532ead2f1c43 /gcc/c | |
| parent | 733ced655ee3fd2d1bcafdd012c650b11dc2a97e (diff) | |
| download | gcc-481ce48135cce519b0a63fa3ea03426513a5dc44.tar.gz | |
PR c/77490
* c.opt (Wbool-operation): New.
* c-typeck.c (build_unary_op): Warn about bit not on expressions that
have boolean value. Warn about ++/-- on booleans.
* typeck.c (cp_build_unary_op): Warn about bit not on expressions that
have boolean value.
* doc/invoke.texi: Document -Wbool-operation.
* c-c++-common/Wbool-operation-1.c: New test.
* gcc.dg/Wbool-operation-1.c: New test.
git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@240462 138bc75d-0d04-0410-961f-82ee72b054a4
Diffstat (limited to 'gcc/c')
| -rw-r--r-- | gcc/c/ChangeLog | 6 | ||||
| -rw-r--r-- | gcc/c/c-typeck.c | 26 |
2 files changed, 32 insertions, 0 deletions
diff --git a/gcc/c/ChangeLog b/gcc/c/ChangeLog index 283cfdacc2f..cae5c922067 100644 --- a/gcc/c/ChangeLog +++ b/gcc/c/ChangeLog @@ -1,3 +1,9 @@ +2016-09-24 Marek Polacek <polacek@redhat.com> + + PR c/77490 + * c-typeck.c (build_unary_op): Warn about bit not on expressions that + have boolean value. Warn about ++/-- on booleans. + 2016-09-23 Jakub Jelinek <jakub@redhat.com> * c-parser.c (incomplete_record_decls): Remove unnecessary diff --git a/gcc/c/c-typeck.c b/gcc/c/c-typeck.c index 059ad1fc2e0..e5c72560397 100644 --- a/gcc/c/c-typeck.c +++ b/gcc/c/c-typeck.c @@ -4196,6 +4196,22 @@ build_unary_op (location_t location, enum tree_code code, tree xarg, || (typecode == VECTOR_TYPE && !VECTOR_FLOAT_TYPE_P (TREE_TYPE (arg)))) { + tree e = arg; + + /* Warn if the expression has boolean value. */ + while (TREE_CODE (e) == COMPOUND_EXPR) + e = TREE_OPERAND (e, 1); + + if ((TREE_CODE (TREE_TYPE (arg)) == BOOLEAN_TYPE + || truth_value_p (TREE_CODE (e))) + && warning_at (location, OPT_Wbool_operation, + "%<~%> on a boolean expression")) + { + gcc_rich_location richloc (location); + richloc.add_fixit_insert_before (location, "!"); + inform_at_rich_loc (&richloc, "did you mean to use logical " + "not?"); + } if (!noconvert) arg = default_conversion (arg); } @@ -4306,6 +4322,16 @@ build_unary_op (location_t location, enum tree_code code, tree xarg, "decrement of enumeration value is invalid in C++"); } + if (TREE_CODE (TREE_TYPE (arg)) == BOOLEAN_TYPE) + { + if (code == PREINCREMENT_EXPR || code == POSTINCREMENT_EXPR) + warning_at (location, OPT_Wbool_operation, + "increment of a boolean expression"); + else + warning_at (location, OPT_Wbool_operation, + "decrement of a boolean expression"); + } + /* Ensure the argument is fully folded inside any SAVE_EXPR. */ arg = c_fully_fold (arg, false, NULL); |