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| author | Jason Merrill <merrill@gnu.org> | 1995-02-23 08:14:12 +0000 |
|---|---|---|
| committer | Jason Merrill <merrill@gnu.org> | 1995-02-23 08:14:12 +0000 |
| commit | d2d7ed3e171414e7ef911590bc0d0e1e2b05e232 (patch) | |
| tree | 5665ef005028b9a1fa6c10becfc6020b17e5f426 /gcc | |
| parent | 71df911299f2944ab5c4bfc6d1fd3df5a23c7ca8 (diff) | |
| download | gcc-d2d7ed3e171414e7ef911590bc0d0e1e2b05e232.zip gcc-d2d7ed3e171414e7ef911590bc0d0e1e2b05e232.tar.gz gcc-d2d7ed3e171414e7ef911590bc0d0e1e2b05e232.tar.bz2 | |
Fix signed/unsigned comparison warning.
From-SVN: r9045
Diffstat (limited to 'gcc')
| -rw-r--r-- | gcc/c-typeck.c | 40 |
1 files changed, 14 insertions, 26 deletions
diff --git a/gcc/c-typeck.c b/gcc/c-typeck.c index ceabea8..b5cd340 100644 --- a/gcc/c-typeck.c +++ b/gcc/c-typeck.c @@ -2438,37 +2438,25 @@ build_binary_op (code, orig_op0, orig_op1, convert_p) if (extra_warnings) { - tree op0_type = TREE_TYPE (orig_op0); - tree op1_type = TREE_TYPE (orig_op1); - int op0_unsigned = TREE_UNSIGNED (op0_type); - int op1_unsigned = TREE_UNSIGNED (op1_type); - + int op0_signed = ! TREE_UNSIGNED (TREE_TYPE (orig_op0)); + int op1_signed = ! TREE_UNSIGNED (TREE_TYPE (orig_op1)); + + tree comp_type = TREE_TYPE (op0); + /* Give warnings for comparisons between signed and unsigned - quantities that will fail. Do not warn if the signed quantity + quantities that may fail. Do not warn if the signed quantity is an unsuffixed integer literal (or some static constant expression involving such literals) and it is positive. - Do not warn if the width of the unsigned quantity is less - than that of the signed quantity, since in this case all - values of the unsigned quantity fit in the signed quantity. - Do not warn if the signed type is the same size as the - result_type since sign extension does not cause trouble in - this case. */ + Do not warn if the comparison is being done in a signed type, + since the signed type will only be chosen if it can represent + all the values of the unsigned type. */ /* Do the checking based on the original operand trees, so that casts will be considered, but default promotions won't be. */ - if (op0_unsigned != op1_unsigned - && ((op0_unsigned - && TYPE_PRECISION (op0_type) >= TYPE_PRECISION (op1_type) - && TYPE_PRECISION (op0_type) < TYPE_PRECISION (result_type) - && (TREE_CODE (op1) != INTEGER_CST - || (TREE_CODE (op1) == INTEGER_CST - && INT_CST_LT (op1, integer_zero_node)))) - || - (op1_unsigned - && TYPE_PRECISION (op1_type) >= TYPE_PRECISION (op0_type) - && TYPE_PRECISION (op1_type) < TYPE_PRECISION (result_type) - && (TREE_CODE (op0) != INTEGER_CST - || (TREE_CODE (op0) == INTEGER_CST - && INT_CST_LT (op0, integer_zero_node)))))) + if (TREE_UNSIGNED (comp_type) + && ((op0_signed && (TREE_CODE (orig_op0) != INTEGER_CST + || tree_int_cst_sgn (orig_op0) == -1)) + || (op1_signed && (TREE_CODE (orig_op1) != INTEGER_CST + || tree_int_cst_sgn (orig_op1) == -1)))) warning ("comparison between signed and unsigned"); } } |