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Diffstat (limited to 'gcc/c-family/c-common.c')
| -rw-r--r-- | gcc/c-family/c-common.c | 16 |
1 files changed, 11 insertions, 5 deletions
diff --git a/gcc/c-family/c-common.c b/gcc/c-family/c-common.c index 9d51815..4c90365 100644 --- a/gcc/c-family/c-common.c +++ b/gcc/c-family/c-common.c @@ -5143,11 +5143,11 @@ c_init_attributes (void) then reject alignments greater than MAX_OFILE_ALIGNMENT when converted to bits. Otherwise, consider valid only alignments that are less than HOST_BITS_PER_INT - LOG2_BITS_PER_UNIT. - If ALLOW_ZERO then 0 is valid and should result in - a return of -1 with no error. */ + Zero is not considered a valid argument (and results in -1 on + return) but it only triggers a warning when WARN_ZERO is set. */ int -check_user_alignment (const_tree align, bool objfile, bool allow_zero) +check_user_alignment (const_tree align, bool objfile, bool warn_zero) { if (error_operand_p (align)) return -1; @@ -5159,8 +5159,14 @@ check_user_alignment (const_tree align, bool objfile, bool allow_zero) return -1; } - if (allow_zero && integer_zerop (align)) - return -1; + if (integer_zerop (align)) + { + if (warn_zero) + warning (OPT_Wattributes, + "requested alignment %qE is not a positive power of 2", + align); + return -1; + } int log2bitalign; if (tree_int_cst_sgn (align) == -1 |