diff options
| -rw-r--r-- | gcc/c-family/c-format.cc | 36 |
1 files changed, 36 insertions, 0 deletions
diff --git a/gcc/c-family/c-format.cc b/gcc/c-family/c-format.cc index b4eeebc..122ff9b 100644 --- a/gcc/c-family/c-format.cc +++ b/gcc/c-family/c-format.cc @@ -1175,6 +1175,7 @@ check_function_format (const_tree fn, tree attrs, int nargs, tree a; tree atname = get_identifier ("format"); + bool skipped_default_format = false; /* See if this function has any format attributes. */ for (a = attrs; a; a = TREE_CHAIN (a)) @@ -1185,6 +1186,38 @@ check_function_format (const_tree fn, tree attrs, int nargs, function_format_info info; decode_format_attr (fn, atname, TREE_VALUE (a), &info, /*validated=*/true); + + /* Mingw32 targets have traditionally used ms_printf format for the + printf function, and this format is built in GCC. But nowadays, + if mingw-w64 is configured to target UCRT, the printf function + uses the gnu_printf format (specified in the stdio.h header). This + causes GCC to check both formats, which means that GCC would + warn twice about the same issue when both formats are violated, + e.g. for %lu used to print long long unsigned. + + Hence, if there is a built-in attribute specifier and at least + one another, we skip the built-in one. See PR 95130 (but note that + GCC ms_printf already supports %llu) and PR 92292. */ + + if (!skipped_default_format + && fn + && TREE_CODE (fn) == FUNCTION_DECL + && fndecl_built_in_p (fn, BUILT_IN_NORMAL) + && (tree_to_uhwi (TREE_PURPOSE (TREE_VALUE (a))) + & (int) ATTR_FLAG_BUILT_IN)) + { + tree aa; + for (aa = attrs; aa; aa = TREE_CHAIN (aa)) + if (a != aa + && is_attribute_p ("format", get_attribute_name (aa))) + { + skipped_default_format = true; + break; + } + if (skipped_default_format) + continue; + } + if (warn_format) { /* FIXME: Rewrite all the internal functions in this file @@ -5190,6 +5223,9 @@ handle_format_attribute (tree node[3], tree atname, tree args, if (TREE_CODE (TREE_VALUE (args)) == IDENTIFIER_NODE) TREE_VALUE (args) = canonicalize_attr_name (TREE_VALUE (args)); + /* record the flags for check_function_format */ + TREE_PURPOSE (args) = build_int_cst (unsigned_type_node, flags); + if (!decode_format_attr (fndecl ? fndecl : type, atname, args, &info, /* validated_p = */false)) { |