diff options
Diffstat (limited to 'gcc/c/c-decl.c')
| -rw-r--r-- | gcc/c/c-decl.c | 69 |
1 files changed, 42 insertions, 27 deletions
diff --git a/gcc/c/c-decl.c b/gcc/c/c-decl.c index 1aa410d..c819fd0 100644 --- a/gcc/c/c-decl.c +++ b/gcc/c/c-decl.c @@ -1649,6 +1649,18 @@ c_bind (location_t loc, tree decl, bool is_global) static GTY(()) tree last_structptr_types[6]; +/* Returns true if types T1 and T2 representing return types or types + of function arguments are close enough to be considered interchangeable + in redeclarations of built-in functions. */ + +static bool +types_close_enough_to_match (tree t1, tree t2) +{ + return (TYPE_MODE (t1) == TYPE_MODE (t2) + && POINTER_TYPE_P (t1) == POINTER_TYPE_P (t2) + && FUNCTION_POINTER_TYPE_P (t1) == FUNCTION_POINTER_TYPE_P (t2)); +} + /* Subroutine of compare_decls. Allow harmless mismatches in return and argument types provided that the type modes match. Set *STRICT and *ARGNO to the expected argument type and number in case of @@ -1659,16 +1671,19 @@ static tree match_builtin_function_types (tree newtype, tree oldtype, tree *strict, unsigned *argno) { - /* Accept the return type of the new declaration if same modes. */ - tree oldrettype = TREE_TYPE (oldtype); - tree newrettype = TREE_TYPE (newtype); - *argno = 0; *strict = NULL_TREE; - if (TYPE_MODE (oldrettype) != TYPE_MODE (newrettype)) + /* Accept the return type of the new declaration if it has the same + mode and if they're both pointers or if neither is. */ + tree oldrettype = TREE_TYPE (oldtype); + tree newrettype = TREE_TYPE (newtype); + + if (!types_close_enough_to_match (oldrettype, newrettype)) return NULL_TREE; + /* Check that the return types are compatible but don't fail if they + are not (e.g., int vs long in ILP32) and just let the caller know. */ if (!comptypes (TYPE_MAIN_VARIANT (oldrettype), TYPE_MAIN_VARIANT (newrettype))) *strict = oldrettype; @@ -1692,15 +1707,7 @@ match_builtin_function_types (tree newtype, tree oldtype, tree oldtype = TYPE_MAIN_VARIANT (TREE_VALUE (oldargs)); tree newtype = TYPE_MAIN_VARIANT (TREE_VALUE (newargs)); - /* Fail for types with incompatible modes/sizes. */ - if (TYPE_MODE (TREE_VALUE (oldargs)) - != TYPE_MODE (TREE_VALUE (newargs))) - return NULL_TREE; - - /* Fail for function and object pointer mismatches. */ - if ((FUNCTION_POINTER_TYPE_P (oldtype) - != FUNCTION_POINTER_TYPE_P (newtype)) - || POINTER_TYPE_P (oldtype) != POINTER_TYPE_P (newtype)) + if (!types_close_enough_to_match (oldtype, newtype)) return NULL_TREE; unsigned j = (sizeof (builtin_structptr_types) @@ -1957,11 +1964,10 @@ diagnose_mismatched_decls (tree newdecl, tree olddecl, && !C_DECL_DECLARED_BUILTIN (olddecl)) { /* Accept "harmless" mismatches in function types such - as missing qualifiers or pointer vs same size integer - mismatches. This is for the ffs and fprintf builtins. - However, with -Wextra in effect, diagnose return and - argument types that are incompatible according to - language rules. */ + as missing qualifiers or int vs long when they're the same + size. However, with -Wextra in effect, diagnose return and + argument types that are incompatible according to language + rules. */ tree mismatch_expect; unsigned mismatch_argno; @@ -1999,16 +2005,25 @@ diagnose_mismatched_decls (tree newdecl, tree olddecl, /* If types match only loosely, print a warning but accept the redeclaration. */ location_t newloc = DECL_SOURCE_LOCATION (newdecl); + bool warned = false; if (mismatch_argno) - warning_at (newloc, OPT_Wbuiltin_declaration_mismatch, - "mismatch in argument %u type of built-in " - "function %qD; expected %qT", - mismatch_argno, newdecl, mismatch_expect); + warned = warning_at (newloc, OPT_Wbuiltin_declaration_mismatch, + "mismatch in argument %u type of built-in " + "function %qD; expected %qT", + mismatch_argno, newdecl, mismatch_expect); else - warning_at (newloc, OPT_Wbuiltin_declaration_mismatch, - "mismatch in return type of built-in " - "function %qD; expected %qT", - newdecl, mismatch_expect); + warned = warning_at (newloc, OPT_Wbuiltin_declaration_mismatch, + "mismatch in return type of built-in " + "function %qD; expected %qT", + newdecl, mismatch_expect); + const char *header = header_for_builtin_fn (olddecl); + if (warned && header) + { + rich_location richloc (line_table, newloc); + maybe_add_include_fixit (&richloc, header, true); + inform (&richloc, + "%qD is declared in header %qs", olddecl, header); + } } } else if (TREE_CODE (olddecl) == FUNCTION_DECL |