PR c/86125 - missing -Wbuiltin-declaration-mismatch on a mismatched return type

PR c/86125 - missing -Wbuiltin-declaration-mismatch on a mismatched return type
PR middle-end/86308 - ICE in verify_gimple calling index() with an invalid declaration
PR c/86125 - missing -Wbuiltin-declaration-mismatch on a mismatched return type
PR c/88886 - [9 Regression] ice in get_constant, at c-family/c-format.c:292

gcc/c/ChangeLog:

	PR c/86125
	PR c/88886
	PR middle-end/86308
	* c-decl.c (match_builtin_function_types): Add arguments.
	(diagnose_mismatched_decls): Diagnose mismatched declarations
	of built-ins more strictly.

gcc/testsuite/ChangeLog:

	PR c/86125
	PR c/88886
	PR middle-end/86308
	* gcc.dg/Wbuiltin-declaration-mismatch-6.c: New test.
	* gcc.dg/Wbuiltin-declaration-mismatch-7.c: New test.
	* gcc.dg/Wbuiltin-declaration-mismatch-8.c: New test.
	* gcc.dg/Wbuiltin-declaration-mismatch-9.c: New test.
	* gcc.dg/Wbuiltin-declaration-mismatch-10.c: New test.
	* gcc.dg/builtins-69.c: New test.
	* gcc.dg/Wint-conversion-2.c: Add expected warning.
	* gcc.c-torture/execute/eeprof-1.c: Adjust function signatures.

From-SVN: r268251

2 files changed, 106 insertions, 23 deletions

diff --git a/gcc/c/ChangeLog b/gcc/c/ChangeLog
index 32c77f9..cb89cd8 100644
--- a/gcc/c/ChangeLog
+++ b/gcc/c/ChangeLog
@@ -1,3 +1,12 @@
+2019-01-24  Martin Sebor  <msebor@redhat.com>
+
+	PR c/86125
+	PR c/88886
+	PR middle-end/86308
+	* c-decl.c (match_builtin_function_types): Add arguments.
+	(diagnose_mismatched_decls): Diagnose mismatched declarations
+	of built-ins more strictly.
+
 2019-01-24  Jakub Jelinek  <jakub@redhat.com>
 
 	PR c++/88976
diff --git a/gcc/c/c-decl.c b/gcc/c/c-decl.c
index 57049f8..b60f155 100644
--- a/gcc/c/c-decl.c
+++ b/gcc/c/c-decl.c
@@ -1631,43 +1631,91 @@ c_bind (location_t loc, tree decl, bool is_global)
   bind (DECL_NAME (decl), decl, scope, false, nested, loc);
 }
 
+
+/* Stores the first FILE* argument type (whatever it is) seen in
+   a declaration of a file I/O built-in.  Subsequent declarations
+   of such built-ins are expected to refer to it rather than to
+   fileptr_type_node which is just void* (or to any other type).
+   Used only by match_builtin_function_types.  */
+
+static GTY(()) tree last_fileptr_type;
+
 /* Subroutine of compare_decls.  Allow harmless mismatches in return
-   and argument types provided that the type modes match.  This function
-   return a unified type given a suitable match, and 0 otherwise.  */
+   and argument types provided that the type modes match.  Set *STRICT
+   and *ARGNO to the expected argument type and number in case of
+   an argument type mismatch or null and zero otherwise.  Return
+   a unified type given a suitable match, and 0 otherwise.  */
 
 static tree
-match_builtin_function_types (tree newtype, tree oldtype)
+match_builtin_function_types (tree newtype, tree oldtype,
+			      tree *strict, unsigned *argno)
 {
-  tree newrettype, oldrettype;
-  tree newargs, oldargs;
-  tree trytype, tryargs;
-
   /* Accept the return type of the new declaration if same modes.  */
-  oldrettype = TREE_TYPE (oldtype);
-  newrettype = TREE_TYPE (newtype);
+  tree oldrettype = TREE_TYPE (oldtype);
+  tree newrettype = TREE_TYPE (newtype);
+
+  *argno = 0;
+  *strict = NULL_TREE;
 
   if (TYPE_MODE (oldrettype) != TYPE_MODE (newrettype))
     return NULL_TREE;
 
-  oldargs = TYPE_ARG_TYPES (oldtype);
-  newargs = TYPE_ARG_TYPES (newtype);
-  tryargs = newargs;
+  if (!comptypes (oldrettype, newrettype))
+    *strict = oldrettype;
 
-  while (oldargs || newargs)
+  tree oldargs = TYPE_ARG_TYPES (oldtype);
+  tree newargs = TYPE_ARG_TYPES (newtype);
+  tree tryargs = newargs;
+
+  for (unsigned i = 1; oldargs || newargs; ++i)
     {
       if (!oldargs
 	  || !newargs
 	  || !TREE_VALUE (oldargs)
-	  || !TREE_VALUE (newargs)
-	  || TYPE_MODE (TREE_VALUE (oldargs))
-	     != TYPE_MODE (TREE_VALUE (newargs)))
+	  || !TREE_VALUE (newargs))
 	return NULL_TREE;
 
+      tree oldtype = TREE_VALUE (oldargs);
+      tree newtype = 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))
+	return NULL_TREE;
+
+      if (oldtype == fileptr_type_node)
+	{
+	  /* Store the first FILE* argument type (whatever it is), and
+	     expect any subsequent declarations of file I/O built-ins
+	     to refer to it rather than to fileptr_type_node which is
+	     just void*.  */
+	  if (last_fileptr_type)
+	    {
+	      if (!comptypes (last_fileptr_type, newtype))
+		{
+		  *argno = i;
+		  *strict = last_fileptr_type;
+		}
+	    }
+	  else
+	    last_fileptr_type = newtype;
+	}
+      else if (!*strict && !comptypes (oldtype, newtype))
+	{
+	  *argno = i;
+	  *strict = oldtype;
+	}
+
       oldargs = TREE_CHAIN (oldargs);
       newargs = TREE_CHAIN (newargs);
     }
 
-  trytype = build_function_type (newrettype, tryargs);
+  tree trytype = build_function_type (newrettype, tryargs);
 
   /* Allow declaration to change transaction_safe attribute.  */
   tree oldattrs = TYPE_ATTRIBUTES (oldtype);
@@ -1881,14 +1929,26 @@ diagnose_mismatched_decls (tree newdecl, tree olddecl,
       if (TREE_CODE (olddecl) == FUNCTION_DECL
 	  && fndecl_built_in_p (olddecl) && !C_DECL_DECLARED_BUILTIN (olddecl))
 	{
-	  /* Accept harmless mismatch in function types.
-	     This is for the ffs and fprintf builtins.  */
-	  tree trytype = match_builtin_function_types (newtype, oldtype);
+	  /* 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.  */
+	  tree mismatch_expect;
+	  unsigned mismatch_argno;
+
+	  tree trytype = match_builtin_function_types (newtype, oldtype,
+						       &mismatch_expect,
+						       &mismatch_argno);
 
 	  if (trytype && comptypes (newtype, trytype))
 	    *oldtypep = oldtype = trytype;
 	  else
 	    {
+	      /* If types don't match for a built-in, throw away the
+		 built-in.  No point in calling locate_old_decl here, it
+		 won't print anything.  */
 	      const char *header
 		= header_for_builtin_fn (DECL_FUNCTION_CODE (olddecl));
 	      location_t loc = DECL_SOURCE_LOCATION (newdecl);
@@ -1905,11 +1965,25 @@ diagnose_mismatched_decls (tree newdecl, tree olddecl,
 		  inform (&richloc,
 			  "%qD is declared in header %qs", olddecl, header);
 		}
-	      /* If types don't match for a built-in, throw away the
-		 built-in.  No point in calling locate_old_decl here, it
-		 won't print anything.  */
 	      return false;
 	    }
+
+	  if (mismatch_expect && extra_warnings)
+	    {
+	      /* If types match only loosely, print a warning but accept
+		 the redeclaration.  */
+	      location_t newloc = DECL_SOURCE_LOCATION (newdecl);
+	      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);
+	      else
+		warning_at (newloc, OPT_Wbuiltin_declaration_mismatch,
+			    "mismatch in return type of built-in "
+			    "function %qD; expected %qT",
+			    newdecl, mismatch_expect);
+	    }
 	}
       else if (TREE_CODE (olddecl) == FUNCTION_DECL
 	       && DECL_IS_BUILTIN (olddecl))