On Wed, Nov 14, 2018 at 7:08 PM Jeff Law <l...@redhat.com> wrote:
>
> On 11/6/18 4:56 PM, Martin Sebor wrote:
> > In response to Joseph's comment I've removed the interaction
> > with -Wpedantic from the updated patch.
> >
> > In addition, to help detect bugs like the one in the test case
> > for pr87886, I have also enhanced the detection of incompatible
> > calls to include integer/real type mismatches so that calls like
> > the one below are diagnosed:
> >
> > extern double sqrt ();
> > int f (int x)
> > {
> > return sqrt (x); // passing int where double is expected
> > }
> >
> > With the removal of the -Wpedantic interaction declaring abort()
> > without a prototype is no longer diagnosed and so the test suite
> > changes to add the prototype are not necessary. I decided not
> > to back them out because Jeff indicated a preference for making
> > these kinds of improvements in general in an unrelated
> > discussion.
> >
> >
> >
> > gcc-83656.diff
> >
> > PR c/83656 - missing -Wbuiltin-declaration-mismatch on declaration without
> > prototype
> >
> > gcc/c/ChangeLog:
> >
> > PR c/83656
> > * c-decl.c (header_for_builtin_fn): Declare.
> > (diagnose_mismatched_decls): Diagnose declarations of built-in
> > functions without a prototype.
> > * c-typeck.c (maybe_warn_builtin_no_proto_arg): New function.
> > (convert_argument): Same.
> > (convert_arguments): Factor code out into convert_argument.
> > Detect mismatches between built-in formal arguments in calls
> > to built-in without prototype.
> > (build_conditional_expr): Same.
> > (type_or_builtin_type): New function.
> > (convert_for_assignment): Add argument. Conditionally issue
> > warnings instead of errors for mismatches.
> >
> > gcc/testsuite/ChangeLog:
> >
> > PR c/83656
> > * gcc.dg/20021006-1.c
> > * gcc.dg/Wbuiltin-declaration-mismatch.c: New test.
> > * gcc.dg/Wbuiltin-declaration-mismatch-2.c: New test.
> > * gcc.dg/Wbuiltin-declaration-mismatch-3.c: New test.
> > * gcc.dg/Wbuiltin-declaration-mismatch-4.c: New test.
> > * gcc.dg/Walloca-16.c: Adjust.
> > * gcc.dg/Wrestrict-4.c: Adjust.
> > * gcc.dg/Wrestrict-5.c: Adjust.
> > * gcc.dg/atomic/stdatomic-generic.c: Adjust.
> > * gcc.dg/atomic/stdatomic-lockfree.c: Adjust.
> > * gcc.dg/initpri1.c: Adjust.
> > * gcc.dg/pr15698-1.c: Adjust.
> > * gcc.dg/pr69156.c: Adjust.
> > * gcc.dg/pr83463.c: Adjust.
> > * gcc.dg/redecl-4.c: Adjust.
> > * gcc.dg/tls/thr-init-2.c: Adjust.
> > * gcc.dg/torture/pr55890-2.c: Adjust.
> > * gcc.dg/torture/pr55890-3.c: Adjust.
> > * gcc.dg/torture/pr67741.c: Adjust.
> > * gcc.dg/torture/stackalign/sibcall-1.c: Adjust.
> > * gcc.dg/torture/tls/thr-init-1.c: Adjust.
> > * gcc.dg/tree-ssa/builtins-folding-gimple-ub.c: Adjust.
> >
>
>
> > @@ -3547,8 +3598,24 @@ convert_arguments (location_t loc, vec<location_t>
> > arg_loc, tree typelist,
> > if (parmval == error_mark_node)
> > error_args = true;
> >
> > + if (!type && builtin_type && TREE_CODE (builtin_type) != VOID_TYPE)
> > + {
> > + /* For a call to a built-in function declared without a prototype,
> > + perform the coversions from the argument to the expected type
> > + but issue warnings rather than errors for any mismatches.
> > + Ignore the converted argument and use the PARMVAL obtained
> > + above by applying default coversions instead. */
> s/coversions/conversions/
>
> Two of 'em in that comment. OK with that nit fixed.
I once had -Wunprototyped-calls... (attached). Because the issue doesn't
exist only for builtins... (originally inspired by a Xorg bug)
Richard.
> jeff
>
>
Index: gcc/c-family/c.opt
===================================================================
--- gcc/c-family/c.opt.orig 2014-11-11 09:38:31.286867405 +0100
+++ gcc/c-family/c.opt 2014-11-17 16:38:44.438078729 +0100
@@ -868,6 +868,10 @@ Wunused-local-typedefs
C ObjC C++ ObjC++ Var(warn_unused_local_typedefs) Warning EnabledBy(Wunused)
Warn when typedefs locally defined in a function are not used
+Wunprototyped-calls
+C Var(warn_unprototyped_calls) Warning LangEnabledBy(C,Wall)
+Warn about calls to unprototyped functions with at least one argument
+
Wunused-macros
C ObjC C++ ObjC++ CppReason(CPP_W_UNUSED_MACROS) Var(cpp_warn_unused_macros) Warning
Warn about macros defined in the main file that are not used
Index: gcc/c/c-typeck.c
===================================================================
--- gcc/c/c-typeck.c.orig 2014-11-11 09:38:32.068867371 +0100
+++ gcc/c/c-typeck.c 2014-11-17 16:38:44.442078729 +0100
@@ -2957,6 +2957,19 @@ build_function_call_vec (location_t loc,
&& !check_builtin_function_arguments (fundecl, nargs, argarray))
return error_mark_node;
+ /* If we cannot check function arguments because a prototype is
+ missing for the callee, warn here. */
+ if (warn_unprototyped_calls
+ && nargs > 0 && !TYPE_ARG_TYPES (fntype)
+ && fundecl && !DECL_BUILT_IN (fundecl) && !C_DECL_IMPLICIT (fundecl)
+ && !DECL_ARGUMENTS (fundecl))
+ {
+ if (warning (OPT_Wunprototyped_calls,
+ "call to function %qD without a real prototype", fundecl))
+ inform (DECL_SOURCE_LOCATION (fundecl), "%qD was declared here",
+ fundecl);
+ }
+
/* Check that the arguments to the function are valid. */
check_function_arguments (fntype, nargs, argarray);
Index: gcc/testsuite/gcc.dg/cleanup-1.c
===================================================================
--- gcc/testsuite/gcc.dg/cleanup-1.c.orig 2010-02-23 12:43:21.000000000 +0100
+++ gcc/testsuite/gcc.dg/cleanup-1.c 2014-11-17 16:38:44.442078729 +0100
@@ -6,7 +6,7 @@
#define C(x) __attribute__((cleanup(x)))
static int f1(void *x U) { return 0; }
-static void f2() { }
+static void f2() { } /* { dg-message "declared here" "" } */
static void f3(void) { } /* { dg-message "note: declared here" } */
static void f4(void *x U) { }
static void f5(int *x U) { }
@@ -18,7 +18,7 @@ static void f9(int x U) { } /* { dg-mess
void test(void)
{
int o1 C(f1);
- int o2 C(f2);
+ int o2 C(f2); /* { dg-warning "without a real prototype" } */
int o3 C(f3); /* { dg-error "too many arguments" } */
int o4 C(f4);
int o5 C(f5);
