re PR c/11234 (-pedantic accepts function pointer <-> void*)

PR c/11234 * c-typeck.c (build_c_cast): If pedantic, warn for conversions between function and object pointers. (digest_init): When comparing a pointer to function type to the target type, only apply TREE_TYPE once to the pointer to function type. * except.c (for_each_eh_label_1): Treat data as a pointer to a function pointer rather than casting it to a function pointer. (for_each_eh_label): Update caller. * recog.h (struct insn_data): Use a struct or union for output. * genoutput.c (output_insn_data): Update. * final.c (get_insn_template): Update. testsuite: * gcc.dg/func-ptr-conv-1.c: New test. * gcc.dg/weak/weak-6.c, gcc.dg/weak/weak-7.c: Update. From-SVN: r75595
2004-01-09 20:03:58 +00:00 · 2004-01-09 20:03:58 +00:00 · 3897f229d5
commit 3897f229d5
parent 0fab64a344
10 changed files with 152 additions and 17 deletions
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@ -1,3 +1,18 @@
+2004-01-09  Joseph S. Myers  <jsm@polyomino.org.uk>
+
+	PR c/11234
+	* c-typeck.c (build_c_cast): If pedantic, warn for conversions
+	between function and object pointers.
+	(digest_init): When comparing a pointer to function type to the
+	target type, only apply TREE_TYPE once to the pointer to function
+	type.
+	* except.c (for_each_eh_label_1): Treat data as a pointer to a
+	function pointer rather than casting it to a function pointer.
+	(for_each_eh_label): Update caller.
+	* recog.h (struct insn_data): Use a struct or union for output.
+	* genoutput.c (output_insn_data): Update.
+	* final.c (get_insn_template): Update.
+
 2004-01-09  Mark Mitchell  <mark@codesourcery.com>

 	* expr.h (expand_expr): Make it a macro, not a function.
--- a/gcc/c-typeck.c
+++ b/gcc/c-typeck.c
@ -3125,6 +3125,25 @@ build_c_cast (tree type, tree expr)
 	    warning ("dereferencing type-punned pointer will break strict-aliasing rules");
 	}

+      /* If pedantic, warn for conversions between function and object
+	 pointer types, except for converting a null pointer constant
+	 to function pointer type.  */
+      if (pedantic
+	  && TREE_CODE (type) == POINTER_TYPE
+	  && TREE_CODE (otype) == POINTER_TYPE
+	  && TREE_CODE (TREE_TYPE (otype)) == FUNCTION_TYPE
+	  && TREE_CODE (TREE_TYPE (type)) != FUNCTION_TYPE)
+	pedwarn ("ISO C forbids conversion of function pointer to object pointer type");
+
+      if (pedantic
+	  && TREE_CODE (type) == POINTER_TYPE
+	  && TREE_CODE (otype) == POINTER_TYPE
+	  && TREE_CODE (TREE_TYPE (type)) == FUNCTION_TYPE
+	  && TREE_CODE (TREE_TYPE (otype)) != FUNCTION_TYPE
+	  && !(integer_zerop (value) && TREE_TYPE (otype) == void_type_node
+	       && TREE_CODE (expr) != NOP_EXPR))
+	pedwarn ("ISO C forbids conversion of object pointer to function pointer type");
+
      ovalue = value;
      /* Replace a nonvolatile const static variable with its value.  */
      if (optimize && TREE_CODE (value) == VAR_DECL)
@ -4088,9 +4107,12 @@ digest_init (tree type, tree init, int require_constant)
 	  || (code == VECTOR_TYPE
 	      && comptypes (TREE_TYPE (inside_init), type, COMPARE_STRICT))
 	  || (code == POINTER_TYPE
-	      && (TREE_CODE (TREE_TYPE (inside_init)) == ARRAY_TYPE
-		  || TREE_CODE (TREE_TYPE (inside_init)) == FUNCTION_TYPE)
+	      && TREE_CODE (TREE_TYPE (inside_init)) == ARRAY_TYPE
 	      && comptypes (TREE_TYPE (TREE_TYPE (inside_init)),
+			    TREE_TYPE (type), COMPARE_STRICT))
+	  || (code == POINTER_TYPE
+	      && TREE_CODE (TREE_TYPE (inside_init)) == FUNCTION_TYPE
+	      && comptypes (TREE_TYPE (inside_init),
 			    TREE_TYPE (type), COMPARE_STRICT))))
    {
      if (code == POINTER_TYPE)
--- a/gcc/except.c
+++ b/gcc/except.c
@ -1,6 +1,6 @@
 /* Implements exception handling.
   Copyright (C) 1989, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
-   1999, 2000, 2001, 2002, 2003 Free Software Foundation, Inc.
+   1999, 2000, 2001, 2002, 2003, 2004 Free Software Foundation, Inc.
   Contributed by Mike Stump <mrs@cygnus.com>.

 This file is part of GCC.
@ -2430,14 +2430,14 @@ void
 for_each_eh_label (void (*callback) (rtx))
 {
  htab_traverse (cfun->eh->exception_handler_label_map, for_each_eh_label_1,
-		 (void *)callback);
+		 (void *) &callback);
 }

 static int
 for_each_eh_label_1 (void **pentry, void *data)
 {
  struct ehl_map_entry *entry = *(struct ehl_map_entry **)pentry;
-  void (*callback) (rtx) = (void (*) (rtx)) data;
+  void (*callback) (rtx) = *(void (**) (rtx)) data;

  (*callback) (entry->label);
  return 1;
--- a/gcc/final.c
+++ b/gcc/final.c
@ -1,6 +1,6 @@
 /* Convert RTL to assembler code and output it, for GNU compiler.
   Copyright (C) 1987, 1988, 1989, 1992, 1993, 1994, 1995, 1996, 1997,
-   1998, 1999, 2000, 2001, 2002, 2003 Free Software Foundation, Inc.
+   1998, 1999, 2000, 2001, 2002, 2003, 2004 Free Software Foundation, Inc.

 This file is part of GCC.

@ -1591,17 +1591,16 @@ final (rtx first, FILE *file, int optimize, int prescan)
 const char *
 get_insn_template (int code, rtx insn)
 {
-  const void *output = insn_data[code].output;
  switch (insn_data[code].output_format)
    {
    case INSN_OUTPUT_FORMAT_SINGLE:
-      return (const char *) output;
+      return insn_data[code].output.single;
    case INSN_OUTPUT_FORMAT_MULTI:
-      return ((const char *const *) output)[which_alternative];
+      return insn_data[code].output.multi[which_alternative];
    case INSN_OUTPUT_FORMAT_FUNCTION:
      if (insn == NULL)
 	abort ();
-      return (*(insn_output_fn) output) (recog_data.operand, insn);
+      return (*insn_data[code].output.function) (recog_data.operand, insn);

    default:
      abort ();
--- a/gcc/genoutput.c
+++ b/gcc/genoutput.c
@ -1,6 +1,6 @@
 /* Generate code from to output assembler insns as recognized from rtl.
   Copyright (C) 1987, 1988, 1992, 1994, 1995, 1997, 1998, 1999, 2000, 2002,
-   2003 Free Software Foundation, Inc.
+   2003, 2004 Free Software Foundation, Inc.

 This file is part of GCC.

@ -286,6 +286,7 @@ output_insn_data (void)
 	break;
      }

+  printf ("#if GCC_VERSION >= 2007\n__extension__\n#endif\n");
  printf ("\nconst struct insn_data insn_data[] = \n{\n");

  for (d = idata; d; d = d->next)
@ -322,13 +323,22 @@ output_insn_data (void)
      switch (d->output_format)
 	{
 	case INSN_OUTPUT_FORMAT_NONE:
-	  printf ("    0,\n");
+	  printf ("#if HAVE_DESIGNATED_INITIALIZERS\n");
+	  printf ("    { 0 },\n");
+	  printf ("#else\n");
+	  printf ("    { 0, 0, 0 },\n");
+	  printf ("#endif\n");
 	  break;
 	case INSN_OUTPUT_FORMAT_SINGLE:
 	  {
 	    const char *p = d->template;
 	    char prev = 0;

+	    printf ("#if HAVE_DESIGNATED_INITIALIZERS\n");
+	    printf ("    { .single =\n");
+	    printf ("#else\n");
+	    printf ("    {\n");
+	    printf ("#endif\n");
 	    printf ("    \"");
 	    while (*p)
 	      {
@ -345,11 +355,26 @@ output_insn_data (void)
 		++p;
 	      }
 	    printf ("\",\n");
+	    printf ("#if HAVE_DESIGNATED_INITIALIZERS\n");
+	    printf ("    },\n");
+	    printf ("#else\n");
+	    printf ("    0, 0 },\n");
+	    printf ("#endif\n");
 	  }
 	  break;
 	case INSN_OUTPUT_FORMAT_MULTI:
+	  printf ("#if HAVE_DESIGNATED_INITIALIZERS\n");
+	  printf ("    { .multi = output_%d },\n", d->code_number);
+	  printf ("#else\n");
+	  printf ("    { 0, output_%d, 0 },\n", d->code_number);
+	  printf ("#endif\n");
+	  break;
 	case INSN_OUTPUT_FORMAT_FUNCTION:
-	  printf ("    (const void *) output_%d,\n", d->code_number);
+	  printf ("#if HAVE_DESIGNATED_INITIALIZERS\n");
+	  printf ("    { .function = output_%d },\n", d->code_number);
+	  printf ("#else\n");
+	  printf ("    { 0, 0, output_%d },\n", d->code_number);
+	  printf ("#endif\n");
 	  break;
 	default:
 	  abort ();
--- a/gcc/recog.h
+++ b/gcc/recog.h
@ -1,5 +1,5 @@
 /* Declarations for interface to insn recognizer and insn-output.c.
-   Copyright (C) 1987, 1996, 1997, 1998, 1999, 2000, 2001, 2003
+   Copyright (C) 1987, 1996, 1997, 1998, 1999, 2000, 2001, 2003, 2004
   Free Software Foundation, Inc.

 This file is part of GCC.
@ -238,7 +238,19 @@ struct insn_operand_data
 struct insn_data
 {
  const char *const name;
-  const void *output;
+#if HAVE_DESIGNATED_INITIALIZERS
+  union {
+    const char *single;
+    const char *const *multi;
+    insn_output_fn function;
+  } output;
+#else
+  struct {
+    const char *single;
+    const char *const *multi;
+    insn_output_fn function;
+  } output;
+#endif
  const insn_gen_fn genfun;
  const struct insn_operand_data *const operand;

--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@ -1,3 +1,9 @@
+2004-01-09  Joseph S. Myers  <jsm@polyomino.org.uk>
+
+	PR c/11234
+	* gcc.dg/func-ptr-conv-1.c: New test.
+	* gcc.dg/weak/weak-6.c, gcc.dg/weak/weak-7.c: Update.
+
 2004-01-09  Kazu Hirata  <kazu@cs.umass.edu>

 	PR target/13380.
--- a/gcc/testsuite/gcc.dg/func-ptr-conv-1.c
+++ b/gcc/testsuite/gcc.dg/func-ptr-conv-1.c
@ -0,0 +1,56 @@
+/* Conversions between function and object pointers are not permitted
+   in any version of ISO C, even with casts, except for the special
+   case of converting a null pointer constant to function pointer
+   type.  Likewise, comparisons between function and object pointers
+   are not permitted.  PR c/11234.  */
+/* Origin: Joseph Myers <jsm@polyomino.org.uk> */
+/* { dg-do compile } */
+/* { dg-options "-pedantic" } */
+
+void f(void);
+
+void *v1 = f; /* { dg-warning "pointer" "bad conversion" } */
+void *v2 = &f; /* { dg-warning "pointer" "bad conversion" } */
+void *v3 = (void *)f; /* { dg-warning "pointer" "bad conversion" } */
+void *v4 = (void *)&f; /* { dg-warning "pointer" "bad conversion" } */
+void *v5;
+char *c1 = f; /* { dg-warning "pointer" "bad conversion" } */
+char *c2 = &f; /* { dg-warning "pointer" "bad conversion" } */
+char *c3 = (char *)f; /* { dg-warning "pointer" "bad conversion" } */
+char *c4 = (char *)&f; /* { dg-warning "pointer" "bad conversion" } */
+char *c5;
+void (*fp)(void);
+int a;
+
+void
+g(void)
+{
+  v5 = f; /* { dg-warning "pointer" "bad conversion" } */
+  v5 = &f; /* { dg-warning "pointer" "bad conversion" } */
+  v5 = (void *)f; /* { dg-warning "pointer" "bad conversion" } */
+  v5 = (void *)&f; /* { dg-warning "pointer" "bad conversion" } */
+  c5 = f; /* { dg-warning "pointer" "bad conversion" } */
+  c5 = &f; /* { dg-warning "pointer" "bad conversion" } */
+  c5 = (char *)f; /* { dg-warning "pointer" "bad conversion" } */
+  c5 = (char *)&f; /* { dg-warning "pointer" "bad conversion" } */
+  fp = v5; /* { dg-warning "pointer" "bad conversion" } */
+  fp = c5; /* { dg-warning "pointer" "bad conversion" } */
+  fp = (void (*)(void))v5; /* { dg-warning "pointer" "bad conversion" } */
+  fp = (void (*)(void))c5; /* { dg-warning "pointer" "bad conversion" } */
+  (a ? f : v3); /* { dg-warning "pointer" "bad conversion" } */
+  (a ? v2 : fp); /* { dg-warning "pointer" "bad conversion" } */
+  /* The following are OK.  */
+  fp = 0;
+  fp = (void *)0;
+  fp = 0L;
+  fp = (void (*)(void))0;
+  fp = (void (*)(void))(void *)0;
+  (a ? f : 0);
+  (a ? f : (void *)0);
+  (a ? (void *)0 : fp);
+  (a ? 0 : fp);
+}
+
+/* The following are OK.  */
+void (*fp2)(void) = 0;
+void (*fp3)(void) = (void *)0;
--- a/gcc/testsuite/gcc.dg/weak/weak-6.c
+++ b/gcc/testsuite/gcc.dg/weak/weak-6.c
@ -3,5 +3,5 @@

 extern void * foo (void);
 void * foo (void) { return (void *)foo; } /* { dg-error "precede" } */
-
+/* { dg-error "function pointer" "pointer conversion" { target *-*-* } 5 } */
 #pragma weak foo
--- a/gcc/testsuite/gcc.dg/weak/weak-7.c
+++ b/gcc/testsuite/gcc.dg/weak/weak-7.c
@ -3,5 +3,5 @@

 extern void * foo (void);
 void * foo (void) { return (void *)foo; } /* { dg-error "precede" } */
-
+/* { dg-error "function pointer" "pointer conversion" { target *-*-* } 5 } */
 extern void * foo (void) __attribute__((weak));