[PATCH 1/7] New obstack_next_free is not an lvalue

[Alan Modra]

New obstack.h casts obstack_next_free to (void *), resulting in it
being a non-lvalue, and warnings on pointer arithmetic.

gcc/
        * gensupport.c (add_mnemonic_string): Make len param a size_t.
        (gen_mnemonic_setattr): Make "size" var a size_t.  Use
        obstack_blank_fast to shrink obstack.  Cast obstack_next_free
        return value.
gcc/objc/
        * objc-encoding.c (encode_aggregate_within): Cast obstack_next_free
        return value.

diff --git a/gcc/gensupport.c b/gcc/gensupport.c
index 0480e17..484ead2 100644
--- a/gcc/gensupport.c
+++ b/gcc/gensupport.c
@@ -2253,7 +2253,7 @@ htab_eq_string (const void *s1, const void *s2)
    and a permanent heap copy of STR is created.  */
 
 static void
-add_mnemonic_string (htab_t mnemonic_htab, const char *str, int len)
+add_mnemonic_string (htab_t mnemonic_htab, const char *str, size_t len)
 {
   char *new_str;
   void **slot;
@@ -2306,7 +2306,7 @@ gen_mnemonic_setattr (htab_t mnemonic_htab, rtx insn)
   for (i = 0; *cp; )
     {
       const char *ep, *sp;
-      int size = 0;
+      size_t size = 0;
 
       while (ISSPACE (*cp))
        cp++;
@@ -2333,8 +2333,7 @@ gen_mnemonic_setattr (htab_t mnemonic_htab, rtx insn)
            {
              /* Don't set a value if there are more than one
                 instruction in the string.  */
-             obstack_next_free (&string_obstack) =
-               obstack_next_free (&string_obstack) - size;
+             obstack_blank_fast (&string_obstack, -size);
              size = 0;
 
              cp = sp;
@@ -2346,7 +2345,7 @@ gen_mnemonic_setattr (htab_t mnemonic_htab, rtx insn)
        obstack_1grow (&string_obstack, '*');
       else
        add_mnemonic_string (mnemonic_htab,
-                            obstack_next_free (&string_obstack) - size,
+                            (char *) obstack_next_free (&string_obstack) - 
size,
                             size);
       i++;
     }
diff --git a/gcc/objc/objc-encoding.c b/gcc/objc/objc-encoding.c
index 4848021..9c577e9 100644
--- a/gcc/objc/objc-encoding.c
+++ b/gcc/objc/objc-encoding.c
@@ -495,13 +495,14 @@ encode_aggregate_within (tree type, int curtype, int 
format, int left,
 
   if (flag_next_runtime)
     {
-      if (ob_size > 0  &&  *(obstack_next_free (&util_obstack) - 1) == '^')
+      if (ob_size > 0
+         && *((char *) obstack_next_free (&util_obstack) - 1) == '^')
        pointed_to = true;
 
       if ((format == OBJC_ENCODE_INLINE_DEFS || generating_instance_variables)
          && (!pointed_to || ob_size - curtype == 1
              || (ob_size - curtype == 2
-                 && *(obstack_next_free (&util_obstack) - 2) == 'r')))
+                 && *((char *) obstack_next_free (&util_obstack) - 2) == 'r')))
        inline_contents = true;
     }
   else
@@ -512,9 +513,10 @@ encode_aggregate_within (tree type, int curtype, int 
format, int left,
         comment above applies: in that case we should avoid encoding
         the names of instance variables.
       */
-      char c1 = ob_size > 1 ? *(obstack_next_free (&util_obstack) - 2) : 0;
-      char c0 = ob_size > 0 ? *(obstack_next_free (&util_obstack) - 1) : 0;
+      char c0, c1;
 
+      c1 = ob_size > 1 ? *((char *) obstack_next_free (&util_obstack) - 2) : 0;
+      c0 = ob_size > 0 ? *((char *) obstack_next_free (&util_obstack) - 1) : 0;
       if (c0 == '^' || (c1 == '^' && c0 == 'r'))
        pointed_to = true;