Revert "String literals are always const"

This reverts commit d4fe9aba3fc6f4b9cc97b100e86ffe7af5c29619.
I was confused by the fact that string literals aren't writable.
Nevertheless the type isn't const.  As extension in GCC it's const
with -Wwrite-string, which is exactly what we had before.

GCC also wonders in a comment if it's really a good idea to change
expression types based on warning flags (IMHO it's not), but let's
be compatible.  So restore the state from before.

1 files changed, 3 insertions, 3 deletions

diff --git a/tccgen.c b/tccgen.c
index 2885f3e..304225e 100644
--- a/tccgen.c
+++ b/tccgen.c
@@ -2829,8 +2829,7 @@ static void gen_assign_cast(CType *dt)
 	    }
         }
         /* check const and volatile */
-        if ((!(type1->t & VT_CONSTANT) && (type2->t & VT_CONSTANT) &&
-	     ((type2->t & VT_BTYPE) != VT_BYTE || tcc_state->warn_write_strings)) ||
+        if ((!(type1->t & VT_CONSTANT) && (type2->t & VT_CONSTANT)) ||
             (!(type1->t & VT_VOLATILE) && (type2->t & VT_VOLATILE)))
             tcc_warning("assignment discards qualifiers from pointer target type");
         break;
@@ -4382,7 +4381,8 @@ ST_FUNC void unary(void)
         /* string parsing */
         t = VT_BYTE;
     str_init:
-        t |= VT_CONSTANT;
+        if (tcc_state->warn_write_strings)
+            t |= VT_CONSTANT;
         type.t = t;
         mk_pointer(&type);
         type.t |= VT_ARRAY;