objc/4582: All objc tests fail on cygwin with gcc-3.1 (regression from 3.0)

[Billinghurst, David (CRTS)]

Most objc tests have failed on cygwin since late June 2001.  I think the
cause is:

2001-06-27  Stan Shebs  <shebs@apple.com>

	* objc/objc-act.c (handle_impent): Rewrite to be more portable
	and to use ASM_DECLARE_CLASS_REFERENCE.
	* config/darwin.h (ASM_DECLARE_CLASS_REFERENCE): Rename from
	undocumented DECLARE_CLASS_REFERENCE, add file argument.
	* doc/tm.texi (ASM_DECLARE_CLASS_REFERENCE): Document.

The symptoms of the failure are:


/usr/local/obj/gcc/i686-pc-cygwin/libobjc/.libs/libobjc.a(linking.o): In
function `__objc_linking':
/usr/local/src/gcc/libobjc/linking.m:37: undefined reference to
`___objc_class_name_Object'
/usr/local/src/gcc/libobjc/linking.m:37: undefined reference to
`___objc_class_name_NXConstantString'
collect2: ld returned 1 exit status

In gcc-3.0, where the tests pass, these symbols are in NXConstStr.o and
Object.o with three leading underscores.

$ nm NXConstStr.o | grep objc_class
00000034 T ___objc_class_name_NXConstantString
U ___objc_class_name_Object

$ nm Object.o | grep objc_class_name
00000d04 T ___objc_class_name_Object

$ nm linking.o | grep objc_class
U ___objc_class_name_NXConstantString
U ___objc_class_name_Object

In gcc-3.1 the symbols only have two leading underscores.

$ nm NXConstStr.o | grep objc_class_name
U ___objc_class_name_Object
00000036 T __objc_class_name_NXConstantString

$ nm Object.o | grep objc_class_name
00000f16 T __objc_class_name_Object

$ nm linking.o | grep objc_class_name
U ___objc_class_name_NXConstantString
U ___objc_class_name_Object


The symbols that (now) only have two leading underscores are emitted in
objc-act.c(handle_impent).  Before this change, another leading
underscore was added by ASM_GLOBALIZE_LABEL, but this is not done now
since the name has a leading '*'.  

The patch below removes the leading '*' from the name and fixes the
problem on cygwin.  I have no idea what it does on other platforms.
With it I get the following test results

Running /usr/local/src/gcc/gcc/testsuite/objc/compile/compile.exp ...
Running /usr/local/src/gcc/gcc/testsuite/objc/execute/execute.exp ...
FAIL: objc/execute/formal_protocol-6.m execution,  -O0
FAIL: objc/execute/formal_protocol-6.m execution,  -O1
FAIL: objc/execute/formal_protocol-6.m execution,  -O2
FAIL: objc/execute/formal_protocol-6.m execution,  -O3
-fomit-frame-pointer
FAIL: objc/execute/formal_protocol-6.m execution,  -O3 -g
FAIL: objc/execute/formal_protocol-6.m execution,  -Os
Running /usr/local/src/gcc/gcc/testsuite/objc.dg/dg.exp ...
Running /usr/local/src/gcc/gcc/testsuite/objc.dg/special/special.exp ...

                === objc Summary ===

# of expected passes            1036
# of unexpected failures        6
/usr/local/obj/gcc/gcc/xgcc version 3.1 20020110 (experimental)


Index: objc-act.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/objc/objc-act.c,v
retrieving revision 1.123
diff -u -p -r1.123 objc-act.c
--- objc-act.c  2002/01/08 18:03:11     1.123
+++ objc-act.c  2002/01/13 12:20:33
@@ -8330,7 +8330,7 @@ handle_impent (impent)

       string = (char *) alloca (strlen (class_name) + 30);

-      sprintf (string, "*%sobjc_class_name_%s",
+      sprintf (string, "%sobjc_class_name_%s",
                (flag_next_runtime ? "." : "__"), class_name);
     }
   else if (TREE_CODE (impent->imp_context) ==
CATEGORY_IMPLEMENTATION_TYPE)