[CLN-list] future GCC 4.3 and modules.h

[Ralf Wildenhues]

Hello CLN people,

Consider this code snippet:

extern "C" void func () {}
__asm__("\t.globl " "_GLOBAL__I_" "func");
static struct S {
  inline S () { }
} S;

On x86_64, with `g++-4.2 -fPIC -c a.cc', this results in
| 0000000000000032 T _GLOBAL__I_func

with mainline GCC (what will eventually be 4.3 or some other number), it
has
| 0000000000000032 t _GLOBAL__I_a.cc

(and of course that will be `T' with the appropriate .globl directive).

This affects .libs/cl_DF_globals.o and some of the other globals
objects, and causes a link failure of the examples due to the CL_REQUIRE
undefined references (global constructor keyed to ...).

The hack below makes things work with mainline, but still needs to be
redone properly, with a configure-time check and so on to not regress
on g++ <= 4.2.  If you like I can take a stab at writing so; I assume
the test should make use of $lt_compiler_pic_CXX and the header file
provide different defines based on whether -DPIC was given?  (I'm not
all that experienced with this stuff, so pointers are greatly
appreciated.)

Cheers,
Ralf

Index: include/cln/modules.h
===================================================================
RCS file: /home/cvs/cln/include/cln/modules.h,v
retrieving revision 1.19
diff -u -r1.19 modules.h
--- include/cln/modules.h	7 May 2006 21:05:24 -0000	1.19
+++ include/cln/modules.h	26 May 2007 16:44:38 -0000
@@ -219,7 +219,7 @@
       };								\
       static _CL_REQUIRE_CLASSNAME(module,__LINE__)			\
         _CL_REQUIRE_CLASSNAME(module##_requirer,__LINE__);
-  #else
+  #elif 0
     // gcc-3.0 -fuse-cxa-atexit doesn't have a single per-module destructor
     // function anymore. Instead, for each object's static constructor it
     // executes, it pushes the corresponding object's destructor onto a list.
@@ -255,9 +255,42 @@
       };								\
       static _CL_REQUIRE_CLASSNAME(module,__LINE__)			\
         _CL_REQUIRE_CLASSNAME(module##_requirer,__LINE__);
-  #endif
   #define _CL_REQUIRE_CLASSNAME(module,line) __CL_REQUIRE_CLASSNAME(module,line)
   #define __CL_REQUIRE_CLASSNAME(module,line) cl_module__##module##__##line
+  #else
+    #define CL_PROVIDE(module)  \
+      extern "C" void cl_module__##module##__ctorend (void);		\
+      CL_GLOBALIZE_JUMP_LABEL(cl_module__##module##__ctorend)		\
+      CL_GLOBALIZE_CTORDTOR_LABEL(					\
+                 ASM_UNDERSCORE_PREFIX CL_GLOBAL_CONSTRUCTOR_PREFIX	\
+                 #module ".cc")		\
+      static int cl_module__##module##__counter;			\
+      struct cl_module__##module##__controller {			\
+        inline cl_module__##module##__controller ()			\
+          { if (cl_module__##module##__counter++)			\
+              { CL_JUMP_TO(cl_module__##module##__ctorend); }		\
+          }								\
+      };								\
+      static cl_module__##module##__controller cl_module__##module##__ctordummy;
+    #define CL_PROVIDE_END(module)  \
+      struct cl_module__##module##__destroyer {				\
+        inline cl_module__##module##__destroyer ()			\
+          { CL_OUTPUT_LABEL (ASM_UNDERSCORE_PREFIX "cl_module__" #module "__ctorend"); } \
+      };								\
+      static cl_module__##module##__destroyer cl_module__##module##__dtordummy;
+    #define CL_REQUIRE(module)  \
+      extern "C" void cl_module__##module##__ctor (void)		\
+        __asm__ (ASM_UNDERSCORE_PREFIX CL_GLOBAL_CONSTRUCTOR_PREFIX	\
+                 #module ".cc");		\
+      struct _CL_REQUIRE_CLASSNAME(module,__LINE__) {			\
+        inline _CL_REQUIRE_CLASSNAME(module,__LINE__) ()		\
+          { cl_module__##module##__ctor (); }				\
+      };								\
+      static _CL_REQUIRE_CLASSNAME(module,__LINE__)			\
+        _CL_REQUIRE_CLASSNAME(module##_requirer,__LINE__);
+  #define _CL_REQUIRE_CLASSNAME(module,line) __CL_REQUIRE_CLASSNAME(module,line)
+  #define __CL_REQUIRE_CLASSNAME(module,line) cl_module__##module##__##line
+#endif
 #else
   #define CL_PROVIDE(module)
   #define CL_PROVIDE_END(module)