builtins: avoid duplicating unwind declarations

[compnerd]

Summary

Use unwind.h to get the declarations for unwinding interfaces. This header is
already provided by clang and gcc, so this adds no additional dependencies for
building the builtins library. It avoids the duplication which may drift over
time though.

[rengolin]

Hi Slaeem,

I agree we should de-duplicate stuff, but the new behaviour is different in more ways than that. Currently, the personality will be included no matter what headers you have, but with your change, it'll only be included if you do have unwind.h. If I understood correctly, this makes sense, since there's no point in having a personality routine without the unwinding framework, but I just want to make sure this is intentional.

Also, the change from struct to pointer is curious...

cheers,
--renato

lib/builtins/gcc_personality_v0.c

148

This change doesn't seem relevant (even if it is correct) to this patch.

[compnerd]

Yes, the additional change of only including it is intentional. However, keep in mind that the header is compiler provided, so you can build this even if you only have a clang installation or if you are building it standalone with a separate copy of libunwind.

lib/builtins/gcc_personality_v0.c

148

Speling change. _Unwind_Context_t was a typedef for struct _Unwind_Context *.

[rengolin]

Sorry it took so long, I lost track of things. LGTM. Thanks!

lib/builtins/gcc_personality_v0.c

148

I see, due to the header change.

[compnerd]

SVN r225990.

CMakeLists.txt

 
 option(COMPILER_RT_DEBUG "Build runtimes with full debug info" OFF)
 # COMPILER_RT_DEBUG_PYBOOL is used by lit.common.configured.in.
 pythonize_bool(COMPILER_RT_DEBUG)
 
 #================================
 # Setup Compiler Flags
 #================================
+include(CheckIncludeFile)
+check_include_file(unwind.h HAVE_UNWIND_H)
+
 include(config-ix)
 
 if(MSVC)
   append_string_if(COMPILER_RT_HAS_W3_FLAG /W3 CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
 else()
   append_string_if(COMPILER_RT_HAS_WALL_FLAG -Wall CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
 endif()
 if(COMPILER_RT_ENABLE_WERROR)

lib/builtins/CMakeLists.txt

set(GENERIC_SOURCES
   floatundidf.c
   floatundisf.c
   floatundixf.c
   floatunsidf.c
   floatunsisf.c
   floatuntidf.c
   floatuntisf.c
   floatuntixf.c
-  gcc_personality_v0.c
   int_util.c
   lshrdi3.c
   lshrti3.c
   moddi3.c
   modsi3.c
   modti3.c
   muldc3.c
   muldf3.c
set(GENERIC_SOURCES
   udivmodsi4.c
   udivmodti4.c
   udivsi3.c
   udivti3.c
   umoddi3.c
   umodsi3.c
   umodti3.c)
 
+if (HAVE_UNWIND_H)
+  set(GENERIC_SOURCES
+      ${GENERIC_SOURCES}
+      gcc_personality_v0.c)
+endif ()
+
 set(x86_64_SOURCES
   x86_64/floatdidf.c
   x86_64/floatdisf.c
   x86_64/floatdixf.c
   x86_64/floatundidf.S
   x86_64/floatundisf.S
   x86_64/floatundixf.S
   ${GENERIC_SOURCES})

lib/builtins/gcc_personality_v0.c

 /* ===-- gcc_personality_v0.c - Implement __gcc_personality_v0 -------------===
  *
  *               The LLVM Compiler Infrastructure
  *
  * This file is dual licensed under the MIT and the University of Illinois Open
  * Source Licenses. See LICENSE.TXT for details.
  *
  * ===----------------------------------------------------------------------===
  *
  */
 
 #include "int_lib.h"
 
-/*
- * _Unwind_* stuff based on C++ ABI public documentation
- * http://refspecs.freestandards.org/abi-eh-1.21.html
- */
-
-typedef enum {
-    _URC_NO_REASON = 0,
-    _URC_FOREIGN_EXCEPTION_CAUGHT = 1,
-    _URC_FATAL_PHASE2_ERROR = 2,
-    _URC_FATAL_PHASE1_ERROR = 3,
-    _URC_NORMAL_STOP = 4,
-    _URC_END_OF_STACK = 5,
-    _URC_HANDLER_FOUND = 6,
-    _URC_INSTALL_CONTEXT = 7,
-    _URC_CONTINUE_UNWIND = 8
-} _Unwind_Reason_Code;
-
-typedef enum {
-    _UA_SEARCH_PHASE = 1,
-    _UA_CLEANUP_PHASE = 2,
-    _UA_HANDLER_FRAME = 4,
-    _UA_FORCE_UNWIND = 8,
-    _UA_END_OF_STACK = 16
-} _Unwind_Action;
-
-typedef struct _Unwind_Context* _Unwind_Context_t;
-
-struct _Unwind_Exception {
-    uint64_t                exception_class;
-    void                    (*exception_cleanup)(_Unwind_Reason_Code reason, 
-                                                 struct _Unwind_Exception* exc);
-    uintptr_t                private_1;    
-    uintptr_t                private_2;    
-};
-
-COMPILER_RT_ABI  const uint8_t*    _Unwind_GetLanguageSpecificData(_Unwind_Context_t c);
-COMPILER_RT_ABI  void              _Unwind_SetGR(_Unwind_Context_t c, int i, uintptr_t n);
-COMPILER_RT_ABI  void              _Unwind_SetIP(_Unwind_Context_t, uintptr_t new_value);
-COMPILER_RT_ABI  uintptr_t         _Unwind_GetIP(_Unwind_Context_t context);
-COMPILER_RT_ABI  uintptr_t         _Unwind_GetRegionStart(_Unwind_Context_t context);
-
+#include <unwind.h>
 
 /*
  * Pointer encodings documented at:
  *   http://refspecs.freestandards.org/LSB_1.3.0/gLSB/gLSB/ehframehdr.html
  */
 
 #define DW_EH_PE_omit      0xff  /* no data follows */
 

  * on each frame as the stack is unwound during a C++ exception
  * throw through a C function compiled with -fexceptions.
  */
 #if __USING_SJLJ_EXCEPTIONS__
 // the setjump-longjump based exceptions personality routine has a different name
 COMPILER_RT_ABI _Unwind_Reason_Code
 __gcc_personality_sj0(int version, _Unwind_Action actions,
          uint64_t exceptionClass, struct _Unwind_Exception* exceptionObject,
-         _Unwind_Context_t context)
+         struct _Unwind_Context *context)
 #else
 COMPILER_RT_ABI _Unwind_Reason_Code
 __gcc_personality_v0(int version, _Unwind_Action actions,
          uint64_t exceptionClass, struct _Unwind_Exception* exceptionObject,
-         _Unwind_Context_t context)
+         struct _Unwind_Context *context)
 #endif
 {
     /* Since C does not have catch clauses, there is nothing to do during */
     /* phase 1 (the search phase). */
     if ( actions & _UA_SEARCH_PHASE ) 
         return _URC_CONTINUE_UNWIND;
         
     /* There is nothing to do if there is no LSDA for this frame. */