unwind: Fix libc++abi and libgcc build.

To build libc++abi without libunwind, we should make sure that all
function calls to _Unwind_{Get,Set}{GR,IP}() are inlined as function
calls to _Unwind_VRS_{Get,Set}().  Otherwise, libc++abi.so will fail to
link since libgcc does not provide these symbol at all.

This commit fixes the problem by providing both the inlined version and
exported version.

llvm-svn: 243073

1 files changed, 7 insertions, 35 deletions

diff --git a/libunwind/src/UnwindLevel1.c b/libunwind/src/UnwindLevel1.c
index caef0cf04dc..ce6eb286bab 100644
--- a/libunwind/src/UnwindLevel1.c
+++ b/libunwind/src/UnwindLevel1.c
@@ -12,6 +12,13 @@
 //
 //===----------------------------------------------------------------------===//
 
+// ARM EHABI does not specify _Unwind_{Get,Set}{GR,IP}().  Thus, we are
+// defining inline functions to delegate the function calls to
+// _Unwind_VRS_{Get,Set}().  However, some applications might declare the
+// function protetype directly (instead of including <unwind.h>), thus we need
+// to export these functions from libunwind.so as well.
+#define _LIBUNWIND_UNWIND_LEVEL1_EXTERNAL_LINKAGE 1
+
 #include <inttypes.h>
 #include <stdint.h>
 #include <stdbool.h>
@@ -496,39 +503,4 @@ _LIBUNWIND_EXPORT void _Unwind_SetIP(struct _Unwind_Context *context,
   unw_set_reg(cursor, UNW_REG_IP, value);
 }
 
-#else
-
-_LIBUNWIND_EXPORT uintptr_t
-_Unwind_GetGR(struct _Unwind_Context *context, int index) {
-  uintptr_t value = 0;
-  _Unwind_VRS_Get(context, _UVRSC_CORE, (uint32_t)index, _UVRSD_UINT32, &value);
-  _LIBUNWIND_TRACE_API("_Unwind_GetGR(context=%p, reg=%d) => 0x%" PRIx64 "\n",
-                       (void *)context, index, (uint64_t)value);
-  return value;
-}
-
-_LIBUNWIND_EXPORT void _Unwind_SetGR(struct _Unwind_Context *context, int index,
-                                     uintptr_t value) {
-  _LIBUNWIND_TRACE_API("_Unwind_SetGR(context=%p, reg=%d, value=0x%0"PRIx64")\n",
-                       (void *)context, index, (uint64_t)value);
-  _Unwind_VRS_Set(context, _UVRSC_CORE, (uint32_t)index, _UVRSD_UINT32, &value);
-}
-
-_LIBUNWIND_EXPORT uintptr_t _Unwind_GetIP(struct _Unwind_Context *context) {
-  // remove the thumb-bit before returning
-  uintptr_t value = _Unwind_GetGR(context, 15) & (~(uintptr_t)0x1);
-  _LIBUNWIND_TRACE_API("_Unwind_GetIP(context=%p) => 0x%" PRIx64 "\n",
-                       (void *)context, (uint64_t)value);
-  return value;
-}
-
-_LIBUNWIND_EXPORT void _Unwind_SetIP(struct _Unwind_Context *context,
-                                     uintptr_t value) {
-  _LIBUNWIND_TRACE_API("_Unwind_SetIP(context=%p, value=0x%0" PRIx64 ")\n",
-                       (void *)context, (uint64_t)value);
-  uintptr_t thumb_bit = _Unwind_GetGR(context, 15) & ((uintptr_t)0x1);
-  _Unwind_SetGR(context, 15, value | thumb_bit);
-}
-
 #endif // !_LIBUNWIND_ARM_EHABI
-