[libcxxabi] r226819 - Allow libc++abi to be built without unwinder.
Logan Chien
tzuhsiang.chien at gmail.com
Thu Jan 22 05:27:36 PST 2015
Author: logan
Date: Thu Jan 22 07:27:36 2015
New Revision: 226819
URL: http://llvm.org/viewvc/llvm-project?rev=226819&view=rev
Log:
Allow libc++abi to be built without unwinder.
This CL adds a new compilation flags LIBCXXABI_USE_LLVM_UNWINDER
to specify whether the LLVM unwinder is enabled. Besides, all
unwinder-specific code are guarded with this definition.
Now, libc++abi will be able to use the unwinding routine from libgcc
when LIBCXXABI_USE_LLVM_UNWINDER is disabled.
Modified:
libcxxabi/trunk/CMakeLists.txt
libcxxabi/trunk/src/cxa_personality.cpp
Modified: libcxxabi/trunk/CMakeLists.txt
URL: http://llvm.org/viewvc/llvm-project/libcxxabi/trunk/CMakeLists.txt?rev=226819&r1=226818&r2=226819&view=diff
==============================================================================
--- libcxxabi/trunk/CMakeLists.txt (original)
+++ libcxxabi/trunk/CMakeLists.txt Thu Jan 22 07:27:36 2015
@@ -247,6 +247,11 @@ if (MSVC)
add_definitions(-D_CRT_SECURE_NO_WARNINGS)
endif()
+# Define LIBCXXABI_USE_LLVM_UNWINDER for conditional compilation.
+if (LIBCXXABI_USE_LLVM_UNWINDER)
+ add_definitions(-DLIBCXXABI_USE_LLVM_UNWINDER=1)
+endif()
+
append_if(LIBCXXABI_COMPILE_FLAGS LIBCXXABI_TARGET_TRIPLE
"-target ${LIBCXXABI_TARGET_TRIPLE}")
append_if(LIBCXXABI_COMPILE_FLAGS LIBCXXABI_GCC_TOOLCHAIN
Modified: libcxxabi/trunk/src/cxa_personality.cpp
URL: http://llvm.org/viewvc/llvm-project/libcxxabi/trunk/src/cxa_personality.cpp?rev=226819&r1=226818&r2=226819&view=diff
==============================================================================
--- libcxxabi/trunk/src/cxa_personality.cpp (original)
+++ libcxxabi/trunk/src/cxa_personality.cpp Thu Jan 22 07:27:36 2015
@@ -1012,22 +1012,55 @@ __gxx_personality_v0
}
#else
+#if !LIBCXXABI_USE_LLVM_UNWINDER
+extern "C" _Unwind_Reason_Code __gnu_unwind_frame(_Unwind_Exception*, _Unwind_Context*);
+#endif
+
// Helper function to unwind one frame.
// ARM EHABI 7.3 and 7.4: If the personality function returns _URC_CONTINUE_UNWIND, the
// personality routine should update the virtual register set (VRS) according to the
// corresponding frame unwinding instructions (ARM EHABI 9.3.)
-static _Unwind_Reason_Code continue_unwind(_Unwind_Context* context,
- uint32_t* unwind_opcodes,
- size_t opcode_words)
+static _Unwind_Reason_Code continue_unwind(_Unwind_Exception* unwind_exception,
+ _Unwind_Context* context)
{
+#if LIBCXXABI_USE_LLVM_UNWINDER
+ // ARM EHABI # 6.2, # 9.2
+ //
+ // +---- ehtp
+ // v
+ // +--------------------------------------+
+ // | +--------+--------+--------+-------+ |
+ // | |0| prel31 to __gxx_personality_v0 | |
+ // | +--------+--------+--------+-------+ |
+ // | | N | unwind opcodes | | <-- unwind_opcodes
+ // | +--------+--------+--------+-------+ |
+ // | | Word 2 unwind opcodes | |
+ // | +--------+--------+--------+-------+ |
+ // | ... |
+ // | +--------+--------+--------+-------+ |
+ // | | Word N unwind opcodes | |
+ // | +--------+--------+--------+-------+ |
+ // | | LSDA | | <-- lsda
+ // | | ... | |
+ // | +--------+--------+--------+-------+ |
+ // +--------------------------------------+
+
+ uint32_t *unwind_opcodes = unwind_exception->pr_cache.ehtp + 1;
+ size_t opcode_words = ((*unwind_opcodes >> 24) & 0xff) + 1;
if (_Unwind_VRS_Interpret(context, unwind_opcodes, 1, opcode_words * 4) !=
_URC_CONTINUE_UNWIND)
return _URC_FAILURE;
+#else
+ if (__gnu_unwind_frame(unwind_exception, context) != _URC_OK)
+ return _URC_FAILURE;
+#endif
return _URC_CONTINUE_UNWIND;
}
// ARM register names
+#if !LIBCXXABI_USE_LLVM_UNWINDER
static const uint32_t REG_UCB = 12; // Register to save _Unwind_Control_Block
+#endif
static const uint32_t REG_SP = 13;
static void save_results_to_barrier_cache(_Unwind_Exception* unwind_exception,
@@ -1061,38 +1094,12 @@ __gxx_personality_v0(_Unwind_State state
bool native_exception = (unwind_exception->exception_class & get_vendor_and_language) ==
(kOurExceptionClass & get_vendor_and_language);
-#if LIBCXXABI_ARM_EHABI
- // ARM EHABI # 6.2, # 9.2
- //
- // +---- ehtp
- // v
- // +--------------------------------------+
- // | +--------+--------+--------+-------+ |
- // | |0| prel31 to __gxx_personality_v0 | |
- // | +--------+--------+--------+-------+ |
- // | | N | unwind opcodes | | <-- UnwindData
- // | +--------+--------+--------+-------+ |
- // | | Word 2 unwind opcodes | |
- // | +--------+--------+--------+-------+ |
- // | ... |
- // | +--------+--------+--------+-------+ |
- // | | Word N unwind opcodes | |
- // | +--------+--------+--------+-------+ |
- // | | LSDA | | <-- lsda
- // | | ... | |
- // | +--------+--------+--------+-------+ |
- // +--------------------------------------+
-
- uint32_t *UnwindData = unwind_exception->pr_cache.ehtp + 1;
- uint32_t FirstDataWord = *UnwindData;
- size_t N = ((FirstDataWord >> 24) & 0xff);
- size_t NDataWords = N + 1;
-#endif
-
+#if !LIBCXXABI_USE_LLVM_UNWINDER
// Copy the address of _Unwind_Control_Block to r12 so that
// _Unwind_GetLanguageSpecificData() and _Unwind_GetRegionStart() can
// return correct address.
_Unwind_SetGR(context, REG_UCB, reinterpret_cast<uint32_t>(unwind_exception));
+#endif
scan_results results;
switch (state) {
@@ -1108,7 +1115,7 @@ __gxx_personality_v0(_Unwind_State state
}
// Did not find the catch handler
if (results.reason == _URC_CONTINUE_UNWIND)
- return continue_unwind(context, UnwindData, NDataWords);
+ return continue_unwind(unwind_exception, context);
return results.reason;
case _US_UNWIND_FRAME_STARTING:
@@ -1156,11 +1163,11 @@ __gxx_personality_v0(_Unwind_State state
// Did not find any handler
if (results.reason == _URC_CONTINUE_UNWIND)
- return continue_unwind(context, UnwindData, NDataWords);
+ return continue_unwind(unwind_exception, context);
return results.reason;
case _US_UNWIND_FRAME_RESUME:
- return continue_unwind(context, UnwindData, NDataWords);
+ return continue_unwind(unwind_exception, context);
}
// We were called improperly: neither a phase 1 or phase 2 search
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