diff options
Diffstat (limited to 'compiler-rt/lib/builtins/gcc_personality_v0.c')
| -rw-r--r-- | compiler-rt/lib/builtins/gcc_personality_v0.c | 111 |
1 files changed, 50 insertions, 61 deletions
diff --git a/compiler-rt/lib/builtins/gcc_personality_v0.c b/compiler-rt/lib/builtins/gcc_personality_v0.c index d50cc369cc3..d12ee03c49f 100644 --- a/compiler-rt/lib/builtins/gcc_personality_v0.c +++ b/compiler-rt/lib/builtins/gcc_personality_v0.c @@ -1,35 +1,29 @@ -/* ===-- gcc_personality_v0.c - Implement __gcc_personality_v0 -------------=== - * - * Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. - * See https://llvm.org/LICENSE.txt for license information. - * SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception - * - * ===----------------------------------------------------------------------=== - * - */ +//===-- gcc_personality_v0.c - Implement __gcc_personality_v0 -------------===// +// +// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. +// See https://llvm.org/LICENSE.txt for license information. +// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception +// +//===----------------------------------------------------------------------===// #include "int_lib.h" #include <unwind.h> #if defined(__arm__) && !defined(__ARM_DWARF_EH__) && \ !defined(__USING_SJLJ_EXCEPTIONS__) -/* - * When building with older compilers (e.g. clang <3.9), it is possible that we - * have a version of unwind.h which does not provide the EHABI declarations - * which are quired for the C personality to conform to the specification. In - * order to provide forward compatibility for such compilers, we re-declare the - * necessary interfaces in the helper to permit a standalone compilation of the - * builtins (which contains the C unwinding personality for historical reasons). - */ +// When building with older compilers (e.g. clang <3.9), it is possible that we +// have a version of unwind.h which does not provide the EHABI declarations +// which are quired for the C personality to conform to the specification. In +// order to provide forward compatibility for such compilers, we re-declare the +// necessary interfaces in the helper to permit a standalone compilation of the +// builtins (which contains the C unwinding personality for historical reasons). #include "unwind-ehabi-helpers.h" #endif -/* - * Pointer encodings documented at: - * http://refspecs.freestandards.org/LSB_1.3.0/gLSB/gLSB/ehframehdr.html - */ +// 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 */ +#define DW_EH_PE_omit 0xff // no data follows #define DW_EH_PE_absptr 0x00 #define DW_EH_PE_uleb128 0x01 @@ -46,9 +40,9 @@ #define DW_EH_PE_datarel 0x30 #define DW_EH_PE_funcrel 0x40 #define DW_EH_PE_aligned 0x50 -#define DW_EH_PE_indirect 0x80 /* gcc extension */ +#define DW_EH_PE_indirect 0x80 // gcc extension -/* read a uleb128 encoded value and advance pointer */ +// read a uleb128 encoded value and advance pointer static uintptr_t readULEB128(const uint8_t **data) { uintptr_t result = 0; uintptr_t shift = 0; @@ -63,7 +57,7 @@ static uintptr_t readULEB128(const uint8_t **data) { return result; } -/* read a pointer encoded value and advance pointer */ +// read a pointer encoded value and advance pointer static uintptr_t readEncodedPointer(const uint8_t **data, uint8_t encoding) { const uint8_t *p = *data; uintptr_t result = 0; @@ -71,7 +65,7 @@ static uintptr_t readEncodedPointer(const uint8_t **data, uint8_t encoding) { if (encoding == DW_EH_PE_omit) return 0; - /* first get value */ + // first get value switch (encoding & 0x0F) { case DW_EH_PE_absptr: result = *((const uintptr_t *)p); @@ -106,15 +100,15 @@ static uintptr_t readEncodedPointer(const uint8_t **data, uint8_t encoding) { break; case DW_EH_PE_sleb128: default: - /* not supported */ + // not supported compilerrt_abort(); break; } - /* then add relative offset */ + // then add relative offset switch (encoding & 0x70) { case DW_EH_PE_absptr: - /* do nothing */ + // do nothing break; case DW_EH_PE_pcrel: result += (uintptr_t)(*data); @@ -124,12 +118,12 @@ static uintptr_t readEncodedPointer(const uint8_t **data, uint8_t encoding) { case DW_EH_PE_funcrel: case DW_EH_PE_aligned: default: - /* not supported */ + // not supported compilerrt_abort(); break; } - /* then apply indirection */ + // then apply indirection if (encoding & DW_EH_PE_indirect) { result = *((const uintptr_t *)result); } @@ -149,32 +143,28 @@ static inline _Unwind_Reason_Code continueUnwind(struct _Unwind_Exception *exceptionObject, struct _Unwind_Context *context) { #if USING_ARM_EHABI - /* - * On ARM EHABI the personality routine is responsible for actually - * unwinding a single stack frame before returning (ARM EHABI Sec. 6.1). - */ + // On ARM EHABI the personality routine is responsible for actually + // unwinding a single stack frame before returning (ARM EHABI Sec. 6.1). if (__gnu_unwind_frame(exceptionObject, context) != _URC_OK) return _URC_FAILURE; #endif return _URC_CONTINUE_UNWIND; } -/* - * The C compiler makes references to __gcc_personality_v0 in - * the dwarf unwind information for translation units that use - * __attribute__((cleanup(xx))) on local variables. - * This personality routine is called by the system unwinder - * on each frame as the stack is unwound during a C++ exception - * throw through a C function compiled with -fexceptions. - */ +// The C compiler makes references to __gcc_personality_v0 in +// the dwarf unwind information for translation units that use +// __attribute__((cleanup(xx))) on local variables. +// This personality routine is called by the system unwinder +// 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 */ +// 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, struct _Unwind_Context *context) #elif USING_ARM_EHABI -/* The ARM EHABI personality routine has a different signature. */ +// The ARM EHABI personality routine has a different signature. COMPILER_RT_ABI _Unwind_Reason_Code __gcc_personality_v0( _Unwind_State state, struct _Unwind_Exception *exceptionObject, struct _Unwind_Context *context) @@ -184,18 +174,18 @@ COMPILER_RT_ABI _Unwind_Reason_Code __gcc_personality_v0( struct _Unwind_Exception *exceptionObject, struct _Unwind_Context *context) #endif { - /* Since C does not have catch clauses, there is nothing to do during */ - /* phase 1 (the search phase). */ + // Since C does not have catch clauses, there is nothing to do during + // phase 1 (the search phase). #if USING_ARM_EHABI - /* After resuming from a cleanup we should also continue on to the next - * frame straight away. */ + // After resuming from a cleanup we should also continue on to the next + // frame straight away. if ((state & _US_ACTION_MASK) != _US_UNWIND_FRAME_STARTING) #else if (actions & _UA_SEARCH_PHASE) #endif return continueUnwind(exceptionObject, context); - /* There is nothing to do if there is no LSDA for this frame. */ + // There is nothing to do if there is no LSDA for this frame. const uint8_t *lsda = (uint8_t *)_Unwind_GetLanguageSpecificData(context); if (lsda == (uint8_t *)0) return continueUnwind(exceptionObject, context); @@ -204,7 +194,7 @@ COMPILER_RT_ABI _Unwind_Reason_Code __gcc_personality_v0( uintptr_t funcStart = (uintptr_t)_Unwind_GetRegionStart(context); uintptr_t pcOffset = pc - funcStart; - /* Parse LSDA header. */ + // Parse LSDA header. uint8_t lpStartEncoding = *lsda++; if (lpStartEncoding != DW_EH_PE_omit) { readEncodedPointer(&lsda, lpStartEncoding); @@ -213,7 +203,7 @@ COMPILER_RT_ABI _Unwind_Reason_Code __gcc_personality_v0( if (ttypeEncoding != DW_EH_PE_omit) { readULEB128(&lsda); } - /* Walk call-site table looking for range that includes current PC. */ + // Walk call-site table looking for range that includes current PC. uint8_t callSiteEncoding = *lsda++; uint32_t callSiteTableLength = readULEB128(&lsda); const uint8_t *callSiteTableStart = lsda; @@ -223,15 +213,14 @@ COMPILER_RT_ABI _Unwind_Reason_Code __gcc_personality_v0( uintptr_t start = readEncodedPointer(&p, callSiteEncoding); uintptr_t length = readEncodedPointer(&p, callSiteEncoding); uintptr_t landingPad = readEncodedPointer(&p, callSiteEncoding); - readULEB128(&p); /* action value not used for C code */ + readULEB128(&p); // action value not used for C code if (landingPad == 0) - continue; /* no landing pad for this entry */ + continue; // no landing pad for this entry if ((start <= pcOffset) && (pcOffset < (start + length))) { - /* Found landing pad for the PC. - * Set Instruction Pointer to so we re-enter function - * at landing pad. The landing pad is created by the compiler - * to take two parameters in registers. - */ + // Found landing pad for the PC. + // Set Instruction Pointer to so we re-enter function + // at landing pad. The landing pad is created by the compiler + // to take two parameters in registers. _Unwind_SetGR(context, __builtin_eh_return_data_regno(0), (uintptr_t)exceptionObject); _Unwind_SetGR(context, __builtin_eh_return_data_regno(1), 0); @@ -240,6 +229,6 @@ COMPILER_RT_ABI _Unwind_Reason_Code __gcc_personality_v0( } } - /* No landing pad found, continue unwinding. */ + // No landing pad found, continue unwinding. return continueUnwind(exceptionObject, context); } |
