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-rw-r--r--lib/builtins/gcc_personality_v0.c407
1 files changed, 195 insertions, 212 deletions
diff --git a/lib/builtins/gcc_personality_v0.c b/lib/builtins/gcc_personality_v0.c
index 68581ef16434..d12ee03c49fe 100644
--- a/lib/builtins/gcc_personality_v0.c
+++ b/lib/builtins/gcc_personality_v0.c
@@ -1,145 +1,135 @@
-/* ===-- 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.
- *
- * ===----------------------------------------------------------------------===
- *
- */
+//===-- 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).
- */
+#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).
#include "unwind-ehabi-helpers.h"
#endif
-/*
- * 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_absptr 0x00
-#define DW_EH_PE_uleb128 0x01
-#define DW_EH_PE_udata2 0x02
-#define DW_EH_PE_udata4 0x03
-#define DW_EH_PE_udata8 0x04
-#define DW_EH_PE_sleb128 0x09
-#define DW_EH_PE_sdata2 0x0A
-#define DW_EH_PE_sdata4 0x0B
-#define DW_EH_PE_sdata8 0x0C
-
-#define DW_EH_PE_pcrel 0x10
-#define DW_EH_PE_textrel 0x20
-#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 */
-
-
-
-/* read a uleb128 encoded value and advance pointer */
-static uintptr_t readULEB128(const uint8_t** data)
-{
- uintptr_t result = 0;
- uintptr_t shift = 0;
- unsigned char byte;
- const uint8_t* p = *data;
- do {
- byte = *p++;
- result |= (byte & 0x7f) << shift;
- shift += 7;
- } while (byte & 0x80);
- *data = p;
- return result;
+// 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_absptr 0x00
+#define DW_EH_PE_uleb128 0x01
+#define DW_EH_PE_udata2 0x02
+#define DW_EH_PE_udata4 0x03
+#define DW_EH_PE_udata8 0x04
+#define DW_EH_PE_sleb128 0x09
+#define DW_EH_PE_sdata2 0x0A
+#define DW_EH_PE_sdata4 0x0B
+#define DW_EH_PE_sdata8 0x0C
+
+#define DW_EH_PE_pcrel 0x10
+#define DW_EH_PE_textrel 0x20
+#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
+
+// read a uleb128 encoded value and advance pointer
+static uintptr_t readULEB128(const uint8_t **data) {
+ uintptr_t result = 0;
+ uintptr_t shift = 0;
+ unsigned char byte;
+ const uint8_t *p = *data;
+ do {
+ byte = *p++;
+ result |= (byte & 0x7f) << shift;
+ shift += 7;
+ } while (byte & 0x80);
+ *data = p;
+ return result;
}
-/* 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;
-
- if ( encoding == DW_EH_PE_omit )
- return 0;
-
- /* first get value */
- switch (encoding & 0x0F) {
- case DW_EH_PE_absptr:
- result = *((const uintptr_t*)p);
- p += sizeof(uintptr_t);
- break;
- case DW_EH_PE_uleb128:
- result = readULEB128(&p);
- break;
- case DW_EH_PE_udata2:
- result = *((const uint16_t*)p);
- p += sizeof(uint16_t);
- break;
- case DW_EH_PE_udata4:
- result = *((const uint32_t*)p);
- p += sizeof(uint32_t);
- break;
- case DW_EH_PE_udata8:
- result = *((const uint64_t*)p);
- p += sizeof(uint64_t);
- break;
- case DW_EH_PE_sdata2:
- result = *((const int16_t*)p);
- p += sizeof(int16_t);
- break;
- case DW_EH_PE_sdata4:
- result = *((const int32_t*)p);
- p += sizeof(int32_t);
- break;
- case DW_EH_PE_sdata8:
- result = *((const int64_t*)p);
- p += sizeof(int64_t);
- break;
- case DW_EH_PE_sleb128:
- default:
- /* not supported */
- compilerrt_abort();
- break;
- }
-
- /* then add relative offset */
- switch ( encoding & 0x70 ) {
- case DW_EH_PE_absptr:
- /* do nothing */
- break;
- case DW_EH_PE_pcrel:
- result += (uintptr_t)(*data);
- break;
- case DW_EH_PE_textrel:
- case DW_EH_PE_datarel:
- case DW_EH_PE_funcrel:
- case DW_EH_PE_aligned:
- default:
- /* not supported */
- compilerrt_abort();
- break;
- }
-
- /* then apply indirection */
- if (encoding & DW_EH_PE_indirect) {
- result = *((const uintptr_t*)result);
- }
-
- *data = p;
- return result;
+// 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;
+
+ if (encoding == DW_EH_PE_omit)
+ return 0;
+
+ // first get value
+ switch (encoding & 0x0F) {
+ case DW_EH_PE_absptr:
+ result = *((const uintptr_t *)p);
+ p += sizeof(uintptr_t);
+ break;
+ case DW_EH_PE_uleb128:
+ result = readULEB128(&p);
+ break;
+ case DW_EH_PE_udata2:
+ result = *((const uint16_t *)p);
+ p += sizeof(uint16_t);
+ break;
+ case DW_EH_PE_udata4:
+ result = *((const uint32_t *)p);
+ p += sizeof(uint32_t);
+ break;
+ case DW_EH_PE_udata8:
+ result = *((const uint64_t *)p);
+ p += sizeof(uint64_t);
+ break;
+ case DW_EH_PE_sdata2:
+ result = *((const int16_t *)p);
+ p += sizeof(int16_t);
+ break;
+ case DW_EH_PE_sdata4:
+ result = *((const int32_t *)p);
+ p += sizeof(int32_t);
+ break;
+ case DW_EH_PE_sdata8:
+ result = *((const int64_t *)p);
+ p += sizeof(int64_t);
+ break;
+ case DW_EH_PE_sleb128:
+ default:
+ // not supported
+ compilerrt_abort();
+ break;
+ }
+
+ // then add relative offset
+ switch (encoding & 0x70) {
+ case DW_EH_PE_absptr:
+ // do nothing
+ break;
+ case DW_EH_PE_pcrel:
+ result += (uintptr_t)(*data);
+ break;
+ case DW_EH_PE_textrel:
+ case DW_EH_PE_datarel:
+ case DW_EH_PE_funcrel:
+ case DW_EH_PE_aligned:
+ default:
+ // not supported
+ compilerrt_abort();
+ break;
+ }
+
+ // then apply indirection
+ if (encoding & DW_EH_PE_indirect) {
+ result = *((const uintptr_t *)result);
+ }
+
+ *data = p;
+ return result;
}
#if defined(__arm__) && !defined(__USING_SJLJ_EXCEPTIONS__) && \
@@ -153,99 +143,92 @@ 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).
- */
- if (__gnu_unwind_frame(exceptionObject, context) != _URC_OK)
- return _URC_FAILURE;
+ // 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;
+ 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 */
-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)
+// 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)
+ _Unwind_State state, struct _Unwind_Exception *exceptionObject,
+ 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,
- struct _Unwind_Context *context)
+COMPILER_RT_ABI _Unwind_Reason_Code __gcc_personality_v0(
+ int version, _Unwind_Action actions, uint64_t exceptionClass,
+ 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. */
- if ((state & _US_ACTION_MASK) != _US_UNWIND_FRAME_STARTING)
+ // 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 )
+ if (actions & _UA_SEARCH_PHASE)
#endif
- return continueUnwind(exceptionObject, context);
-
- /* 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);
+ return continueUnwind(exceptionObject, context);
- uintptr_t pc = (uintptr_t)_Unwind_GetIP(context)-1;
- uintptr_t funcStart = (uintptr_t)_Unwind_GetRegionStart(context);
- uintptr_t pcOffset = pc - funcStart;
+ // 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);
- /* Parse LSDA header. */
- uint8_t lpStartEncoding = *lsda++;
- if (lpStartEncoding != DW_EH_PE_omit) {
- readEncodedPointer(&lsda, lpStartEncoding);
- }
- uint8_t ttypeEncoding = *lsda++;
- if (ttypeEncoding != DW_EH_PE_omit) {
- readULEB128(&lsda);
- }
- /* 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;
- const uint8_t* callSiteTableEnd = callSiteTableStart + callSiteTableLength;
- const uint8_t* p=callSiteTableStart;
- while (p < callSiteTableEnd) {
- 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 */
- if ( landingPad == 0 )
- 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.
- */
- _Unwind_SetGR(context, __builtin_eh_return_data_regno(0),
- (uintptr_t)exceptionObject);
- _Unwind_SetGR(context, __builtin_eh_return_data_regno(1), 0);
- _Unwind_SetIP(context, (funcStart + landingPad));
- return _URC_INSTALL_CONTEXT;
- }
+ uintptr_t pc = (uintptr_t)_Unwind_GetIP(context) - 1;
+ uintptr_t funcStart = (uintptr_t)_Unwind_GetRegionStart(context);
+ uintptr_t pcOffset = pc - funcStart;
+
+ // Parse LSDA header.
+ uint8_t lpStartEncoding = *lsda++;
+ if (lpStartEncoding != DW_EH_PE_omit) {
+ readEncodedPointer(&lsda, lpStartEncoding);
+ }
+ uint8_t ttypeEncoding = *lsda++;
+ if (ttypeEncoding != DW_EH_PE_omit) {
+ readULEB128(&lsda);
+ }
+ // 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;
+ const uint8_t *callSiteTableEnd = callSiteTableStart + callSiteTableLength;
+ const uint8_t *p = callSiteTableStart;
+ while (p < callSiteTableEnd) {
+ 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
+ if (landingPad == 0)
+ 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.
+ _Unwind_SetGR(context, __builtin_eh_return_data_regno(0),
+ (uintptr_t)exceptionObject);
+ _Unwind_SetGR(context, __builtin_eh_return_data_regno(1), 0);
+ _Unwind_SetIP(context, (funcStart + landingPad));
+ return _URC_INSTALL_CONTEXT;
}
+ }
- /* No landing pad found, continue unwinding. */
- return continueUnwind(exceptionObject, context);
+ // No landing pad found, continue unwinding.
+ return continueUnwind(exceptionObject, context);
}
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