Initial import of compiler-rt.
-
git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@74292 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/gcc_personality_v0.c b/lib/gcc_personality_v0.c
new file mode 100644
index 0000000..55d1166
--- /dev/null
+++ b/lib/gcc_personality_v0.c
@@ -0,0 +1,237 @@
+//===-- gcc_personality_v0.c - Implement __gcc_personality_v0 -------------===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.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;
+ _Unwind_Reason_Code (*exception_cleanup)(_Unwind_Reason_Code reason,
+ struct _Unwind_Exception* exc);
+ uintptr_t private_1;
+ uintptr_t private_2;
+};
+
+extern const uint8_t* _Unwind_GetLanguageSpecificData(_Unwind_Context_t c);
+extern void _Unwind_SetGR(_Unwind_Context_t c, int i, uintptr_t n);
+extern void _Unwind_SetIP(_Unwind_Context_t, uintptr_t new_value);
+extern uintptr_t _Unwind_GetIP(_Unwind_Context_t context);
+extern uintptr_t _Unwind_GetRegionStart(_Unwind_Context_t context);
+
+
+//
+// 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 = *((uintptr_t*)p);
+ p += sizeof(uintptr_t);
+ break;
+ case DW_EH_PE_uleb128:
+ result = readULEB128(&p);
+ break;
+ case DW_EH_PE_udata2:
+ result = *((uint16_t*)p);
+ p += sizeof(uint16_t);
+ break;
+ case DW_EH_PE_udata4:
+ result = *((uint32_t*)p);
+ p += sizeof(uint32_t);
+ break;
+ case DW_EH_PE_udata8:
+ result = *((uint64_t*)p);
+ p += sizeof(uint64_t);
+ break;
+ case DW_EH_PE_sdata2:
+ result = *((int16_t*)p);
+ p += sizeof(int16_t);
+ break;
+ case DW_EH_PE_sdata4:
+ result = *((int32_t*)p);
+ p += sizeof(int32_t);
+ break;
+ case DW_EH_PE_sdata8:
+ result = *((int64_t*)p);
+ p += sizeof(int64_t);
+ break;
+ case DW_EH_PE_sleb128:
+ default:
+ // not supported
+ 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
+ abort();
+ break;
+ }
+
+ // then apply indirection
+ if (encoding & DW_EH_PE_indirect) {
+ result = *((uintptr_t*)result);
+ }
+
+ *data = p;
+ return result;
+}
+
+
+//
+// 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.
+//
+_Unwind_Reason_Code __gcc_personality_v0(int version, _Unwind_Action actions,
+ uint64_t exceptionClass, struct _Unwind_Exception* exceptionObject,
+ _Unwind_Context_t context)
+{
+ // 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.
+ const uint8_t* lsda = _Unwind_GetLanguageSpecificData(context);
+ if ( lsda == NULL )
+ return _URC_CONTINUE_UNWIND;
+
+ uintptr_t pc = _Unwind_GetIP(context)-1;
+ uintptr_t funcStart = _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 _URC_CONTINUE_UNWIND;
+}
+