aboutsummaryrefslogtreecommitdiffstats
path: root/src/UnwindLevel1-gcc-ext.c
diff options
context:
space:
mode:
authorEd Maste <emaste@FreeBSD.org>2015-09-23 19:02:06 +0000
committerEd Maste <emaste@FreeBSD.org>2015-09-23 19:02:06 +0000
commitdc24fbd60e4b3f6e03821d47536d759368ce57c8 (patch)
treea7c1aff5f903a0230569106cb36189a46db54032 /src/UnwindLevel1-gcc-ext.c
downloadsrc-dc24fbd60e4b3f6e03821d47536d759368ce57c8.tar.gz
src-dc24fbd60e4b3f6e03821d47536d759368ce57c8.zip
Import LLVM libunwind snapshot revision 246528vendor/llvm-libunwind/libunwind-r246528
Notes
Notes: svn path=/vendor/llvm-libunwind/dist/; revision=288149 svn path=/vendor/llvm-libunwind/libunwind-r246528/; revision=288150; tag=vendor/llvm-libunwind/libunwind-r246528
Diffstat (limited to 'src/UnwindLevel1-gcc-ext.c')
-rw-r--r--src/UnwindLevel1-gcc-ext.c316
1 files changed, 316 insertions, 0 deletions
diff --git a/src/UnwindLevel1-gcc-ext.c b/src/UnwindLevel1-gcc-ext.c
new file mode 100644
index 000000000000..28ba0928121f
--- /dev/null
+++ b/src/UnwindLevel1-gcc-ext.c
@@ -0,0 +1,316 @@
+//===--------------------- UnwindLevel1-gcc-ext.c -------------------------===//
+//
+// 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.
+//
+//
+// Implements gcc extensions to the C++ ABI Exception Handling Level 1.
+//
+//===----------------------------------------------------------------------===//
+
+#include <inttypes.h>
+#include <stdbool.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "config.h"
+#include "libunwind_ext.h"
+#include "libunwind.h"
+#include "Unwind-EHABI.h"
+#include "unwind.h"
+
+#if _LIBUNWIND_BUILD_ZERO_COST_APIS
+
+/// Called by __cxa_rethrow().
+_LIBUNWIND_EXPORT _Unwind_Reason_Code
+_Unwind_Resume_or_Rethrow(_Unwind_Exception *exception_object) {
+#if _LIBUNWIND_ARM_EHABI
+ _LIBUNWIND_TRACE_API("_Unwind_Resume_or_Rethrow(ex_obj=%p), private_1=%ld\n",
+ (void *)exception_object,
+ (long)exception_object->unwinder_cache.reserved1);
+#else
+ _LIBUNWIND_TRACE_API("_Unwind_Resume_or_Rethrow(ex_obj=%p), private_1=%ld\n",
+ (void *)exception_object,
+ (long)exception_object->private_1);
+#endif
+
+#if _LIBUNWIND_ARM_EHABI
+ // _Unwind_RaiseException on EHABI will always set the reserved1 field to 0,
+ // which is in the same position as private_1 below.
+ return _Unwind_RaiseException(exception_object);
+#else
+ // If this is non-forced and a stopping place was found, then this is a
+ // re-throw.
+ // Call _Unwind_RaiseException() as if this was a new exception
+ if (exception_object->private_1 == 0) {
+ return _Unwind_RaiseException(exception_object);
+ // Will return if there is no catch clause, so that __cxa_rethrow can call
+ // std::terminate().
+ }
+
+ // Call through to _Unwind_Resume() which distiguishes between forced and
+ // regular exceptions.
+ _Unwind_Resume(exception_object);
+ _LIBUNWIND_ABORT("_Unwind_Resume_or_Rethrow() called _Unwind_RaiseException()"
+ " which unexpectedly returned");
+#endif
+}
+
+
+/// Called by personality handler during phase 2 to get base address for data
+/// relative encodings.
+_LIBUNWIND_EXPORT uintptr_t
+_Unwind_GetDataRelBase(struct _Unwind_Context *context) {
+ (void)context;
+ _LIBUNWIND_TRACE_API("_Unwind_GetDataRelBase(context=%p)\n", (void *)context);
+ _LIBUNWIND_ABORT("_Unwind_GetDataRelBase() not implemented");
+}
+
+
+/// Called by personality handler during phase 2 to get base address for text
+/// relative encodings.
+_LIBUNWIND_EXPORT uintptr_t
+_Unwind_GetTextRelBase(struct _Unwind_Context *context) {
+ (void)context;
+ _LIBUNWIND_TRACE_API("_Unwind_GetTextRelBase(context=%p)\n", (void *)context);
+ _LIBUNWIND_ABORT("_Unwind_GetTextRelBase() not implemented");
+}
+
+
+/// Scans unwind information to find the function that contains the
+/// specified code address "pc".
+_LIBUNWIND_EXPORT void *_Unwind_FindEnclosingFunction(void *pc) {
+ _LIBUNWIND_TRACE_API("_Unwind_FindEnclosingFunction(pc=%p)\n", pc);
+ // This is slow, but works.
+ // We create an unwind cursor then alter the IP to be pc
+ unw_cursor_t cursor;
+ unw_context_t uc;
+ unw_proc_info_t info;
+ unw_getcontext(&uc);
+ unw_init_local(&cursor, &uc);
+ unw_set_reg(&cursor, UNW_REG_IP, (unw_word_t)(long) pc);
+ if (unw_get_proc_info(&cursor, &info) == UNW_ESUCCESS)
+ return (void *)(long) info.start_ip;
+ else
+ return NULL;
+}
+
+/// Walk every frame and call trace function at each one. If trace function
+/// returns anything other than _URC_NO_REASON, then walk is terminated.
+_LIBUNWIND_EXPORT _Unwind_Reason_Code
+_Unwind_Backtrace(_Unwind_Trace_Fn callback, void *ref) {
+ unw_cursor_t cursor;
+ unw_context_t uc;
+ unw_getcontext(&uc);
+ unw_init_local(&cursor, &uc);
+
+ _LIBUNWIND_TRACE_API("_Unwind_Backtrace(callback=%p)\n",
+ (void *)(uintptr_t)callback);
+
+#if _LIBUNWIND_ARM_EHABI
+ // Create a mock exception object for force unwinding.
+ _Unwind_Exception ex;
+ memset(&ex, '\0', sizeof(ex));
+ ex.exception_class = 0x434C4E47554E5700; // CLNGUNW\0
+#endif
+
+ // walk each frame
+ while (true) {
+ _Unwind_Reason_Code result;
+
+#if !_LIBUNWIND_ARM_EHABI
+ // ask libuwind to get next frame (skip over first frame which is
+ // _Unwind_Backtrace())
+ if (unw_step(&cursor) <= 0) {
+ _LIBUNWIND_TRACE_UNWINDING(" _backtrace: ended because cursor reached "
+ "bottom of stack, returning %d\n",
+ _URC_END_OF_STACK);
+ return _URC_END_OF_STACK;
+ }
+#else
+ // Get the information for this frame.
+ unw_proc_info_t frameInfo;
+ if (unw_get_proc_info(&cursor, &frameInfo) != UNW_ESUCCESS) {
+ return _URC_END_OF_STACK;
+ }
+
+ // Update the pr_cache in the mock exception object.
+ const uint32_t* unwindInfo = (uint32_t *) frameInfo.unwind_info;
+ ex.pr_cache.fnstart = frameInfo.start_ip;
+ ex.pr_cache.ehtp = (_Unwind_EHT_Header *) unwindInfo;
+ ex.pr_cache.additional= frameInfo.flags;
+
+ struct _Unwind_Context *context = (struct _Unwind_Context *)&cursor;
+ // Get and call the personality function to unwind the frame.
+ __personality_routine handler = (__personality_routine) frameInfo.handler;
+ if (handler == NULL) {
+ return _URC_END_OF_STACK;
+ }
+ if (handler(_US_VIRTUAL_UNWIND_FRAME | _US_FORCE_UNWIND, &ex, context) !=
+ _URC_CONTINUE_UNWIND) {
+ return _URC_END_OF_STACK;
+ }
+#endif // _LIBUNWIND_ARM_EHABI
+
+ // debugging
+ if (_LIBUNWIND_TRACING_UNWINDING) {
+ char functionName[512];
+ unw_proc_info_t frame;
+ unw_word_t offset;
+ unw_get_proc_name(&cursor, functionName, 512, &offset);
+ unw_get_proc_info(&cursor, &frame);
+ _LIBUNWIND_TRACE_UNWINDING(
+ " _backtrace: start_ip=0x%llX, func=%s, lsda=0x%llX, context=%p\n",
+ (long long)frame.start_ip, functionName, (long long)frame.lsda,
+ (void *)&cursor);
+ }
+
+ // call trace function with this frame
+ result = (*callback)((struct _Unwind_Context *)(&cursor), ref);
+ if (result != _URC_NO_REASON) {
+ _LIBUNWIND_TRACE_UNWINDING(
+ " _backtrace: ended because callback returned %d\n", result);
+ return result;
+ }
+ }
+}
+
+
+/// Find dwarf unwind info for an address 'pc' in some function.
+_LIBUNWIND_EXPORT const void *_Unwind_Find_FDE(const void *pc,
+ struct dwarf_eh_bases *bases) {
+ // This is slow, but works.
+ // We create an unwind cursor then alter the IP to be pc
+ unw_cursor_t cursor;
+ unw_context_t uc;
+ unw_proc_info_t info;
+ unw_getcontext(&uc);
+ unw_init_local(&cursor, &uc);
+ unw_set_reg(&cursor, UNW_REG_IP, (unw_word_t)(long) pc);
+ unw_get_proc_info(&cursor, &info);
+ bases->tbase = (uintptr_t)info.extra;
+ bases->dbase = 0; // dbase not used on Mac OS X
+ bases->func = (uintptr_t)info.start_ip;
+ _LIBUNWIND_TRACE_API("_Unwind_Find_FDE(pc=%p) => %p\n", pc,
+ (void *)(long) info.unwind_info);
+ return (void *)(long) info.unwind_info;
+}
+
+/// Returns the CFA (call frame area, or stack pointer at start of function)
+/// for the current context.
+_LIBUNWIND_EXPORT uintptr_t _Unwind_GetCFA(struct _Unwind_Context *context) {
+ unw_cursor_t *cursor = (unw_cursor_t *)context;
+ unw_word_t result;
+ unw_get_reg(cursor, UNW_REG_SP, &result);
+ _LIBUNWIND_TRACE_API("_Unwind_GetCFA(context=%p) => 0x%" PRIx64 "\n",
+ (void *)context, (uint64_t)result);
+ return (uintptr_t)result;
+}
+
+
+/// Called by personality handler during phase 2 to get instruction pointer.
+/// ipBefore is a boolean that says if IP is already adjusted to be the call
+/// site address. Normally IP is the return address.
+_LIBUNWIND_EXPORT uintptr_t _Unwind_GetIPInfo(struct _Unwind_Context *context,
+ int *ipBefore) {
+ _LIBUNWIND_TRACE_API("_Unwind_GetIPInfo(context=%p)\n", (void *)context);
+ *ipBefore = 0;
+ return _Unwind_GetIP(context);
+}
+
+#if _LIBUNWIND_SUPPORT_DWARF_UNWIND
+
+/// Called by programs with dynamic code generators that want
+/// to register a dynamically generated FDE.
+/// This function has existed on Mac OS X since 10.4, but
+/// was broken until 10.6.
+_LIBUNWIND_EXPORT void __register_frame(const void *fde) {
+ _LIBUNWIND_TRACE_API("__register_frame(%p)\n", fde);
+ _unw_add_dynamic_fde((unw_word_t)(uintptr_t) fde);
+}
+
+
+/// Called by programs with dynamic code generators that want
+/// to unregister a dynamically generated FDE.
+/// This function has existed on Mac OS X since 10.4, but
+/// was broken until 10.6.
+_LIBUNWIND_EXPORT void __deregister_frame(const void *fde) {
+ _LIBUNWIND_TRACE_API("__deregister_frame(%p)\n", fde);
+ _unw_remove_dynamic_fde((unw_word_t)(uintptr_t) fde);
+}
+
+
+// The following register/deregister functions are gcc extensions.
+// They have existed on Mac OS X, but have never worked because Mac OS X
+// before 10.6 used keymgr to track known FDEs, but these functions
+// never got updated to use keymgr.
+// For now, we implement these as do-nothing functions to keep any existing
+// applications working. We also add the not in 10.6 symbol so that nwe
+// application won't be able to use them.
+
+#if _LIBUNWIND_SUPPORT_FRAME_APIS
+_LIBUNWIND_EXPORT void __register_frame_info_bases(const void *fde, void *ob,
+ void *tb, void *db) {
+ (void)fde;
+ (void)ob;
+ (void)tb;
+ (void)db;
+ _LIBUNWIND_TRACE_API("__register_frame_info_bases(%p,%p, %p, %p)\n",
+ fde, ob, tb, db);
+ // do nothing, this function never worked in Mac OS X
+}
+
+_LIBUNWIND_EXPORT void __register_frame_info(const void *fde, void *ob) {
+ (void)fde;
+ (void)ob;
+ _LIBUNWIND_TRACE_API("__register_frame_info(%p, %p)\n", fde, ob);
+ // do nothing, this function never worked in Mac OS X
+}
+
+_LIBUNWIND_EXPORT void __register_frame_info_table_bases(const void *fde,
+ void *ob, void *tb,
+ void *db) {
+ (void)fde;
+ (void)ob;
+ (void)tb;
+ (void)db;
+ _LIBUNWIND_TRACE_API("__register_frame_info_table_bases"
+ "(%p,%p, %p, %p)\n", fde, ob, tb, db);
+ // do nothing, this function never worked in Mac OS X
+}
+
+_LIBUNWIND_EXPORT void __register_frame_info_table(const void *fde, void *ob) {
+ (void)fde;
+ (void)ob;
+ _LIBUNWIND_TRACE_API("__register_frame_info_table(%p, %p)\n", fde, ob);
+ // do nothing, this function never worked in Mac OS X
+}
+
+_LIBUNWIND_EXPORT void __register_frame_table(const void *fde) {
+ (void)fde;
+ _LIBUNWIND_TRACE_API("__register_frame_table(%p)\n", fde);
+ // do nothing, this function never worked in Mac OS X
+}
+
+_LIBUNWIND_EXPORT void *__deregister_frame_info(const void *fde) {
+ (void)fde;
+ _LIBUNWIND_TRACE_API("__deregister_frame_info(%p)\n", fde);
+ // do nothing, this function never worked in Mac OS X
+ return NULL;
+}
+
+_LIBUNWIND_EXPORT void *__deregister_frame_info_bases(const void *fde) {
+ (void)fde;
+ _LIBUNWIND_TRACE_API("__deregister_frame_info_bases(%p)\n", fde);
+ // do nothing, this function never worked in Mac OS X
+ return NULL;
+}
+#endif // _LIBUNWIND_SUPPORT_FRAME_APIS
+
+#endif // _LIBUNWIND_SUPPORT_DWARF_UNWIND
+
+#endif // _LIBUNWIND_BUILD_ZERO_COST_APIS