commit 4ec93a7ee518b559261c068558373ff7e1a2ee0b
author Christopher Ferris <cferris@google.com> Thu Jul 18 14:11:07 2019 -0700
committer Christopher Ferris <cferris@google.com> Thu Jul 18 17:57:04 2019 -0700
tree a138b6bcc55c3bbaadf94bad786fe29c011512f4
parent 45a1c998d1602219756c52e2de2d0ffa0f953a63

Move to the libc++ demangler.

Bug: 136138882

Test: Unit tests pass.
Test: Did a kill -3 on a zygote process to verify art demangles properly.
Change-Id: Iaf4fab191e84871be906b39cc32dd7c97c5d385a

libbacktrace/Android.bp

diff --git a/libbacktrace/Android.bp b/libbacktrace/Android.bp
index 9ece847..565f2c3 100644
--- a/libbacktrace/Android.bp
+++ b/libbacktrace/Android.bp
@@ -97,7 +97,6 @@
             cflags: ["-DNO_LIBDEXFILE_SUPPORT"],
         },
     },
-    whole_static_libs: ["libdemangle"],
 }
 
 cc_test_library {

libbacktrace/Backtrace.cpp

diff --git a/libbacktrace/Backtrace.cpp b/libbacktrace/Backtrace.cpp
index 71980d7..3e050ab 100644
--- a/libbacktrace/Backtrace.cpp
+++ b/libbacktrace/Backtrace.cpp
@@ -28,13 +28,13 @@
 #include <backtrace/Backtrace.h>
 #include <backtrace/BacktraceMap.h>
 
-#include <demangle.h>
-
 #include "BacktraceLog.h"
 #include "UnwindStack.h"
 
 using android::base::StringPrintf;
 
+extern "C" char* __cxa_demangle(const char*, char*, size_t*, int*);
+
 //-------------------------------------------------------------------------
 // Backtrace functions.
 //-------------------------------------------------------------------------
@@ -63,7 +63,14 @@
   if (map->start == 0 || (map->flags & PROT_DEVICE_MAP)) {
     return "";
   }
-  return demangle(GetFunctionNameRaw(pc, offset).c_str());
+  std::string name(GetFunctionNameRaw(pc, offset));
+  char* demangled_name = __cxa_demangle(name.c_str(), nullptr, nullptr, nullptr);
+  if (demangled_name != nullptr) {
+    name = demangled_name;
+    free(demangled_name);
+    return name;
+  }
+  return name;
 }
 
 bool Backtrace::VerifyReadWordArgs(uint64_t ptr, word_t* out_value) {

libbacktrace/UnwindStack.cpp

diff --git a/libbacktrace/UnwindStack.cpp b/libbacktrace/UnwindStack.cpp
index a128623..624711f 100644
--- a/libbacktrace/UnwindStack.cpp
+++ b/libbacktrace/UnwindStack.cpp
@@ -24,7 +24,6 @@
 #include <string>
 
 #include <backtrace/Backtrace.h>
-#include <demangle.h>
 #include <unwindstack/Elf.h>
 #include <unwindstack/MapInfo.h>
 #include <unwindstack/Maps.h>
@@ -41,6 +40,8 @@
 #include "UnwindStack.h"
 #include "UnwindStackMap.h"
 
+extern "C" char* __cxa_demangle(const char*, char*, size_t*, int*);
+
 bool Backtrace::Unwind(unwindstack::Regs* regs, BacktraceMap* back_map,
                        std::vector<backtrace_frame_data_t>* frames, size_t num_ignore_frames,
                        std::vector<std::string>* skip_names, BacktraceUnwindError* error) {
@@ -115,7 +116,13 @@
     back_frame->pc = frame->pc;
     back_frame->sp = frame->sp;
 
-    back_frame->func_name = demangle(frame->function_name.c_str());
+    char* demangled_name = __cxa_demangle(frame->function_name.c_str(), nullptr, nullptr, nullptr);
+    if (demangled_name != nullptr) {
+      back_frame->func_name = demangled_name;
+      free(demangled_name);
+    } else {
+      back_frame->func_name = frame->function_name;
+    }
     back_frame->func_offset = frame->function_offset;
 
     back_frame->map.name = frame->map_name;