From 8ad7a05bb43c45845107e1c1ba2ebf08848dbe05 Mon Sep 17 00:00:00 2001
From: Alexey Samsonov <samsonov@google.com>
Date: Wed, 5 Mar 2014 15:00:36 +0000
Subject: [PATCH] Improve llvm-symbolizer discovery in asan_symbolize.py

llvm-svn: 202982
---
 .../lib/asan/scripts/asan_symbolize.py        | 41 +++++++++++--------
 .../TestCases/asan-symbolize-sanity-test.cc   |  2 +-
 2 files changed, 25 insertions(+), 18 deletions(-)

diff --git a/compiler-rt/lib/asan/scripts/asan_symbolize.py b/compiler-rt/lib/asan/scripts/asan_symbolize.py
index a398fcf10361..49bc1c02cb8a 100755
--- a/compiler-rt/lib/asan/scripts/asan_symbolize.py
+++ b/compiler-rt/lib/asan/scripts/asan_symbolize.py
@@ -16,7 +16,6 @@ import subprocess
 import sys
 import termios
 
-llvm_symbolizer = None
 symbolizers = {}
 DEBUG = False
 demangle = False;
@@ -30,6 +29,12 @@ def fix_filename(file_name):
   file_name = re.sub('.*crtstuff.c:0', '???:0', file_name)
   return file_name
 
+def GuessArch(addr):
+  # Guess which arch we're running. 10 = len('0x') + 8 hex digits.
+  if len(addr) > 10:
+    return 'x86_64'
+  else:
+    return 'i386'
 
 class Symbolizer(object):
   def __init__(self):
@@ -52,23 +57,27 @@ class Symbolizer(object):
 
 
 class LLVMSymbolizer(Symbolizer):
-  def __init__(self, symbolizer_path):
+  def __init__(self, symbolizer_path, addr):
     super(LLVMSymbolizer, self).__init__()
     self.symbolizer_path = symbolizer_path
+    self.default_arch = GuessArch(addr)
     self.pipe = self.open_llvm_symbolizer()
 
   def open_llvm_symbolizer(self):
-    if not os.path.exists(self.symbolizer_path):
-      return None
     cmd = [self.symbolizer_path,
            '--use-symbol-table=true',
            '--demangle=%s' % demangle,
            '--functions=true',
-           '--inlining=true']
+           '--inlining=true',
+           '--default-arch=%s' % self.default_arch]
     if DEBUG:
       print ' '.join(cmd)
-    return subprocess.Popen(cmd, stdin=subprocess.PIPE,
-                            stdout=subprocess.PIPE)
+    try:
+      result = subprocess.Popen(cmd, stdin=subprocess.PIPE,
+                                stdout=subprocess.PIPE)
+    except OSError:
+      result = None
+    return result
 
   def symbolize(self, addr, binary, offset):
     """Overrides Symbolizer.symbolize."""
@@ -98,14 +107,14 @@ class LLVMSymbolizer(Symbolizer):
     return result
 
 
-def LLVMSymbolizerFactory(system):
+def LLVMSymbolizerFactory(system, addr):
   symbolizer_path = os.getenv('LLVM_SYMBOLIZER_PATH')
   if not symbolizer_path:
     symbolizer_path = os.getenv('ASAN_SYMBOLIZER_PATH')
     if not symbolizer_path:
       # Assume llvm-symbolizer is in PATH.
       symbolizer_path = 'llvm-symbolizer'
-  return LLVMSymbolizer(symbolizer_path)
+  return LLVMSymbolizer(symbolizer_path, addr)
 
 
 class Addr2LineSymbolizer(Symbolizer):
@@ -173,11 +182,7 @@ class DarwinSymbolizer(Symbolizer):
   def __init__(self, addr, binary):
     super(DarwinSymbolizer, self).__init__()
     self.binary = binary
-    # Guess which arch we're running. 10 = len('0x') + 8 hex digits.
-    if len(addr) > 10:
-      self.arch = 'x86_64'
-    else:
-      self.arch = 'i386'
+    self.arch = GuessArch(addr)
     self.open_atos()
 
   def open_atos(self):
@@ -323,12 +328,14 @@ class SymbolizationLoop(object):
     # E.g. in Chrome several binaries may share a single .dSYM.
     self.binary_name_filter = binary_name_filter
     self.system = os.uname()[0]
-    if self.system in ['Linux', 'Darwin']:
-      self.llvm_symbolizer = LLVMSymbolizerFactory(self.system)
-    else:
+    if self.system not in ['Linux', 'Darwin']:
       raise Exception('Unknown system')
+    self.llvm_symbolizer = None
 
   def symbolize_address(self, addr, binary, offset):
+    # Initialize llvm-symbolizer lazily.
+    if not self.llvm_symbolizer:
+      self.llvm_symbolizer = LLVMSymbolizerFactory(self.system, addr)
     # Use the chain of symbolizers:
     # Breakpad symbolizer -> LLVM symbolizer -> addr2line/atos
     # (fall back to next symbolizer if the previous one fails).
diff --git a/compiler-rt/test/asan/TestCases/asan-symbolize-sanity-test.cc b/compiler-rt/test/asan/TestCases/asan-symbolize-sanity-test.cc
index 991dcec97a10..c61850f5d707 100644
--- a/compiler-rt/test/asan/TestCases/asan-symbolize-sanity-test.cc
+++ b/compiler-rt/test/asan/TestCases/asan-symbolize-sanity-test.cc
@@ -3,7 +3,7 @@
 
 // RUN: %clangxx_asan -O0 %p/SharedLibs/shared-lib-test-so.cc -fPIC -shared -o %t-so.so
 // RUN: %clangxx_asan -O0 %s -o %t
-// RUN: ASAN_SYMBOLIZER_PATH= not %t 2>&1 | %asan_symbolize | FileCheck %s
+// RUN: ASAN_OPTIONS=symbolize=0 not %t 2>&1 | %asan_symbolize | FileCheck %s
 #include <dlfcn.h>
 #include <stdio.h>
 #include <stdlib.h>