Suppress repetitive errors for libs not available in stack tool

tools/python/llvm_symbolizer.py generates error logs, which when
called from the stack symbolization scripts can produce a lot of
unhelpful logs, notably the error logged when the |lib| parameter
of |GetSymbolInformation| is not valid:
"Can't run llvm-symbolizer! Given binary is not a valid target. path=%s"
See for instance these logs:
https://chromium-swarm.appspot.com/task?id=61a979f2cac67b10&w=true

This intents to silence most of those errors, especially for the test
bots, by updating the stack tool:
third_party/android_platform/development/scripts/stack et al.
This prevent calls to |GetSymbolInformation| if:
  - the library is not a .so file
  - the library is not a valid file
Logs are produced only if the script is run in verbose mode.

Bug: 1340999
Change-Id: I36e21e6f0567809297e83002722743dda30288f3
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4444157
Reviewed-by: Andrew Grieve <agrieve@chromium.org>
Commit-Queue: Pâris Meuleman <pmeuleman@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1139389}

third_party/android_platform/development/scripts/stack_core.py

@@ -31,9 +31,6 @@ import symbol
 
 from pylib import constants
 
-UNKNOWN = '<unknown>'
-HEAP = '[heap]'
-STACK = '[stack]'
 _DEFAULT_JOBS=8
 _CHUNK_SIZE = 1000
 
@@ -456,7 +453,6 @@ def ResolveCrashSymbol(lines, more_info, llvm_symbolizer):
       frame, code_addr, area, _, symbol_name = match.group(
           'frame', 'address', 'lib', 'symbol_present', 'symbol_name')
       frame = int(frame)
-      logging.debug('Found trace line: %s' % line.strip())
 
       if frame <= last_frame and (trace_lines or value_lines):
         java_lines = []
@@ -469,45 +465,67 @@ def ResolveCrashSymbol(lines, more_info, llvm_symbolizer):
         pid = -1
       last_frame = frame
 
-      if area in (UNKNOWN, HEAP, STACK):
-        trace_lines.append((code_addr, '', area))
+      if not symbol_name:
+        symbol_name = ''
+
+      if not area.endswith('.so'):
+        logging.debug('Library is not a .so file. path=%s', area)
+        trace_lines.append((code_addr, symbol_name, area))
       else:
-        logging.debug('Identified lib: %s' % area)
+        logging.debug('Identified lib: %s', area)
         # If a calls b which further calls c and c is inlined to b, we want to
         # display "a -> b -> c" in the stack trace instead of just "a -> c"
         library = os.path.join(symbol.SYMBOLS_DIR,
                                symbol.TranslateLibPath(area))
-        info = llvm_symbolizer.GetSymbolInformation(library, int(code_addr,16))
-        logging.debug('symbol information: %s' % info)
-        nest_count = len(info) - 1
-        for source_symbol, source_location in info:
-          if nest_count > 0:
-            nest_count = nest_count - 1
-            trace_lines.append(('v------>', source_symbol, source_location))
-          elif '<UNKNOWN>' in source_symbol and symbol_name:
-            # If the symbolizer couldn't find a symbol name, but the trace had
-            # one, use what the trace had.
-            trace_lines.append((code_addr, symbol_name, source_location))
-          else:
-            trace_lines.append((code_addr,
-                                source_symbol,
-                                source_location))
+        if not llvm_symbolizer.IsValidTarget(library):
+          # The library was not found in SYMBOLS_DIR, it is probably a system
+          # library.
+          logging.debug('Library is not a valid target. path=%s', library)
+          trace_lines.append((code_addr, symbol_name, area))
+        else:
+          info = llvm_symbolizer.GetSymbolInformation(library,
+                                                      int(code_addr,16))
+          logging.debug('symbol information: %s', info)
+          nest_count = len(info) - 1
+          for source_symbol, source_location in info:
+            if nest_count > 0:
+              nest_count = nest_count - 1
+              trace_lines.append(('v------>', source_symbol, source_location))
+            elif '<UNKNOWN>' in source_symbol and symbol_name:
+              # If the symbolizer couldn't find a symbol name, but the trace had
+              # one, use what the trace had.
+              trace_lines.append((code_addr, symbol_name, source_location))
+            else:
+              trace_lines.append((code_addr,
+                                  source_symbol,
+                                  source_location))
 
     match = _VALUE_LINE.match(line)
     if match:
+      logging.debug('Found value line: %s', line.strip())
       (_, addr, value, area, _, symbol_name) = match.groups()
-      if area == UNKNOWN or area == HEAP or area == STACK or not area:
-        value_lines.append((addr, value, '', area))
+      if not symbol_name:
+        symbol_name = ''
+      if not area.endswith('.so'):
+        logging.debug('Library is not a .so file. path=%s', area)
+        value_lines.append((addr, value, symbol_name, area))
       else:
         library = os.path.join(symbol.SYMBOLS_DIR,
                                symbol.TranslateLibPath(area))
-        info = llvm_symbolizer.GetSymbolInformation(library, int(value,16))
-        source_symbol, source_location = info.pop()
+        if not llvm_symbolizer.IsValidTarget(library):
+          # The library was not found in SYMBOLS_DIR, it is probably a system
+          # library.
+          logging.debug('Library is not a valid target. path=%s', library)
+          value_lines.append((addr, value, symbol_name, area))
+        else:
+          info = llvm_symbolizer.GetSymbolInformation(library, int(value,16))
+          logging.debug('symbol information: %s', info)
+          source_symbol, source_location = info.pop()
 
-        value_lines.append((addr,
-                            value,
-                            source_symbol,
-                            source_location))
+          value_lines.append((addr,
+                              value,
+                              source_symbol,
+                              source_location))
 
   java_lines = []
   if pid != -1 and pid in java_stderr_by_pid:
@@ -572,7 +590,7 @@ def _GetSharedLibraryInHost(soname, sosize, dirs):
       continue
     if os.path.getsize(host_so_file) != sosize:
       continue
-    logging.debug("%s match to the one in APK" % host_so_file)
+    logging.debug("%s match to the one in APK", host_so_file)
     return host_so_file
 
 

third_party/android_platform/development/scripts/stack_test.py

@@ -80,6 +80,10 @@ class FakeSymbolizer:
     method_name = '{}::Func_{:X}'.format(namespace, address)
     return [(method_name, '{}.cc:1:1'.format(namespace))]
 
+  @staticmethod
+  def IsValidTarget(path):
+    # pylint: disable=unused-argument
+    return True
 
 class StackDecodeTest(unittest.TestCase):
   def setUp(self):

tools/python/llvm_symbolizer.py

@@ -2,6 +2,7 @@
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
+import functools
 import logging
 import os
 import subprocess
@@ -16,7 +17,7 @@ _UNKNOWN = '<UNKNOWN>'
 
 _ELF_MAGIC_HEADER_BYTES = b'\x7f\x45\x4c\x46'
 
-
+@functools.lru_cache
 def IsValidLLVMSymbolizerTarget(file_path):
   """ Verify the passed file is a valid target for llvm-symbolization
 
@@ -127,3 +128,7 @@ class LLVMSymbolizer(object):
           result.append((line[:-1], line_numbers[:-1]))
         else:
           return result
+
+  @staticmethod
+  def IsValidTarget(path):
+    return IsValidLLVMSymbolizerTarget(path)