Add support for ASAN.

AMBuildScript

@@ -1,6 +1,7 @@
 # vim: set sts=2 ts=8 sw=2 tw=99 et ft=python:
 import collections
 import os, sys
+import subprocess
 import traceback
 
 class SDK(object):
@@ -121,7 +122,8 @@ class SMConfig(object):
     self.versionlib = None
     self.all_targets = []
     self.target_archs = set()
-
+    self.enable_asan = getattr(builder.options, 'enable_asan', False)
+    self.asan_libs = {}
 
     if builder.options.targets:
       target_archs = builder.options.targets.split(',')
@@ -349,6 +351,11 @@ class SMConfig(object):
         cxx.cxxflags += ['-Wno-deprecated']
       cxx.cflags += ['-Wno-sometimes-uninitialized']
 
+    if self.enable_asan:
+      if not have_clang:
+        raise Exception('--enable-asan only supported when using Clang')
+      self.configure_asan(cxx)
+
     # Work around SDK warnings.
     if cxx.version >= 'clang-10.0' or cxx.version >= 'apple-clang-12.0':
         cxx.cflags += [
@@ -361,12 +368,18 @@ class SMConfig(object):
       cxx.cflags += ['-Wno-maybe-uninitialized']
 
     if builder.options.opt == '1':
-      cxx.cflags += ['-O3']
+      if self.enable_asan:
+        cxx.cflags += ['-O1']
+      else:
+        cxx.cflags += ['-O3']
 
     # Don't omit the frame pointer.
     cxx.cflags += ['-fno-omit-frame-pointer']
 
   def configure_msvc(self, cxx):
+    if self.enable_asan:
+      raise Exception('--enable-asan only supported when using Clang')
+
     if builder.options.debug == '1':
       cxx.cflags += ['/MTd']
       cxx.linkflags += ['/NODEFAULTLIB:libcmt']
@@ -412,6 +425,29 @@ class SMConfig(object):
     # Don't omit the frame pointer.
     cxx.cflags += ['/Oy-']
 
+  def configure_asan(self, cxx):
+    if cxx.target.platform != 'linux':
+      raise Exception('--enable-asan only supported on Linux')
+    cxx.cflags += ['-fsanitize=address']
+    cxx.linkflags += ['-fsanitize=address']
+    if cxx.target.arch == 'x86':
+      libclang_rt = 'libclang_rt.asan-i386.so'
+    else:
+      libclang_rt = 'libclang_rt.asan-x86_64.so'
+
+    try:
+      argv = cxx.cxx_argv + ['--print-file-name', libclang_rt]
+      output = subprocess.check_output(argv)
+      output = output.decode('utf-8')
+      output = output.strip()
+    except:
+      raise Exception('Could not find {}'.format(libclang_rt))
+
+    print('ASAN library for {}: {}'.format(cxx.target.arch, output))
+    print('You will need to LD_PRELOAD this into srcds.')
+
+    self.asan_libs[cxx.target.arch] = os.path.dirname(output)
+
   def configure_linux(self, cxx):
     cxx.defines += ['_LINUX', 'POSIX', '_FILE_OFFSET_BITS=64']
     cxx.linkflags += ['-lm']
@@ -469,13 +505,22 @@ class SMConfig(object):
     self.AddVersioning(binary)
     if binary.compiler.like('msvc'):
       binary.compiler.linkflags += ['/SUBSYSTEM:WINDOWS']
+
+    # Dumb clang behavior means we have to manually find libclang_rt.
+    if self.enable_asan:
+      binary.compiler.linkflags += [
+        '-shared-libsan',
+        '-Wl,-rpath={}'.format(self.asan_libs[binary.compiler.target.arch]),
+      ]
     return binary
 
   def ProgramBuilder(self, compiler, name):
     binary = compiler.Program(name)
     self.AddVersioning(binary)
     if '-static-libgcc' in binary.compiler.linkflags:
       binary.compiler.linkflags.remove('-static-libgcc')
+    if self.enable_asan:
+      binary.compiler.linkflags.append('-static-libsan')
     if '-lgcc_eh' in binary.compiler.linkflags:
       binary.compiler.linkflags.remove('-lgcc_eh')
     if binary.compiler.like('gcc'):

configure.py

@@ -1,30 +1,30 @@
 # vim: set ts=2 sw=2 tw=99 noet:
 import sys
 try:
-	from ambuild2 import run, util
+  from ambuild2 import run, util
 except:
-	try:
-		import ambuild
-		sys.stderr.write('It looks like you have AMBuild 1 installed, but this project uses AMBuild 2.\n')
-		sys.stderr.write('Upgrade to the latest version of AMBuild to continue.\n')
-	except:
-		sys.stderr.write('AMBuild must be installed to build this project.\n')
-		sys.stderr.write('http://www.alliedmods.net/ambuild\n')
-	sys.exit(1)
+  try:
+    import ambuild
+    sys.stderr.write('It looks like you have AMBuild 1 installed, but this project uses AMBuild 2.\n')
+    sys.stderr.write('Upgrade to the latest version of AMBuild to continue.\n')
+  except:
+    sys.stderr.write('AMBuild must be installed to build this project.\n')
+    sys.stderr.write('http://www.alliedmods.net/ambuild\n')
+  sys.exit(1)
 
 # Hack to show a decent upgrade message, which wasn't done until 2.2.
 ambuild_version = getattr(run, 'CURRENT_API', '2.1')
 if ambuild_version.startswith('2.1'):
-	sys.stderr.write("AMBuild 2.2 or higher is required; please update\n")
-	sys.exit(1)
+  sys.stderr.write("AMBuild 2.2 or higher is required; please update\n")
+  sys.exit(1)
 
 parser = run.BuildParser(sourcePath=sys.path[0], api='2.2')
 parser.options.add_argument('--hl2sdk-root', type=str, dest='hl2sdk_root', default=None,
-		                   help='Root search folder for HL2SDKs')
+                       help='Root search folder for HL2SDKs')
 parser.options.add_argument('--mysql-path', type=str, dest='mysql_path', default=None,
-		                   help='Path to MySQL 5')
+                       help='Path to MySQL 5')
 parser.options.add_argument('--mysql64-path', type=str, dest='mysql64_path', default=None,
-		                   help='Path to 64-bit MySQL 5')
+                       help='Path to 64-bit MySQL 5')
 parser.options.add_argument('--mms-path', type=str, dest='mms_path', default=None,
                        help='Path to Metamod:Source')
 parser.options.add_argument('--enable-debug', action='store_const', const='1', dest='debug',
@@ -37,11 +37,13 @@
                        help='Build against specified SDKs; valid args are "none", "all", "present",'
                             ' or comma-delimited list of engine names')
 parser.options.add_argument('--breakpad-dump', action='store_true', dest='breakpad_dump',
-											 default=False, help='Dump and upload breakpad symbols')
+                       default=False, help='Dump and upload breakpad symbols')
 parser.options.add_argument('--disable-auto-versioning', action='store_true', dest='disable_auto_versioning',
                        default=False, help='Disable the auto versioning script')
 parser.options.add_argument('--targets', type=str, dest='targets', default=None,
-		                      help="Override the target architecture (use commas to separate multiple targets).")
+                          help="Override the target architecture (use commas to separate multiple targets).")
 parser.options.add_argument('--scripting-only', action='store_true', dest='scripting_only', default=False,
-		                      help="Only build and package the files required for scripting in SourcePawn.")
+                          help="Only build and package the files required for scripting in SourcePawn.")
+parser.options.add_argument('--enable-asan', action='store_true', dest='enable_asan',
+                            default=False, help='Enable ASAN (clang only)')
 parser.Configure()