Add experimental support for compiling with clang and ASan on Linux.

build/standalone.gypi

Index: build/standalone.gypi
diff --git a/build/standalone.gypi b/build/standalone.gypi
index c0eaef419df30e2ff6538aed44e0940d87aa128d..d012e7501344b466dce769fa9aa5fb74d8b1792e 100644
--- a/build/standalone.gypi
+++ b/build/standalone.gypi
@@ -8,6 +8,8 @@
   'variables': {
     'component%': 'static_library',
     'clang%': 0,
+    'asan%': 0,
+    'sanitizer_coverage%': 0,
     'msvs_multi_core_compile%': '1',
     'variables': {
       'variables': {
@@ -36,7 +38,9 @@
       },
       'host_arch%': '<(host_arch)',
       'target_arch%': '<(target_arch)',
+      'base_dir%': '<!(cd <(DEPTH) && python -c "import os; print os.getcwd()")',

[Nico, 2015/10/15 23:41:22]

I don't think you need this…build/common.gypi doesn't have it.

[Oliver Chang, 2015/10/16 00:52:15]

Ah, I based this off v8's standalone.gypi, but I guess that's not needed here.

     },
+    'clang_dir%': '<(base_dir)/third_party/llvm-build/Release+Asserts',

[Nico, 2015/10/15 23:41:22]

try removing the <(base_dir)/ prefix here

[Oliver Chang, 2015/10/16 00:52:15]

Done.

     # These two are needed by V8.
     'host_arch%': '<(host_arch)',
     'target_arch%': '<(target_arch)',
@@ -161,6 +165,22 @@
     'ldflags': [
       '-pthread',
     ],
+    'conditions': [
+      ['asan==1', {
+        'cflags': [
+          '-fsanitize=address',
+          '-gline-tables-only',
+        ],
+        'ldflags': [
+          '-fsanitize=address',
+        ],
+      }],
+      ['sanitizer_coverage!=0', {
+        'cflags': [
+          '-fsanitize-coverage=<(sanitizer_coverage)',
+        ],
+      }],
+    ],
     'defines': [
       # Don't use deprecated V8 APIs anywhere.
       'V8_DEPRECATION_WARNINGS',
@@ -250,6 +270,16 @@
         '-fPIC',
       ],
     }],
+    ['OS=="linux"', {

[Nico, 2015/10/15 23:41:22]

don't you want this on mac too?

actually, shouldn't clang default to 1 on mac and linux (since it does in
chromium)? (question for thestig, i suppose)

[Lei Zhang, 2015/10/16 00:23:16]

I don't build on Mac much, but I suppose we should use (our) Clang on Mac too.

[Oliver Chang, 2015/10/16 00:52:15]

I don't have a Mac to test this on, but I guess it doesn't hurt to include Mac
in this.

I've gone ahead and set clang to 1 by default for mac and linux. Will setting
this break anything infrastructure-wise, Lei?

+      'conditions': [
+        ['clang==1', {
+          'make_global_settings': [
+            ['CC', '<(clang_dir)/bin/clang'],
+            ['CXX', '<(clang_dir)/bin/clang++'],
+          ],
+        }],
+      ],
+    }],  # OS=="linux"
     ['OS=="win"', {
       'target_defaults': {
         'defines': [