GN: add extra_cflags et al.

Adding flags to the end of cc or cxx is pretty useful, but these always end up
on the command line before the GN generated flags, thus setting defaults that
GN will override.

For full flexibility we want to be able to add flags after the flags GN has
added, so that custom flags can override _it_.

I've updated the Fast bots with an example here: if we said cc="clang -O3 ...",
that '-O3' would be overriden later by the default Release-mode '-Os'.  By
putting it in extra_cflags, we get the last word: our '-O3' overrides the
default '-Os'.

Another good use case is a hypothetical Actually-Shippable-Release mode.  Our
Release mode bundles in tons of debug symbols via '-g'.  libskia.a is about 10x
larger than it needs to be when built that way, but it helps us debug the bot
failures immensely.  To build a libskia.{a,so} that you'd really ship, you can
now set extra_cflags="-g0" to override '-g'.  You could set '-march' flags there
too, '-fomit-frame-pointer', etc.

There are lots of flags that won't matter where they end up in the command line.
To keep everything simple I've put them in extra_cflags with the rest.  This means
the only time we change 'cc' or 'cxx' in our recipes is to prefix 'ccache'.

BUG=skia:
GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2241263003

Review-Url: https://codereview.chromium.org/2241263003

diff --git a/gn/BUILD.gn b/gn/BUILD.gn
index 1f7bd82bf2cf15cd8762c2b2bd501407b5911251..26e80f8dfc45f9e1ab6cfb95116d6967a8c58d5f 100644 (file)
--- a/gn/BUILD.gn
+++ b/gn/BUILD.gn
@@ -7,6 +7,10 @@ declare_args() {
   ar = "ar"
   cc = "cc"
   cxx = "c++"
+
+  extra_cflags = ""
+  extra_cflags_c = ""
+  extra_cflags_cc = ""
 }
 
 config("no_rtti") {
@@ -64,7 +68,7 @@ toolchain("gcc_like") {
 
   tool("cc") {
     depfile = "{{output}}.d"
-    command = "$cc -MMD -MF $depfile {{defines}} {{include_dirs}} {{cflags}} {{cflags_c}} -c {{source}} -o {{output}}"
+    command = "$cc -MMD -MF $depfile {{defines}} {{include_dirs}} {{cflags}} {{cflags_c}} $extra_cflags $extra_cflags_c -c {{source}} -o {{output}}"
     depsformat = "gcc"
     outputs = [
       "{{source_out_dir}}/{{target_output_name}}.{{source_name_part}}.o",
@@ -74,7 +78,7 @@ toolchain("gcc_like") {
 
   tool("cxx") {
     depfile = "{{output}}.d"
-    command = "$cxx -MMD -MF $depfile {{defines}} {{include_dirs}} {{cflags}} {{cflags_cc}} -c {{source}} -o {{output}}"
+    command = "$cxx -MMD -MF $depfile {{defines}} {{include_dirs}} {{cflags}} {{cflags_cc}} $extra_cflags $extra_cflags_cc -c {{source}} -o {{output}}"
     depsformat = "gcc"
     outputs = [
       "{{source_out_dir}}/{{target_output_name}}.{{source_name_part}}.o",

diff --git a/infra/bots/recipe_modules/flavor/gn_flavor.py b/infra/bots/recipe_modules/flavor/gn_flavor.py
index ef258965695f7e144dc728a583a90a7909662d4d..75c318f818335c16c32bb3ac0e7150100b18efdb 100644 (file)
--- a/infra/bots/recipe_modules/flavor/gn_flavor.py
+++ b/infra/bots/recipe_modules/flavor/gn_flavor.py
@@ -21,12 +21,8 @@ class GNFlavorUtils(default_flavor.DefaultFlavorUtils):
     configuration = self.m.vars.builder_cfg.get('configuration', '')
     extra_config  = self.m.vars.builder_cfg.get('extra_config',  '')
 
-    gn_args = []
-    if configuration != 'Debug':
-      gn_args.append('is_debug=false')
-
     cc, cxx = 'cc', 'c++'
-    cflags = []
+    extra_cflags = []
 
     if compiler == 'Clang':
       cc, cxx = 'clang', 'clang++'
@@ -38,19 +34,24 @@ class GNFlavorUtils(default_flavor.DefaultFlavorUtils):
       cc, cxx = '%s %s' % (ccache, cc), '%s %s' % (ccache, cxx)
       if compiler == 'Clang':
         # Stifle "argument unused during compilation: ..." warnings.
-        cflags.append('-Qunused-arguments')
+        extra_cflags.append('-Qunused-arguments')
 
     if extra_config == 'Fast':
-      cflags.extend(['-march=native', '-fomit-frame-pointer'])
+      extra_cflags.extend(['-march=native', '-fomit-frame-pointer', '-O3'])
     if extra_config.startswith('SK'):
-      cflags.append('-D' + extra_config)
+      extra_cflags.append('-D' + extra_config)
 
-    cflags = ' '.join(cflags)
-    gn_args += [ 'cc="%s %s"' % (cc, cflags), 'cxx="%s %s"' % (cxx, cflags) ]
+    quote = lambda x: '"%s"' % x
+    gn_args = ' '.join('%s=%s' % (k,v) for (k,v) in {
+        'cc': quote(cc),
+        'cxx': quote(cxx),
+        'extra_cflags': quote(' '.join(extra_cflags)),
+        'is_debug': 'true' if configuration == 'Debug' else 'false',
+    }.iteritems())
 
     run = lambda title, cmd: self.m.run(self.m.step, title, cmd=cmd,
                                         cwd=self.m.vars.skia_dir, **kwargs)
 
     run('fetch-gn', [self.m.vars.skia_dir.join('bin', 'fetch-gn')])
-    run('gn gen', ['gn', 'gen', self.out_dir, '--args=%s' % ' '.join(gn_args)])
+    run('gn gen', ['gn', 'gen', self.out_dir, '--args=' + gn_args])
     run('ninja', ['ninja', '-C', self.out_dir])

diff --git a/infra/bots/recipes/swarm_compile.expected/Build-Ubuntu-Clang-x86_64-Debug-GN.json b/infra/bots/recipes/swarm_compile.expected/Build-Ubuntu-Clang-x86_64-Debug-GN.json
index 40c9a2b21d3528d3abad7e2ff99526c72a28fce3..3e3ef0e0bdfa0f941ff33a2e76414ed96be51f74 100644 (file)
--- a/infra/bots/recipes/swarm_compile.expected/Build-Ubuntu-Clang-x86_64-Debug-GN.json
+++ b/infra/bots/recipes/swarm_compile.expected/Build-Ubuntu-Clang-x86_64-Debug-GN.json
@@ -127,7 +127,7 @@
       "gn",
       "gen",
       "[CUSTOM_/_B_WORK]/skia/out/Build-Ubuntu-Clang-x86_64-Debug-GN/Debug",
-      "--args=cc=\"/usr/bin/ccache clang -Qunused-arguments\" cxx=\"/usr/bin/ccache clang++ -Qunused-arguments\""
+      "--args=cc=\"/usr/bin/ccache clang\" cxx=\"/usr/bin/ccache clang++\" is_debug=true extra_cflags=\"-Qunused-arguments\""
     ],
     "cwd": "[CUSTOM_/_B_WORK]/skia",
     "env": {

diff --git a/infra/bots/recipes/swarm_compile.expected/Build-Ubuntu-GCC-x86_64-Debug-GN.json b/infra/bots/recipes/swarm_compile.expected/Build-Ubuntu-GCC-x86_64-Debug-GN.json
index 5ad5558822dee985cd79b4127a09dbd1a4601632..10ff8c3307ff4ec935d4750dfe36fb0d9b30870a 100644 (file)
--- a/infra/bots/recipes/swarm_compile.expected/Build-Ubuntu-GCC-x86_64-Debug-GN.json
+++ b/infra/bots/recipes/swarm_compile.expected/Build-Ubuntu-GCC-x86_64-Debug-GN.json
@@ -125,7 +125,7 @@
       "gn",
       "gen",
       "[CUSTOM_/_B_WORK]/skia/out/Build-Ubuntu-GCC-x86_64-Debug-GN/Debug",
-      "--args=cc=\"/usr/bin/ccache gcc \" cxx=\"/usr/bin/ccache g++ \""
+      "--args=cc=\"/usr/bin/ccache gcc\" cxx=\"/usr/bin/ccache g++\" is_debug=true extra_cflags=\"\""
     ],
     "cwd": "[CUSTOM_/_B_WORK]/skia",
     "env": {

diff --git a/infra/bots/recipes/swarm_compile.expected/Build-Ubuntu-GCC-x86_64-Debug-SK_USE_DISCARDABLE_SCALEDIMAGECACHE.json b/infra/bots/recipes/swarm_compile.expected/Build-Ubuntu-GCC-x86_64-Debug-SK_USE_DISCARDABLE_SCALEDIMAGECACHE.json
index 5d0dd78b6dbb897c7949955cf4acbdf6e2d89a10..12314f87cc65208543771a45853f3b74dff646b5 100644 (file)
--- a/infra/bots/recipes/swarm_compile.expected/Build-Ubuntu-GCC-x86_64-Debug-SK_USE_DISCARDABLE_SCALEDIMAGECACHE.json
+++ b/infra/bots/recipes/swarm_compile.expected/Build-Ubuntu-GCC-x86_64-Debug-SK_USE_DISCARDABLE_SCALEDIMAGECACHE.json
@@ -124,7 +124,7 @@
       "gn",
       "gen",
       "[CUSTOM_/_B_WORK]/skia/out/Build-Ubuntu-GCC-x86_64-Debug-SK_USE_DISCARDABLE_SCALEDIMAGECACHE/Debug",
-      "--args=cc=\"gcc -DSK_USE_DISCARDABLE_SCALEDIMAGECACHE\" cxx=\"g++ -DSK_USE_DISCARDABLE_SCALEDIMAGECACHE\""
+      "--args=cc=\"gcc\" cxx=\"g++\" is_debug=true extra_cflags=\"-DSK_USE_DISCARDABLE_SCALEDIMAGECACHE\""
     ],
     "cwd": "[CUSTOM_/_B_WORK]/skia",
     "env": {

diff --git a/infra/bots/recipes/swarm_compile.expected/Build-Ubuntu-GCC-x86_64-Release-Fast.json b/infra/bots/recipes/swarm_compile.expected/Build-Ubuntu-GCC-x86_64-Release-Fast.json
index 5dd7797b654404b2493f6237171af80d5838c9ee..091b29ebb1b35f2030441ed5e11a03bc5660eb15 100644 (file)
--- a/infra/bots/recipes/swarm_compile.expected/Build-Ubuntu-GCC-x86_64-Release-Fast.json
+++ b/infra/bots/recipes/swarm_compile.expected/Build-Ubuntu-GCC-x86_64-Release-Fast.json
@@ -123,7 +123,7 @@
       "gn",
       "gen",
       "[CUSTOM_/_B_WORK]/skia/out/Build-Ubuntu-GCC-x86_64-Release-Fast/Release",
-      "--args=is_debug=false cc=\"gcc -march=native -fomit-frame-pointer\" cxx=\"g++ -march=native -fomit-frame-pointer\""
+      "--args=cc=\"gcc\" cxx=\"g++\" is_debug=false extra_cflags=\"-march=native -fomit-frame-pointer -O3\""
     ],
     "cwd": "[CUSTOM_/_B_WORK]/skia",
     "env": {

diff --git a/infra/bots/recipes/swarm_compile.expected/Build-Win-MSVC-x86-Release-GN.json b/infra/bots/recipes/swarm_compile.expected/Build-Win-MSVC-x86-Release-GN.json
index 1cd02d02666ecb240568e7b06ebf956dd857d96a..fe8c2423690e82da24b4a36ea4486aaca7b21ed8 100644 (file)
--- a/infra/bots/recipes/swarm_compile.expected/Build-Win-MSVC-x86-Release-GN.json
+++ b/infra/bots/recipes/swarm_compile.expected/Build-Win-MSVC-x86-Release-GN.json
@@ -93,7 +93,7 @@
       "gn",
       "gen",
       "[CUSTOM_C:\\_B_WORK]\\skia\\out\\Build-Win-MSVC-x86-Release-GN\\Release",
-      "--args=is_debug=false cc=\"cc \" cxx=\"c++ \""
+      "--args=cc=\"cc\" cxx=\"c++\" is_debug=false extra_cflags=\"\""
     ],
     "cwd": "[CUSTOM_C:\\_B_WORK]\\skia",
     "env": {