Desktop Chrome OS: Build with precise sysroot (Reland)

build/config/sysroot.gni

 # Copyright (c) 2013 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 # This header file defines the "sysroot" variable which is the absolute path
 # of the sysroot. If no sysroot applies, the variable will be an empty string.
 
 import("//build/config/chrome_build.gni")
 
 declare_args() {
@@ skipping 26 matching lines @@
     sysroot = "$android_ndk_root/$mips_android_sysroot_subdir"
   } else if (current_cpu == "x64") {
     sysroot = "$android_ndk_root/$x86_64_android_sysroot_subdir"
   } else if (current_cpu == "arm64") {
     sysroot = "$android_ndk_root/$arm64_android_sysroot_subdir"
   } else if (current_cpu == "mips64el") {
     sysroot = "$android_ndk_root/$mips64_android_sysroot_subdir"
   } else {
     sysroot = ""
   }
-} else if (is_linux && !is_chromeos && use_sysroot) {
+} else if (is_linux && use_sysroot) {
   # By default build against a sysroot image downloaded from Cloud Storage
   # during gclient runhooks.
-  if (current_cpu == "x64") {
-    sysroot = "//build/linux/debian_wheezy_amd64-sysroot"
-  } else if (current_cpu == "x86") {
-    sysroot = "//build/linux/debian_wheezy_i386-sysroot"
-  } else if (current_cpu == "mipsel") {
-    sysroot = "//build/linux/debian_wheezy_mips-sysroot"
-  } else if (current_cpu == "arm") {
-    sysroot = "//build/linux/debian_wheezy_arm-sysroot"
-  } else if (current_cpu == "arm64") {
-    sysroot = "//build/linux/debian_jessie_arm64-sysroot"
+  if (is_chromeos) {
+    sysroot = "//build/linux/ubuntu_precise_amd64-sysroot"

[Dirk Pranke, 2016/08/25 03:27:22]

add a comment here about why we're using a precise image for this and not some
weird custom sysroot or the default wheezy sysroots (answer is that regular cros
builds use custom sys roots but the "desktop chromeos" case needs to run on the
builders (which are precise) and a cros build depends on things that aren't in
the normal wheezy sysroots).

[Tom (Use chromium acct), 2016/08/25 18:28:51]

Done.

   } else {
-    # Any other builds don't use a sysroot.
-    sysroot = ""
+    if (current_cpu == "x64") {
+      sysroot = "//build/linux/debian_wheezy_amd64-sysroot"
+    } else if (current_cpu == "x86") {
+      sysroot = "//build/linux/debian_wheezy_i386-sysroot"
+    } else if (current_cpu == "mipsel") {
+      sysroot = "//build/linux/debian_wheezy_mips-sysroot"
+    } else if (current_cpu == "arm") {
+      sysroot = "//build/linux/debian_wheezy_arm-sysroot"
+    } else if (current_cpu == "arm64") {
+      sysroot = "//build/linux/debian_jessie_arm64-sysroot"
+    } else {
+      # Any other builds don't use a sysroot.
+      sysroot = ""
+    }
   }
 
   if (sysroot != "") {
     # Our sysroot images only contains gcc 4.6 headers, but chromium requires
     # gcc 4.9. Clang is able to detect and work with the 4.6 headers while
     # gcc is not. This check can be removed if we ever update to a more modern
     # sysroot.
     assert(is_clang, "sysroot images require clang (try use_sysroot=false)")
 
     _script_arch = current_cpu
@@ skipping 10 matching lines @@
   }
 } else if (is_mac) {
   import("//build/config/mac/mac_sdk.gni")
   sysroot = mac_sdk_path
 } else if (is_ios) {
   import("//build/config/ios/ios_sdk.gni")
   sysroot = ios_sdk_path
 } else {
   sysroot = ""
 }