[infra] Fixes for cross-toolchains

toolchain_prefix was not correctly propagated everywhere it needed to
go. This CL also adds an error to build.py if someone tries to use
--toolchain as it is not supported there.

R=rmacnak@google.com

Review-Url: https://codereview.chromium.org/2797303005 .

DEPS

@@ -46,7 +46,7 @@ vars = {
   "barback_tag" : "@0.15.2+9",
   "bazel_worker_tag": "@0.1.2",
   "boolean_selector_tag" : "@1.0.2",
-  "boringssl_gen_rev": "@1a810313a0290e1caace9da73fa3ab89995ad2c7",
+  "boringssl_gen_rev": "@753224969dbe43dad29343146529727b5066c0f3",
   "boringssl_rev" : "@d519bf6be0b447fb80fbc539d4bff4479b5482a2",
   "charcode_tag": "@v1.1.1",
   "chrome_rev" : "@19997",

build/toolchain/linux/BUILD.gn

@@ -22,13 +22,18 @@ if (use_goma) {
 }
 
 gcc_toolchain("arm") {
-  cc = "${compiler_prefix}arm-linux-gnueabihf-gcc"
-  cxx = "${compiler_prefix}arm-linux-gnueabihf-g++"
+  prefix = "arm-linux-gnueabihf-"
+  if (toolchain_prefix != "") {
+    prefix = toolchain_prefix
+  }
 
-  ar = "arm-linux-gnueabihf-ar"
+  cc = "${compiler_prefix}${prefix}gcc"
+  cxx = "${compiler_prefix}${prefix}g++"
+
+  ar = "${prefix}ar"
   ld = cxx
-  readelf = "arm-linux-gnueabihf-readelf"
-  nm = "arm-linux-gnueabihf-nm"
+  readelf = "${prefix}readelf"
+  nm = "${prefix}nm"
 
   toolchain_cpu = "arm"
   toolchain_os = "linux"
@@ -36,13 +41,18 @@ gcc_toolchain("arm") {
 }
 
 gcc_toolchain("arm64") {
-  cc = "${compiler_prefix}aarch64-linux-gnu-gcc"
-  cxx = "${compiler_prefix}aarch64-linux-gnu-g++"
+  prefix = "aarch64-linux-gnu-"
+  if (toolchain_prefix != "") {
+    prefix = toolchain_prefix
+  }
 
-  ar = "aarch64-linux-gnu-ar"
+  cc = "${compiler_prefix}${prefix}gcc"
+  cxx = "${compiler_prefix}${prefix}g++"
+
+  ar = "${prefix}ar"
   ld = cxx
-  readelf = "aarch64-linux-gnu-readelf"
-  nm = "aarch64-linux-gnu-nm"
+  readelf = "${prefix}readelf"
+  nm = "${prefix}nm"
 
   toolchain_cpu = "arm64"
   toolchain_os = "linux"
@@ -109,8 +119,8 @@ gcc_toolchain("x64") {
 }
 
 gcc_toolchain("mipsel") {
-  cc = "${toolchain_prefix}gcc"
-  cxx = "${toolchain_prefix}g++"
+  cc = "${compiler_prefix}${toolchain_prefix}gcc"
+  cxx = "${compiler_prefix}${toolchain_prefix}g++"
   ar = "${toolchain_prefix}ar"
   ld = cxx
   readelf = "${toolchain_prefix}readelf"

third_party/tcmalloc/BUILD.gn

@@ -101,7 +101,7 @@ source_set("tcmalloc") {
     "-fpermissive",
   ]
 
-  if (!is_clang && current_cpu == "x86") {
+  if (!is_clang) {
     cflags += [ "-Wno-format" ]
   }
 

tools/build.py

@@ -107,6 +107,10 @@ def ProcessOptions(options, args):
   options.mode = options.mode.split(',')
   options.arch = options.arch.split(',')
   options.os = options.os.split(',')
+  if not options.gyp and options.toolchain != None:
+    print "The --toolchain flag is only supported by the gyp build."
+    print "When using the GN build, set the toolchain and sysroot using gn.py."
+    return False
   for mode in options.mode:
     if not mode in ['debug', 'release', 'product']:
       print "Unknown mode %s" % mode