Roll buildtools to 31d4da

build/config/compiler/BUILD.gn

Index: build/config/compiler/BUILD.gn
diff --git a/build/config/compiler/BUILD.gn b/build/config/compiler/BUILD.gn
index 7eb4fb3f3e8886c46ed457de778f4f3ff637838a..95996abcec489f52a20da2d9fb3eb2b7f742179d 100644
--- a/build/config/compiler/BUILD.gn
+++ b/build/config/compiler/BUILD.gn
@@ -421,6 +421,13 @@ config("compiler") {
     cflags += [ "-B$binutils_path" ]
   }
 
+  if (is_linux) {
+    cflags += [ "-pthread" ]
+    # Do not use the -pthread ldflag here since it becomes a no-op
+    # when using -nodefaultlibs, which would cause an unused argument
+    # error.  "-lpthread" is added in //build/config:default_libs.
+  }
+
   # Clang-specific compiler flags setup.
   # ------------------------------------
   if (is_clang) {
@@ -545,16 +552,6 @@ config("compiler") {
   }
 }
 
-# This is separate from :compiler (and not even a sub-config there)
-# so that some targets can remove it from the list with:
-#   configs -= [ "//build/config/compiler:pthread" ]

[Nico, 2017/06/02 01:48:12]

Huh, I'm surprised nobody seems to do this.

-config("pthread") {
-  if (is_linux) {
-    cflags = [ "-pthread" ]
-    ldflags = [ "-pthread" ]
-  }
-}
-
 # This provides the basic options to select the target CPU and ABI.
 # It is factored out of "compiler" so that special cases can use this
 # without using everything that "compiler" brings in.  Options that