Add Clang static analyzer to Clang toolchain defs in GN

build/toolchain/gcc_toolchain.gni

Index: build/toolchain/gcc_toolchain.gni
diff --git a/build/toolchain/gcc_toolchain.gni b/build/toolchain/gcc_toolchain.gni
index 7ee2b6ad25e011bdbba41a6f11e9e7145204771d..5d9e8d2beedd648cd3c5d53ea14fa424c3154a1b 100644
--- a/build/toolchain/gcc_toolchain.gni
+++ b/build/toolchain/gcc_toolchain.gni
@@ -8,6 +8,7 @@ import("//build/config/nacl/config.gni")
 import("//build/config/sanitizers/sanitizers.gni")
 import("//build/config/v8_target_cpu.gni")
 import("//build/toolchain/cc_wrapper.gni")
+import("//build/toolchain/clang_static_analyzer.gni")
 import("//build/toolchain/goma.gni")
 import("//build/toolchain/toolchain.gni")
 
@@ -485,11 +486,26 @@ template("clang_toolchain") {
     prefix = rebase_path("$clang_base_path/bin", root_build_dir)
     cc = "$prefix/clang"
     cxx = "$prefix/clang++"
-    ld = cxx
+
+    if (use_clang_static_analyzer) {
+      # Call "ccc-analyzer" or "c++-analyzer" instead of directly calling Clang.
+      # |wrapper_tool| sets the environment variables which are read by the
+      # analyzer tools.
+      analyzer_wrapper =
+          rebase_path("//build/toolchain/clang_static_analyzer_wrapper.py",
+                      root_build_dir)
+      cc = analyzer_wrapper + " --clang-cc-path=${cc} --analyzer=" + rebase_path(
+               "//third_party/llvm/tools/clang/tools/scan-build/libexec/ccc-analyzer",
+               root_build_dir)
+      cxx = analyzer_wrapper + " --clang-cxx-path=${cxx} --analyzer=" + rebase_path(
+                "//third_party/llvm/tools/clang/tools/scan-build/libexec/c++-analyzer",
+                root_build_dir)

[Wez, 2017/01/10 02:41:48]

As noted in the script itself, if we make it a script with two generic
parameters e.g. --compiler and --analyzer with a flag to indicate explicitly
whether it's CC or CXX, might be cleaner.

+    }
 
     readelf = "${toolprefix}readelf"
     ar = "${toolprefix}ar"
     nm = "${toolprefix}nm"
+    ld = cxx
 
     forward_variables_from(invoker, [ "strip" ])