Partition libcxx build code from build/config/sanitizers

build/config/sanitizers/BUILD.gn

Index: build/config/sanitizers/BUILD.gn
diff --git a/build/config/sanitizers/BUILD.gn b/build/config/sanitizers/BUILD.gn
index f6b88c718941ac3437109bbe9b3b2ed9db93b8e3..67d9568c22cb7d380c0fc071f794f294e1c455e5 100644
--- a/build/config/sanitizers/BUILD.gn
+++ b/build/config/sanitizers/BUILD.gn
@@ -18,9 +18,6 @@ if (is_ios) {
 # "//build/config:exe_and_shlib_deps" to pull in this target.
 group("deps") {
   visibility = [ "//build/config:exe_and_shlib_deps" ]
-  public_deps = [
-    ":deps_no_options",
-  ]
   if (using_sanitizer) {
     public_configs = [
       ":sanitizer_options_link_helper",
@@ -33,32 +30,15 @@ group("deps") {
     deps = [
       ":options_sources",
     ]
-  }
-  if (use_afl) {
-    deps += [ "//third_party/afl" ]
-  }
-}
-
-group("deps_no_options") {
-  if (using_sanitizer) {
-    public_configs = [
-      # Even when a target removes default_sanitizer_flags, it may be depending
-      # on a library that did not remove default_sanitizer_flags. Thus, we need
-      # to add the ldflags here as well as in default_sanitizer_flags.
-      ":default_sanitizer_ldflags",
-    ]
-    deps = []
-    public_deps = []
-
-    data = [
-      "//tools/valgrind/asan/",
-    ]
     if (is_win) {
       exe = ".exe"
     } else {
       exe = ""
     }
-    data += [ "$clang_base_path/bin/llvm-symbolizer${exe}" ]
+    data = [
+      "//tools/valgrind/asan/",
+      "$clang_base_path/bin/llvm-symbolizer${exe}",
+    ]
     if (is_linux) {
       # llvm-symbolizer needs this.
       data += [ "$clang_base_path/lib/libstdc++.so.6" ]
@@ -68,10 +48,6 @@ group("deps_no_options") {
         use_locally_built_instrumented_libraries) {
       deps += [ "//third_party/instrumented_libraries:deps" ]
     }
-    if (use_custom_libcxx) {
-      public_deps += [ "//buildtools/third_party/libc++:libcxx_proxy" ]
-      data += [ "$root_out_dir/libc++.so" ]
-    }
 
     # ASAN is supported on iOS but the runtime library depends on the compiler
     # used (Chromium version of clang versus Xcode version of clang). Only copy
@@ -82,7 +58,9 @@ group("deps_no_options") {
       ]
     }
     if (is_mac || (is_ios && !use_xcode_clang)) {
-      public_deps += [ ":asan_runtime_bundle_data" ]
+      public_deps = [
+        ":asan_runtime_bundle_data",
+      ]
     }
   }
 }
@@ -275,7 +253,6 @@ config("default_sanitizer_ldflags") {
 
 config("common_sanitizer_flags") {
   cflags = []
-  cflags_cc = []
 
   # Sanitizers need line table info for stack traces. They don't need type info
   # or variable info, so we can leave that out to speed up the build (unless
@@ -303,11 +280,14 @@ config("common_sanitizer_flags") {
       cflags += [ "/Oy-" ]
     }
   }
+}
 
+# TODO(thomasanderson): Move this out of build/config/sanitizers.
+config("libcxx_flags") {
   if (use_custom_libcxx) {
     prefix = "//buildtools/third_party"
     include = "trunk/include"
-    cflags_cc += [
+    cflags_cc = [
       "-nostdinc++",
       "-isystem" + rebase_path("$prefix/libc++/$include", root_build_dir),
       "-isystem" + rebase_path("$prefix/libc++abi/$include", root_build_dir),
@@ -558,6 +538,7 @@ config("fuzzing_build_mode") {
 
 all_sanitizer_configs = [
   ":common_sanitizer_flags",
+  ":libcxx_flags",
   ":coverage_flags",
   ":default_sanitizer_ldflags",
   ":asan_flags",