Un-nest configs in GN files.

People sometimes nest targets or configs, usually with the assumption that this limits the visibility of a config to within a target. But this nesting provides no visibility restrictions over declaring it outside of a block.

Un-nest for clarity.

Re-land of http://crrev.com/1318823008 while preserving config ordering.

Review URL: https://codereview.chromium.org/1307223010

Cr-Commit-Position: refs/heads/master@{#346964}

build/secondary/testing/gtest/BUILD.gn

@@ -58,6 +58,15 @@ config("gtest_direct_config") {
   defines = [ "UNIT_TEST" ]
 }
 
+config("gtest_warnings") {
+  if (is_win && is_clang) {
+    # The Mutex constructor initializer list in gtest-port.cc is incorrectly
+    # ordered. See
+    # https://groups.google.com/d/msg/googletestframework/S5uSV8L2TX8/U1FaTDa6J6sJ.
+    cflags = [ "-Wno-reorder" ]
+  }
+}
+
 static_library("gtest") {
   # TODO http://crbug.com/412064 enable this flag all the time.
   testonly = !is_component_build
@@ -121,17 +130,12 @@ static_library("gtest") {
   public_configs = [ ":gtest_direct_config" ]
 
   configs -= [ "//build/config/compiler:chromium_code" ]
-  configs += [ "//build/config/compiler:no_chromium_code" ]
+  configs += [
+    "//build/config/compiler:no_chromium_code",
 
-  config("gtest_warnings") {
-    if (is_win && is_clang) {
-      # The Mutex constructor initializer list in gtest-port.cc is incorrectly
-      # ordered. See
-      # https://groups.google.com/d/msg/googletestframework/S5uSV8L2TX8/U1FaTDa6J6sJ.
-      cflags = [ "-Wno-reorder" ]
-    }
-  }
-  configs += [ ":gtest_warnings" ]
+    # Must be after no_chromium_code for warning flags to be ordered correctly.
+    ":gtest_warnings",
+  ]
 }
 
 source_set("gtest_main") {

sdch/BUILD.gn

@@ -6,6 +6,17 @@ config("sdch_config") {
   include_dirs = [ "open-vcdiff/src" ]
 }
 
+# gn orders flags on a target before flags from configs. The default config
+# adds -Wall, and these flags have to be after -Wall -- so they need to come
+# from a config and can't be on the target directly.
+config("sdch_warnings") {
+  cflags = []
+  if (is_linux) {
+    # TODO(mostynb): remove this if open-vcdiff is ever updated for c++11:
+    cflags += [ "-Wno-deprecated-declarations" ]
+  }
+}
+
 static_library("sdch") {
   sources = [
     "logging_forward.h",
@@ -42,6 +53,7 @@ static_library("sdch") {
     "open-vcdiff/vsprojects/stdint.h",
   ]
 
+  configs += [ ":sdch_warnings" ]
   public_configs = [ ":sdch_config" ]
 
   deps = [
@@ -49,18 +61,6 @@ static_library("sdch") {
     "//third_party/zlib",
   ]
 
-  # gn orders flags on a target before flags from configs. The default config
-  # adds -Wall, and these flags have to be after -Wall -- so they need to come
-  # from a config and can't be on the target directly.
-  config("sdch_warnings") {
-    cflags = []
-    if (is_linux) {
-      # TODO(mostynb): remove this if open-vcdiff is ever updated for c++11:
-      cflags += [ "-Wno-deprecated-declarations" ]
-    }
-  }
-  configs += [ ":sdch_warnings" ]
-
   if (is_linux || is_android) {
     include_dirs = [ "linux" ]
   } else if (is_ios) {

third_party/brotli/BUILD.gn

@@ -2,6 +2,15 @@
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
+config("brotli_warnings") {
+  if (is_clang) {
+    # IncrementalCopyFastPath in decode.c can be unused.
+    # (The file looks very different upstream, this is probably no longer
+    # needed after rolling brotli the next time.)
+    cflags = [ "-Wno-unused-function" ]
+  }
+}
+
 source_set("brotli") {
   sources = [
     "dec/bit_reader.c",
@@ -23,17 +32,13 @@ source_set("brotli") {
     "dec/types.h",
   ]
 
-  config("brotli_warnings") {
-    if (is_clang) {
-      # IncrementalCopyFastPath in decode.c can be unused.
-      # (The file looks very different upstream, this is probably no longer
-      # needed after rolling brotli the next time.)
-      cflags = [ "-Wno-unused-function" ]
-    }
-  }
   configs -= [ "//build/config/compiler:chromium_code" ]
-  configs += [ "//build/config/compiler:no_chromium_code" ]
-  configs += [ ":brotli_warnings" ]
+  configs += [
+    "//build/config/compiler:no_chromium_code",
+
+    # Must be after no_chromium_code for warning flags to be ordered correctly.
+    ":brotli_warnings",
+  ]
 
   # Since we are never debug brotli, freeze the optimizations to -O2.
   if (is_debug) {

third_party/cld_2/BUILD.gn

@@ -33,6 +33,14 @@ cld2_platform_support = "static"
 
 cld2_table_size = 2
 
+config("cld2_data_warnings") {
+  visibility = [ ":*" ]
+  if (is_clang) {
+    # The generated files don't have braces around subobject initializers.
+    cflags = [ "-Wno-missing-braces" ]
+  }
+}
+
 source_set("cld2_data") {
   sources = gypi_values.cld2_data_sources
   if (cld2_table_size == 0) {
@@ -46,15 +54,13 @@ source_set("cld2_data") {
     "src/public",
   ]
 
-  config("cld2_data_warnings") {
-    if (is_clang) {
-      # The generated files don't have braces around subobject initializers.
-      cflags = [ "-Wno-missing-braces" ]
-    }
-  }
   configs -= [ "//build/config/compiler:chromium_code" ]
-  configs += [ "//build/config/compiler:no_chromium_code" ]
-  configs += [ ":cld2_data_warnings" ]
+  configs += [
+    "//build/config/compiler:no_chromium_code",
+
+    # Must be after no_chromium_code for warning flags to be ordered correctly.
+    ":cld2_data_warnings",
+  ]
 }
 
 # As in the corresponding gyp file, this just builds the core interfaces for

third_party/harfbuzz-ng/BUILD.gn

@@ -41,6 +41,36 @@ if (use_system_harfbuzz) {
     include_dirs = [ "src" ]
   }
 
+  config("harfbuzz_warnings") {
+    cflags = []
+    if (is_clang) {
+      cflags += [
+        "-Wno-unused-value",
+
+        # Harfbuzz uses unused typedefs for its static asserts (and its
+        # static asserts are strange enough that they can't be replaced
+        # by static_assert).
+        "-Wno-unused-local-typedef",
+      ]
+    }
+    if (is_win) {
+      # Result of 32-bit shift implicitly converted to 64 bits.
+      cflags += [ "/wd4334" ]
+    }
+  }
+
+  # See also chrome/browser/ui/libgtk2ui/BUILD.gn which pulls this.
+  config("pangoft2_link_hack") {
+    if (is_linux && use_pango && !is_chromeos && !is_official_build &&
+        current_cpu != "arm" && current_cpu != "mipsel" &&
+        !is_component_build) {
+      # These symbols are referenced from libpangoft2, which will be
+      # dynamically linked later.
+      ldflags =
+          [ "-Wl,-uhb_ft_face_create_cached,-uhb_glib_get_unicode_funcs" ]
+    }
+  }
+
   static_library("harfbuzz-ng") {
     sources = [
       "src/hb-atomic-private.hh",
@@ -146,26 +176,13 @@ if (use_system_harfbuzz) {
     ]
 
     configs -= [ "//build/config/compiler:chromium_code" ]
-    configs += [ "//build/config/compiler:no_chromium_code" ]
-
-    config("harfbuzz_warnings") {
-      cflags = []
-      if (is_clang) {
-        cflags += [
-          "-Wno-unused-value",
-
-          # Harfbuzz uses unused typedefs for its static asserts (and its
-          # static asserts are strange enough that they can't be replaced
-          # by static_assert).
-          "-Wno-unused-local-typedef",
-        ]
-      }
-      if (is_win) {
-        cflags += [ "/wd4334" ]  # Result of 32-bit shift implicitly converted to 64 bits.
-      }
-    }
-    configs += [ ":harfbuzz_warnings" ]
+    configs += [
+      "//build/config/compiler:no_chromium_code",
 
+      # Must be after no_chromium_code for warning flags to be ordered
+      # correctly.
+      ":harfbuzz_warnings",
+    ]
     public_configs = [ ":harfbuzz-ng_config" ]
 
     deps = [
@@ -199,16 +216,5 @@ if (use_system_harfbuzz) {
       ]
     }
 
-    # See also chrome/browser/ui/libgtk2ui/BUILD.gn which pulls this.
-    config("pangoft2_link_hack") {
-      if (is_linux && use_pango && !is_chromeos && !is_official_build &&
-          current_cpu != "arm" && current_cpu != "mipsel" &&
-          !is_component_build) {
-        # These symbols are referenced from libpangoft2, which will be
-        # dynamically linked later.
-        ldflags =
-            [ "-Wl,-uhb_ft_face_create_cached,-uhb_glib_get_unicode_funcs" ]
-      }
-    }
   }
 }

third_party/hunspell/BUILD.gn

@@ -10,6 +10,12 @@ config("hunspell_config") {
   ]
 }
 
+config("hunspell_warnings") {
+  if (is_clang) {
+    cflags = [ "-Wno-unused-private-field" ]
+  }
+}
+
 source_set("hunspell") {
   sources = [
     "google/bdict.cc",
@@ -51,15 +57,11 @@ source_set("hunspell") {
     "src/parsers/textparser.hxx",
   ]
 
-  config("hunspell_warnings") {
-    if (is_clang) {
-      cflags = [ "-Wno-unused-private-field" ]
-    }
-  }
-
   configs -= [ "//build/config/compiler:chromium_code" ]
   configs += [
     "//build/config/compiler:no_chromium_code",
+
+    # Must be after no_chromium_code for warning flags to be ordered correctly.
     ":hunspell_warnings",
   ]
   public_configs = [ ":hunspell_config" ]

third_party/libpng/BUILD.gn

@@ -25,6 +25,15 @@ config("libpng_config") {
   }
 }
 
+# Must be in a config because of how GN orders flags (otherwise -Wall will
+# appear after this, and turn it back on).
+config("clang_warnings") {
+  if (is_clang) {
+    # Upstream uses self-assignment to avoid warnings.
+    cflags = [ "-Wno-self-assign" ]
+  }
+}
+
 source_set("libpng_sources") {
   sources = [
     "png.c",
@@ -62,14 +71,6 @@ source_set("libpng_sources") {
     "//third_party/zlib",
   ]
 
-  # Must be in a config because of how GN orders flags (otherwise -Wall will
-  # appear after this, and turn it back on).
-  config("clang_warnings") {
-    if (is_clang) {
-      # Upstream uses self-assignment to avoid warnings.
-      cflags = [ "-Wno-self-assign" ]
-    }
-  }
   configs += [ ":clang_warnings" ]
 }
 

third_party/libusb/BUILD.gn

@@ -10,6 +10,17 @@ config("libusb_config") {
   include_dirs = [ "src/libusb" ]
 }
 
+config("libusb_warnings") {
+  visibility = [ ":*" ]
+  if (is_clang) {
+    # guid_eq in windows_usb.c is unused.
+    cflags = [ "-Wno-unused-function" ]
+    if (is_linux && !use_udev) {
+      cflags += [ "-Wno-pointer-sign" ]
+    }
+  }
+}
+
 static_library("libusb") {
   sources = [
     "src/config.h",
@@ -46,18 +57,13 @@ static_library("libusb") {
   deps = []
   include_dirs = [ "src/libusb/os" ]
 
-  config("libusb_warnings") {
-    if (is_clang) {
-      # guid_eq in windows_usb.c is unused.
-      cflags = [ "-Wno-unused-function" ]
-      if (is_linux && !use_udev) {
-        cflags += [ "-Wno-pointer-sign" ]
-      }
-    }
-  }
   configs -= [ "//build/config/compiler:chromium_code" ]
-  configs += [ "//build/config/compiler:no_chromium_code" ]
-  configs += [ ":libusb_warnings" ]
+  configs += [
+    "//build/config/compiler:no_chromium_code",
+
+    # Must be after no_chromium_code for warning flags to be ordered correctly.
+    ":libusb_warnings",
+  ]
 
   public_configs = [ ":libusb_config" ]
 

third_party/libwebp/BUILD.gn

@@ -162,6 +162,13 @@ source_set("libwebp_enc") {
   ]
 }
 
+config("libwebp_utils_warnings") {
+  if (is_clang) {
+    # See https://code.google.com/p/webp/issues/detail?id=253.
+    cflags = [ "-Wno-incompatible-pointer-types" ]
+  }
+}
+
 source_set("libwebp_utils") {
   sources = [
     "utils/bit_reader.c",
@@ -182,12 +189,6 @@ source_set("libwebp_utils") {
 
   all_dependent_configs = [ ":libwebp_config" ]
 
-  config("libwebp_utils_warnings") {
-    if (is_clang) {
-      # See https://code.google.com/p/webp/issues/detail?id=253.
-      cflags = [ "-Wno-incompatible-pointer-types" ]
-    }
-  }
   public_configs = [ ":libwebp_utils_warnings" ]
 }
 

third_party/libxml/BUILD.gn

@@ -24,6 +24,44 @@ config("libxml_config") {
   ]
 }
 
+config("libxml_warnings") {
+  if (is_win) {
+    cflags_c = [
+      "/wd4018",  # Signed/unsigned mismatch in comparison.
+      "/wd4101",  # Unreferenced local variable.
+    ]
+  }
+  if (is_clang) {
+    cflags = [
+      # libxml passes `const unsigned char*` through `const char*`.
+      "-Wno-pointer-sign",
+
+      # pattern.c and uri.c both have an intentional `for (...);` /
+      # `while(...);` loop. I submitted a patch to move the `'` to its own
+      # line, but until that's landed suppress the warning:
+      "-Wno-empty-body",
+
+      # debugXML.c compares array 'arg' to NULL.
+      "-Wno-tautological-pointer-compare",
+
+      # threads.c attempts to forward declare a pthread_equal which doesn't
+      # match the prototype in pthreads.h
+      "-Wno-ignored-attributes",
+
+      # libxml casts from int to long to void*.
+      "-Wno-int-to-void-pointer-cast",
+
+      # libxml passes a volatile LPCRITICAL_SECTION* to a function expecting
+      # a void* volatile*.
+      "-Wno-incompatible-pointer-types",
+
+      # trio_is_special_quantity and trio_is_negative are only
+      # used with certain preprocessor defines set.
+      "-Wno-unused-function",
+    ]
+  }
+}
+
 static_library("libxml") {
   output_name = "libxml2"
   sources = [
@@ -144,7 +182,12 @@ static_library("libxml") {
   ]
 
   configs -= [ "//build/config/compiler:chromium_code" ]
-  configs += [ "//build/config/compiler:no_chromium_code" ]
+  configs += [
+    "//build/config/compiler:no_chromium_code",
+
+    # Must be after no_chromium_code for warning flags to be ordered correctly.
+    ":libxml_warnings",
+  ]
 
   public_configs = [ ":libxml_config" ]
   public_deps = [
@@ -154,12 +197,7 @@ static_library("libxml") {
     "//third_party/zlib",
   ]
 
-  if (is_win) {
-    cflags_c = [
-      "/wd4018",  # Signed/unsigned mismatch in comparison.
-      "/wd4101",  # Unreferenced local variable.
-    ]
-  } else if (is_mac || is_ios || is_android) {
+  if (is_mac || is_ios || is_android) {
     # http://www.xmlsoft.org/threads.html says that this is required when using
     # libxml from several threads, which can possibly happen in chrome. On
     # linux, this is picked up by transitivity from pkg-config output from
@@ -167,38 +205,5 @@ static_library("libxml") {
     defines = [ "_REENTRANT" ]
   }
 
-  config("libxml_warnings") {
-    if (is_clang) {
-      cflags = [
-        # libxml passes `const unsigned char*` through `const char*`.
-        "-Wno-pointer-sign",
-
-        # pattern.c and uri.c both have an intentional `for (...);` /
-        # `while(...);` loop. I submitted a patch to move the `'` to its own
-        # line, but until that's landed suppress the warning:
-        "-Wno-empty-body",
-
-        # debugXML.c compares array 'arg' to NULL.
-        "-Wno-tautological-pointer-compare",
-
-        # threads.c attempts to forward declare a pthread_equal which doesn't
-        # match the prototype in pthreads.h
-        "-Wno-ignored-attributes",
-
-        # libxml casts from int to long to void*.
-        "-Wno-int-to-void-pointer-cast",
-
-        # libxml passes a volatile LPCRITICAL_SECTION* to a function expecting
-        # a void* volatile*.
-        "-Wno-incompatible-pointer-types",
-
-        # trio_is_special_quantity and trio_is_negative are only
-        # used with certain preprocessor defines set.
-        "-Wno-unused-function",
-      ]
-    }
-  }
-  configs += [ ":libxml_warnings" ]
-
   include_dirs = [ "$os_include" ]
 }

third_party/libxslt/BUILD.gn

@@ -7,6 +7,19 @@ config("libxslt_config") {
   include_dirs = [ "." ]
 }
 
+config("libxslt_warnings") {
+  if (is_clang) {
+    cflags = [
+      # libxslt stores a char[3] in a `const unsigned char*`.
+      "-Wno-pointer-sign",
+
+      # xsltDefaultRegion and xsltCalibrateTimestamps are only
+      # used with certain preprocessor defines set.
+      "-Wno-unused-function",
+    ]
+  }
+}
+
 static_library("libxslt") {
   sources = [
     "libxslt/attributes.c",
@@ -59,21 +72,13 @@ static_library("libxslt") {
     "win32/config.h",
   ]
 
-  config("libxslt_warnings") {
-    if (is_clang) {
-      cflags = [
-        # libxslt stores a char[3] in a `const unsigned char*`.
-        "-Wno-pointer-sign",
-
-        # xsltDefaultRegion and xsltCalibrateTimestamps are only
-        # used with certain preprocessor defines set.
-        "-Wno-unused-function",
-      ]
-    }
-  }
   configs -= [ "//build/config/compiler:chromium_code" ]
-  configs += [ "//build/config/compiler:no_chromium_code" ]
-  configs += [ ":libxslt_warnings" ]
+  configs += [
+    "//build/config/compiler:no_chromium_code",
+
+    # Must be after no_chromium_code for warning flags to be ordered correctly.
+    ":libxslt_warnings",
+  ]
   public_configs = [ ":libxslt_config" ]
 
   cflags = []

third_party/lzma_sdk/BUILD.gn

@@ -6,6 +6,15 @@ config("lzma_sdk_config") {
   include_dirs = [ "." ]
 }
 
+# Must be in a config because of how GN orders flags (otherwise -Wall will
+# appear after this, and turn it back on).
+config("clang_warnings") {
+  if (is_clang) {
+    # Upstream uses self-assignment to avoid warnings.
+    cflags = [ "-Wno-self-assign" ]
+  }
+}
+
 static_library("lzma_sdk") {
   sources = [
     "7z.h",
@@ -50,17 +59,11 @@ static_library("lzma_sdk") {
   ]
 
   configs -= [ "//build/config/compiler:chromium_code" ]
-  configs += [ "//build/config/compiler:no_chromium_code" ]
+  configs += [
+    "//build/config/compiler:no_chromium_code",
 
+    # Must be after no_chromium_code for warning flags to be ordered correctly.
+    ":clang_warnings",
+  ]
   public_configs = [ ":lzma_sdk_config" ]
-
-  # Must be in a config because of how GN orders flags (otherwise -Wall will
-  # appear after this, and turn it back on).
-  config("clang_warnings") {
-    if (is_clang) {
-      # Upstream uses self-assignment to avoid warnings.
-      cflags = [ "-Wno-self-assign" ]
-    }
-  }
-  configs += [ ":clang_warnings" ]
 }

third_party/mesa/BUILD.gn

@@ -148,6 +148,15 @@ config("mesa_internal_warnings") {
   }
 }
 
+config("mesa_libglslcommon_warnings") {
+  if (is_clang) {
+    cflags = [
+      # https://bugs.freedesktop.org/show_bug.cgi?id=91645:
+      "-Wno-overloaded-virtual",
+    ]
+  }
+}
+
 static_library("mesa_libglslcommon") {
   sources = [
     "$generated_src_dir/mesa/glcpp-lex.c",
@@ -252,15 +261,6 @@ static_library("mesa_libglslcommon") {
     "src/src/glsl/strtod.h",
   ]
 
-  config("mesa_libglslcommon_warnings") {
-    if (is_clang) {
-      cflags = [
-        # https://bugs.freedesktop.org/show_bug.cgi?id=91645:
-        "-Wno-overloaded-virtual",
-      ]
-    }
-  }
-
   configs -= [ "//build/config/compiler:chromium_code" ]
   configs += [ "//build/config/compiler:no_chromium_code" ]
   previous_configs = configs

third_party/snappy/BUILD.gn

@@ -16,6 +16,14 @@ config("snappy_config") {
   }
 }
 
+config("snappy_warnings") {
+  if (is_clang) {
+    # ComputeTable is unused,
+    # https://code.google.com/p/snappy/issues/detail?id=96
+    cflags = [ "-Wno-unused-function" ]
+  }
+}
+
 static_library("snappy") {
   sources = [
     "src/snappy-internal.h",
@@ -27,16 +35,13 @@ static_library("snappy") {
     "src/snappy.h",
   ]
 
-  config("snappy_warnings") {
-    if (is_clang) {
-      # ComputeTable is unused,
-      # https://code.google.com/p/snappy/issues/detail?id=96
-      cflags = [ "-Wno-unused-function" ]
-    }
-  }
   configs -= [ "//build/config/compiler:chromium_code" ]
-  configs += [ "//build/config/compiler:no_chromium_code" ]
-  configs += [ ":snappy_warnings" ]
+  configs += [
+    "//build/config/compiler:no_chromium_code",
+
+    # Must be after no_chromium_code for warning flags to be ordered correctly.
+    ":snappy_warnings",
+  ]
   public_configs = [ ":snappy_config" ]
 
   if (is_win) {

third_party/sqlite/BUILD.gn

@@ -16,6 +16,27 @@ if (!use_system_sqlite) {
     include_dirs = [ "." ]
   }
 
+  config("sqlite_warnings") {
+    cflags = []
+    if (is_clang) {
+      # sqlite contains a few functions that are unused, at least on
+      # Windows with Chromium's sqlite patches applied
+      # (interiorCursorEOF fts3EvalDeferredPhrase
+      # fts3EvalSelectDeferred sqlite3Fts3InitHashTable
+      # sqlite3Fts3InitTok).
+      cflags += [ "-Wno-unused-function" ]
+    }
+    if (is_linux) {
+      cflags += [
+        # SQLite doesn"t believe in compiler warnings,
+        # preferring testing.
+        #   http://www.sqlite.org/faq.html#q17
+        "-Wno-int-to-pointer-cast",
+        "-Wno-pointer-to-int-cast",
+      ]
+    }
+  }
+
   # "sqlite3" can cause conflicts with the system library.
   component("chromium_sqlite3") {
     visibility = [ ":*" ]
@@ -69,29 +90,14 @@ if (!use_system_sqlite) {
 
     include_dirs = [ "amalgamation" ]
 
-    config("sqlite_warnings") {
-      cflags = []
-      if (is_clang) {
-        # sqlite contains a few functions that are unused, at least on
-        # Windows with Chromium's sqlite patches applied
-        # (interiorCursorEOF fts3EvalDeferredPhrase
-        # fts3EvalSelectDeferred sqlite3Fts3InitHashTable
-        # sqlite3Fts3InitTok).
-        cflags += [ "-Wno-unused-function" ]
-      }
-      if (is_linux) {
-        cflags += [
-          # SQLite doesn"t believe in compiler warnings,
-          # preferring testing.
-          #   http://www.sqlite.org/faq.html#q17
-          "-Wno-int-to-pointer-cast",
-          "-Wno-pointer-to-int-cast",
-        ]
-      }
-    }
     configs -= [ "//build/config/compiler:chromium_code" ]
-    configs += [ "//build/config/compiler:no_chromium_code" ]
-    configs += [ ":sqlite_warnings" ]
+    configs += [
+      "//build/config/compiler:no_chromium_code",
+
+      # Must be after no_chromium_code for warning flags to be ordered
+      # correctly.
+      ":sqlite_warnings",
+    ]
 
     if (is_linux) {
       libs = [ "dl" ]

third_party/usrsctp/BUILD.gn

@@ -11,6 +11,13 @@ config("usrsctp_config") {
   ]
 }
 
+config("usrsctp_warnings") {
+  if (is_clang) {
+    # atomic_init in user_atomic.h is a static function in a header.
+    cflags = [ "-Wno-unused-function" ]
+  }
+}
+
 static_library("usrsctp") {
   sources = [
     "usrsctplib/netinet/sctp.h",
@@ -84,16 +91,15 @@ static_library("usrsctp") {
     # "SCTP_DEBUG", # Uncomment for SCTP debugging.
   ]
 
-  config("usrsctp_warnings") {
-    if (is_clang) {
-      # atomic_init in user_atomic.h is a static function in a header.
-      cflags = [ "-Wno-unused-function" ]
-    }
-  }
   configs -= [ "//build/config/compiler:chromium_code" ]
-  configs += [ "//build/config/compiler:no_chromium_code" ]
-  configs += [ "//build/config/compiler:no_incompatible_pointer_warnings" ]
-  configs += [ ":usrsctp_warnings" ]
+  configs += [
+    "//build/config/compiler:no_chromium_code",
+
+    # These must be after no_chromium_code for warning flags to be ordered
+    # correctly.
+    "//build/config/compiler:no_incompatible_pointer_warnings",
+    ":usrsctp_warnings",
+  ]
 
   public_configs = [ ":usrsctp_config" ]
 

third_party/yasm/BUILD.gn

@@ -135,6 +135,20 @@ if (current_toolchain == host_toolchain) {
     ]
   }
 
+  config("re2c_warnings") {
+    # re2c is missing CLOSEVOP from one switch.
+    if (is_clang) {
+      cflags = [
+        # re2c is missing CLOSEVOP from one switch.
+        "-Wno-switch",
+
+        # re2c contains many static functions in headers (because it's
+        # a C library predating C99.)
+        "-Wno-unused-function",
+      ]
+    }
+  }
+
   executable("re2c") {
     sources = [
       "source/patched-yasm/tools/re2c/actions.c",
@@ -148,23 +162,13 @@ if (current_toolchain == host_toolchain) {
       "source/patched-yasm/tools/re2c/translate.c",
     ]
 
-    config("re2c_warnings") {
-      # re2c is missing CLOSEVOP from one switch.
-      if (is_clang) {
-        cflags = [
-          # re2c is missing CLOSEVOP from one switch.
-          "-Wno-switch",
-
-          # re2c contains many static functions in headers (because it's
-          # a C library predating C99.)
-          "-Wno-unused-function",
-        ]
-      }
-    }
     configs -= [ "//build/config/compiler:chromium_code" ]
     configs += [
       ":yasm_config",
       "//build/config/compiler:no_chromium_code",
+
+      # Must be after no_chromium_code for warning flags to be ordered
+      # correctly.
       ":re2c_warnings",
     ]
     deps = [
@@ -172,6 +176,15 @@ if (current_toolchain == host_toolchain) {
     ]
   }
 
+  config("yasm_warnings") {
+    if (is_clang) {
+      cflags = [
+        # reg3264type in x86expr.c is unused.
+        "-Wno-unused-local-typedef",
+      ]
+    }
+  }
+
   executable("yasm") {
     sources = [
       "source/patched-yasm/frontends/yasm/yasm-options.c",
@@ -260,17 +273,11 @@ if (current_toolchain == host_toolchain) {
       ":yasm_config",
       "//build/config/compiler:no_chromium_code",
       "//build/config/compiler:no_incompatible_pointer_warnings",
-    ]
 
-    config("yasm_warnings") {
-      if (is_clang) {
-        cflags = [
-          # reg3264type in x86expr.c is unused.
-          "-Wno-unused-local-typedef",
-        ]
-      }
-    }
-    configs += [ ":yasm_warnings" ]
+      # Must be after no_chromium_code for warning flags to be ordered
+      # correctly.
+      ":yasm_warnings",
+    ]
 
     # Yasm generates a bunch of .c files which its source file #include.
     # Add the |target_gen_dir| into the include path so it can find them.

third_party/zlib/BUILD.gn

@@ -28,6 +28,13 @@ static_library("zlib_x86_simd") {
   configs += [ "//build/config/compiler:no_chromium_code" ]
 }
 
+config("zlib_warnings") {
+  if (is_clang && !is_ios &&
+      (current_cpu == "x86" || current_cpu == "x64")) {
+    cflags = [ "-Wno-incompatible-pointer-types" ]
+  }
+}
+
 static_library("zlib") {
   if (!is_win) {
     # Don't stomp on "libzlib" on other platforms.
@@ -67,17 +74,15 @@ static_library("zlib") {
 
   if (!is_ios && (current_cpu == "x86" || current_cpu == "x64")) {
     sources += [ "x86.c" ]
-
-    config("zlib_warnings") {
-      if (is_clang) {
-        cflags = [ "-Wno-incompatible-pointer-types" ]
-      }
-    }
-    configs += [ ":zlib_warnings" ]
   }
 
   configs -= [ "//build/config/compiler:chromium_code" ]
-  configs += [ "//build/config/compiler:no_chromium_code" ]
+  configs += [
+    "//build/config/compiler:no_chromium_code",
+
+    # Must be after no_chromium_code for warning flags to be ordered correctly.
+    ":zlib_warnings",
+  ]
 
   public_configs = [ ":zlib_config" ]
   deps = [
@@ -85,6 +90,14 @@ static_library("zlib") {
   ]
 }
 
+config("minizip_warnings") {
+  visibility = [ ":*" ]
+  if (is_clang) {
+    # zlib uses `if ((a == b))` for some reason.
+    cflags = [ "-Wno-parentheses-equality" ]
+  }
+}
+
 static_library("minizip") {
   sources = [
     "contrib/minizip/ioapi.c",
@@ -113,16 +126,13 @@ static_library("minizip") {
     ":zlib",
   ]
 
-  config("minizip_warnings") {
-    if (is_clang) {
-      # zlib uses `if ((a == b))` for some reason.
-      cflags = [ "-Wno-parentheses-equality" ]
-    }
-  }
-
   configs -= [ "//build/config/compiler:chromium_code" ]
-  configs += [ "//build/config/compiler:no_chromium_code" ]
-  configs += [ ":minizip_warnings" ]
+  configs += [
+    "//build/config/compiler:no_chromium_code",
+
+    # Must be after no_chromium_code for warning flags to be ordered correctly.
+    ":minizip_warnings",
+  ]
   public_configs = [ ":zlib_config" ]
 }