Revert of Un-nest configs in GN files. (patchset #3 id:40001 of https://codereview.chromium.org/1318823008/ )

Reason for revert:
This breaks why these configs exist in the first place and seriously breaks the clang/win gn build (which is what these configs exist for).

Original issue's description:
> 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.
>
> Committed: https://crrev.com/4af2eac8e84692d94f88504ab6e0b244b88dddcb
> Cr-Commit-Position: refs/heads/master@{#346461}

TBR=dpranke@chromium.org,brettw@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true

Review URL: https://codereview.chromium.org/1316843006

Cr-Commit-Position: refs/heads/master@{#346695}

16 files changed, 224 insertions, 256 deletions

diff --git a/third_party/brotli/BUILD.gn b/third_party/brotli/BUILD.gn
index f18c802..2975f03 100644
--- a/third_party/brotli/BUILD.gn
+++ b/third_party/brotli/BUILD.gn
@@ -2,15 +2,6 @@
 # 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",
@@ -32,11 +23,17 @@ 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 += [
-   ":brotli_warnings",
-    "//build/config/compiler:no_chromium_code",
-  ]
+  configs += [ "//build/config/compiler:no_chromium_code" ]
+  configs += [ ":brotli_warnings" ]
 
   # Since we are never debug brotli, freeze the optimizations to -O2.
   if (is_debug) {
diff --git a/third_party/cld_2/BUILD.gn b/third_party/cld_2/BUILD.gn
index 9b05615..fc42c4f 100644
--- a/third_party/cld_2/BUILD.gn
+++ b/third_party/cld_2/BUILD.gn
@@ -33,14 +33,6 @@ 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) {
@@ -54,11 +46,15 @@ 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 += [
-    ":cld2_data_warnings",
-    "//build/config/compiler:no_chromium_code",
-  ]
+  configs += [ "//build/config/compiler:no_chromium_code" ]
+  configs += [ ":cld2_data_warnings" ]
 }
 
 # As in the corresponding gyp file, this just builds the core interfaces for
diff --git a/third_party/harfbuzz-ng/BUILD.gn b/third_party/harfbuzz-ng/BUILD.gn
index 29573fe..144130a 100644
--- a/third_party/harfbuzz-ng/BUILD.gn
+++ b/third_party/harfbuzz-ng/BUILD.gn
@@ -41,36 +41,6 @@ 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",
@@ -176,10 +146,26 @@ if (use_system_harfbuzz) {
     ]
 
     configs -= [ "//build/config/compiler:chromium_code" ]
-    configs += [
-      ":harfbuzz_warnings",
-      "//build/config/compiler:no_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" ]
+
     public_configs = [ ":harfbuzz-ng_config" ]
 
     deps = [
@@ -213,5 +199,16 @@ 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" ]
+      }
+    }
   }
 }
diff --git a/third_party/hunspell/BUILD.gn b/third_party/hunspell/BUILD.gn
index 84f0ae7..9e9f249 100644
--- a/third_party/hunspell/BUILD.gn
+++ b/third_party/hunspell/BUILD.gn
@@ -10,12 +10,6 @@ config("hunspell_config") {
   ]
 }
 
-config("hunspell_warnings") {
-  if (is_clang) {
-    cflags = [ "-Wno-unused-private-field" ]
-  }
-}
-
 source_set("hunspell") {
   sources = [
     "google/bdict.cc",
@@ -57,6 +51,12 @@ 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",
diff --git a/third_party/libpng/BUILD.gn b/third_party/libpng/BUILD.gn
index 2142059..c4e2650c 100644
--- a/third_party/libpng/BUILD.gn
+++ b/third_party/libpng/BUILD.gn
@@ -25,15 +25,6 @@ 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",
@@ -71,6 +62,14 @@ 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" ]
 }
 
diff --git a/third_party/libusb/BUILD.gn b/third_party/libusb/BUILD.gn
index 82aeabd..cce639e 100644
--- a/third_party/libusb/BUILD.gn
+++ b/third_party/libusb/BUILD.gn
@@ -10,17 +10,6 @@ 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",
@@ -57,6 +46,15 @@ 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" ]
diff --git a/third_party/libwebp/BUILD.gn b/third_party/libwebp/BUILD.gn
index d52e1da..3259ec3 100644
--- a/third_party/libwebp/BUILD.gn
+++ b/third_party/libwebp/BUILD.gn
@@ -162,13 +162,6 @@ 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",
@@ -189,6 +182,12 @@ 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" ]
 }
 
diff --git a/third_party/libxml/BUILD.gn b/third_party/libxml/BUILD.gn
index 39b5962..c967608 100644
--- a/third_party/libxml/BUILD.gn
+++ b/third_party/libxml/BUILD.gn
@@ -24,38 +24,6 @@ config("libxml_config") {
   ]
 }
 
-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",
-    ]
-  }
-}
-
 static_library("libxml") {
   output_name = "libxml2"
   sources = [
@@ -176,10 +144,7 @@ static_library("libxml") {
   ]
 
   configs -= [ "//build/config/compiler:chromium_code" ]
-  configs += [
-    ":libxml_warnings",
-    "//build/config/compiler:no_chromium_code",
-  ]
+  configs += [ "//build/config/compiler:no_chromium_code" ]
 
   public_configs = [ ":libxml_config" ]
   public_deps = [
@@ -202,5 +167,38 @@ 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" ]
 }
diff --git a/third_party/libxslt/BUILD.gn b/third_party/libxslt/BUILD.gn
index 1ecb11c..6b46db3 100644
--- a/third_party/libxslt/BUILD.gn
+++ b/third_party/libxslt/BUILD.gn
@@ -7,19 +7,6 @@ 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",
@@ -72,11 +59,21 @@ 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 += [
-    ":libxslt_warnings",
-    "//build/config/compiler:no_chromium_code",
-  ]
+  configs += [ "//build/config/compiler:no_chromium_code" ]
+  configs += [ ":libxslt_warnings" ]
   public_configs = [ ":libxslt_config" ]
 
   cflags = []
diff --git a/third_party/lzma_sdk/BUILD.gn b/third_party/lzma_sdk/BUILD.gn
index 74fff2d..2afe7b4 100644
--- a/third_party/lzma_sdk/BUILD.gn
+++ b/third_party/lzma_sdk/BUILD.gn
@@ -6,15 +6,6 @@ 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",
@@ -59,9 +50,17 @@ static_library("lzma_sdk") {
   ]
 
   configs -= [ "//build/config/compiler:chromium_code" ]
-  configs += [
-    ":clang_warnings",
-    "//build/config/compiler:no_chromium_code",
-  ]
+  configs += [ "//build/config/compiler:no_chromium_code" ]
+
   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" ]
 }
diff --git a/third_party/mesa/BUILD.gn b/third_party/mesa/BUILD.gn
index 58cb60c..052401f 100644
--- a/third_party/mesa/BUILD.gn
+++ b/third_party/mesa/BUILD.gn
@@ -148,15 +148,6 @@ 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",
@@ -261,6 +252,15 @@ 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
diff --git a/third_party/snappy/BUILD.gn b/third_party/snappy/BUILD.gn
index 8ab472d..97cce89 100644
--- a/third_party/snappy/BUILD.gn
+++ b/third_party/snappy/BUILD.gn
@@ -16,14 +16,6 @@ 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",
@@ -35,11 +27,16 @@ 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 += [
-    ":snappy_warnings",
-    "//build/config/compiler:no_chromium_code",
-  ]
+  configs += [ "//build/config/compiler:no_chromium_code" ]
+  configs += [ ":snappy_warnings" ]
   public_configs = [ ":snappy_config" ]
 
   if (is_win) {
diff --git a/third_party/sqlite/BUILD.gn b/third_party/sqlite/BUILD.gn
index ac14a2c..92d0d88 100644
--- a/third_party/sqlite/BUILD.gn
+++ b/third_party/sqlite/BUILD.gn
@@ -14,27 +14,6 @@ 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",
-      ]
-    }
-  }
-
   source_set("sqlite") {
     sources = [
       "amalgamation/sqlite3.c",
@@ -78,6 +57,26 @@ 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" ]
diff --git a/third_party/usrsctp/BUILD.gn b/third_party/usrsctp/BUILD.gn
index 3accc19..bbea24b 100644
--- a/third_party/usrsctp/BUILD.gn
+++ b/third_party/usrsctp/BUILD.gn
@@ -11,13 +11,6 @@ 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",
@@ -91,12 +84,16 @@ 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 += [
-    ":usrsctp_warnings",
-    "//build/config/compiler:no_chromium_code",
-    "//build/config/compiler:no_incompatible_pointer_warnings",
-  ]
+  configs += [ "//build/config/compiler:no_chromium_code" ]
+  configs += [ "//build/config/compiler:no_incompatible_pointer_warnings" ]
+  configs += [ ":usrsctp_warnings" ]
 
   public_configs = [ ":usrsctp_config" ]
 
diff --git a/third_party/yasm/BUILD.gn b/third_party/yasm/BUILD.gn
index b301a10..fcb779a 100644
--- a/third_party/yasm/BUILD.gn
+++ b/third_party/yasm/BUILD.gn
@@ -135,20 +135,6 @@ 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",
@@ -162,26 +148,30 @@ 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 += [
-      ":re2c_warnings",
       ":yasm_config",
       "//build/config/compiler:no_chromium_code",
+      ":re2c_warnings",
     ]
     deps = [
       "//build/config/sanitizers:deps",
     ]
   }
 
-  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",
@@ -268,11 +258,20 @@ if (current_toolchain == host_toolchain) {
     configs -= [ "//build/config/compiler:chromium_code" ]
     configs += [
       ":yasm_config",
-      ":yasm_warnings",
       "//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" ]
+
     # 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.
     # Ideally, these generated .c files would be placed into a separate
diff --git a/third_party/zlib/BUILD.gn b/third_party/zlib/BUILD.gn
index 66e0305..0d59218 100644
--- a/third_party/zlib/BUILD.gn
+++ b/third_party/zlib/BUILD.gn
@@ -28,13 +28,6 @@ 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.
@@ -74,13 +67,17 @@ 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 += [
-    ":zlib_warnings",
-    "//build/config/compiler:no_chromium_code",
-  ]
+  configs += [ "//build/config/compiler:no_chromium_code" ]
 
   public_configs = [ ":zlib_config" ]
   deps = [
@@ -88,14 +85,6 @@ 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",
@@ -124,6 +113,13 @@ 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" ]