clang: Use -Wheader-hygiene instead of a custom check in the plugin.

Revert the parts of http://codereview.chromium.org/6698051/ that added
the custom plugin code, and use the new warning we added to upstream
clang instead.

Define U_USING_ICU_NAMESPACE=0 to make ICU not use
|using namespace icu;| in its header and adapt cc files that use ICU.

Depends on http://codereview.chromium.org/6691062

BUG=none
TEST=none

Review URL: http://codereview.chromium.org/6677115

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@80509 0039d316-1c4b-4281-b951-d872f2087c98

8 files changed, 8 insertions, 83 deletions

diff --git a/build/common.gypi b/build/common.gypi
index 0a27489..3eab5ac 100644
--- a/build/common.gypi
+++ b/build/common.gypi
@@ -1248,6 +1248,7 @@
             'target_conditions': [
               ['_toolset=="target"', {
                 'cflags': [
+                  '-Wheader-hygiene',
                   # Clang spots more unused functions.
                   '-Wno-unused-function',
                   # Don't die on dtoa code that uses a char as an array index.
@@ -1381,6 +1382,7 @@
             ],
             ['clang==1', {
               'WARNING_CFLAGS': [
+                '-Wheader-hygiene',
                 # Don't die on dtoa code that uses a char as an array index.
                 # This is required solely for base/third_party/dmg_fp/dtoa.cc.
                 '-Wno-char-subscripts',
diff --git a/tools/clang/plugins/ChromeClassTester.cpp b/tools/clang/plugins/ChromeClassTester.cpp
index 32ea1ea..0f6d847 100644
--- a/tools/clang/plugins/ChromeClassTester.cpp
+++ b/tools/clang/plugins/ChromeClassTester.cpp
@@ -175,37 +175,6 @@ void ChromeClassTester::HandleTagDeclDefinition(TagDecl* tag) {
   }
 }
 
-void ChromeClassTester::HandleTranslationUnit(clang::ASTContext& ctx) {
-  RecursivelyCheckTopLevels(ctx.getTranslationUnitDecl());
-}
-
-void ChromeClassTester::RecursivelyCheckTopLevels(Decl* d) {
-  // Unlike HandleTagDeclDefinition, we can only rely on having parsing
-  // information here. We absoluetly shouldn't check that any semantic data
-  // here because we will assert.
-  //
-  // This method will NOT recurse into classes declarations or any record
-  // types.
-
-  Decl::Kind kind = d->getKind();
-  if (kind == Decl::UsingDirective) {
-    UsingDirectiveDecl* record = cast<UsingDirectiveDecl>(d);
-    SourceLocation record_location = record->getLocation();
-    if (!InBannedDirectory(record_location))
-      CheckChromeUsingDirective(record_location, record);
-  }
-
-  // If this is a DeclContext that isn't a function/method, recurse.
-  if (DeclContext* context = dyn_cast<DeclContext>(d)) {
-    if (context->isFileContext()) {
-      for (DeclContext::decl_iterator it = context->decls_begin();
-           it != context->decls_end(); ++it) {
-        RecursivelyCheckTopLevels(*it);
-      }
-    }
-  }
-}
-
 void ChromeClassTester::emitWarning(SourceLocation loc, const char* raw_error) {
   FullSourceLoc full(loc, instance().getSourceManager());
   std::string err;
diff --git a/tools/clang/plugins/ChromeClassTester.h b/tools/clang/plugins/ChromeClassTester.h
index a61cd01..f00bb6a 100644
--- a/tools/clang/plugins/ChromeClassTester.h
+++ b/tools/clang/plugins/ChromeClassTester.h
@@ -26,7 +26,6 @@ class ChromeClassTester : public clang::ASTConsumer {
 
   // ASTConsumer:
   virtual void HandleTagDeclDefinition(clang::TagDecl* tag);
-  virtual void HandleTranslationUnit(clang::ASTContext& ctx);
 
  protected:
   clang::CompilerInstance& instance() { return instance_; }
@@ -46,13 +45,6 @@ class ChromeClassTester : public clang::ASTConsumer {
   // chrome header files.
   virtual void CheckChromeClass(const clang::SourceLocation& record_location,
                                 clang::CXXRecordDecl* record) = 0;
-  virtual void CheckChromeUsingDirective(
-      const clang::SourceLocation& record_location,
-      clang::UsingDirectiveDecl* record) = 0;
-
-  // The ChromeClassTester receives each top level declaration, looking for
-  // Decls we are interested in.
-  void RecursivelyCheckTopLevels(clang::Decl* d);
 
   // Utility methods used for filtering out non-chrome classes (and ones we
   // delibrately ignore) in HandleTagDeclDefinition().
diff --git a/tools/clang/plugins/FindBadConstructs.cpp b/tools/clang/plugins/FindBadConstructs.cpp
index 3c8f623..d7bcdae 100644
--- a/tools/clang/plugins/FindBadConstructs.cpp
+++ b/tools/clang/plugins/FindBadConstructs.cpp
@@ -47,16 +47,6 @@ class FindBadConstructsConsumer : public ChromeClassTester {
     CheckVirtualMethods(record_location, record);
   }
 
-  virtual void CheckChromeUsingDirective(
-      const clang::SourceLocation& record_location,
-      clang::UsingDirectiveDecl* record) {
-    // |record| is a using directive in a chrome header. This should never be
-    // allowed.
-    emitWarning(record_location,
-                "Using namespace directives are banned in headers in Google "
-                "style.");
-  }
-
   // Prints errors if the constructor/destructor weight it too heavy.
   void CheckCtorDtorWeight(const SourceLocation& record_location,
                            CXXRecordDecl* record) {
diff --git a/tools/clang/plugins/tests/test.sh b/tools/clang/plugins/tests/test.sh
index ef0070f..e22e0d7 100755
--- a/tools/clang/plugins/tests/test.sh
+++ b/tools/clang/plugins/tests/test.sh
@@ -21,7 +21,7 @@ usage() {
 # Runs a single test case.
 do_testcase() {
   local output="$("${CLANG_DIR}"/bin/clang -cc1 \
-      -load "${CLANG_DIR}"/lib/libFindBadConstructs.so \
+      -load "${CLANG_DIR}"/lib/libFindBadConstructs.${LIB} \
       -plugin find-bad-constructs ${1} 2>&1)"
   local diffout="$(echo "${output}" | diff - "${2}")"
   if [ "${diffout}" = "" ]; then
@@ -44,6 +44,11 @@ elif [[ ! -d "${1}" ]]; then
 else
   echo "Using clang directory ${1}..."
   export CLANG_DIR="${1}"
+  if [ "$(uname -s)" = "Linux" ]; then
+    export LIB=so
+  elif [ "$(uname -s)" = "Darwin" ]; then
+    export LIB=dylib
+  fi
 fi
 
 for input in *.cpp; do
diff --git a/tools/clang/plugins/tests/using_directive.cpp b/tools/clang/plugins/tests/using_directive.cpp
deleted file mode 100644
index f48f2c1..0000000
--- a/tools/clang/plugins/tests/using_directive.cpp
+++ /dev/null
@@ -1,15 +0,0 @@
-// Copyright (c) 2011 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#include "using_directive.h"
-
-int main() {
-  // Don't warn here. We use this pattern in unit tests and it's probably
-  // harmless. Headers included in multiple translation units could be harmful
-  // though.
-  using namespace std;
-  vector<int> a;
-  a.push_back(1);
-  return 0;
-}
diff --git a/tools/clang/plugins/tests/using_directive.h b/tools/clang/plugins/tests/using_directive.h
deleted file mode 100644
index d31840f..0000000
--- a/tools/clang/plugins/tests/using_directive.h
+++ /dev/null
@@ -1,13 +0,0 @@
-// Copyright (c) 2011 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#ifndef USING_DIRECTIVE_H_
-#define USING_DIRECTIVE_H_
-
-#include <vector>
-
-// Should warn in headers.
-using namespace std;
-
-#endif  // USING_DIRECTIVE_H_
diff --git a/tools/clang/plugins/tests/using_directive.txt b/tools/clang/plugins/tests/using_directive.txt
deleted file mode 100644
index d415fa5..0000000
--- a/tools/clang/plugins/tests/using_directive.txt
+++ /dev/null
@@ -1,5 +0,0 @@
-In file included from using_directive.cpp:5:
-./using_directive.h:11:17: warning: [chromium-style] Using namespace directives are banned in headers in Google style.
-using namespace std;
-                ^
-1 warning generated.