Added Fixer implementation and fix() interface in clang-format for removing redundant code.

Summary:
After applying replacements, redundant code like extra commas or empty namespaces
might be introduced. Fixer can detect and remove any redundant code introduced by replacements.
The current implementation only handles redundant commas.

Reviewers: djasper, klimek

Subscribers: ioeric, mprobst, klimek, cfe-commits

Differential Revision: http://reviews.llvm.org/D18551

llvm-svn: 267416

3 files changed, 148 insertions, 0 deletions

diff --git a/clang/unittests/Format/CMakeLists.txt b/clang/unittests/Format/CMakeLists.txt
index a93783cedff..4cf8b731a0d 100644
--- a/clang/unittests/Format/CMakeLists.txt
+++ b/clang/unittests/Format/CMakeLists.txt
@@ -3,6 +3,7 @@ set(LLVM_LINK_COMPONENTS
   )
 
 add_clang_unittest(FormatTests
+  CleanupTest.cpp
   FormatTest.cpp
   FormatTestJava.cpp
   FormatTestJS.cpp
diff --git a/clang/unittests/Format/CleanupTest.cpp b/clang/unittests/Format/CleanupTest.cpp
new file mode 100644
index 00000000000..5ea8e651a38
--- /dev/null
+++ b/clang/unittests/Format/CleanupTest.cpp
@@ -0,0 +1,118 @@
+//===- unittest/Format/CleanupTest.cpp - Code cleanup unit tests ----------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/Format/Format.h"
+
+#include "clang/Tooling/Core/Replacement.h"
+
+#include "gtest/gtest.h"
+
+namespace clang {
+namespace format {
+namespace {
+
+class CleanupTest : public ::testing::Test {
+protected:
+  std::string cleanup(llvm::StringRef Code,
+                      const std::vector<tooling::Range> &Ranges,
+                      const FormatStyle &Style = getLLVMStyle()) {
+    tooling::Replacements Replaces = format::cleanup(Style, Code, Ranges);
+
+    std::string Result = applyAllReplacements(Code, Replaces);
+    EXPECT_NE("", Result);
+    return Result;
+  }
+};
+
+TEST_F(CleanupTest, DeleteEmptyNamespaces) {
+  std::string Code = "namespace A {\n"
+                     "namespace B {\n"
+                     "} // namespace B\n"
+                     "} // namespace A\n\n"
+                     "namespace C {\n"
+                     "namespace D { int i; }\n"
+                     "inline namespace E { namespace { } }\n"
+                     "}";
+  std::string Expected = "\n\n\n\n\nnamespace C {\n"
+                         "namespace D { int i; }\n   \n"
+                         "}";
+  std::vector<tooling::Range> Ranges;
+  Ranges.push_back(tooling::Range(28, 0));
+  Ranges.push_back(tooling::Range(91, 6));
+  Ranges.push_back(tooling::Range(132, 0));
+  std::string Result = cleanup(Code, Ranges);
+  EXPECT_EQ(Expected, Result);
+}
+
+TEST_F(CleanupTest, NamespaceWithSyntaxError) {
+  std::string Code = "namespace A {\n"
+                     "namespace B {\n" // missing r_brace
+                     "} // namespace A\n\n"
+                     "namespace C {\n"
+                     "namespace D int i; }\n"
+                     "inline namespace E { namespace { } }\n"
+                     "}";
+  std::string Expected = "namespace A {\n"
+                         "\n\n\nnamespace C {\n"
+                         "namespace D int i; }\n   \n"
+                         "}";
+  std::vector<tooling::Range> Ranges(1, tooling::Range(0, Code.size()));
+  std::string Result = cleanup(Code, Ranges);
+  EXPECT_EQ(Expected, Result);
+}
+
+TEST_F(CleanupTest, EmptyNamespaceNotAffected) {
+  std::string Code = "namespace A {\n\n"
+                     "namespace {\n\n}}";
+  // Even though the namespaces are empty, but the inner most empty namespace
+  // block is not affected by the changed ranges.
+  std::string Expected = "namespace A {\n\n"
+                         "namespace {\n\n}}";
+  // Set the changed range to be the second "\n".
+  std::vector<tooling::Range> Ranges(1, tooling::Range(14, 0));
+  std::string Result = cleanup(Code, Ranges);
+  EXPECT_EQ(Expected, Result);
+}
+
+TEST_F(CleanupTest, EmptyNamespaceWithCommentsNoBreakBeforeBrace) {
+  std::string Code = "namespace A {\n"
+                     "namespace B {\n"
+                     "// Yo\n"
+                     "} // namespace B\n"
+                     "} // namespace A\n"
+                     "namespace C { // Yo\n"
+                     "}";
+  std::string Expected = "\n\n\n\n\n\n";
+  std::vector<tooling::Range> Ranges(1, tooling::Range(0, Code.size()));
+  std::string Result = cleanup(Code, Ranges);
+  EXPECT_EQ(Expected, Result);
+}
+
+TEST_F(CleanupTest, EmptyNamespaceWithCommentsBreakBeforeBrace) {
+  std::string Code = "namespace A\n"
+                     "/* Yo */ {\n"
+                     "namespace B\n"
+                     "{\n"
+                     "// Yo\n"
+                     "} // namespace B\n"
+                     "} // namespace A\n"
+                     "namespace C\n"
+                     "{ // Yo\n"
+                     "}\n";
+  std::string Expected = "\n\n\n\n\n\n\n\n\n\n";
+  std::vector<tooling::Range> Ranges(1, tooling::Range(0, Code.size()));
+  FormatStyle Style = getLLVMStyle();
+  Style.BraceWrapping.AfterNamespace = true;
+  std::string Result = cleanup(Code, Ranges, Style);
+  EXPECT_EQ(Expected, Result);
+}
+
+} // end namespace
+} // end namespace format
+} // end namespace clang
diff --git a/clang/unittests/Format/FormatTest.cpp b/clang/unittests/Format/FormatTest.cpp
index 0a9969a9b70..0f785705d9e 100644
--- a/clang/unittests/Format/FormatTest.cpp
+++ b/clang/unittests/Format/FormatTest.cpp
@@ -11526,6 +11526,35 @@ TEST_F(ReplacementTest, FormatCodeAfterReplacements) {
                           Code, formatReplacements(Code, Replaces, Style)));
 }
 
+TEST_F(ReplacementTest, FixOnlyAffectedCodeAfterReplacements) {
+  std::string Code = "namespace A {\n"
+                     "namespace B {\n"
+                     "  int x;\n"
+                     "} // namespace B\n"
+                     "} // namespace A\n"
+                     "\n"
+                     "namespace C {\n"
+                     "namespace D { int i; }\n"
+                     "inline namespace E { namespace { int y; } }\n"
+                     "int x=     0;"
+                     "}";
+  std::string Expected = "\n\nnamespace C {\n"
+                         "namespace D { int i; }\n\n"
+                         "int x=     0;"
+                         "}";
+  FileID ID = Context.createInMemoryFile("fix.cpp", Code);
+  tooling::Replacements Replaces;
+  Replaces.insert(tooling::Replacement(
+      Context.Sources, Context.getLocation(ID, 3, 3), 6, ""));
+  Replaces.insert(tooling::Replacement(
+      Context.Sources, Context.getLocation(ID, 9, 34), 6, ""));
+
+  format::FormatStyle Style = format::getLLVMStyle();
+  auto FinalReplaces = formatReplacements(
+      Code, cleanupAroundReplacements(Code, Replaces, Style), Style);
+  EXPECT_EQ(Expected, applyAllReplacements(Code, FinalReplaces));
+}
+
 } // end namespace
 } // end namespace format
 } // end namespace clang