Add clang-format-fuzzer target

[kcc]

Summary

This adds clang-format-fuzzer binary,
which depends on the Fuzzer lib,
see http://reviews.llvm.org/D7184

This fuzer has found ~15 bugs so far, and I hope to set up a bot for it.

[kcc]

Update the cmake rule to use LLVMFuzzer
(http://reviews.llvm.org/rL227252 is committed)

[samsonov]

Looks good, but I'll let clang-format owners approve this.

tools/clang-format/CMakeLists.txt

8

Maybe, we could introduce

set(CLANG_FORMAT_LIB_DEPS
  clangBasic
  clangFormat
  clangRewrite
  clangToolingCore
  )

and use ${CLANG_FORMAT_LIB_DEPS} in both clang-format and clang-format-fuzzer. I have no strong preference, though.

tools/clang-format/fuzzer/ClangFormatFuzzer.cpp

2

clang-format/fizzer/ClangFormatFuzzer.cpp ?

[kcc]

addressed Alexey's comments.

tools/clang-format/CMakeLists.txt

8

no preference here.
changed to use CLANG_FORMAT_LIB_DEPS

tools/clang-format/fuzzer/ClangFormatFuzzer.cpp

2

actually, just ClangFormatFuzzer.cpp

[djasper]

Nice, thank you!

tools/clang-format/CMakeLists.txt

 set(LLVM_LINK_COMPONENTS support)
 
 add_clang_executable(clang-format
   ClangFormat.cpp
   )
 
-target_link_libraries(clang-format
+set(CLANG_FORMAT_LIB_DEPS
   clangBasic
   clangFormat
   clangRewrite
   clangToolingCore
   )
 
+target_link_libraries(clang-format
+  $CLANG_FORMAT_LIB_DEPS
+  )
+
+add_subdirectory(fuzzer)
+
 install(TARGETS clang-format RUNTIME DESTINATION bin)
 install(PROGRAMS clang-format-bbedit.applescript DESTINATION share/clang)
 install(PROGRAMS clang-format-diff.py DESTINATION share/clang)
 install(PROGRAMS clang-format-sublime.py DESTINATION share/clang)
 install(PROGRAMS clang-format.el DESTINATION share/clang)
 install(PROGRAMS clang-format.py DESTINATION share/clang)
 install(PROGRAMS git-clang-format DESTINATION bin)

tools/clang-format/fuzzer/CMakeLists.txt

+set(LLVM_LINK_COMPONENTS support)
+
+add_clang_executable(clang-format-fuzzer
+  EXCLUDE_FROM_ALL
+  ClangFormatFuzzer.cpp
+  )
+
+target_link_libraries(clang-format-fuzzer
+  ${CLANG_FORMAT_LIB_DEPS}
+  LLVMFuzzer
+  )

tools/clang-format/fuzzer/ClangFormatFuzzer.cpp

+//===-- ClangFormatFuzzer.cpp - Fuzz the Clang format tool ----------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+///
+/// \file
+/// \brief This file implements a function that runs Clang format on a single
+///  input. This function is then linked into the Fuzzer library.
+///
+//===----------------------------------------------------------------------===//
+
+#include "clang/Format/Format.h"
+
+extern "C" void TestOneInput(uint8_t *data, size_t size) {
+  // FIXME: fuzz more things: different styles, different style features.
+  std::string s((const char *)data, size);
+  auto Style = getGoogleStyle(clang::format::FormatStyle::LK_Cpp);
+  Style.ColumnLimit = 60;
+  applyAllReplacements(s, clang::format::reformat(
+                              Style, s, {clang::tooling::Range(0, s.size())}));
+}