[clang-move] Compare with real paths of symlinks

[hokein]

Summary

MakeAbsolutePath does wrong things with symlinks previously. When comparing with a symlink, we need to compare with the real path of it. This fixes issues when the build directory is a symlink.

[hokein]

Update the patch based on offline discussion.

[ioeric]

Lg with one nit.

clang-move/ClangMove.cpp

410

This duplicates MakeAbsolutePath in line 400

[hokein]

Update.

clang-move/ClangMove.cpp

 // The Path can be a path relative to the build directory, or retrieved from
 // the SourceManager.
 std::string MakeAbsolutePath(const SourceManager& SM, StringRef Path) {
   llvm::SmallString<128> AbsolutePath(Path);
   if (std::error_code EC =
        SM.getFileManager().getVirtualFileSystem()->makeAbsolute(AbsolutePath))
     llvm::errs() << "Warning: could not make absolute file: '" <<  EC.message()
                  << '\n';
-  llvm::sys::path::remove_dots(AbsolutePath, /*remove_dot_dot=*/true);
-  llvm::sys::path::native(AbsolutePath);
+  // Handle symbolic link path cases.
+  // We are trying to get the real file path of the symlink.
+  const DirectoryEntry *Dir = SM.getFileManager().getDirectory(
+       llvm::sys::path::parent_path(AbsolutePath.str()));
+  if (Dir) {
+    StringRef DirName = SM.getFileManager().getCanonicalName(Dir);
+    SmallVector<char, 128> AbsoluteFilename;
+    llvm::sys::path::append(AbsoluteFilename, DirName,
+                            llvm::sys::path::filename(AbsolutePath.str()));
+    return llvm::StringRef(AbsoluteFilename.data(), AbsoluteFilename.size())
+        .str();
+  }
   return AbsolutePath.str();
 }
 
 // Matches AST nodes that are expanded within the given AbsoluteFilePath.
 AST_POLYMORPHIC_MATCHER_P(isExpansionInFile,
                           AST_POLYMORPHIC_SUPPORTED_TYPES(Decl, Stmt, TypeLoc),
                           std::string, AbsoluteFilePath) {
   auto &SourceManager = Finder->getASTContext().getSourceManager();
void ClangMoveTool::run(const ast_matchers::MatchFinder::MatchResult &Result) {
   }
 }
 
 void ClangMoveTool::addIncludes(llvm::StringRef IncludeHeader,
                                 bool IsAngled,
                                 llvm::StringRef SearchPath,
                                 llvm::StringRef FileName,
                                 const SourceManager& SM) {
-  auto AbsoluteSearchPath = MakeAbsolutePath(SM, SearchPath);
+  SmallVector<char, 128> HeaderWithSearchPath;
+  llvm::sys::path::append(HeaderWithSearchPath, SearchPath, IncludeHeader);
   // FIXME: Add old.h to the new.cc/h when the new target has dependencies on
   // old.h/c. For instance, when moved class uses another class defined in
   // old.h, the old.h should be added in new.h.
   if (MakeAbsolutePath(OriginalRunningDirectory, Spec.OldHeader) ==
-      MakeAbsolutePath(AbsoluteSearchPath, IncludeHeader))
+      MakeAbsolutePath(SM, llvm::StringRef(HeaderWithSearchPath.data(),
+                                           HeaderWithSearchPath.size())))
     return;
 
   std::string IncludeLine =
       IsAngled ? ("#include <" + IncludeHeader + ">\n").str()
                : ("#include \"" + IncludeHeader + "\"\n").str();
 
   std::string AbsolutePath = MakeAbsolutePath(SM, FileName);
   if (MakeAbsolutePath(OriginalRunningDirectory, Spec.OldHeader) ==
       AbsolutePath) {
     HeaderIncludes.push_back(IncludeLine);
   } else if (MakeAbsolutePath(OriginalRunningDirectory, Spec.OldCC) ==
              AbsolutePath) {
     CCIncludes.push_back(IncludeLine);
   }
 }
 

test/clang-move/Inputs/database_template.json

 [
 {
   "directory": "$test_dir/build",
-  "command": "clang++ -o test.o $test_dir/test.cpp",
+  "command": "clang++ -o test.o -I../include $test_dir/test.cpp",
   "file": "$test_dir/test.cpp"
 }
 ]

test/clang-move/move-class.cpp

 // RUN: mkdir -p %T/clang-move/build
+// RUN: mkdir -p %T/clang-move/include
 // RUN: sed 's|$test_dir|%/T/clang-move|g' %S/Inputs/database_template.json > %T/clang-move/compile_commands.json
-// RUN: cp %S/Inputs/test*  %T/clang-move/
-// RUN: touch %T/clang-move/test2.h
-// RUN: cd %T/clang-move
-// RUN: clang-move -name="a::Foo" -new_cc=%T/clang-move/new_test.cpp -new_header=%T/clang-move/new_test.h -old_cc=../clang-move/test.cpp -old_header=../clang-move/test.h %T/clang-move/test.cpp
+// RUN: cp %S/Inputs/test.h  %T/clang-move/include
+// RUN: cp %S/Inputs/test.cpp %T/clang-move
+// RUN: touch %T/clang-move/include/test2.h
+// RUN: cd %T/clang-move/build
+// RUN: clang-move -name="a::Foo" -new_cc=%T/clang-move/new_test.cpp -new_header=%T/clang-move/new_test.h -old_cc=../test.cpp -old_header=../include/test.h %T/clang-move/test.cpp
 // RUN: FileCheck -input-file=%T/clang-move/new_test.cpp -check-prefix=CHECK-NEW-TEST-CPP %s
 // RUN: FileCheck -input-file=%T/clang-move/new_test.h -check-prefix=CHECK-NEW-TEST-H %s
 // RUN: FileCheck -input-file=%T/clang-move/test.cpp -check-prefix=CHECK-OLD-TEST-CPP %s
-// RUN: FileCheck -input-file=%T/clang-move/test.h %s -implicit-check-not='{{namespace.*}}'
+// RUN: FileCheck -input-file=%T/clang-move/include/test.h %s -implicit-check-not='{{namespace.*}}'
 //
-// RUN: cp %S/Inputs/test*  %T/clang-move/
-// RUN: cd %T/clang-move
-// RUN: clang-move -name="a::Foo" -new_cc=%T/clang-move/new_test.cpp -new_header=%T/clang-move/new_test.h -old_cc=%T/clang-move/test.cpp -old_header=%T/clang-move/test.h %T/clang-move/test.cpp
+// RUN: cp %S/Inputs/test.h  %T/clang-move/include
+// RUN: cp %S/Inputs/test.cpp %T/clang-move
+// RUN: cd %T/clang-move/build
+// RUN: clang-move -name="a::Foo" -new_cc=%T/clang-move/new_test.cpp -new_header=%T/clang-move/new_test.h -old_cc=%T/clang-move/test.cpp -old_header=%T/clang-move/include/test.h %T/clang-move/test.cpp
 // RUN: FileCheck -input-file=%T/clang-move/new_test.cpp -check-prefix=CHECK-NEW-TEST-CPP %s
 // RUN: FileCheck -input-file=%T/clang-move/new_test.h -check-prefix=CHECK-NEW-TEST-H %s
 // RUN: FileCheck -input-file=%T/clang-move/test.cpp -check-prefix=CHECK-OLD-TEST-CPP %s
-// RUN: FileCheck -input-file=%T/clang-move/test.h %s -implicit-check-not='{{namespace.*}}'
+// RUN: FileCheck -input-file=%T/clang-move/include/test.h %s -implicit-check-not='{{namespace.*}}'
 //
 // CHECK-NEW-TEST-H: namespace a {
 // CHECK-NEW-TEST-H: class Foo {
 // CHECK-NEW-TEST-H: public:
 // CHECK-NEW-TEST-H:   int f();
 // CHECK-NEW-TEST-H: };
 // CHECK-NEW-TEST-H: } // namespace a
 //
 // CHECK-NEW-TEST-CPP: #include "{{.*}}new_test.h"
 // CHECK-NEW-TEST-CPP: #include "test2.h"
 // CHECK-NEW-TEST-CPP: namespace a {
 // CHECK-NEW-TEST-CPP: int Foo::f() { return 0; }
 // CHECK-NEW-TEST-CPP: } // namespace a
 //
 // CHECK-OLD-TEST-CPP: #include "test.h"
 // CHECK-OLD-TEST-CPP: #include "test2.h"