Adds support for auto-detection of compilation databases

from a source file and changes clang-check to make use of this.

This makes clang-check just work on in-tree builds, and allows
easy setup via a symlink per source directory to make clang-check
work without any extra configuration.

llvm-svn: 159990

2 files changed, 25 insertions, 21 deletions

diff --git a/clang/lib/Tooling/CompilationDatabase.cpp b/clang/lib/Tooling/CompilationDatabase.cpp
index 227fa82926c..8e911123bc8 100644
--- a/clang/lib/Tooling/CompilationDatabase.cpp
+++ b/clang/lib/Tooling/CompilationDatabase.cpp
@@ -12,6 +12,7 @@
 //===----------------------------------------------------------------------===//
 
 #include "clang/Tooling/CompilationDatabase.h"
+#include "clang/Tooling/Tooling.h"
 #include "llvm/ADT/SmallString.h"
 #include "llvm/Support/YAMLParser.h"
 #include "llvm/Support/Path.h"
@@ -121,6 +122,23 @@ CompilationDatabase::loadFromDirectory(StringRef BuildDirectory,
   return Database.take();
 }
 
+CompilationDatabase *
+CompilationDatabase::autoDetectFromSource(StringRef SourceFile,
+                                          std::string &ErrorMessage) {
+  llvm::SmallString<1024> AbsolutePath(getAbsolutePath(SourceFile));
+  StringRef Directory = llvm::sys::path::parent_path(AbsolutePath);
+  while (!Directory.empty()) {
+    std::string LoadErrorMessage;
+    if (CompilationDatabase *DB = loadFromDirectory(Directory,
+                                                    LoadErrorMessage))
+      return DB;
+    Directory = llvm::sys::path::parent_path(Directory);
+  }
+  ErrorMessage = ("Could not auto-detect compilation database for file \"" +
+                  SourceFile + "\"").str();
+  return NULL;
+}
+
 FixedCompilationDatabase *
 FixedCompilationDatabase::loadFromCommandLine(int &Argc,
                                               const char **Argv,
@@ -283,4 +301,3 @@ bool JSONCompilationDatabase::parse(std::string &ErrorMessage) {
 
 } // end namespace tooling
 } // end namespace clang
-
diff --git a/clang/lib/Tooling/Tooling.cpp b/clang/lib/Tooling/Tooling.cpp
index abac182b215..5d41172a919 100644
--- a/clang/lib/Tooling/Tooling.cpp
+++ b/clang/lib/Tooling/Tooling.cpp
@@ -115,20 +115,13 @@ bool runToolOnCode(clang::FrontendAction *ToolAction, const Twine &Code,
   return Invocation.run();
 }
 
-/// \brief Returns the absolute path of 'File', by prepending it with
-/// 'BaseDirectory' if 'File' is not absolute.
-///
-/// Otherwise returns 'File'.
-/// If 'File' starts with "./", the returned path will not contain the "./".
-/// Otherwise, the returned path will contain the literal path-concatenation of
-/// 'BaseDirectory' and 'File'.
-///
-/// \param File Either an absolute or relative path.
-/// \param BaseDirectory An absolute path.
-static std::string getAbsolutePath(
-    StringRef File, StringRef BaseDirectory) {
+std::string getAbsolutePath(StringRef File) {
+  llvm::SmallString<1024> BaseDirectory;
+  if (const char *PWD = ::getenv("PWD"))
+    BaseDirectory = PWD;
+  else
+    llvm::sys::fs::current_path(BaseDirectory);
   SmallString<1024> PathStorage;
-  assert(llvm::sys::path::is_absolute(BaseDirectory));
   if (llvm::sys::path::is_absolute(File)) {
     llvm::sys::path::native(File, PathStorage);
     return PathStorage.str();
@@ -240,14 +233,8 @@ ClangTool::ClangTool(const CompilationDatabase &Compilations,
                      ArrayRef<std::string> SourcePaths)
     : Files((FileSystemOptions())),
       ArgsAdjuster(new ClangSyntaxOnlyAdjuster()) {
-  llvm::SmallString<1024> BaseDirectory;
-  if (const char *PWD = ::getenv("PWD"))
-    BaseDirectory = PWD;
-  else
-    llvm::sys::fs::current_path(BaseDirectory);
   for (unsigned I = 0, E = SourcePaths.size(); I != E; ++I) {
-    llvm::SmallString<1024> File(getAbsolutePath(
-        SourcePaths[I], BaseDirectory));
+    llvm::SmallString<1024> File(getAbsolutePath(SourcePaths[I]));
 
     std::vector<CompileCommand> CompileCommandsForFile =
       Compilations.getCompileCommands(File.str());