[PECOFF] Use RAII object for mutex.

llvm-svn: 204853

lld/include/lld/Driver/Driver.h

@@ -115,9 +115,6 @@ public:
                     bool isDirective = false);
 
 private:
-  static bool doParse(int argc, const char *argv[], PECOFFLinkingContext &info,
-                      raw_ostream &diagnostics, bool isDirective);
-
   WinLinkDriver() LLVM_DELETED_FUNCTION;
 };
 

lld/include/lld/Driver/WinLinkInputGraph.h

@@ -67,13 +67,11 @@ public:
   /// \brief Parse the group members.
   error_code parse(const LinkingContext &ctx, raw_ostream &diagnostics) override {
     auto *pctx = (PECOFFLinkingContext *)(&ctx);
-    error_code ec = error_code::success();
-    pctx->lock();
+    std::lock_guard<std::recursive_mutex> lock(pctx->getMutex());
     for (auto &elem : _elements)
-      if ((ec = elem->parse(ctx, diagnostics)))
-        break;
-    pctx->unlock();
-    return ec;
+      if (error_code ec = elem->parse(ctx, diagnostics))
+        return ec;
+    return error_code::success();
   }
 };
 

lld/include/lld/ReaderWriter/PECOFFLinkingContext.h

@@ -265,8 +265,7 @@ public:
   void setLibraryGroup(Group *group) { _libraryGroup = group; }
   Group *getLibraryGroup() const { return _libraryGroup; }
 
-  void lock() { _mutex.lock(); }
-  void unlock() { _mutex.unlock(); }
+  std::recursive_mutex &getMutex() { return _mutex; }
 
 protected:
   /// Method to create a internal file for the entry symbol

lld/lib/Driver/WinLinkDriver.cpp

@@ -780,9 +780,14 @@ bool WinLinkDriver::linkPECOFF(int argc, const char **argv, raw_ostream &diag) {
   return link(context, diag);
 }
 
-bool WinLinkDriver::doParse(int argc, const char *argv[],
-                            PECOFFLinkingContext &ctx, raw_ostream &diag,
-                            bool isReadingDirectiveSection) {
+bool WinLinkDriver::parse(int argc, const char *argv[],
+                          PECOFFLinkingContext &ctx, raw_ostream &diag,
+                          bool isReadingDirectiveSection) {
+  // Parse may be called from multiple threads simultaneously to parse .drectve
+  // sections. This function is not thread-safe because it mutates the context
+  // object. So acquire the lock.
+  std::lock_guard<std::recursive_mutex> lock(ctx.getMutex());
+
   std::map<StringRef, StringRef> failIfMismatchMap;
   // Parse the options.
   std::unique_ptr<llvm::opt::InputArgList> parsedArgs =
@@ -1260,16 +1265,4 @@ bool WinLinkDriver::doParse(int argc, const char *argv[],
   return ctx.validate(diag);
 }
 
-// Parse may be called from multiple threads simultaneously to parse .drectve
-// sections. doParse() is not thread-safe because it mutates the context
-// object. This function wraps doParse() with a mutex.
-bool WinLinkDriver::parse(int argc, const char *argv[],
-                          PECOFFLinkingContext &ctx, raw_ostream &diag,
-                          bool isReadingDirectiveSection) {
-  ctx.lock();
-  bool r = doParse(argc, argv, ctx, diag, isReadingDirectiveSection);
-  ctx.unlock();
-  return r;
-}
-
 } // namespace lld