Allow interfaces to operate on in-memory buffers with no source location info.

[tapaswenipathak]

Summary

Allow interfaces to operate on in-memory buffers with no source location info.

This patch avoid an assert PresumedLoc::getFilename if it is invalid.

Add unittests for allowing interface to operate on in-memory buffers with no
source location info.

Co-authored-by: Vassil Vassilev <[e-mail]>

[tapaswenipathak]

Ref: https://reviews.llvm.org/D126600, https://reviews.llvm.org/D126271.

include/clang/Basic/SourceManager.h

 
   /// Returns whether \p Loc is located in a <built-in> file.
   bool isWrittenInBuiltinFile(SourceLocation Loc) const {
-    StringRef Filename(getPresumedLoc(Loc).getFilename());
+    PresumedLoc Presumed = getPresumedLoc(Loc);
+    if (Presumed.isInvalid())
+      return false;
+    StringRef Filename(Presumed.getFilename());
     return Filename.equals("<built-in>");
   }
 
   /// Returns whether \p Loc is located in a <command line> file.
   bool isWrittenInCommandLineFile(SourceLocation Loc) const {
-    StringRef Filename(getPresumedLoc(Loc).getFilename());
+    PresumedLoc Presumed = getPresumedLoc(Loc);
+    if (Presumed.isInvalid())
+      return false;
+    StringRef Filename(Presumed.getFilename());
     return Filename.equals("<command line>");
   }
 
   /// Returns whether \p Loc is located in a <scratch space> file.
   bool isWrittenInScratchSpace(SourceLocation Loc) const {
-    StringRef Filename(getPresumedLoc(Loc).getFilename());
+    PresumedLoc Presumed = getPresumedLoc(Loc);
+    if (Presumed.isInvalid())
+      return false;
+    StringRef Filename(Presumed.getFilename());
     return Filename.equals("<scratch space>");
   }
 
   /// Returns if a SourceLocation is in a system header.
   bool isInSystemHeader(SourceLocation Loc) const {
+    if (Loc.isInvalid())
+      return false;
     return isSystem(getFileCharacteristic(Loc));
   }
 

unittests/Basic/SourceManagerTest.cpp

   IntrusiveRefCntPtr<TargetInfo> Target;
 };
 
+TEST_F(SourceManagerTest, isInMemoryBuffersNoSourceLocationInfo) {
+  SourceLocation Loc = NULL;
+  bool isWrittenInBuiltInFileFalse = SourceMgr.isWrittenInBuiltinFile(Loc);
+  bool isWrittenInCommandLineFileFalse =
+      SourceManager::isWrittenInCommandLineFile(Loc);
+  bool isWrittenInScratchSpaceFalse = SourceMgr.isWrittenInScratchSpace(Loc);
+
+  EXPECT_FALSE(inBuiltInFileFalse);
+  EXPECT_FALSE(isWrittenInCommandLindFileFalse);
+  EXPECT_FALSE(isWrittenInScratchSpaceFalse);
+
+  const char *Source = "int x";
+
+  std::unique_ptr<llvm::MemoryBuffer> BuiltInBuf =
+      llvm::MemoryBuffer::getMemBuffer(Source);
+  const FileEntry *BuiltInFile =
+      FileMgr.getVirtualFile("<built-in>", BuiltInBuf->getBufferSize(), 0);
+  SourceMgr.overrideFileContents(BuiltInFile, std::move(BuiltInBuf));
+  FileID BuiltInFileID =
+      SourceMgr.getOrCreateFileID(BuiltInFile, SrcMgr::C_User);
+  SourceMgr.setMainFileID(BuiltInFileID);
+  Loc = SourceMgr.getLocForStartOfFile(SourceMgr.getMainFileID());
+  bool isWrittenInBuiltInFileTrue = SourceMgr.isWrittenInBuiltinFile(Loc);
+
+  std::unique_ptr<llvm::MemoryBuffer> CommandLineBuf =
+      llvm::MemoryBuffer::getMemBuffer(Source);
+  const FileEntry *CommandLineFile = FileMgr.getVirtualFile(
+      "<command-line>", CommandLineBuf->getBufferSize(), 0);
+  SourceMgr.overrideFileContents(CommandLineFile, std::move(CommandLineBuf));
+  FileID BuiltInFileID =
+      SourceMgr.getOrCreateFileID(CommandLineFile, SrcMgr::C_User);
+  SourceMgr.setMainFileID(CommandLineFileID);
+  Loc = SourceMgr.getLocForStartOfFile(SourceMgr.getMainFileID());
+  bool isWrittenInCommandLineFileTrue =
+      SourceMgr.isWrittenInCommandLineFile(Loc);
+
+  std::unique_ptr<llvm::MemoryBuffer> ScratchSpaceBuf =
+      llvm::MemoryBuffer::getMemBuffer(Source);
+  const FileEntry *ScratchSpaceFile = FileMgr.getVirtualFile(
+      "<scratch space>", ScratchSpaceBuf->getBufferSize(), 0);
+  SourceMgr.overrideFileContents(CommandLineFile, std::move(ScratchSpaceBuf));
+  FileID ScratchSpaceID =
+      SourceMgr.getOrCreateFileID(ScratchSpaceFile, SrcMgr::C_User);
+  SourceMgr.setMainFileID(ScratchSpaceFileID);
+  Loc = SourceMgr.getLocForStartOfFile(SourceMgr.getMainFileID());
+  bool isWrittenInScratchSpaceTrue = SourceMgr.isWrittenInScratchSpace(Loc);
+
+  EXPECT_TRUE(inWrittenInBuiltInFileTrue);
+  EXPECT_TRUE(isWrittenInCommandLineFileTrue);
+  EXPECT_TRUE(isWrittenInScratchSpaceTrue);
+}
+
+TEST_F(SourceManagerTest, isInSystemHeader) {
+  SourceLocation Loc = NULL;
+  bool isInSystemHeaderFalse = SourceMgr.isInSystemHeader(Loc);
+  ASSERT_FALSE(isInSystemHeaderFalse);
+}
+
 TEST_F(SourceManagerTest, isBeforeInTranslationUnit) {
   const char *source =
     "#define M(x) [x]\n"