Make sure SLocEntry is an expansion before using getExpansion() method in SourceManager.

[hokein]

Summary

Make it not trigger the assertion in getExpansion().

Fixes PR24749.

[bkramer]

This doesn't have a test case. Also I don't understand why this is the correct fix. If someone is calling one of those method with a file SourceLocation (as opposed to a macro SourceLocation) they should stop doing that.

[hokein]

In D17722#365267, @bkramer wrote:

This doesn't have a test case. Also I don't understand why this is the correct fix. If someone is calling one of those method with a file SourceLocation (as opposed to a macro SourceLocation) they should stop doing that.

After a more deep investigation, I think the bug isn't related to SourceManger now. I'm closing this as in favor of D17805 .

lib/Basic/SourceManager.cpp

SourceManager::getExpansionRange(SourceLocation Loc) const {
   return Res;
 }
 
 bool SourceManager::isMacroArgExpansion(SourceLocation Loc,
                                         SourceLocation *StartLoc) const {
   if (!Loc.isMacroID()) return false;
 
   FileID FID = getFileID(Loc);
-  const SrcMgr::ExpansionInfo &Expansion = getSLocEntry(FID).getExpansion();
+  const SrcMgr::SLocEntry &Entry = getSLocEntry(FID);
+  if (!Entry.isExpansion()) return false;
+  const SrcMgr::ExpansionInfo &Expansion = Entry.getExpansion();
   if (!Expansion.isMacroArgExpansion()) return false;
 
   if (StartLoc)
     *StartLoc = Expansion.getExpansionLocStart();
   return true;
 }
 
 bool SourceManager::isMacroBodyExpansion(SourceLocation Loc) const {
   if (!Loc.isMacroID()) return false;
 
   FileID FID = getFileID(Loc);
-  const SrcMgr::ExpansionInfo &Expansion = getSLocEntry(FID).getExpansion();
+  const SrcMgr::SLocEntry &Entry = getSLocEntry(FID);
+  if (!Entry.isExpansion()) return false;
+  const SrcMgr::ExpansionInfo &Expansion = Entry.getExpansion();
   return Expansion.isMacroBodyExpansion();
 }
 
 bool SourceManager::isAtStartOfImmediateMacroExpansion(SourceLocation Loc,
                                              SourceLocation *MacroBegin) const {
   assert(Loc.isValid() && Loc.isMacroID() && "Expected a valid macro loc");
 
   std::pair<FileID, unsigned> DecompLoc = getDecomposedLoc(Loc);
   if (DecompLoc.second > 0)
     return false; // Does not point at the start of expansion range.
 
   bool Invalid = false;
-  const SrcMgr::ExpansionInfo &ExpInfo =
-      getSLocEntry(DecompLoc.first, &Invalid).getExpansion();
-  if (Invalid)
+  const SrcMgr::SLocEntry &Entry = getSLocEntry(DecompLoc.first, &Invalid);
+  if (Invalid || !Entry.isExpansion())
     return false;
+  const SrcMgr::ExpansionInfo &ExpInfo = Entry.getExpansion();
   SourceLocation ExpLoc = ExpInfo.getExpansionLocStart();
 
   if (ExpInfo.isMacroArgExpansion()) {
     // For macro argument expansions, check if the previous FileID is part of
     // the same argument expansion, in which case this Loc is not at the
     // beginning of the expansion.
     FileID PrevFID = getPreviousFileID(DecompLoc.first);
     if (!PrevFID.isInvalid()) {
bool SourceManager::isAtEndOfImmediateMacroExpansion(SourceLocation Loc,
   assert(Loc.isValid() && Loc.isMacroID() && "Expected a valid macro loc");
 
   FileID FID = getFileID(Loc);
   SourceLocation NextLoc = Loc.getLocWithOffset(1);
   if (isInFileID(NextLoc, FID))
     return false; // Does not point at the end of expansion range.
 
   bool Invalid = false;
-  const SrcMgr::ExpansionInfo &ExpInfo =
-      getSLocEntry(FID, &Invalid).getExpansion();
-  if (Invalid)
+  const SrcMgr::SLocEntry &Entry = getSLocEntry(FID, &Invalid);
+  if (Invalid || !Entry.isExpansion())
     return false;
+  const SrcMgr::ExpansionInfo &ExpInfo = Entry.getExpansion();
 
   if (ExpInfo.isMacroArgExpansion()) {
     // For macro argument expansions, check if the next FileID is part of the
     // same argument expansion, in which case this Loc is not at the end of the
     // expansion.
     FileID NextFID = getNextFileID(FID);
     if (!NextFID.isInvalid()) {
       const SrcMgr::SLocEntry &NextEntry = getSLocEntry(NextFID, &Invalid);