Make sure to always check the result of

SourceManager::getPresumedLoc(), so that we don't try to make use of
an invalid presumed location. Doing so can cause crashes.

llvm-svn: 118885

3 files changed, 20 insertions, 8 deletions

diff --git a/clang/lib/Lex/PPDirectives.cpp b/clang/lib/Lex/PPDirectives.cpp
index 7d428402db4..7aa3b31bc73 100644
--- a/clang/lib/Lex/PPDirectives.cpp
+++ b/clang/lib/Lex/PPDirectives.cpp
@@ -804,7 +804,9 @@ static bool ReadLineMarkerFlags(bool &IsFileEntry, bool &IsFileExit,
     FileID CurFileID =
       SM.getDecomposedInstantiationLoc(FlagTok.getLocation()).first;
     PresumedLoc PLoc = SM.getPresumedLoc(FlagTok.getLocation());
-
+    if (PLoc.isInvalid())
+      return true;
+    
     // If there is no include loc (main file) or if the include loc is in a
     // different physical file, then we aren't in a "1" line marker flag region.
     SourceLocation IncLoc = PLoc.getIncludeLoc();
diff --git a/clang/lib/Lex/PPMacroExpansion.cpp b/clang/lib/Lex/PPMacroExpansion.cpp
index b779dd56543..2428f9af450 100644
--- a/clang/lib/Lex/PPMacroExpansion.cpp
+++ b/clang/lib/Lex/PPMacroExpansion.cpp
@@ -723,7 +723,7 @@ void Preprocessor::ExpandBuiltinMacro(Token &Tok) {
     PresumedLoc PLoc = SourceMgr.getPresumedLoc(Loc);
 
     // __LINE__ expands to a simple numeric value.
-    OS << PLoc.getLine();
+    OS << (PLoc.isValid()? PLoc.getLine() : 1);
     Tok.setKind(tok::numeric_constant);
   } else if (II == Ident__FILE__ || II == Ident__BASE_FILE__) {
     // C99 6.10.8: "__FILE__: The presumed name of the current source file (a
@@ -732,19 +732,24 @@ void Preprocessor::ExpandBuiltinMacro(Token &Tok) {
 
     // __BASE_FILE__ is a GNU extension that returns the top of the presumed
     // #include stack instead of the current file.
-    if (II == Ident__BASE_FILE__) {
+    if (II == Ident__BASE_FILE__ && PLoc.isValid()) {
       SourceLocation NextLoc = PLoc.getIncludeLoc();
       while (NextLoc.isValid()) {
         PLoc = SourceMgr.getPresumedLoc(NextLoc);
+        if (PLoc.isInvalid())
+          break;
+        
         NextLoc = PLoc.getIncludeLoc();
       }
     }
 
     // Escape this filename.  Turn '\' -> '\\' '"' -> '\"'
     llvm::SmallString<128> FN;
-    FN += PLoc.getFilename();
-    Lexer::Stringify(FN);
-    OS << '"' << FN.str() << '"';
+    if (PLoc.isValid()) {
+      FN += PLoc.getFilename();
+      Lexer::Stringify(FN);
+      OS << '"' << FN.str() << '"';
+    }
     Tok.setKind(tok::string_literal);
   } else if (II == Ident__DATE__) {
     if (!DATELoc.isValid())
@@ -770,9 +775,11 @@ void Preprocessor::ExpandBuiltinMacro(Token &Tok) {
     unsigned Depth = 0;
 
     PresumedLoc PLoc = SourceMgr.getPresumedLoc(Tok.getLocation());
-    PLoc = SourceMgr.getPresumedLoc(PLoc.getIncludeLoc());
-    for (; PLoc.isValid(); ++Depth)
+    if (PLoc.isValid()) {
       PLoc = SourceMgr.getPresumedLoc(PLoc.getIncludeLoc());
+      for (; PLoc.isValid(); ++Depth)
+        PLoc = SourceMgr.getPresumedLoc(PLoc.getIncludeLoc());
+    }
 
     // __INCLUDE_LEVEL__ expands to a simple numeric value.
     OS << Depth;
diff --git a/clang/lib/Lex/Pragma.cpp b/clang/lib/Lex/Pragma.cpp
index 8d469f609de..58625520a99 100644
--- a/clang/lib/Lex/Pragma.cpp
+++ b/clang/lib/Lex/Pragma.cpp
@@ -329,6 +329,9 @@ void Preprocessor::HandlePragmaSystemHeader(Token &SysHeaderTok) {
 
 
   PresumedLoc PLoc = SourceMgr.getPresumedLoc(SysHeaderTok.getLocation());
+  if (PLoc.isInvalid())
+    return;
+  
   unsigned FilenameLen = strlen(PLoc.getFilename());
   unsigned FilenameID = SourceMgr.getLineTableFilenameID(PLoc.getFilename(),
                                                          FilenameLen);