When the parser is live, print out the location and spelling of its current token.
For example:

Stack dump:
0.	Program arguments: clang t.cpp 
1.	t.cpp:4:8: current parser token: ';'
2.	t.cpp:3:1: parsing struct/union/class body 'x'
Abort

It is weird that the parser is always "underneath" any parse context 
actions, but the parser is created first.



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@66148 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Parse/Parser.cpp b/lib/Parse/Parser.cpp
index 3cdaab6..70a3366 100644
--- a/lib/Parse/Parser.cpp
+++ b/lib/Parse/Parser.cpp
@@ -15,12 +15,13 @@
 #include "clang/Parse/ParseDiagnostic.h"
 #include "clang/Parse/DeclSpec.h"
 #include "clang/Parse/Scope.h"
+#include "llvm/Support/raw_ostream.h"
 #include "ExtensionRAIIObject.h"
 #include "ParsePragma.h"
 using namespace clang;
 
 Parser::Parser(Preprocessor &pp, Action &actions)
-  : PP(pp), Actions(actions), Diags(PP.getDiagnostics()), 
+  : CrashInfo(*this), PP(pp), Actions(actions), Diags(PP.getDiagnostics()), 
     GreaterThanIsOperator(true) {
   Tok.setKind(tok::eof);
   CurScope = 0;
@@ -38,30 +39,23 @@
   PushTopClassStack();
 }
 
-///  Out-of-line virtual destructor to provide home for Action class.
-ActionBase::~ActionBase() {}
-
-///  Out-of-line virtual destructor to provide home for Action class.
-Action::~Action() {}
-
-// Defined out-of-line here because of dependecy on AttributeList
-Action::DeclTy *Action::ActOnUsingDirective(Scope *CurScope,
-                                            SourceLocation UsingLoc,
-                                            SourceLocation NamespcLoc,
-                                            const CXXScopeSpec &SS,
-                                            SourceLocation IdentLoc,
-                                            IdentifierInfo *NamespcName,
-                                            AttributeList *AttrList) {
-
-  // FIXME: Parser seems to assume that Action::ActOn* takes ownership over
-  // passed AttributeList, however other actions don't free it, is it
-  // temporary state or bug?
-  delete AttrList;
-  return 0;
+/// If a crash happens while the parser is active, print out a line indicating
+/// what the current token is.
+void PrettyStackTraceParserEntry::print(llvm::raw_ostream &OS) const {
+  const Token &Tok = P.getCurToken();
+  if (Tok.getLocation().isInvalid()) {
+    OS << "<eof> parser at end of file\n";
+    return;
+  }
+  
+  const Preprocessor &PP = P.getPreprocessor();
+  Tok.getLocation().print(OS, PP.getSourceManager());
+  OS << ": current parser token '" << PP.getSpelling(Tok) << "'\n";
 }
 
+
 DiagnosticBuilder Parser::Diag(SourceLocation Loc, unsigned DiagID) {
-  return Diags.Report(FullSourceLoc(Loc,PP.getSourceManager()), DiagID);
+  return Diags.Report(FullSourceLoc(Loc, PP.getSourceManager()), DiagID);
 }
 
 DiagnosticBuilder Parser::Diag(const Token &Tok, unsigned DiagID) {