Sink PrettyDeclStackTrace down to the AST library

[jordan_rose]

Summary

...and add some very basic stack trace entries for module building. This would have helped track down rdar://problem/38434694 sooner (which I can't share, sorry).

[bruno]

Hi Jordan,

Thanks for improving this. LGTM

[jordan_rose]

Committed in rL328276.

include/clang/AST/PrettyDeclStackTrace.h

 //===- PrettyDeclStackTrace.h - Stack trace for decl processing -*- C++ -*-===//
 //
 //                     The LLVM Compiler Infrastructure
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 //
 // This file defines an llvm::PrettyStackTraceEntry object for showing
 // that a particular declaration was being processed when a crash
 // occurred.
 //
 //===----------------------------------------------------------------------===//
 
-#ifndef LLVM_CLANG_SEMA_PRETTYDECLSTACKTRACE_H
-#define LLVM_CLANG_SEMA_PRETTYDECLSTACKTRACE_H
+#ifndef LLVM_CLANG_AST_PRETTYDECLSTACKTRACE_H
+#define LLVM_CLANG_AST_PRETTYDECLSTACKTRACE_H
 
 #include "clang/Basic/SourceLocation.h"
 #include "llvm/Support/PrettyStackTrace.h"
 
 namespace clang {
 
+class ASTContext;
 class Decl;
-class Sema;
 class SourceManager;
 
 /// PrettyDeclStackTraceEntry - If a crash occurs in the parser while
 /// parsing something related to a declaration, include that
 /// declaration in the stack trace.
 class PrettyDeclStackTraceEntry : public llvm::PrettyStackTraceEntry {
-  Sema &S;
+  ASTContext &Context;
   Decl *TheDecl;
   SourceLocation Loc;
   const char *Message;
 
 public:
-  PrettyDeclStackTraceEntry(Sema &S, Decl *D, SourceLocation Loc,
+  PrettyDeclStackTraceEntry(ASTContext &Ctx, Decl *D, SourceLocation Loc,
                             const char *Msg)
-    : S(S), TheDecl(D), Loc(Loc), Message(Msg) {}
+    : Context(Ctx), TheDecl(D), Loc(Loc), Message(Msg) {}
 
   void print(raw_ostream &OS) const override;
 };
 
 }
 
 #endif

lib/AST/Decl.cpp

 #include "clang/AST/DeclObjC.h"
 #include "clang/AST/DeclOpenMP.h"
 #include "clang/AST/DeclTemplate.h"
 #include "clang/AST/DeclarationName.h"
 #include "clang/AST/Expr.h"
 #include "clang/AST/ExprCXX.h"
 #include "clang/AST/ExternalASTSource.h"
 #include "clang/AST/ODRHash.h"
+#include "clang/AST/PrettyDeclStackTrace.h"
 #include "clang/AST/PrettyPrinter.h"
 #include "clang/AST/Redeclarable.h"
 #include "clang/AST/Stmt.h"
 #include "clang/AST/TemplateBase.h"
 #include "clang/AST/Type.h"
 #include "clang/AST/TypeLoc.h"
 #include "clang/Basic/Builtins.h"
 #include "clang/Basic/IdentifierTable.h"

 #include <type_traits>
 
 using namespace clang;
 
 Decl *clang::getPrimaryMergedDecl(Decl *D) {
   return D->getASTContext().getPrimaryMergedDecl(D);
 }
 
+void PrettyDeclStackTraceEntry::print(raw_ostream &OS) const {
+  SourceLocation Loc = this->Loc;
+  if (!Loc.isValid() && TheDecl) Loc = TheDecl->getLocation();
+  if (Loc.isValid()) {
+    Loc.print(OS, Context.getSourceManager());
+    OS << ": ";
+  }
+  OS << Message;
+
+  if (auto *ND = dyn_cast_or_null<NamedDecl>(TheDecl)) {
+    OS << " '";
+    ND->getNameForDiagnostic(OS, Context.getPrintingPolicy(), true);
+    OS << "'";
+  }
+
+  OS << '\n';
+}
+
 // Defined here so that it can be inlined into its direct callers.
 bool Decl::isOutOfLine() const {
   return !getLexicalDeclContext()->Equals(getDeclContext());
 }
 
 TranslationUnitDecl::TranslationUnitDecl(ASTContext &ctx)
     : Decl(TranslationUnit, nullptr, SourceLocation()),
       DeclContext(TranslationUnit), Ctx(ctx) {}

lib/Frontend/CompilerInstance.cpp

   PreBuildStep(Instance);
 
   // Execute the action to actually build the module in-place. Use a separate
   // thread so that we get a stack large enough.
   const unsigned ThreadStackSize = 8 << 20;
   llvm::CrashRecoveryContext CRC;
   CRC.RunSafelyOnThread(
       [&]() {
+        SmallString<64> CrashInfoMessage("While building module for '");
+        CrashInfoMessage += ModuleName;
+        CrashInfoMessage += "'";
+        llvm::PrettyStackTraceString CrashInfo(CrashInfoMessage.c_str());
+
         // FIXME: I have no idea what the best way to do this is, but it's
         // probably not this. Interfaces changed upstream.
         std::unique_ptr<FrontendAction> Action(
             new GenerateModuleFromModuleMapAction);
         if (wrapGenModuleAction) {
           Action = wrapGenModuleAction(FrontendOpts, std::move(Action));
         }
         Instance.ExecuteAction(*Action);

lib/Parse/ParseDecl.cpp

 //  This file implements the Declaration portions of the Parser interfaces.
 //
 //===----------------------------------------------------------------------===//
 
 #include "clang/Parse/Parser.h"
 #include "clang/Parse/RAIIObjectsForParser.h"
 #include "clang/AST/ASTContext.h"
 #include "clang/AST/DeclTemplate.h"
+#include "clang/AST/PrettyDeclStackTrace.h"
 #include "clang/Basic/AddressSpaces.h"
 #include "clang/Basic/Attributes.h"
 #include "clang/Basic/CharInfo.h"
 #include "clang/Basic/TargetInfo.h"
 #include "clang/Parse/ParseDiagnostic.h"
 #include "clang/Sema/Lookup.h"
 #include "clang/Sema/ParsedTemplate.h"
-#include "clang/Sema/PrettyDeclStackTrace.h"
 #include "clang/Sema/Scope.h"
 #include "clang/Sema/SemaDiagnostic.h"
 #include "llvm/ADT/Optional.h"
 #include "llvm/ADT/SmallSet.h"
 #include "llvm/ADT/SmallString.h"
 #include "llvm/ADT/StringSwitch.h"
 #include "llvm/Support/ScopedPrinter.h"
 

 /// [GNU]   "struct-declaration-list" without terminatoring ';'
 ///       struct-declaration-list:
 ///         struct-declaration
 ///         struct-declaration-list struct-declaration
 /// [OBC]   '@' 'defs' '(' class-name ')'
 ///
 void Parser::ParseStructUnionBody(SourceLocation RecordLoc,
                                   unsigned TagType, Decl *TagDecl) {
-  PrettyDeclStackTraceEntry CrashInfo(Actions, TagDecl, RecordLoc,
+  PrettyDeclStackTraceEntry CrashInfo(Actions.Context, TagDecl, RecordLoc,
                                       "parsing struct/union body");
   assert(!getLangOpts().CPlusPlus && "C++ declarations not supported");
 
   BalancedDelimiterTracker T(*this, tok::l_brace);
   if (T.consumeOpen())
     return;
 
   ParseScope StructScope(this, Scope::ClassScope|Scope::DeclScope);

lib/Parse/ParseDeclCXX.cpp

 //===--- ParseDeclCXX.cpp - C++ Declaration Parsing -------------*- C++ -*-===//
 //
 //                     The LLVM Compiler Infrastructure
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 //
 //  This file implements the C++ Declaration portions of the Parser interfaces.
 //
 //===----------------------------------------------------------------------===//
 
 #include "clang/Parse/Parser.h"
 #include "clang/AST/ASTContext.h"
 #include "clang/AST/DeclTemplate.h"
+#include "clang/AST/PrettyDeclStackTrace.h"
 #include "clang/Basic/Attributes.h"
 #include "clang/Basic/CharInfo.h"
 #include "clang/Basic/OperatorKinds.h"
 #include "clang/Basic/TargetInfo.h"
 #include "clang/Parse/ParseDiagnostic.h"
 #include "clang/Parse/RAIIObjectsForParser.h"
 #include "clang/Sema/DeclSpec.h"
 #include "clang/Sema/ParsedTemplate.h"
-#include "clang/Sema/PrettyDeclStackTrace.h"
 #include "clang/Sema/Scope.h"
 #include "clang/Sema/SemaDiagnostic.h"
 #include "llvm/ADT/SmallString.h"
 
 using namespace clang;
 
 /// ParseNamespace - We know that the current token is a namespace keyword. This
 /// may either be a top level namespace or a block-level namespace alias. If

   ParseScope NamespaceScope(this, Scope::DeclScope);
 
   UsingDirectiveDecl *ImplicitUsingDirectiveDecl = nullptr;
   Decl *NamespcDecl =
     Actions.ActOnStartNamespaceDef(getCurScope(), InlineLoc, NamespaceLoc,
                                    IdentLoc, Ident, T.getOpenLocation(), 
                                    attrs.getList(), ImplicitUsingDirectiveDecl);
 
-  PrettyDeclStackTraceEntry CrashInfo(Actions, NamespcDecl, NamespaceLoc,
-                                      "parsing namespace");
+  PrettyDeclStackTraceEntry CrashInfo(Actions.Context, NamespcDecl,
+                                      NamespaceLoc, "parsing namespace");
 
   // Parse the contents of the namespace.  This includes parsing recovery on 
   // any improperly nested namespaces.
   ParseInnerNamespace(ExtraIdentLoc, ExtraIdent, ExtraNamespaceLoc, 0,
                       InlineLoc, attrs, T);
 
   // Leave the namespace scope.
   NamespaceScope.Exit();

                                          SourceLocation AttrFixitLoc,
                                          ParsedAttributesWithRange &Attrs,
                                          unsigned TagType, Decl *TagDecl) {
   assert((TagType == DeclSpec::TST_struct ||
          TagType == DeclSpec::TST_interface ||
          TagType == DeclSpec::TST_union  ||
          TagType == DeclSpec::TST_class) && "Invalid TagType!");
 
-  PrettyDeclStackTraceEntry CrashInfo(Actions, TagDecl, RecordLoc,
+  PrettyDeclStackTraceEntry CrashInfo(Actions.Context, TagDecl, RecordLoc,
                                       "parsing struct/union/class body");
 
   // Determine whether this is a non-nested class. Note that local
   // classes are *not* considered to be nested classes.
   bool NonNestedClass = true;
   if (!ClassStack.empty()) {
     for (const Scope *S = getCurScope(); S; S = S->getParent()) {
       if (S->isClassScope()) {

lib/Parse/ParseObjc.cpp

 //===--- ParseObjC.cpp - Objective C Parsing ------------------------------===//
 //
 //                     The LLVM Compiler Infrastructure
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 //
 //  This file implements the Objective-C portions of the Parser interface.
 //
 //===----------------------------------------------------------------------===//
 
 #include "clang/Parse/Parser.h"
 #include "clang/AST/ASTContext.h"
+#include "clang/AST/PrettyDeclStackTrace.h"
 #include "clang/Basic/CharInfo.h"
 #include "clang/Parse/ParseDiagnostic.h"
 #include "clang/Parse/RAIIObjectsForParser.h"
 #include "clang/Sema/DeclSpec.h"
-#include "clang/Sema/PrettyDeclStackTrace.h"
 #include "clang/Sema/Scope.h"
 #include "llvm/ADT/SmallVector.h"
 #include "llvm/ADT/StringExtras.h"
 
 using namespace clang;
 
 /// Skips attributes after an Objective-C @ directive. Emits a diagnostic.
 void Parser::MaybeSkipAttributes(tok::ObjCKeywordKind Kind) {

   }
 }
 
 ///   objc-method-def: objc-method-proto ';'[opt] '{' body '}'
 ///
 Decl *Parser::ParseObjCMethodDefinition() {
   Decl *MDecl = ParseObjCMethodPrototype();
 
-  PrettyDeclStackTraceEntry CrashInfo(Actions, MDecl, Tok.getLocation(),
+  PrettyDeclStackTraceEntry CrashInfo(Actions.Context, MDecl, Tok.getLocation(),
                                       "parsing Objective-C method");
 
   // parse optional ';'
   if (Tok.is(tok::semi)) {
     if (CurParsedObjCImpl) {
       Diag(Tok, diag::warn_semicolon_before_method_body)
         << FixItHint::CreateRemoval(Tok.getLocation());
     }

lib/Parse/ParseStmt.cpp

 //===--- ParseStmt.cpp - Statement and Block Parser -----------------------===//
 //
 //                     The LLVM Compiler Infrastructure
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 //
 // This file implements the Statement and Block portions of the Parser
 // interface.
 //
 //===----------------------------------------------------------------------===//
 
+#include "clang/AST/PrettyDeclStackTrace.h"
 #include "clang/Basic/Attributes.h"
 #include "clang/Basic/PrettyStackTrace.h"
 #include "clang/Parse/Parser.h"
 #include "clang/Parse/RAIIObjectsForParser.h"
 #include "clang/Sema/DeclSpec.h"
 #include "clang/Sema/LoopHint.h"
-#include "clang/Sema/PrettyDeclStackTrace.h"
 #include "clang/Sema/Scope.h"
 #include "clang/Sema/TypoCorrection.h"
 using namespace clang;
 
 //===----------------------------------------------------------------------===//
 // C99 6.8: Statements and Blocks.
 //===----------------------------------------------------------------------===//
 
StmtResult Parser::ParsePragmaLoopHint(StmtVector &Stmts,
   Attrs.takeAllFrom(TempAttrs);
   return S;
 }
 
 Decl *Parser::ParseFunctionStatementBody(Decl *Decl, ParseScope &BodyScope) {
   assert(Tok.is(tok::l_brace));
   SourceLocation LBraceLoc = Tok.getLocation();
 
-  PrettyDeclStackTraceEntry CrashInfo(Actions, Decl, LBraceLoc,
+  PrettyDeclStackTraceEntry CrashInfo(Actions.Context, Decl, LBraceLoc,
                                       "parsing function body");
 
   // Save and reset current vtordisp stack if we have entered a C++ method body.
   bool IsCXXMethod =
       getLangOpts().CPlusPlus && Decl && isa<CXXMethodDecl>(Decl);
   Sema::PragmaStackSentinelRAII
     PragmaStackSentinel(Actions, "InternalPragmaState", IsCXXMethod);
 

 ///
 ///       function-try-block:
 ///         'try' ctor-initializer[opt] compound-statement handler-seq
 ///
 Decl *Parser::ParseFunctionTryBlock(Decl *Decl, ParseScope &BodyScope) {
   assert(Tok.is(tok::kw_try) && "Expected 'try'");
   SourceLocation TryLoc = ConsumeToken();
 
-  PrettyDeclStackTraceEntry CrashInfo(Actions, Decl, TryLoc,
+  PrettyDeclStackTraceEntry CrashInfo(Actions.Context, Decl, TryLoc,
                                       "parsing function try block");
 
   // Constructor initializer list?
   if (Tok.is(tok::colon))
     ParseConstructorInitializer(Decl);
   else
     Actions.ActOnDefaultCtorInitializers(Decl);
 

lib/Sema/Sema.cpp

 
 #include "clang/AST/ASTContext.h"
 #include "clang/AST/ASTDiagnostic.h"
 #include "clang/AST/DeclCXX.h"
 #include "clang/AST/DeclFriend.h"
 #include "clang/AST/DeclObjC.h"
 #include "clang/AST/Expr.h"
 #include "clang/AST/ExprCXX.h"
+#include "clang/AST/PrettyDeclStackTrace.h"
 #include "clang/AST/StmtCXX.h"
 #include "clang/Basic/DiagnosticOptions.h"
 #include "clang/Basic/PartialDiagnostic.h"
 #include "clang/Basic/TargetInfo.h"
 #include "clang/Lex/HeaderSearch.h"
 #include "clang/Lex/Preprocessor.h"
 #include "clang/Sema/CXXFieldCollector.h"
 #include "clang/Sema/DelayedDiagnostic.h"
 #include "clang/Sema/ExternalSemaSource.h"
 #include "clang/Sema/Initialization.h"
 #include "clang/Sema/MultiplexExternalSemaSource.h"
 #include "clang/Sema/ObjCMethodList.h"
-#include "clang/Sema/PrettyDeclStackTrace.h"
 #include "clang/Sema/Scope.h"
 #include "clang/Sema/ScopeInfo.h"
 #include "clang/Sema/SemaConsumer.h"
 #include "clang/Sema/SemaInternal.h"
 #include "clang/Sema/TemplateDeduction.h"
 #include "llvm/ADT/DenseMap.h"
 #include "llvm/ADT/SmallSet.h"
 using namespace clang;

 }
 
 void ExternalSemaSource::ReadUndefinedButUsed(
     llvm::MapVector<NamedDecl *, SourceLocation> &Undefined) {}
 
 void ExternalSemaSource::ReadMismatchingDeleteExpressions(llvm::MapVector<
     FieldDecl *, llvm::SmallVector<std::pair<SourceLocation, bool>, 4>> &) {}
 
-void PrettyDeclStackTraceEntry::print(raw_ostream &OS) const {
-  SourceLocation Loc = this->Loc;
-  if (!Loc.isValid() && TheDecl) Loc = TheDecl->getLocation();
-  if (Loc.isValid()) {
-    Loc.print(OS, S.getSourceManager());
-    OS << ": ";
-  }
-  OS << Message;
-
-  if (auto *ND = dyn_cast_or_null<NamedDecl>(TheDecl)) {
-    OS << " '";
-    ND->getNameForDiagnostic(OS, ND->getASTContext().getPrintingPolicy(), true);
-    OS << "'";
-  }
-
-  OS << '\n';
-}
-
 /// \brief Figure out if an expression could be turned into a call.
 ///
 /// Use this when trying to recover from an error where the programmer may have
 /// written just the name of a function instead of actually calling it.
 ///
 /// \param E - The expression to examine.
 /// \param ZeroArgCallReturnTy - If the expression can be turned into a call
 ///  with no arguments, this parameter is set to the type returned by such a

lib/Sema/SemaTemplateInstantiate.cpp

 #include "clang/Sema/SemaInternal.h"
 #include "TreeTransform.h"
 #include "clang/AST/ASTConsumer.h"
 #include "clang/AST/ASTContext.h"
 #include "clang/AST/ASTLambda.h"
 #include "clang/AST/ASTMutationListener.h"
 #include "clang/AST/DeclTemplate.h"
 #include "clang/AST/Expr.h"
+#include "clang/AST/PrettyDeclStackTrace.h"
 #include "clang/Basic/LangOptions.h"
 #include "clang/Sema/DeclSpec.h"
 #include "clang/Sema/Initialization.h"
 #include "clang/Sema/Lookup.h"
-#include "clang/Sema/PrettyDeclStackTrace.h"
 #include "clang/Sema/Template.h"
 #include "clang/Sema/TemplateDeduction.h"
 
 using namespace clang;
 using namespace sema;
 
 //===----------------------------------------------------------------------===/
 // Template Instantiation Support
if (MemberSpecializationInfo *MSInfo
     Spec->setTemplateSpecializationKind(TSK);
     Spec->setPointOfInstantiation(PointOfInstantiation);
   }
 
   InstantiatingTemplate Inst(*this, PointOfInstantiation, Instantiation);
   if (Inst.isInvalid())
     return true;
   assert(!Inst.isAlreadyInstantiating() && "should have been caught by caller");
-  PrettyDeclStackTraceEntry CrashInfo(*this, Instantiation, SourceLocation(),
+  PrettyDeclStackTraceEntry CrashInfo(Context, Instantiation, SourceLocation(),
                                       "instantiating class definition");
 
   // Enter the scope of this instantiation. We don't use
   // PushDeclContext because we don't have a scope.
   ContextRAII SavedContext(*this, Instantiation);
   EnterExpressionEvaluationContext EvalContext(
       *this, Sema::ExpressionEvaluationContext::PotentiallyEvaluated);
 
if (MemberSpecializationInfo *MSInfo
     MSInfo->setPointOfInstantiation(PointOfInstantiation);
   }
 
   InstantiatingTemplate Inst(*this, PointOfInstantiation, Instantiation);
   if (Inst.isInvalid())
     return true;
   if (Inst.isAlreadyInstantiating())
     return false;
-  PrettyDeclStackTraceEntry CrashInfo(*this, Instantiation, SourceLocation(),
+  PrettyDeclStackTraceEntry CrashInfo(Context, Instantiation, SourceLocation(),
                                       "instantiating enum definition");
 
   // The instantiation is visible here, even if it was first declared in an
   // unimported module.
   Instantiation->setVisibleDespiteOwningModule();
 
   // Enter the scope of this instantiation. We don't use
   // PushDeclContext because we don't have a scope.
bool Sema::InstantiateInClassInitializer(
   if (Inst.isInvalid())
     return true;
   if (Inst.isAlreadyInstantiating()) {
     // Error out if we hit an instantiation cycle for this initializer.
     Diag(PointOfInstantiation, diag::err_in_class_initializer_cycle)
       << Instantiation;
     return true;
   }
-  PrettyDeclStackTraceEntry CrashInfo(*this, Instantiation, SourceLocation(),
+  PrettyDeclStackTraceEntry CrashInfo(Context, Instantiation, SourceLocation(),
                                       "instantiating default member init");
 
   // Enter the scope of this instantiation. We don't use PushDeclContext because
   // we don't have a scope.
   ContextRAII SavedContext(*this, Instantiation->getParent());
   EnterExpressionEvaluationContext EvalContext(
       *this, Sema::ExpressionEvaluationContext::PotentiallyEvaluated);
 

lib/Sema/SemaTemplateInstantiateDecl.cpp

 #include "clang/AST/ASTConsumer.h"
 #include "clang/AST/ASTContext.h"
 #include "clang/AST/ASTMutationListener.h"
 #include "clang/AST/DeclTemplate.h"
 #include "clang/AST/DeclVisitor.h"
 #include "clang/AST/DependentDiagnostic.h"
 #include "clang/AST/Expr.h"
 #include "clang/AST/ExprCXX.h"
+#include "clang/AST/PrettyDeclStackTrace.h"
 #include "clang/AST/TypeLoc.h"
 #include "clang/Sema/Initialization.h"
 #include "clang/Sema/Lookup.h"
-#include "clang/Sema/PrettyDeclStackTrace.h"
 #include "clang/Sema/Template.h"
 
 using namespace clang;
 
 static bool isDeclWithinFunction(const Decl *D) {
   const DeclContext *DC = D->getDeclContext();
   if (DC->isFunctionOrMethod())
     return true;

       if (D == Function)
         break;
     }
   }
 
   InstantiatingTemplate Inst(*this, PointOfInstantiation, Function);
   if (Inst.isInvalid() || Inst.isAlreadyInstantiating())
     return;
-  PrettyDeclStackTraceEntry CrashInfo(*this, Function, SourceLocation(),
+  PrettyDeclStackTraceEntry CrashInfo(Context, Function, SourceLocation(),
                                       "instantiating function definition");
 
   // The instantiation is visible here, even if it was first declared in an
   // unimported module.
   Function->setVisibleDespiteOwningModule();
 
   // Copy the inner loc start from the pattern.
   Function->setInnerLocStart(PatternDecl->getInnerLocStart());

     if (PatternDecl->isStaticDataMember() &&
         (PatternDecl = PatternDecl->getFirstDecl())->hasInit() &&
         !Var->hasInit()) {
       // FIXME: Factor out the duplicated instantiation context setup/tear down
       // code here.
       InstantiatingTemplate Inst(*this, PointOfInstantiation, Var);
       if (Inst.isInvalid() || Inst.isAlreadyInstantiating())
         return;
-      PrettyDeclStackTraceEntry CrashInfo(*this, Var, SourceLocation(),
+      PrettyDeclStackTraceEntry CrashInfo(Context, Var, SourceLocation(),
                                           "instantiating variable initializer");
 
       // The instantiation is visible here, even if it was first declared in an
       // unimported module.
       Var->setVisibleDespiteOwningModule();
 
       // If we're performing recursive template instantiation, create our own
       // queue of pending implicit instantiations that we will instantiate

     Def->setTemplateSpecializationKind(Var->getTemplateSpecializationKind(),
                                        PointOfInstantiation);
     return;
   }
 
   InstantiatingTemplate Inst(*this, PointOfInstantiation, Var);
   if (Inst.isInvalid() || Inst.isAlreadyInstantiating())
     return;
-  PrettyDeclStackTraceEntry CrashInfo(*this, Var, SourceLocation(),
+  PrettyDeclStackTraceEntry CrashInfo(Context, Var, SourceLocation(),
                                       "instantiating variable definition");
 
   // If we're performing recursive template instantiation, create our own
   // queue of pending implicit instantiations that we will instantiate later,
   // while we're still within our own instantiation context.
   GlobalEagerInstantiationScope GlobalInstantiations(*this,
                                                      /*Enabled=*/Recursive);
 

       // explicit instantiation.
       if (Var != Var->getMostRecentDecl())
         continue;
       break;
     case TSK_ImplicitInstantiation:
       break;
     }
 
-    PrettyDeclStackTraceEntry CrashInfo(*this, Var, SourceLocation(),
+    PrettyDeclStackTraceEntry CrashInfo(Context, Var, SourceLocation(),
                                         "instantiating variable definition");
     bool DefinitionRequired = Var->getTemplateSpecializationKind() ==
                               TSK_ExplicitInstantiationDefinition;
 
     // Instantiate static data member definitions or variable template
     // specializations.
     InstantiateVariableDefinition(/*FIXME:*/ Inst.second, Var, true,
                                   DefinitionRequired, true);

lib/Serialization/ASTWriterDecl.cpp

 //===----------------------------------------------------------------------===//
 
 #include "ASTCommon.h"
 #include "clang/AST/DeclCXX.h"
 #include "clang/AST/DeclContextInternals.h"
 #include "clang/AST/DeclTemplate.h"
 #include "clang/AST/DeclVisitor.h"
 #include "clang/AST/Expr.h"
+#include "clang/AST/PrettyDeclStackTrace.h"
 #include "clang/Basic/SourceManager.h"
 #include "clang/Serialization/ASTReader.h"
 #include "clang/Serialization/ASTWriter.h"
 #include "llvm/Bitcode/BitstreamWriter.h"
 #include "llvm/Support/ErrorHandling.h"
 using namespace clang;
 using namespace serialization;
 

     // if and when the module is imported, rather than being emitted eagerly.
     return false;
   }
 
   return Context.DeclMustBeEmitted(D);
 }
 
 void ASTWriter::WriteDecl(ASTContext &Context, Decl *D) {
+  PrettyDeclStackTraceEntry CrashInfo(Context, D, SourceLocation(),
+                                      "serializing");
+
   // Determine the ID for this declaration.
   serialization::DeclID ID;
   assert(!D->isFromASTFile() && "should not be emitting imported decl");
   serialization::DeclID &IDR = DeclIDs[D];
   if (IDR == 0)
     IDR = NextDeclID++;
     
   ID = IDR;