r174943 - Fix a bug reduced from a crash when trying to use modules with libc++. We check

[Richard Smith]

Author: rsmith
Date: Mon Feb 11 23:48:23 2013
New Revision: 174943

URL: http://llvm.org/viewvc/llvm-project?rev=174943&view=rev
Log:
Fix a bug reduced from a crash when trying to use modules with libc++. We check
the linkage of functions and variables while merging declarations from modules,
and we don't necessarily have enough of the rest of the AST loaded at that
point to allow us to compute linkage, so serialize it instead.

Added:
    cfe/trunk/test/Modules/Inputs/cxx-linkage-cache.h
    cfe/trunk/test/Modules/cxx-linkage-cache.cpp
Modified:
    cfe/trunk/lib/AST/Decl.cpp
    cfe/trunk/lib/Serialization/ASTReaderDecl.cpp
    cfe/trunk/lib/Serialization/ASTWriterDecl.cpp
    cfe/trunk/test/Modules/Inputs/module.map

Modified: cfe/trunk/lib/AST/Decl.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/AST/Decl.cpp?rev=174943&r1=174942&r2=174943&view=diff
==============================================================================
--- cfe/trunk/lib/AST/Decl.cpp (original)
+++ cfe/trunk/lib/AST/Decl.cpp Mon Feb 11 23:48:23 2013
@@ -610,11 +610,8 @@ void NamedDecl::ClearLinkageCache() {
 }
 
 Linkage NamedDecl::getLinkage() const {
-  if (HasCachedLinkage) {
-    assert(Linkage(CachedLinkage) ==
-           getLVForDecl(this, true).linkage());
+  if (HasCachedLinkage)
     return Linkage(CachedLinkage);
-  }
 
   CachedLinkage = getLVForDecl(this, true).linkage();
   HasCachedLinkage = 1;

Modified: cfe/trunk/lib/Serialization/ASTReaderDecl.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Serialization/ASTReaderDecl.cpp?rev=174943&r1=174942&r2=174943&view=diff
==============================================================================
--- cfe/trunk/lib/Serialization/ASTReaderDecl.cpp (original)
+++ cfe/trunk/lib/Serialization/ASTReaderDecl.cpp Mon Feb 11 23:48:23 2013
@@ -526,6 +526,8 @@ void ASTDeclReader::VisitFunctionDecl(Fu
   FD->HasImplicitReturnZero = Record[Idx++];
   FD->IsConstexpr = Record[Idx++];
   FD->HasSkippedBody = Record[Idx++];
+  FD->HasCachedLinkage = true;
+  FD->CachedLinkage = Record[Idx++];
   FD->EndRangeLoc = ReadSourceLocation(Record, Idx);
 
   switch ((FunctionDecl::TemplatedKind)Record[Idx++]) {
@@ -908,6 +910,8 @@ void ASTDeclReader::VisitVarDecl(VarDecl
   VD->VarDeclBits.CXXForRangeDecl = Record[Idx++];
   VD->VarDeclBits.ARCPseudoStrong = Record[Idx++];
   VD->VarDeclBits.IsConstexpr = Record[Idx++];
+  VD->HasCachedLinkage = true;
+  VD->CachedLinkage = Record[Idx++];
   
   // Only true variables (not parameters or implicit parameters) can be merged.
   if (VD->getKind() == Decl::Var)

Modified: cfe/trunk/lib/Serialization/ASTWriterDecl.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Serialization/ASTWriterDecl.cpp?rev=174943&r1=174942&r2=174943&view=diff
==============================================================================
--- cfe/trunk/lib/Serialization/ASTWriterDecl.cpp (original)
+++ cfe/trunk/lib/Serialization/ASTWriterDecl.cpp Mon Feb 11 23:48:23 2013
@@ -330,6 +330,7 @@ void ASTDeclWriter::VisitFunctionDecl(Fu
   Record.push_back(D->hasImplicitReturnZero());
   Record.push_back(D->isConstexpr());
   Record.push_back(D->HasSkippedBody);
+  Record.push_back(D->getLinkage());
   Writer.AddSourceLocation(D->getLocEnd(), Record);
 
   Record.push_back(D->getTemplatedKind());
@@ -682,6 +683,7 @@ void ASTDeclWriter::VisitVarDecl(VarDecl
   Record.push_back(D->isCXXForRangeDecl());
   Record.push_back(D->isARCPseudoStrong());
   Record.push_back(D->isConstexpr());
+  Record.push_back(D->getLinkage());
 
   if (D->getInit()) {
     Record.push_back(!D->isInitKnownICE() ? 1 : (D->isInitICE() ? 3 : 2));
@@ -1505,6 +1507,7 @@ void ASTWriter::WriteDeclsBlockAbbrevs()
   Abv->Add(BitCodeAbbrevOp(0));                       // isCXXForRangeDecl
   Abv->Add(BitCodeAbbrevOp(0));                       // isARCPseudoStrong
   Abv->Add(BitCodeAbbrevOp(0));                       // isConstexpr
+  Abv->Add(BitCodeAbbrevOp(0));                       // Linkage
   Abv->Add(BitCodeAbbrevOp(0));                       // HasInit
   Abv->Add(BitCodeAbbrevOp(0));                   // HasMemberSpecializationInfo
   // ParmVarDecl
@@ -1584,6 +1587,7 @@ void ASTWriter::WriteDeclsBlockAbbrevs()
   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isCXXForRangeDecl
   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isARCPseudoStrong
   Abv->Add(BitCodeAbbrevOp(0));                         // isConstexpr
+  Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 2)); // Linkage
   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // HasInit
   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // HasMemberSpecInfo
   // Type Source Info

Added: cfe/trunk/test/Modules/Inputs/cxx-linkage-cache.h
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Modules/Inputs/cxx-linkage-cache.h?rev=174943&view=auto
==============================================================================
--- cfe/trunk/test/Modules/Inputs/cxx-linkage-cache.h (added)
+++ cfe/trunk/test/Modules/Inputs/cxx-linkage-cache.h Mon Feb 11 23:48:23 2013
@@ -0,0 +1,11 @@
+// Reduced from a crash encountered with a modularized libc++, where
+// we would try to compute the linkage of a declaration before we
+// finish loading the relevant pieces of it.
+inline namespace D {
+  template<class>
+  struct U {
+    friend bool f(const U &);
+  };
+
+  template class U<int>;
+}

Modified: cfe/trunk/test/Modules/Inputs/module.map
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Modules/Inputs/module.map?rev=174943&r1=174942&r2=174943&view=diff
==============================================================================
--- cfe/trunk/test/Modules/Inputs/module.map (original)
+++ cfe/trunk/test/Modules/Inputs/module.map Mon Feb 11 23:48:23 2013
@@ -179,3 +179,7 @@ module cxx_many_overloads {
 module cxx_inline_namespace {
   header "cxx-inline-namespace.h"
 }
+
+module cxx_linkage_cache {
+  header "cxx-linkage-cache.h"
+}

Added: cfe/trunk/test/Modules/cxx-linkage-cache.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Modules/cxx-linkage-cache.cpp?rev=174943&view=auto
==============================================================================
--- cfe/trunk/test/Modules/cxx-linkage-cache.cpp (added)
+++ cfe/trunk/test/Modules/cxx-linkage-cache.cpp Mon Feb 11 23:48:23 2013
@@ -0,0 +1,8 @@
+// RUN: rm -rf %t
+// RUN: %clang_cc1 -x objective-c++ -fmodules -fmodules-cache-path=%t -I %S/Inputs %s -verify -std=c++11
+
+ at import cxx_linkage_cache;
+
+T x; // expected-error {{unknown type name 'T'}}
+D::U<int> u;
+bool b = f(u);