[PATCH] D86514: Correctly parse LateParsedTemplates in case of multiple dependent modules

[Vaibhav Garg via Phabricator via cfe-commits]

gargvaibhav64 created this revision.
gargvaibhav64 added reviewers: rsmith, v.g.vassilev.
Herald added a project: clang.
Herald added a subscriber: cfe-commits.
gargvaibhav64 requested review of this revision.

While parsing LateParsedTemplates, Clang assumes that the Global DeclID matches with the Local DeclID of a Decl. This is not the case when we have multiple dependent modules have their own LateParsedTemplate section. In such a case, a Local/Global DeclID confusion occurs which leads to improper casting of Functions.

This commit creates a MapVector to map the LateParsedTemplate section of each Module with their module file and therefore resolving the Global/Local DeclID confusion.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D86514

Files:
  clang/include/clang/Serialization/ASTReader.h
  clang/lib/Serialization/ASTReader.cpp


Index: clang/lib/Serialization/ASTReader.cpp
===================================================================
--- clang/lib/Serialization/ASTReader.cpp
+++ clang/lib/Serialization/ASTReader.cpp
@@ -3721,6 +3721,9 @@
 
     case LATE_PARSED_TEMPLATE:
       LateParsedTemplates.append(Record.begin(), Record.end());
+      LateParsedTemplatesModulesMap.insert(
+          std::make_pair(&F, std::move(LateParsedTemplates)));
+      LateParsedTemplates.clear();
       break;
 
     case OPTIMIZE_PRAGMA_OPTIONS:
@@ -8386,25 +8389,28 @@
 void ASTReader::ReadLateParsedTemplates(
     llvm::MapVector<const FunctionDecl *, std::unique_ptr<LateParsedTemplate>>
         &LPTMap) {
-  for (unsigned Idx = 0, N = LateParsedTemplates.size(); Idx < N;
-       /* In loop */) {
-    FunctionDecl *FD = cast<FunctionDecl>(GetDecl(LateParsedTemplates[Idx++]));
+  for (auto &LPT : LateParsedTemplatesModulesMap) {
+    ModuleFile *FMod = LPT.first;
+    SmallVector<uint64_t, 1> LateParsed(LPT.second);
+    for (unsigned Idx = 0, N = LateParsed.size(); Idx < N;
+         /* In loop */) {
+      FunctionDecl *FD =
+          cast<FunctionDecl>(GetLocalDecl(*FMod, LateParsed[Idx++]));
 
-    auto LT = std::make_unique<LateParsedTemplate>();
-    LT->D = GetDecl(LateParsedTemplates[Idx++]);
+      auto LT = llvm::make_unique<LateParsedTemplate>();
+      LT->D = GetLocalDecl(*FMod, LateParsed[Idx++]);
 
-    ModuleFile *F = getOwningModuleFile(LT->D);
-    assert(F && "No module");
+      ModuleFile *F = getOwningModuleFile(LT->D);
+      assert(F && "No module");
 
-    unsigned TokN = LateParsedTemplates[Idx++];
-    LT->Toks.reserve(TokN);
-    for (unsigned T = 0; T < TokN; ++T)
-      LT->Toks.push_back(ReadToken(*F, LateParsedTemplates, Idx));
+      unsigned TokN = LateParsed[Idx++];
+      LT->Toks.reserve(TokN);
+      for (unsigned T = 0; T < TokN; ++T)
+        LT->Toks.push_back(ReadToken(*F, LateParsed, Idx));
 
-    LPTMap.insert(std::make_pair(FD, std::move(LT)));
+      LPTMap.insert(std::make_pair(FD, std::move(LT)));
+    }
   }
-
-  LateParsedTemplates.clear();
 }
 
 void ASTReader::LoadSelector(Selector Sel) {
Index: clang/include/clang/Serialization/ASTReader.h
===================================================================
--- clang/include/clang/Serialization/ASTReader.h
+++ clang/include/clang/Serialization/ASTReader.h
@@ -903,6 +903,10 @@
   // A list of late parsed template function data.
   SmallVector<uint64_t, 1> LateParsedTemplates;
 
+  // A list of LateParsedTemplates paired with their module files.
+  llvm::MapVector<ModuleFile *, SmallVector<uint64_t, 1>>
+      LateParsedTemplatesModulesMap;
+
   /// The IDs of all decls to be checked for deferred diags.
   ///
   /// Sema tracks these to emit deferred diags.


-------------- next part --------------
A non-text attachment was scrubbed...
Name: D86514.287604.patch
Type: text/x-patch
Size: 2772 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/cfe-commits/attachments/20200825/3be53218/attachment.bin>