[PATCH] D127730: Reland "[CodeGen] Keep track info of lazy-emitted symbols in ModuleBuilder"

[Jun Zhang via Phabricator via cfe-commits]

junaire created this revision.
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This reverts commits:
d3ddc251acae631bf5ab4da13878f7e8b5b5a451 <https://reviews.llvm.org/rGd3ddc251acae631bf5ab4da13878f7e8b5b5a451>
d90eecff5c9e7e9f8263de6cd72d70322400829f <https://reviews.llvm.org/rGd90eecff5c9e7e9f8263de6cd72d70322400829f>

This relands below commit with asan fix:

The intent of this patch is to selectively carry some states over to
the Builder so we won't lose the information of the previous symbols.

This used to be several downstream patches of Cling, it aims to fix
errors in Clang Interpreter when trying to use inline functions.
Before this patch:

clang-repl> inline int foo() { return 42;}
clang-repl> int x = foo();

JIT session error: Symbols not found: [ _Z3foov ]
error: Failed to materialize symbols:
{ (main, { x, $.incr_module_1.__inits.0, __orc_init_func.incr_module_1 }) }

Co-authored-by: Axel Naumann <Axel.Naumann at cern.ch>
Signed-off-by: Jun Zhang <jun at junz.org>


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D127730

Files:
  clang/lib/CodeGen/CodeGenModule.h
  clang/lib/CodeGen/ModuleBuilder.cpp
  clang/test/Interpreter/execute.cpp


Index: clang/test/Interpreter/execute.cpp
===================================================================
--- clang/test/Interpreter/execute.cpp
+++ clang/test/Interpreter/execute.cpp
@@ -13,4 +13,8 @@
 
 auto r2 = printf("S[f=%f, m=0x%llx]\n", s.f, reinterpret_cast<unsigned long long>(s.m));
 // CHECK-NEXT: S[f=1.000000, m=0x0]
+
+inline int foo() { return 42; }
+int r3 = foo();
+
 quit
Index: clang/lib/CodeGen/ModuleBuilder.cpp
===================================================================
--- clang/lib/CodeGen/ModuleBuilder.cpp
+++ clang/lib/CodeGen/ModuleBuilder.cpp
@@ -134,7 +134,14 @@
                               llvm::LLVMContext &C) {
       assert(!M && "Replacing existing Module?");
       M.reset(new llvm::Module(ExpandModuleName(ModuleName, CodeGenOpts), C));
+
+      std::unique_ptr<CodeGenModule> OldBuilder = std::move(Builder);
+
       Initialize(*Ctx);
+
+      if (OldBuilder)
+        OldBuilder->moveLazyEmissionStates(Builder.get());
+
       return M.get();
     }
 
Index: clang/lib/CodeGen/CodeGenModule.h
===================================================================
--- clang/lib/CodeGen/CodeGenModule.h
+++ clang/lib/CodeGen/CodeGenModule.h
@@ -1486,6 +1486,33 @@
   void printPostfixForExternalizedDecl(llvm::raw_ostream &OS,
                                        const Decl *D) const;
 
+  /// Move some lazily-emitted states to the NewBuilder. This is especially
+  /// essential for the incremental parsing environment like Clang Interpreter,
+  /// because we'll lose all important information after each repl.
+  void moveLazyEmissionStates(CodeGenModule *NewBuilder) {
+    assert(DeferredDeclsToEmit.empty() &&
+           "Should have emitted all decls deferred to emit.");
+    assert(NewBuilder->DeferredDecls.empty() &&
+           "Newly created module should not have deferred decls");
+    std::swap(NewBuilder->DeferredDecls, DeferredDecls);
+
+    assert(NewBuilder->DeferredVTables.empty() &&
+           "Newly created module should not have deferred vtables");
+    std::swap(NewBuilder->DeferredVTables, DeferredVTables);
+
+    assert(NewBuilder->MangledDeclNames.empty() &&
+           "Newly created module should not have mangled decl names");
+    assert(NewBuilder->Manglings.empty() &&
+           "Newly created module should not have manglings");
+    std::swap(NewBuilder->Manglings, Manglings);
+
+    assert(WeakRefReferences.empty() &&
+           "Not all WeakRefRefs have been applied");
+    std::swap(NewBuilder->WeakRefReferences, WeakRefReferences);
+
+    std::swap(NewBuilder->TBAA, TBAA);
+  }
+
 private:
   llvm::Constant *GetOrCreateLLVMFunction(
       StringRef MangledName, llvm::Type *Ty, GlobalDecl D, bool ForVTable,


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