[PATCH] D54014: [Sema] Push and Pop Expression Evaluation Context Records at the start and end of function definitions

[Leonard Chan via Phabricator via cfe-commits]

leonardchan updated this revision to Diff 176893.
leonardchan marked an inline comment as done.

Repository:
  rC Clang

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D54014/new/

https://reviews.llvm.org/D54014

Files:
  clang/lib/Sema/SemaDecl.cpp
  clang/lib/Sema/SemaDeclObjC.cpp
  clang/lib/Sema/SemaExpr.cpp


Index: clang/lib/Sema/SemaExpr.cpp
===================================================================
--- clang/lib/Sema/SemaExpr.cpp
+++ clang/lib/Sema/SemaExpr.cpp
@@ -14414,11 +14414,8 @@
   // Pop the current expression evaluation context off the stack.
   ExprEvalContexts.pop_back();
 
-  if (!ExprEvalContexts.empty())
-    ExprEvalContexts.back().NumTypos += NumTypos;
-  else
-    assert(NumTypos == 0 && "There are outstanding typos after popping the "
-                            "last ExpressionEvaluationContextRecord");
+  // The global expression evaluation context record is never popped.
+  ExprEvalContexts.back().NumTypos += NumTypos;
 }
 
 void Sema::DiscardCleanupsInEvaluationContext() {
Index: clang/lib/Sema/SemaDeclObjC.cpp
===================================================================
--- clang/lib/Sema/SemaDeclObjC.cpp
+++ clang/lib/Sema/SemaDeclObjC.cpp
@@ -363,6 +363,8 @@
   assert((getCurMethodDecl() == nullptr) && "Methodparsing confused");
   ObjCMethodDecl *MDecl = dyn_cast_or_null<ObjCMethodDecl>(D);
 
+  PushExpressionEvaluationContext(ExprEvalContexts.back().Context);
+
   // If we don't have a valid method decl, simply return.
   if (!MDecl)
     return;
Index: clang/lib/Sema/SemaDecl.cpp
===================================================================
--- clang/lib/Sema/SemaDecl.cpp
+++ clang/lib/Sema/SemaDecl.cpp
@@ -12828,6 +12828,7 @@
     // Parsing the function declaration failed in some way. Push on a fake scope
     // anyway so we can try to parse the function body.
     PushFunctionScope();
+    PushExpressionEvaluationContext(ExprEvalContexts.back().Context);
     return D;
   }
 
@@ -12838,6 +12839,11 @@
   else
     FD = cast<FunctionDecl>(D);
 
+  // Do not push if it is a lambda because one is already pushed when building
+  // the lambda in ActOnStartOfLambdaDefinition().
+  if (!isLambdaCallOperator(FD))
+    PushExpressionEvaluationContext(ExprEvalContexts.back().Context);
+
   // Check for defining attributes before the check for redefinition.
   if (const auto *Attr = FD->getAttr<AliasAttr>()) {
     Diag(Attr->getLocation(), diag::err_alias_is_definition) << FD << 0;
@@ -13046,6 +13052,21 @@
   return ActOnFinishFunctionBody(D, BodyArg, false);
 }
 
+/// RAII object that pops an ExpressionEvaluationContext when exiting a function
+/// body.
+class ExitFunctionBodyRAII {
+public:
+  ExitFunctionBodyRAII(Sema &S, bool IsLambda) : S(S), IsLambda(IsLambda) {}
+  ~ExitFunctionBodyRAII() {
+    if (!IsLambda)
+      S.PopExpressionEvaluationContext();
+  }
+
+private:
+  Sema &S;
+  bool IsLambda = false;
+};
+
 Decl *Sema::ActOnFinishFunctionBody(Decl *dcl, Stmt *Body,
                                     bool IsInstantiation) {
   FunctionDecl *FD = dcl ? dcl->getAsFunction() : nullptr;
@@ -13056,6 +13077,11 @@
   if (getLangOpts().CoroutinesTS && getCurFunction()->isCoroutine())
     CheckCompletedCoroutineBody(FD, Body);
 
+  // Do not call PopExpressionEvaluationContext() if it is a lambda because one
+  // is already popped when finishing the lambda in BuildLambdaExpr(). This is
+  // meant to pop the context added in ActOnStartOfFunctionDef().
+  ExitFunctionBodyRAII ExitRAII(*this, isLambdaCallOperator(FD));
+
   if (FD) {
     FD->setBody(Body);
     FD->setWillHaveBody(false);


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