Revert "[Sema] Make getCurFunction() return null outside function parsing"

This reverts r326965. It seems to have caused repeating test failures in
clang/test/Sema/diagnose_if.c on some buildbots.

I cannot reproduce the problem, and it's not immediately obvious what
the problem is, so let's revert to green.

llvm-svn: 326974

1 files changed, 10 insertions, 8 deletions

diff --git a/clang/lib/Sema/SemaExprCXX.cpp b/clang/lib/Sema/SemaExprCXX.cpp
index 4baf52f5b78..d3ab003a339 100644
--- a/clang/lib/Sema/SemaExprCXX.cpp
+++ b/clang/lib/Sema/SemaExprCXX.cpp
@@ -1114,9 +1114,8 @@ bool Sema::CheckCXXThisCapture(SourceLocation Loc, const bool Explicit,
 
   assert((!ByCopy || Explicit) && "cannot implicitly capture *this by value");
 
-  const int MaxFunctionScopesIndex = FunctionScopeIndexToStopAt
-                                         ? *FunctionScopeIndexToStopAt
-                                         : FunctionScopes.size() - 1;
+  const unsigned MaxFunctionScopesIndex = FunctionScopeIndexToStopAt ?
+    *FunctionScopeIndexToStopAt : FunctionScopes.size() - 1;
 
   // Check that we can capture the *enclosing object* (referred to by '*this')
   // by the capturing-entity/closure (lambda/block/etc) at
@@ -1142,7 +1141,7 @@ bool Sema::CheckCXXThisCapture(SourceLocation Loc, const bool Explicit,
 
 
   unsigned NumCapturingClosures = 0;
-  for (int idx = MaxFunctionScopesIndex; idx >= 0; idx--) {
+  for (unsigned idx = MaxFunctionScopesIndex; idx != 0; idx--) {
     if (CapturingScopeInfo *CSI =
             dyn_cast<CapturingScopeInfo>(FunctionScopes[idx])) {
       if (CSI->CXXThisCaptureIndex != 0) {
@@ -1197,8 +1196,8 @@ bool Sema::CheckCXXThisCapture(SourceLocation Loc, const bool Explicit,
   // FIXME: We need to delay this marking in PotentiallyPotentiallyEvaluated
   // contexts.
   QualType ThisTy = getCurrentThisType();
-  for (int idx = MaxFunctionScopesIndex; NumCapturingClosures;
-       --idx, --NumCapturingClosures) {
+  for (unsigned idx = MaxFunctionScopesIndex; NumCapturingClosures;
+      --idx, --NumCapturingClosures) {
     CapturingScopeInfo *CSI = cast<CapturingScopeInfo>(FunctionScopes[idx]);
     Expr *ThisExpr = nullptr;
 
@@ -7177,6 +7176,9 @@ static void CheckIfAnyEnclosingLambdasMustCaptureAnyPotentialCaptures(
 
   const bool IsFullExprInstantiationDependent = FE->isInstantiationDependent();
 
+  ArrayRef<const FunctionScopeInfo *> FunctionScopesArrayRef(
+      S.FunctionScopes.data(), S.FunctionScopes.size());
+
   // All the potentially captureable variables in the current nested
   // lambda (within a generic outer lambda), must be captured by an
   // outer lambda that is enclosed within a non-dependent context.
@@ -7205,7 +7207,7 @@ static void CheckIfAnyEnclosingLambdasMustCaptureAnyPotentialCaptures(
     // capture the variable in that lambda (and all its enclosing lambdas).
     if (const Optional<unsigned> Index =
             getStackIndexOfNearestEnclosingCaptureCapableLambda(
-                S.FunctionScopes, Var, S)) {
+                FunctionScopesArrayRef, Var, S)) {
       const unsigned FunctionScopeIndexOfCapturableLambda = Index.getValue();
       MarkVarDeclODRUsed(Var, VarExpr->getExprLoc(), S,
                          &FunctionScopeIndexOfCapturableLambda);
@@ -7241,7 +7243,7 @@ static void CheckIfAnyEnclosingLambdasMustCaptureAnyPotentialCaptures(
     // 'this' in that lambda (and all its enclosing lambdas).
     if (const Optional<unsigned> Index =
             getStackIndexOfNearestEnclosingCaptureCapableLambda(
-                S.FunctionScopes, /*0 is 'this'*/ nullptr, S)) {
+                FunctionScopesArrayRef, /*0 is 'this'*/ nullptr, S)) {
       const unsigned FunctionScopeIndexOfCapturableLambda = Index.getValue();
       S.CheckCXXThisCapture(CurrentLSI->PotentialThisCaptureLocation,
                             /*Explicit*/ false, /*BuildAndDiagnose*/ true,