r286584 - Fix for PR28523: unexpected compilation error.
Alexey Bataev via cfe-commits
cfe-commits at lists.llvm.org
Fri Nov 11 04:36:21 PST 2016
Author: abataev
Date: Fri Nov 11 06:36:20 2016
New Revision: 286584
URL: http://llvm.org/viewvc/llvm-project?rev=286584&view=rev
Log:
Fix for PR28523: unexpected compilation error.
Clang emits error message for the following code:
```
template <class F> void parallel_loop(F &&f) { f(0); }
int main() {
int x;
parallel_loop([&](auto y) {
{
x = y;
};
});
}
```
$ clang++ --std=gnu++14 clang_test.cc -o clang_test
clang_test.cc:9:7: error: reference to local variable 'x' declared in enclosing function 'main'
x = y;
^
clang_test.cc:2:48: note: in instantiation of function template specialization 'main()::(anonymous class)::operator()<int>' requested here
template <class F> void parallel_loop(F &&f) { f(0); }
^
clang_test.cc:6:3: note: in instantiation of function template specialization 'parallel_loop<(lambda at clang_test.cc:6:17)>' requested here parallel_loop([&](auto y) {
^
clang_test.cc:5:7: note: 'x' declared here
int x;
^
1 error generated.
Patch fixes this issue.
Added:
cfe/trunk/test/CodeGenCXX/PR28523.cpp
Modified:
cfe/trunk/include/clang/Sema/Sema.h
cfe/trunk/lib/Sema/Sema.cpp
cfe/trunk/lib/Sema/SemaExpr.cpp
cfe/trunk/lib/Sema/SemaExprCXX.cpp
cfe/trunk/lib/Sema/SemaLambda.cpp
Modified: cfe/trunk/include/clang/Sema/Sema.h
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Sema/Sema.h?rev=286584&r1=286583&r2=286584&view=diff
==============================================================================
--- cfe/trunk/include/clang/Sema/Sema.h (original)
+++ cfe/trunk/include/clang/Sema/Sema.h Fri Nov 11 06:36:20 2016
@@ -1228,8 +1228,10 @@ public:
/// \brief Retrieve the current block, if any.
sema::BlockScopeInfo *getCurBlock();
- /// \brief Retrieve the current lambda scope info, if any.
- sema::LambdaScopeInfo *getCurLambda();
+ /// Retrieve the current lambda scope info, if any.
+ /// \param IgnoreCapturedRegions true if should find the top-most lambda scope
+ /// info ignoring all inner captured regions scope infos.
+ sema::LambdaScopeInfo *getCurLambda(bool IgnoreCapturedRegions = false);
/// \brief Retrieve the current generic lambda info, if any.
sema::LambdaScopeInfo *getCurGenericLambda();
Modified: cfe/trunk/lib/Sema/Sema.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/Sema.cpp?rev=286584&r1=286583&r2=286584&view=diff
==============================================================================
--- cfe/trunk/lib/Sema/Sema.cpp (original)
+++ cfe/trunk/lib/Sema/Sema.cpp Fri Nov 11 06:36:20 2016
@@ -1201,11 +1201,19 @@ BlockScopeInfo *Sema::getCurBlock() {
return CurBSI;
}
-LambdaScopeInfo *Sema::getCurLambda() {
+LambdaScopeInfo *Sema::getCurLambda(bool IgnoreCapturedRegions) {
if (FunctionScopes.empty())
return nullptr;
- auto CurLSI = dyn_cast<LambdaScopeInfo>(FunctionScopes.back());
+ auto I = FunctionScopes.rbegin();
+ if (IgnoreCapturedRegions) {
+ auto E = FunctionScopes.rend();
+ while (I != E && isa<CapturedRegionScopeInfo>(*I))
+ ++I;
+ if (I == E)
+ return nullptr;
+ }
+ auto *CurLSI = dyn_cast<LambdaScopeInfo>(*I);
if (CurLSI && CurLSI->Lambda &&
!CurLSI->Lambda->Encloses(CurContext)) {
// We have switched contexts due to template instantiation.
Modified: cfe/trunk/lib/Sema/SemaExpr.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaExpr.cpp?rev=286584&r1=286583&r2=286584&view=diff
==============================================================================
--- cfe/trunk/lib/Sema/SemaExpr.cpp (original)
+++ cfe/trunk/lib/Sema/SemaExpr.cpp Fri Nov 11 06:36:20 2016
@@ -14079,7 +14079,8 @@ static void DoMarkVarDeclReferenced(Sema
(SemaRef.CurContext != Var->getDeclContext() &&
Var->getDeclContext()->isFunctionOrMethod() && Var->hasLocalStorage());
if (RefersToEnclosingScope) {
- if (LambdaScopeInfo *const LSI = SemaRef.getCurLambda()) {
+ if (LambdaScopeInfo *const LSI =
+ SemaRef.getCurLambda(/*IgnoreCapturedRegions=*/true)) {
// If a variable could potentially be odr-used, defer marking it so
// until we finish analyzing the full expression for any
// lvalue-to-rvalue
Modified: cfe/trunk/lib/Sema/SemaExprCXX.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaExprCXX.cpp?rev=286584&r1=286583&r2=286584&view=diff
==============================================================================
--- cfe/trunk/lib/Sema/SemaExprCXX.cpp (original)
+++ cfe/trunk/lib/Sema/SemaExprCXX.cpp Fri Nov 11 06:36:20 2016
@@ -6879,8 +6879,14 @@ static void CheckIfAnyEnclosingLambdasMu
assert(!S.isUnevaluatedContext());
assert(S.CurContext->isDependentContext());
- assert(CurrentLSI->CallOperator == S.CurContext &&
+#ifndef NDEBUG
+ DeclContext *DC = S.CurContext;
+ while (DC && isa<CapturedDecl>(DC))
+ DC = DC->getParent();
+ assert(
+ CurrentLSI->CallOperator == DC &&
"The current call operator must be synchronized with Sema's CurContext");
+#endif // NDEBUG
const bool IsFullExprInstantiationDependent = FE->isInstantiationDependent();
@@ -7346,7 +7352,8 @@ ExprResult Sema::ActOnFinishFullExpr(Exp
// and then the full-expression +n + ({ 0; }); ends, but it's too late
// for us to see that we need to capture n after all.
- LambdaScopeInfo *const CurrentLSI = getCurLambda();
+ LambdaScopeInfo *const CurrentLSI =
+ getCurLambda(/*IgnoreCapturedRegions=*/true);
// FIXME: PR 17877 showed that getCurLambda() can return a valid pointer
// even if CurContext is not a lambda call operator. Refer to that Bug Report
// for an example of the code that might cause this asynchrony.
@@ -7361,7 +7368,10 @@ ExprResult Sema::ActOnFinishFullExpr(Exp
// constructor/destructor.
// - Teach the handful of places that iterate over FunctionScopes to
// stop at the outermost enclosing lexical scope."
- const bool IsInLambdaDeclContext = isLambdaCallOperator(CurContext);
+ DeclContext *DC = CurContext;
+ while (DC && isa<CapturedDecl>(DC))
+ DC = DC->getParent();
+ const bool IsInLambdaDeclContext = isLambdaCallOperator(DC);
if (IsInLambdaDeclContext && CurrentLSI &&
CurrentLSI->hasPotentialCaptures() && !FullExpr.isInvalid())
CheckIfAnyEnclosingLambdasMustCaptureAnyPotentialCaptures(FE, CurrentLSI,
Modified: cfe/trunk/lib/Sema/SemaLambda.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaLambda.cpp?rev=286584&r1=286583&r2=286584&view=diff
==============================================================================
--- cfe/trunk/lib/Sema/SemaLambda.cpp (original)
+++ cfe/trunk/lib/Sema/SemaLambda.cpp Fri Nov 11 06:36:20 2016
@@ -66,17 +66,20 @@ getStackIndexOfNearestEnclosingCaptureRe
// Label failure to capture.
const Optional<unsigned> NoLambdaIsCaptureReady;
+ // Ignore all inner captured regions.
+ unsigned CurScopeIndex = FunctionScopes.size() - 1;
+ while (CurScopeIndex > 0 && isa<clang::sema::CapturedRegionScopeInfo>(
+ FunctionScopes[CurScopeIndex]))
+ --CurScopeIndex;
assert(
- isa<clang::sema::LambdaScopeInfo>(
- FunctionScopes[FunctionScopes.size() - 1]) &&
+ isa<clang::sema::LambdaScopeInfo>(FunctionScopes[CurScopeIndex]) &&
"The function on the top of sema's function-info stack must be a lambda");
-
+
// If VarToCapture is null, we are attempting to capture 'this'.
const bool IsCapturingThis = !VarToCapture;
const bool IsCapturingVariable = !IsCapturingThis;
// Start with the current lambda at the top of the stack (highest index).
- unsigned CurScopeIndex = FunctionScopes.size() - 1;
DeclContext *EnclosingDC =
cast<sema::LambdaScopeInfo>(FunctionScopes[CurScopeIndex])->CallOperator;
Added: cfe/trunk/test/CodeGenCXX/PR28523.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGenCXX/PR28523.cpp?rev=286584&view=auto
==============================================================================
--- cfe/trunk/test/CodeGenCXX/PR28523.cpp (added)
+++ cfe/trunk/test/CodeGenCXX/PR28523.cpp Fri Nov 11 06:36:20 2016
@@ -0,0 +1,19 @@
+// RUN: %clang_cc1 -std=c++14 -verify -triple %itanium_abi_triple -emit-llvm %s -o - | FileCheck %s
+// expected-no-diagnostics
+
+template <class F> void parallel_loop(F &&f) { f(0); }
+
+//CHECK-LABEL: @main
+int main() {
+// CHECK: [[X_ADDR:%.+]] = alloca i32,
+ int x;
+// CHECK: getelementptr inbounds
+// CHECK: store i32* [[X_ADDR]], i32** %
+// CHECK: call
+ parallel_loop([&](auto y) {
+#pragma clang __debug captured
+ {
+ x = y;
+ };
+ });
+}
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