Start refactoring code for capturing variables and 'this' so that it is shared between lambda expressions and block literals.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@147917 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Sema/SemaExpr.cpp b/lib/Sema/SemaExpr.cpp
index f9fb3bc..ceb836b 100644
--- a/lib/Sema/SemaExpr.cpp
+++ b/lib/Sema/SemaExpr.cpp
@@ -1248,20 +1248,16 @@
/// There is a well-formed capture at a particular scope level;
/// propagate it through all the nested blocks.
static CaptureResult propagateCapture(Sema &S, unsigned ValidScopeIndex,
- const BlockDecl::Capture &Capture) {
- VarDecl *var = Capture.getVariable();
-
+ const CapturingScopeInfo::Capture &Cap) {
// Update all the inner blocks with the capture information.
for (unsigned i = ValidScopeIndex + 1, e = S.FunctionScopes.size();
i != e; ++i) {
BlockScopeInfo *innerBlock = cast<BlockScopeInfo>(S.FunctionScopes[i]);
- innerBlock->Captures.push_back(
- BlockDecl::Capture(Capture.getVariable(), Capture.isByRef(),
- /*nested*/ true, Capture.getCopyExpr()));
- innerBlock->CaptureMap[var] = innerBlock->Captures.size(); // +1
+ innerBlock->AddCapture(Cap.getVariable(), Cap.isReferenceCapture(),
+ /*nested*/ true, Cap.getCopyExpr());
}
- return Capture.isByRef() ? CR_CaptureByRef : CR_Capture;
+ return Cap.isReferenceCapture() ? CR_CaptureByRef : CR_Capture;
}
/// shouldCaptureValueReference - Determine if a reference to the
@@ -1372,9 +1368,7 @@
cast<BlockScopeInfo>(S.FunctionScopes[functionScopesIndex]);
// Build a valid capture in this scope.
- blockScope->Captures.push_back(
- BlockDecl::Capture(var, byRef, /*nested*/ false, copyExpr));
- blockScope->CaptureMap[var] = blockScope->Captures.size(); // +1
+ blockScope->AddCapture(var, byRef, /*nested*/ false, copyExpr);
// Propagate that to inner captures if necessary.
return propagateCapture(S, functionScopesIndex,
@@ -8861,8 +8855,18 @@
QualType BlockTy;
// Set the captured variables on the block.
- BSI->TheDecl->setCaptures(Context, BSI->Captures.begin(), BSI->Captures.end(),
- BSI->CapturesCXXThis);
+ // FIXME: Share capture structure between BlockDecl and CapturingScopeInfo!
+ SmallVector<BlockDecl::Capture, 4> Captures;
+ for (unsigned i = 0, e = BSI->Captures.size(); i != e; i++) {
+ CapturingScopeInfo::Capture &Cap = BSI->Captures[i];
+ if (Cap.isThisCapture())
+ continue;
+ BlockDecl::Capture NewCap(Cap.getVariable(), Cap.isReferenceCapture(),
+ Cap.isNested(), Cap.getCopyExpr());
+ Captures.push_back(NewCap);
+ }
+ BSI->TheDecl->setCaptures(Context, Captures.begin(), Captures.end(),
+ BSI->CXXThisCaptureIndex != 0);
// If the user wrote a function type in some form, try to use that.
if (!BSI->FunctionType.isNull()) {
diff --git a/lib/Sema/SemaExprCXX.cpp b/lib/Sema/SemaExprCXX.cpp
index d4efa78..da7ba1a 100644
--- a/lib/Sema/SemaExprCXX.cpp
+++ b/lib/Sema/SemaExprCXX.cpp
@@ -680,19 +680,21 @@
// Otherwise, check that we can capture 'this'.
unsigned NumClosures = 0;
for (unsigned idx = FunctionScopes.size() - 1; idx != 0; idx--) {
- if (LambdaScopeInfo *LSI = dyn_cast<LambdaScopeInfo>(FunctionScopes[idx])) {
- if (LSI->CapturesCXXThis) {
- // This lambda already captures 'this'; there isn't anything more to do.
+ if (CapturingScopeInfo *CSI =
+ dyn_cast<CapturingScopeInfo>(FunctionScopes[idx])) {
+ if (CSI->CXXThisCaptureIndex != 0) {
+ // 'this' is already being captured; there isn't anything more to do.
break;
}
- if (LSI->Default == LCD_ByRef) {
- // This lambda can implicitly capture 'this'; continue looking upwards.
+ if (CSI->ImpCaptureStyle == CapturingScopeInfo::ImpCap_LambdaByref ||
+ CSI->ImpCaptureStyle == CapturingScopeInfo::ImpCap_Block) {
+ // This closure can implicitly capture 'this'; continue looking upwards.
// FIXME: Is this check correct? The rules in the standard are a bit
// unclear.
NumClosures++;
continue;
}
- // This lambda can't implicitly capture 'this'; fail out.
+ // This context can't implicitly capture 'this'; fail out.
// (We need to delay the diagnostic in the
// PotentiallyPotentiallyEvaluated case because it doesn't apply to
// unevaluated contexts.)
@@ -703,10 +705,6 @@
Diag(Loc, diag::err_implicit_this_capture);
return;
}
- if (isa<BlockScopeInfo>(FunctionScopes[idx])) {
- NumClosures++;
- continue;
- }
break;
}
@@ -715,14 +713,9 @@
// contexts.
for (unsigned idx = FunctionScopes.size() - 1;
NumClosures; --idx, --NumClosures) {
- if (BlockScopeInfo *BSI = dyn_cast<BlockScopeInfo>(FunctionScopes[idx])) {
- BSI->CapturesCXXThis = true;
- } else {
- LambdaScopeInfo *LSI = dyn_cast<LambdaScopeInfo>(FunctionScopes[idx]);
- assert(LSI && "Unexpected closure");
- LSI->CapturesCXXThis = true;
- LSI->Captures.push_back(LambdaScopeInfo::Capture::ThisCapture);
- }
+ CapturingScopeInfo *CSI = cast<CapturingScopeInfo>(FunctionScopes[idx]);
+ bool isNested = NumClosures > 1;
+ CSI->AddThisCapture(isNested);
}
}
@@ -4831,8 +4824,9 @@
CurContext->addDecl(Class);
QualType ThisCaptureType;
+ llvm::DenseMap<VarDecl*, unsigned> CaptureMap;
+ unsigned CXXThisCaptureIndex = 0;
llvm::SmallVector<LambdaScopeInfo::Capture, 4> Captures;
- llvm::DenseMap<const IdentifierInfo*, SourceLocation> CapturesSoFar;
for (llvm::SmallVector<LambdaCapture, 4>::const_iterator
C = Intro.Captures.begin(), E = Intro.Captures.end(); C != E; ++C) {
if (C->Kind == LCK_This) {
@@ -4853,7 +4847,12 @@
}
CheckCXXThisCapture(C->Loc);
- Captures.push_back(LambdaScopeInfo::Capture::ThisCapture);
+ // FIXME: Need getCurCapture().
+ bool isNested = getCurBlock() || getCurLambda();
+ CapturingScopeInfo::Capture Cap(CapturingScopeInfo::Capture::ThisCapture,
+ isNested);
+ Captures.push_back(Cap);
+ CXXThisCaptureIndex = Captures.size();
continue;
}
@@ -4867,16 +4866,6 @@
continue;
}
- llvm::DenseMap<const IdentifierInfo*, SourceLocation>::iterator Appearance;
- bool IsFirstAppearance;
- llvm::tie(Appearance, IsFirstAppearance)
- = CapturesSoFar.insert(std::make_pair(C->Id, C->Loc));
-
- if (!IsFirstAppearance) {
- Diag(C->Loc, diag::err_capture_more_than_once) << C->Id;
- continue;
- }
-
DeclarationNameInfo Name(C->Id, C->Loc);
LookupResult R(*this, Name, LookupOrdinaryName);
CXXScopeSpec ScopeSpec;
@@ -4893,16 +4882,22 @@
continue;
}
+ if (CaptureMap.count(Var)) {
+ Diag(C->Loc, diag::err_capture_more_than_once) << C->Id;
+ continue;
+ }
+
if (!Var->hasLocalStorage()) {
Diag(C->Loc, diag::err_capture_non_automatic_variable) << C->Id;
continue;
}
- // FIXME: Actually capturing a variable is much more complicated than this
- // in the general case; see shouldCaptureValueReference.
- // FIXME: Should we be building a DeclRefExpr here? We don't really need
- // it until the point where we're actually building the LambdaExpr.
- Captures.push_back(LambdaScopeInfo::Capture(Var, C->Kind));
+ // FIXME: This is completely wrong for nested captures and variables
+ // with a non-trivial constructor.
+ // FIXME: We should refuse to capture __block variables.
+ Captures.push_back(LambdaScopeInfo::Capture(Var, C->Kind == LCK_ByRef,
+ /*isNested*/false, 0));
+ CaptureMap[Var] = Captures.size();
}
// Build the call operator; we don't really have all the relevant information
@@ -4982,15 +4977,20 @@
PushLambdaScope(Class);
LambdaScopeInfo *LSI = getCurLambda();
- LSI->Default = Intro.Default;
- if (!ThisCaptureType.isNull())
- LSI->CapturesCXXThis = true;
+ LSI->CXXThisCaptureIndex = CXXThisCaptureIndex;
+ std::swap(LSI->CaptureMap, CaptureMap);
std::swap(LSI->Captures, Captures);
+ LSI->NumExplicitCaptures = Captures.size();
+ if (Intro.Default == LCD_ByCopy)
+ LSI->ImpCaptureStyle = LambdaScopeInfo::ImpCap_LambdaByval;
+ else if (Intro.Default == LCD_ByRef)
+ LSI->ImpCaptureStyle = LambdaScopeInfo::ImpCap_LambdaByref;
const FunctionType *Fn = MethodTy->getAs<FunctionType>();
QualType RetTy = Fn->getResultType();
if (RetTy != Context.DependentTy) {
LSI->ReturnType = RetTy;
+ } else {
LSI->HasImplicitReturnType = true;
}
diff --git a/lib/Sema/SemaExprObjC.cpp b/lib/Sema/SemaExprObjC.cpp
index 20c3b75..d229c18 100644
--- a/lib/Sema/SemaExprObjC.cpp
+++ b/lib/Sema/SemaExprObjC.cpp
@@ -265,8 +265,7 @@
if (captureIndex) break;
bool nested = isa<BlockScopeInfo>(FunctionScopes[idx-1]);
- blockScope->Captures.push_back(
- BlockDecl::Capture(self, /*byref*/ false, nested, /*copy*/ 0));
+ blockScope->AddCapture(self, /*byref*/ false, nested, /*copy*/ 0);
captureIndex = blockScope->Captures.size(); // +1
}
diff --git a/lib/Sema/TreeTransform.h b/lib/Sema/TreeTransform.h
index 7995b0b..4908e88 100644
--- a/lib/Sema/TreeTransform.h
+++ b/lib/Sema/TreeTransform.h
@@ -1890,6 +1890,7 @@
ExprResult RebuildCXXThisExpr(SourceLocation ThisLoc,
QualType ThisType,
bool isImplicit) {
+ getSema().CheckCXXThisCapture(ThisLoc);
return getSema().Owned(
new (getSema().Context) CXXThisExpr(ThisLoc, ThisType,
isImplicit));
@@ -8114,10 +8115,6 @@
BlockScopeInfo *blockScope = SemaRef.getCurBlock();
blockScope->TheDecl->setIsVariadic(oldBlock->isVariadic());
- // We built a new blockScopeInfo in call to ActOnBlockStart
- // in above, CapturesCXXThis need be set here from the block
- // expression.
- blockScope->CapturesCXXThis = oldBlock->capturesCXXThis();
blockScope->TheDecl->setBlockMissingReturnType(
oldBlock->blockMissingReturnType());