Explictly track tentative definitions within Sema, then hand those
tentative definitions off to the ASTConsumer at the end of the
translation unit.
Eliminate CodeGen's internal tracking of tentative definitions, and
instead hook into ASTConsumer::CompleteTentativeDefinition. Also,
tweak the definition-deferal logic for C++, where there are no
tentative definitions.
Fixes <rdar://problem/6808352>, and will make it much easier for
precompiled headers to cope with tentative definitions in the future.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@69681 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Sema/Sema.cpp b/lib/Sema/Sema.cpp
index ed5c431..19155b6 100644
--- a/lib/Sema/Sema.cpp
+++ b/lib/Sema/Sema.cpp
@@ -13,6 +13,7 @@
//===----------------------------------------------------------------------===//
#include "Sema.h"
+#include "clang/AST/ASTConsumer.h"
#include "clang/AST/ASTContext.h"
#include "clang/AST/DeclObjC.h"
#include "clang/AST/Expr.h"
@@ -232,41 +233,39 @@
// translation unit contains a file scope declaration of that
// identifier, with the composite type as of the end of the
// translation unit, with an initializer equal to 0.
- if (!getLangOptions().CPlusPlus) {
- // Note: we traverse the scope's list of declarations rather than
- // the DeclContext's list, because we only want to see the most
- // recent declaration of each identifier.
- for (Scope::decl_iterator I = TUScope->decl_begin(),
- IEnd = TUScope->decl_end();
- I != IEnd; ++I) {
- Decl *D = (*I).getAs<Decl>();
- if (D->isInvalidDecl())
- continue;
+ for (llvm::DenseMap<DeclarationName, VarDecl *>::iterator
+ D = TentativeDefinitions.begin(),
+ DEnd = TentativeDefinitions.end();
+ D != DEnd; ++D) {
+ VarDecl *VD = D->second;
- if (VarDecl *VD = dyn_cast<VarDecl>(D)) {
- if (VD->isTentativeDefinition(Context)) {
- if (const IncompleteArrayType *ArrayT
- = Context.getAsIncompleteArrayType(VD->getType())) {
- if (RequireCompleteType(VD->getLocation(),
- ArrayT->getElementType(),
- diag::err_tentative_def_incomplete_type_arr))
- VD->setInvalidDecl();
- else {
- // Set the length of the array to 1 (C99 6.9.2p5).
- Diag(VD->getLocation(), diag::warn_tentative_incomplete_array);
- llvm::APInt One(Context.getTypeSize(Context.getSizeType()),
- true);
- QualType T
- = Context.getConstantArrayType(ArrayT->getElementType(),
- One, ArrayType::Normal, 0);
- VD->setType(T);
- }
- } else if (RequireCompleteType(VD->getLocation(), VD->getType(),
- diag::err_tentative_def_incomplete_type))
- VD->setInvalidDecl();
- }
+ if (VD->isInvalidDecl() || !VD->isTentativeDefinition(Context))
+ continue;
+
+ if (const IncompleteArrayType *ArrayT
+ = Context.getAsIncompleteArrayType(VD->getType())) {
+ if (RequireCompleteType(VD->getLocation(),
+ ArrayT->getElementType(),
+ diag::err_tentative_def_incomplete_type_arr))
+ VD->setInvalidDecl();
+ else {
+ // Set the length of the array to 1 (C99 6.9.2p5).
+ Diag(VD->getLocation(), diag::warn_tentative_incomplete_array);
+ llvm::APInt One(Context.getTypeSize(Context.getSizeType()),
+ true);
+ QualType T
+ = Context.getConstantArrayType(ArrayT->getElementType(),
+ One, ArrayType::Normal, 0);
+ VD->setType(T);
}
- }
+ } else if (RequireCompleteType(VD->getLocation(), VD->getType(),
+ diag::err_tentative_def_incomplete_type))
+ VD->setInvalidDecl();
+
+ // Notify the consumer that we've completed a tentative definition.
+ if (!VD->isInvalidDecl())
+ Consumer.CompleteTentativeDefinition(VD);
+
}
}
diff --git a/lib/Sema/Sema.h b/lib/Sema/Sema.h
index 1f6cd04..f3c337c 100644
--- a/lib/Sema/Sema.h
+++ b/lib/Sema/Sema.h
@@ -233,6 +233,14 @@
/// not visible.
llvm::DenseMap<DeclarationName, NamedDecl *> LocallyScopedExternalDecls;
+ /// \brief The set of tentative declarations seen so far in this
+ /// translation unit for which no definition has been seen.
+ ///
+ /// The tentative declarations are indexed by the name of the
+ /// declaration, and only the most recent tentative declaration for
+ /// a given variable will be recorded here.
+ llvm::DenseMap<DeclarationName, VarDecl *> TentativeDefinitions;
+
IdentifierResolver IdResolver;
// Enum values used by KnownFunctionIDs (see below).
diff --git a/lib/Sema/SemaDecl.cpp b/lib/Sema/SemaDecl.cpp
index 716219c..abde26a 100644
--- a/lib/Sema/SemaDecl.cpp
+++ b/lib/Sema/SemaDecl.cpp
@@ -2545,6 +2545,18 @@
// Attach the initializer to the decl.
VDecl->setInit(Init);
+
+ // If the previous declaration of VDecl was a tentative definition,
+ // remove it from the set of tentative definitions.
+ if (VDecl->getPreviousDeclaration() &&
+ VDecl->getPreviousDeclaration()->isTentativeDefinition(Context)) {
+ llvm::DenseMap<DeclarationName, VarDecl *>::iterator Pos
+ = TentativeDefinitions.find(VDecl->getDeclName());
+ assert(Pos != TentativeDefinitions.end() &&
+ "Unrecorded tentative definition?");
+ TentativeDefinitions.erase(Pos);
+ }
+
return;
}
@@ -2557,6 +2569,11 @@
if (VarDecl *Var = dyn_cast<VarDecl>(RealDecl)) {
QualType Type = Var->getType();
+
+ // Record tentative definitions.
+ if (Var->isTentativeDefinition(Context))
+ TentativeDefinitions[Var->getDeclName()] = Var;
+
// C++ [dcl.init.ref]p3:
// The initializer can be omitted for a reference only in a
// parameter declaration (8.3.5), in the declaration of a