[ASTImporter] Add importer specific lookup
Summary:
There are certain cases when normal C/C++ lookup (localUncachedLookup)
does not find AST nodes. E.g.:
Example 1:
template <class T>
struct X {
friend void foo(); // this is never found in the DC of the TU.
};
Example 2:
// The fwd decl to Foo is not found in the lookupPtr of the DC of the
// translation unit decl.
struct A { struct Foo *p; };
In these cases we create a new node instead of returning with the old one.
To fix it we create a new lookup table which holds every node and we are
not interested in any C++ specific visibility considerations.
Simply, we must know if there is an existing Decl in a given DC.
Reviewers: a_sidorin, a.sidorin
Subscribers: mgorny, rnkovacs, dkrupp, Szelethus, cfe-commits
Differential Revision: https://reviews.llvm.org/D53708
llvm-svn: 349351
diff --git a/clang/lib/AST/ASTImporterLookupTable.cpp b/clang/lib/AST/ASTImporterLookupTable.cpp
new file mode 100644
index 0000000..fbcd4f5
--- /dev/null
+++ b/clang/lib/AST/ASTImporterLookupTable.cpp
@@ -0,0 +1,129 @@
+//===- ASTImporterLookupTable.cpp - ASTImporter specific lookup -----------===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file defines the ASTImporterLookupTable class which implements a
+// lookup procedure for the import mechanism.
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/AST/ASTImporterLookupTable.h"
+#include "clang/AST/Decl.h"
+#include "clang/AST/RecursiveASTVisitor.h"
+
+namespace clang {
+
+namespace {
+
+struct Builder : RecursiveASTVisitor<Builder> {
+ ASTImporterLookupTable <
+ Builder(ASTImporterLookupTable <) : LT(LT) {}
+ bool VisitNamedDecl(NamedDecl *D) {
+ LT.add(D);
+ return true;
+ }
+ bool VisitFriendDecl(FriendDecl *D) {
+ if (D->getFriendType()) {
+ QualType Ty = D->getFriendType()->getType();
+ // FIXME Can this be other than elaborated?
+ QualType NamedTy = cast<ElaboratedType>(Ty)->getNamedType();
+ if (!NamedTy->isDependentType()) {
+ if (const auto *RTy = dyn_cast<RecordType>(NamedTy))
+ LT.add(RTy->getAsCXXRecordDecl());
+ else if (const auto *SpecTy =
+ dyn_cast<TemplateSpecializationType>(NamedTy)) {
+ LT.add(SpecTy->getAsCXXRecordDecl());
+ }
+ }
+ }
+ return true;
+ }
+
+ // Override default settings of base.
+ bool shouldVisitTemplateInstantiations() const { return true; }
+ bool shouldVisitImplicitCode() const { return true; }
+};
+
+} // anonymous namespace
+
+ASTImporterLookupTable::ASTImporterLookupTable(TranslationUnitDecl &TU) {
+ Builder B(*this);
+ B.TraverseDecl(&TU);
+}
+
+void ASTImporterLookupTable::add(DeclContext *DC, NamedDecl *ND) {
+ DeclList &Decls = LookupTable[DC][ND->getDeclName()];
+ // Inserts if and only if there is no element in the container equal to it.
+ Decls.insert(ND);
+}
+
+void ASTImporterLookupTable::remove(DeclContext *DC, NamedDecl *ND) {
+ DeclList &Decls = LookupTable[DC][ND->getDeclName()];
+ bool EraseResult = Decls.remove(ND);
+ (void)EraseResult;
+ assert(EraseResult == true && "Trying to remove not contained Decl");
+}
+
+void ASTImporterLookupTable::add(NamedDecl *ND) {
+ assert(ND);
+ DeclContext *DC = ND->getDeclContext()->getPrimaryContext();
+ add(DC, ND);
+ DeclContext *ReDC = DC->getRedeclContext()->getPrimaryContext();
+ if (DC != ReDC)
+ add(ReDC, ND);
+}
+
+void ASTImporterLookupTable::remove(NamedDecl *ND) {
+ assert(ND);
+ DeclContext *DC = ND->getDeclContext()->getPrimaryContext();
+ remove(DC, ND);
+ DeclContext *ReDC = DC->getRedeclContext()->getPrimaryContext();
+ if (DC != ReDC)
+ remove(ReDC, ND);
+}
+
+ASTImporterLookupTable::LookupResult
+ASTImporterLookupTable::lookup(DeclContext *DC, DeclarationName Name) const {
+ auto DCI = LookupTable.find(DC->getPrimaryContext());
+ if (DCI == LookupTable.end())
+ return {};
+
+ const auto &FoundNameMap = DCI->second;
+ auto NamesI = FoundNameMap.find(Name);
+ if (NamesI == FoundNameMap.end())
+ return {};
+
+ return NamesI->second;
+}
+
+void ASTImporterLookupTable::dump(DeclContext *DC) const {
+ auto DCI = LookupTable.find(DC->getPrimaryContext());
+ if (DCI == LookupTable.end())
+ llvm::errs() << "empty\n";
+ const auto &FoundNameMap = DCI->second;
+ for (const auto &Entry : FoundNameMap) {
+ DeclarationName Name = Entry.first;
+ llvm::errs() << "==== Name: ";
+ Name.dump();
+ const DeclList& List = Entry.second;
+ for (NamedDecl *ND : List) {
+ ND->dump();
+ }
+ }
+}
+
+void ASTImporterLookupTable::dump() const {
+ for (const auto &Entry : LookupTable) {
+ DeclContext *DC = Entry.first;
+ StringRef Primary = DC->getPrimaryContext() ? " primary" : "";
+ llvm::errs() << "== DC:" << cast<Decl>(DC) << Primary << "\n";
+ dump(DC);
+ }
+}
+
+} // namespace clang