kadircet created this revision.
kadircet added a reviewer: ilya-biryukov.
Herald added subscribers: cfe-commits, usaxena95, arphaman, jkorous, MaskRay.
Herald added a project: clang.
Introduce a new helper for getting minimally required qualifiers
necessary to spell a name at a point in a given DeclContext. Currently takes
using directives and nested namespecifier of DeclContext itself into account.
Initially will be used in define inline and outline actions.
Repository:
rG LLVM Github Monorepo
https://reviews.llvm.org/D69608
Files:
clang-tools-extra/clangd/AST.cpp
clang-tools-extra/clangd/AST.h
clang-tools-extra/clangd/unittests/ASTTests.cpp
Index: clang-tools-extra/clangd/unittests/ASTTests.cpp
===================================================================
--- clang-tools-extra/clangd/unittests/ASTTests.cpp
+++ clang-tools-extra/clangd/unittests/ASTTests.cpp
@@ -7,7 +7,16 @@
//===----------------------------------------------------------------------===//
#include "AST.h"
+#include "Annotations.h"
+#include "ParsedAST.h"
+#include "TestTU.h"
+#include "clang/AST/Decl.h"
+#include "clang/AST/DeclBase.h"
+#include "llvm/ADT/StringRef.h"
+#include "gmock/gmock.h"
#include "gtest/gtest.h"
+#include <cstddef>
+#include <vector>
namespace clang {
namespace clangd {
@@ -36,6 +45,66 @@
"testns1::TestClass<testns1::OtherClass>", "testns1"));
}
+TEST(ClangdAST, GetQualification) {
+ struct {
+ llvm::StringRef Test;
+ std::vector<llvm::StringRef> Qualifications;
+ } Cases[] = {
+ {
+ R"cpp(
+ namespace ns1 { namespace ns2 { class Foo {}; } }
+ void insert(); // ns1::ns2::Foo
+ namespace ns1 {
+ void insert(); // ns2::Foo
+ namespace ns2 {
+ void insert(); // Foo
+ }
+ using namespace ns2;
+ void insert(); // Foo
+ }
+ using namespace ns1;
+ void insert(); // ns2::Foo
+ using namespace ns2;
+ void insert(); // Foo
+ )cpp",
+ {"ns1::ns2::", "ns2::", "", "", "ns2::", ""},
+ },
+ };
+ for (const auto &Case : Cases) {
+ Annotations Test(Case.Test);
+ TestTU TU = TestTU::withCode(Test.code());
+ ParsedAST AST = TU.build();
+ std::vector<const Decl *> InsertionPoints;
+ const NamedDecl *TargetDecl;
+ findDecl(AST, [&](const NamedDecl &ND) {
+ if (ND.getNameAsString() == "Foo") {
+ TargetDecl = &ND;
+ return true;
+ }
+
+ if (ND.getNameAsString() == "insert")
+ InsertionPoints.push_back(&ND);
+ return false;
+ });
+
+ ASSERT_EQ(InsertionPoints.size(), Case.Qualifications.size());
+ for (size_t I = 0, E = InsertionPoints.size(); I != E; ++I) {
+ const Decl *D = InsertionPoints[I];
+ auto Qual =
+ getQualification(AST.getASTContext(), D->getLexicalDeclContext(),
+ D->getBeginLoc(), TargetDecl);
+ if (!Qual)
+ EXPECT_TRUE(Case.Qualifications[I].empty());
+ else {
+ std::string Qualifier;
+ llvm::raw_string_ostream OS(Qualifier);
+ Qual->print(OS, AST.getASTContext().getPrintingPolicy(), true);
+ EXPECT_EQ(OS.str(), Case.Qualifications[I]);
+ }
+ }
+ }
+}
+
} // namespace
} // namespace clangd
} // namespace clang
Index: clang-tools-extra/clangd/AST.h
===================================================================
--- clang-tools-extra/clangd/AST.h
+++ clang-tools-extra/clangd/AST.h
@@ -15,8 +15,10 @@
#include "index/SymbolID.h"
#include "clang/AST/Decl.h"
+#include "clang/AST/NestedNameSpecifier.h"
#include "clang/Basic/SourceLocation.h"
#include "clang/Lex/MacroInfo.h"
+#include "llvm/ADT/DenseSet.h"
namespace clang {
class SourceManager;
@@ -110,6 +112,20 @@
/// void foo() -> returns null
NestedNameSpecifierLoc getQualifierLoc(const NamedDecl &ND);
+/// Gets the nested name specifier necessary for spelling \p ND in \p
+/// DestContext, at \p InsertionPoint. It selects the shortest suffix of \p ND
+/// such that it is visible in \p DestContext, considering all the using
+/// directives before \p InsertionPoint.
+/// Returns null if no qualification is necessary. For example, if you want to
+/// qualify clang::clangd::bar::foo in clang::clangd::x, this function will
+/// return bar. Also if you have `using namespace clang::clangd::bar` before \p
+/// InsertionPoint this function will return null, since no qualification is
+/// necessary in that case.
+NestedNameSpecifier *getQualification(ASTContext &Context,
+ const DeclContext *DestContext,
+ SourceLocation InsertionPoint,
+ const NamedDecl *ND);
+
} // namespace clangd
} // namespace clang
Index: clang-tools-extra/clangd/AST.cpp
===================================================================
--- clang-tools-extra/clangd/AST.cpp
+++ clang-tools-extra/clangd/AST.cpp
@@ -244,6 +244,59 @@
printNamespaceScope(Context) );
}
+NestedNameSpecifier *getQualification(ASTContext &Context,
+ const DeclContext *DestContext,
+ SourceLocation InsertionPoint,
+ const NamedDecl *ND) {
+ const auto &SM = Context.getSourceManager();
+ // Store all UsingDirectiveDecls in parent contexts of DestContext, that were
+ // introduced before InsertionPoint.
+ llvm::DenseSet<const NamespaceDecl *> VisibleNamespaceDecls;
+ for (const auto *DC = DestContext; DC; DC = DC->getLookupParent()) {
+ for (const auto *D : DC->decls()) {
+ if (!SM.isWrittenInSameFile(D->getLocation(), InsertionPoint) ||
+ !SM.isBeforeInTranslationUnit(D->getLocation(), InsertionPoint))
+ continue;
+ if (auto *UDD = llvm::dyn_cast<UsingDirectiveDecl>(D)) {
+ VisibleNamespaceDecls.insert(
+ UDD->getNominatedNamespace()->getCanonicalDecl());
+ }
+ }
+ }
+
+ // Goes over all parents of ND until we find a comman ancestor for DestContext
+ // and ND. Any qualifier including and above common ancestor is redundant,
+ // therefore we stop at lowest common ancestor.
+ std::vector<const NamespaceDecl *> SourceParents;
+ for (const DeclContext *Context = ND->getLexicalDeclContext(); Context;
+ Context = Context->getLookupParent()) {
+ // Stop once we reach a common ancestor.
+ if (Context->Encloses(DestContext))
+ break;
+ // Inline namespace names are not spelled while qualifying a name, so skip
+ // those.
+ if (Context->isInlineNamespace())
+ continue;
+
+ auto *NSD = llvm::dyn_cast<NamespaceDecl>(Context);
+ assert(NSD && "Non-namespace decl context found.");
+ // Stop if this namespace is already visible at DestContext.
+ if (VisibleNamespaceDecls.count(NSD->getCanonicalDecl()))
+ break;
+ // Again, ananoymous namespaces are not spelled while qualifying a name.
+ if (NSD->isAnonymousNamespace())
+ continue;
+
+ SourceParents.push_back(NSD);
+ }
+
+ // Go over name-specifiers in reverse order to create necessary qualification,
+ // since we stored inner-most parent first.
+ NestedNameSpecifier *Result = nullptr;
+ for (const auto *Parent : llvm::reverse(SourceParents))
+ Result = NestedNameSpecifier::Create(Context, Result, Parent);
+ return Result;
+}
} // namespace clangd
} // namespace clang
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