nridge updated this revision to Diff 276320.
nridge added a comment.
Split patch
Repository:
rG LLVM Github Monorepo
CHANGES SINCE LAST ACTION
https://reviews.llvm.org/D82739/new/
https://reviews.llvm.org/D82739
Files:
clang-tools-extra/clangd/FindTarget.cpp
clang-tools-extra/clangd/unittests/FindTargetTests.cpp
Index: clang-tools-extra/clangd/unittests/FindTargetTests.cpp
===================================================================
--- clang-tools-extra/clangd/unittests/FindTargetTests.cpp
+++ clang-tools-extra/clangd/unittests/FindTargetTests.cpp
@@ -548,6 +548,23 @@
EXPECT_DECLS("UnresolvedMemberExpr", "void func(int *)", "void func(char *)");
}
+TEST_F(TargetDeclTest, DependentExprs) {
+ Flags = {"-fno-delayed-template-parsing"};
+
+ // Heuristic resolution of method of dependent field
+ Code = R"cpp(
+ struct A { void foo() {} };
+ template <typename T>
+ struct B {
+ A a;
+ void bar() {
+ this->a.[[foo]]();
+ }
+ };
+ )cpp";
+ EXPECT_DECLS("CXXDependentScopeMemberExpr", "void foo()");
+}
+
TEST_F(TargetDeclTest, ObjC) {
Flags = {"-xobjective-c"};
Code = R"cpp(
Index: clang-tools-extra/clangd/FindTarget.cpp
===================================================================
--- clang-tools-extra/clangd/FindTarget.cpp
+++ clang-tools-extra/clangd/FindTarget.cpp
@@ -58,6 +58,10 @@
return S;
}
+// Forward declaration, needed as this function is mutually recursive
+// with some of the other helpers below.
+std::vector<const NamedDecl *> resolveDependentExprToDecls(const Expr *E);
+
// Helper function for getMembersReferencedViaDependentName()
// which takes a possibly-dependent type `T` and heuristically
// resolves it to a CXXRecordDecl in which we can try name lookup.
@@ -79,6 +83,19 @@
return TD->getTemplatedDecl();
}
+// Try to heuristically resolve the type of a dependent expression `E`.
+const Type *resolveDependentExprToType(const Expr *E) {
+ std::vector<const NamedDecl *> Decls = resolveDependentExprToDecls(E);
+ if (Decls.size() != 1) // Names an overload set -- just bail.
+ return nullptr;
+ if (const auto *TD = dyn_cast<TypeDecl>(Decls[0])) {
+ return TD->getTypeForDecl();
+ } else if (const auto *VD = dyn_cast<ValueDecl>(Decls[0])) {
+ return VD->getType().getTypePtrOrNull();
+ }
+ return nullptr;
+}
+
// Given a dependent type and a member name, heuristically resolve the
// name to one or more declarations.
// The current heuristic is simply to look up the name in the primary
@@ -92,12 +109,27 @@
// an ASTContext, because an ASTContext may be needed to obtain the
// name (e.g. if it's an operator name), but the caller may not have
// access to an ASTContext.
+// Optionally, in cases where the type represents the type of a
+// dependent expression, the expression `E` in question can be
+// provided, which allows us to provide richer heuristics by
+// introspecting the expression and trying to reason about its type.
std::vector<const NamedDecl *> getMembersReferencedViaDependentName(
- const Type *T,
+ Expr *E, const Type *T,
llvm::function_ref<DeclarationName(ASTContext &)> NameFactory,
bool IsNonstaticMember) {
if (!T)
return {};
+ if (auto *BT = T->getAs<BuiltinType>()) {
+ // If T is the type of a dependent expression, it's just represented
+ // as BultinType::Dependent which gives us no information. If the
+ // caller provides the expression `E`, we can get further by
+ // analyzing it.
+ if (E && BT->getKind() == BuiltinType::Dependent) {
+ T = resolveDependentExprToType(E);
+ if (!T)
+ return {};
+ }
+ }
if (auto *ET = T->getAs<EnumType>()) {
auto Result =
ET->getDecl()->lookup(NameFactory(ET->getDecl()->getASTContext()));
@@ -132,7 +164,7 @@
// Look up operator-> in the primary template. If we find one, it's probably a
// smart pointer type.
auto ArrowOps = getMembersReferencedViaDependentName(
- T,
+ nullptr, T,
[](ASTContext &Ctx) {
return Ctx.DeclarationNames.getCXXOperatorName(OO_Arrow);
},
@@ -167,14 +199,15 @@
if (ME->isArrow()) {
BaseType = getPointeeType(BaseType);
}
+ Expr *Base = ME->isImplicitAccess() ? nullptr : ME->getBase();
return getMembersReferencedViaDependentName(
- BaseType, [ME](ASTContext &) { return ME->getMember(); },
+ Base, BaseType, [ME](ASTContext &) { return ME->getMember(); },
/*IsNonstaticMember=*/true);
}
case Stmt::DependentScopeDeclRefExprClass: {
const auto *RE = llvm::cast<DependentScopeDeclRefExpr>(E);
return getMembersReferencedViaDependentName(
- RE->getQualifier()->getAsType(),
+ nullptr, RE->getQualifier()->getAsType(),
[RE](ASTContext &) { return RE->getDeclName(); },
/*IsNonstaticMember=*/false);
}
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