[llvm-branch-commits] [clang-tools-extra] release/18.x: [clangd] [HeuristicResolver] Protect against infinite recursion on DependentNameTypes (#83542) (PR #84117)
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llvm-branch-commits at lists.llvm.org
Tue Mar 5 20:48:39 PST 2024
llvmbot wrote:
<!--LLVM PR SUMMARY COMMENT-->
@llvm/pr-subscribers-clang-tools-extra
Author: None (llvmbot)
<details>
<summary>Changes</summary>
Backport e6e53ca8470d719882539359ebe3ad8b442a8cb0
Requested by: @<!-- -->HighCommander4
---
Full diff: https://github.com/llvm/llvm-project/pull/84117.diff
3 Files Affected:
- (modified) clang-tools-extra/clangd/HeuristicResolver.cpp (+138-32)
- (modified) clang-tools-extra/clangd/HeuristicResolver.h (-37)
- (modified) clang-tools-extra/clangd/unittests/FindTargetTests.cpp (+27)
``````````diff
diff --git a/clang-tools-extra/clangd/HeuristicResolver.cpp b/clang-tools-extra/clangd/HeuristicResolver.cpp
index 3c147b6b582bf0..26d54200eeffd2 100644
--- a/clang-tools-extra/clangd/HeuristicResolver.cpp
+++ b/clang-tools-extra/clangd/HeuristicResolver.cpp
@@ -16,6 +16,80 @@
namespace clang {
namespace clangd {
+namespace {
+
+// Helper class for implementing HeuristicResolver.
+// Unlike HeuristicResolver which is a long-lived class,
+// a new instance of this class is created for every external
+// call into a HeuristicResolver operation. That allows this
+// class to store state that's local to such a top-level call,
+// particularly "recursion protection sets" that keep track of
+// nodes that have already been seen to avoid infinite recursion.
+class HeuristicResolverImpl {
+public:
+ HeuristicResolverImpl(ASTContext &Ctx) : Ctx(Ctx) {}
+
+ // These functions match the public interface of HeuristicResolver
+ // (but aren't const since they may modify the recursion protection sets).
+ std::vector<const NamedDecl *>
+ resolveMemberExpr(const CXXDependentScopeMemberExpr *ME);
+ std::vector<const NamedDecl *>
+ resolveDeclRefExpr(const DependentScopeDeclRefExpr *RE);
+ std::vector<const NamedDecl *> resolveTypeOfCallExpr(const CallExpr *CE);
+ std::vector<const NamedDecl *> resolveCalleeOfCallExpr(const CallExpr *CE);
+ std::vector<const NamedDecl *>
+ resolveUsingValueDecl(const UnresolvedUsingValueDecl *UUVD);
+ std::vector<const NamedDecl *>
+ resolveDependentNameType(const DependentNameType *DNT);
+ std::vector<const NamedDecl *> resolveTemplateSpecializationType(
+ const DependentTemplateSpecializationType *DTST);
+ const Type *resolveNestedNameSpecifierToType(const NestedNameSpecifier *NNS);
+ const Type *getPointeeType(const Type *T);
+
+private:
+ ASTContext &Ctx;
+
+ // Recursion protection sets
+ llvm::SmallSet<const DependentNameType *, 4> SeenDependentNameTypes;
+
+ // Given a tag-decl 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
+ // template. This is a heuristic because the template could potentially
+ // have specializations that declare different members.
+ // Multiple declarations could be returned if the name is overloaded
+ // (e.g. an overloaded method in the primary template).
+ // This heuristic will give the desired answer in many cases, e.g.
+ // for a call to vector<T>::size().
+ std::vector<const NamedDecl *>
+ resolveDependentMember(const Type *T, DeclarationName Name,
+ llvm::function_ref<bool(const NamedDecl *ND)> Filter);
+
+ // Try to heuristically resolve the type of a possibly-dependent expression
+ // `E`.
+ const Type *resolveExprToType(const Expr *E);
+ std::vector<const NamedDecl *> resolveExprToDecls(const Expr *E);
+
+ // Helper function for HeuristicResolver::resolveDependentMember()
+ // which takes a possibly-dependent type `T` and heuristically
+ // resolves it to a CXXRecordDecl in which we can try name lookup.
+ CXXRecordDecl *resolveTypeToRecordDecl(const Type *T);
+
+ // This is a reimplementation of CXXRecordDecl::lookupDependentName()
+ // so that the implementation can call into other HeuristicResolver helpers.
+ // FIXME: Once HeuristicResolver is upstreamed to the clang libraries
+ // (https://github.com/clangd/clangd/discussions/1662),
+ // CXXRecordDecl::lookupDepenedentName() can be removed, and its call sites
+ // can be modified to benefit from the more comprehensive heuristics offered
+ // by HeuristicResolver instead.
+ std::vector<const NamedDecl *>
+ lookupDependentName(CXXRecordDecl *RD, DeclarationName Name,
+ llvm::function_ref<bool(const NamedDecl *ND)> Filter);
+ bool findOrdinaryMemberInDependentClasses(const CXXBaseSpecifier *Specifier,
+ CXXBasePath &Path,
+ DeclarationName Name);
+};
+
// Convenience lambdas for use as the 'Filter' parameter of
// HeuristicResolver::resolveDependentMember().
const auto NoFilter = [](const NamedDecl *D) { return true; };
@@ -31,8 +105,6 @@ const auto TemplateFilter = [](const NamedDecl *D) {
return isa<TemplateDecl>(D);
};
-namespace {
-
const Type *resolveDeclsToType(const std::vector<const NamedDecl *> &Decls,
ASTContext &Ctx) {
if (Decls.size() != 1) // Names an overload set -- just bail.
@@ -46,12 +118,10 @@ const Type *resolveDeclsToType(const std::vector<const NamedDecl *> &Decls,
return nullptr;
}
-} // namespace
-
// Helper function for HeuristicResolver::resolveDependentMember()
// which takes a possibly-dependent type `T` and heuristically
// resolves it to a CXXRecordDecl in which we can try name lookup.
-CXXRecordDecl *HeuristicResolver::resolveTypeToRecordDecl(const Type *T) const {
+CXXRecordDecl *HeuristicResolverImpl::resolveTypeToRecordDecl(const Type *T) {
assert(T);
// Unwrap type sugar such as type aliases.
@@ -84,7 +154,7 @@ CXXRecordDecl *HeuristicResolver::resolveTypeToRecordDecl(const Type *T) const {
return TD->getTemplatedDecl();
}
-const Type *HeuristicResolver::getPointeeType(const Type *T) const {
+const Type *HeuristicResolverImpl::getPointeeType(const Type *T) {
if (!T)
return nullptr;
@@ -117,8 +187,8 @@ const Type *HeuristicResolver::getPointeeType(const Type *T) const {
return FirstArg.getAsType().getTypePtrOrNull();
}
-std::vector<const NamedDecl *> HeuristicResolver::resolveMemberExpr(
- const CXXDependentScopeMemberExpr *ME) const {
+std::vector<const NamedDecl *> HeuristicResolverImpl::resolveMemberExpr(
+ const CXXDependentScopeMemberExpr *ME) {
// If the expression has a qualifier, try resolving the member inside the
// qualifier's type.
// Note that we cannot use a NonStaticFilter in either case, for a couple
@@ -164,14 +234,14 @@ std::vector<const NamedDecl *> HeuristicResolver::resolveMemberExpr(
return resolveDependentMember(BaseType, ME->getMember(), NoFilter);
}
-std::vector<const NamedDecl *> HeuristicResolver::resolveDeclRefExpr(
- const DependentScopeDeclRefExpr *RE) const {
+std::vector<const NamedDecl *>
+HeuristicResolverImpl::resolveDeclRefExpr(const DependentScopeDeclRefExpr *RE) {
return resolveDependentMember(RE->getQualifier()->getAsType(),
RE->getDeclName(), StaticFilter);
}
std::vector<const NamedDecl *>
-HeuristicResolver::resolveTypeOfCallExpr(const CallExpr *CE) const {
+HeuristicResolverImpl::resolveTypeOfCallExpr(const CallExpr *CE) {
const auto *CalleeType = resolveExprToType(CE->getCallee());
if (!CalleeType)
return {};
@@ -187,7 +257,7 @@ HeuristicResolver::resolveTypeOfCallExpr(const CallExpr *CE) const {
}
std::vector<const NamedDecl *>
-HeuristicResolver::resolveCalleeOfCallExpr(const CallExpr *CE) const {
+HeuristicResolverImpl::resolveCalleeOfCallExpr(const CallExpr *CE) {
if (const auto *ND = dyn_cast_or_null<NamedDecl>(CE->getCalleeDecl())) {
return {ND};
}
@@ -195,29 +265,31 @@ HeuristicResolver::resolveCalleeOfCallExpr(const CallExpr *CE) const {
return resolveExprToDecls(CE->getCallee());
}
-std::vector<const NamedDecl *> HeuristicResolver::resolveUsingValueDecl(
- const UnresolvedUsingValueDecl *UUVD) const {
+std::vector<const NamedDecl *> HeuristicResolverImpl::resolveUsingValueDecl(
+ const UnresolvedUsingValueDecl *UUVD) {
return resolveDependentMember(UUVD->getQualifier()->getAsType(),
UUVD->getNameInfo().getName(), ValueFilter);
}
-std::vector<const NamedDecl *> HeuristicResolver::resolveDependentNameType(
- const DependentNameType *DNT) const {
+std::vector<const NamedDecl *>
+HeuristicResolverImpl::resolveDependentNameType(const DependentNameType *DNT) {
+ if (auto [_, inserted] = SeenDependentNameTypes.insert(DNT); !inserted)
+ return {};
return resolveDependentMember(
resolveNestedNameSpecifierToType(DNT->getQualifier()),
DNT->getIdentifier(), TypeFilter);
}
std::vector<const NamedDecl *>
-HeuristicResolver::resolveTemplateSpecializationType(
- const DependentTemplateSpecializationType *DTST) const {
+HeuristicResolverImpl::resolveTemplateSpecializationType(
+ const DependentTemplateSpecializationType *DTST) {
return resolveDependentMember(
resolveNestedNameSpecifierToType(DTST->getQualifier()),
DTST->getIdentifier(), TemplateFilter);
}
std::vector<const NamedDecl *>
-HeuristicResolver::resolveExprToDecls(const Expr *E) const {
+HeuristicResolverImpl::resolveExprToDecls(const Expr *E) {
if (const auto *ME = dyn_cast<CXXDependentScopeMemberExpr>(E)) {
return resolveMemberExpr(ME);
}
@@ -236,7 +308,7 @@ HeuristicResolver::resolveExprToDecls(const Expr *E) const {
return {};
}
-const Type *HeuristicResolver::resolveExprToType(const Expr *E) const {
+const Type *HeuristicResolverImpl::resolveExprToType(const Expr *E) {
std::vector<const NamedDecl *> Decls = resolveExprToDecls(E);
if (!Decls.empty())
return resolveDeclsToType(Decls, Ctx);
@@ -244,8 +316,8 @@ const Type *HeuristicResolver::resolveExprToType(const Expr *E) const {
return E->getType().getTypePtr();
}
-const Type *HeuristicResolver::resolveNestedNameSpecifierToType(
- const NestedNameSpecifier *NNS) const {
+const Type *HeuristicResolverImpl::resolveNestedNameSpecifierToType(
+ const NestedNameSpecifier *NNS) {
if (!NNS)
return nullptr;
@@ -270,8 +342,6 @@ const Type *HeuristicResolver::resolveNestedNameSpecifierToType(
return nullptr;
}
-namespace {
-
bool isOrdinaryMember(const NamedDecl *ND) {
return ND->isInIdentifierNamespace(Decl::IDNS_Ordinary | Decl::IDNS_Tag |
Decl::IDNS_Member);
@@ -287,11 +357,9 @@ bool findOrdinaryMember(const CXXRecordDecl *RD, CXXBasePath &Path,
return false;
}
-} // namespace
-
-bool HeuristicResolver::findOrdinaryMemberInDependentClasses(
+bool HeuristicResolverImpl::findOrdinaryMemberInDependentClasses(
const CXXBaseSpecifier *Specifier, CXXBasePath &Path,
- DeclarationName Name) const {
+ DeclarationName Name) {
CXXRecordDecl *RD =
resolveTypeToRecordDecl(Specifier->getType().getTypePtr());
if (!RD)
@@ -299,9 +367,9 @@ bool HeuristicResolver::findOrdinaryMemberInDependentClasses(
return findOrdinaryMember(RD, Path, Name);
}
-std::vector<const NamedDecl *> HeuristicResolver::lookupDependentName(
+std::vector<const NamedDecl *> HeuristicResolverImpl::lookupDependentName(
CXXRecordDecl *RD, DeclarationName Name,
- llvm::function_ref<bool(const NamedDecl *ND)> Filter) const {
+ llvm::function_ref<bool(const NamedDecl *ND)> Filter) {
std::vector<const NamedDecl *> Results;
// Lookup in the class.
@@ -332,9 +400,9 @@ std::vector<const NamedDecl *> HeuristicResolver::lookupDependentName(
return Results;
}
-std::vector<const NamedDecl *> HeuristicResolver::resolveDependentMember(
+std::vector<const NamedDecl *> HeuristicResolverImpl::resolveDependentMember(
const Type *T, DeclarationName Name,
- llvm::function_ref<bool(const NamedDecl *ND)> Filter) const {
+ llvm::function_ref<bool(const NamedDecl *ND)> Filter) {
if (!T)
return {};
if (auto *ET = T->getAs<EnumType>()) {
@@ -349,6 +417,44 @@ std::vector<const NamedDecl *> HeuristicResolver::resolveDependentMember(
}
return {};
}
+} // namespace
+
+std::vector<const NamedDecl *> HeuristicResolver::resolveMemberExpr(
+ const CXXDependentScopeMemberExpr *ME) const {
+ return HeuristicResolverImpl(Ctx).resolveMemberExpr(ME);
+}
+std::vector<const NamedDecl *> HeuristicResolver::resolveDeclRefExpr(
+ const DependentScopeDeclRefExpr *RE) const {
+ return HeuristicResolverImpl(Ctx).resolveDeclRefExpr(RE);
+}
+std::vector<const NamedDecl *>
+HeuristicResolver::resolveTypeOfCallExpr(const CallExpr *CE) const {
+ return HeuristicResolverImpl(Ctx).resolveTypeOfCallExpr(CE);
+}
+std::vector<const NamedDecl *>
+HeuristicResolver::resolveCalleeOfCallExpr(const CallExpr *CE) const {
+ return HeuristicResolverImpl(Ctx).resolveCalleeOfCallExpr(CE);
+}
+std::vector<const NamedDecl *> HeuristicResolver::resolveUsingValueDecl(
+ const UnresolvedUsingValueDecl *UUVD) const {
+ return HeuristicResolverImpl(Ctx).resolveUsingValueDecl(UUVD);
+}
+std::vector<const NamedDecl *> HeuristicResolver::resolveDependentNameType(
+ const DependentNameType *DNT) const {
+ return HeuristicResolverImpl(Ctx).resolveDependentNameType(DNT);
+}
+std::vector<const NamedDecl *>
+HeuristicResolver::resolveTemplateSpecializationType(
+ const DependentTemplateSpecializationType *DTST) const {
+ return HeuristicResolverImpl(Ctx).resolveTemplateSpecializationType(DTST);
+}
+const Type *HeuristicResolver::resolveNestedNameSpecifierToType(
+ const NestedNameSpecifier *NNS) const {
+ return HeuristicResolverImpl(Ctx).resolveNestedNameSpecifierToType(NNS);
+}
+const Type *HeuristicResolver::getPointeeType(const Type *T) const {
+ return HeuristicResolverImpl(Ctx).getPointeeType(T);
+}
} // namespace clangd
} // namespace clang
diff --git a/clang-tools-extra/clangd/HeuristicResolver.h b/clang-tools-extra/clangd/HeuristicResolver.h
index dc04123d37593c..dcc063bbc4adc0 100644
--- a/clang-tools-extra/clangd/HeuristicResolver.h
+++ b/clang-tools-extra/clangd/HeuristicResolver.h
@@ -77,43 +77,6 @@ class HeuristicResolver {
private:
ASTContext &Ctx;
-
- // Given a tag-decl 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
- // template. This is a heuristic because the template could potentially
- // have specializations that declare different members.
- // Multiple declarations could be returned if the name is overloaded
- // (e.g. an overloaded method in the primary template).
- // This heuristic will give the desired answer in many cases, e.g.
- // for a call to vector<T>::size().
- std::vector<const NamedDecl *> resolveDependentMember(
- const Type *T, DeclarationName Name,
- llvm::function_ref<bool(const NamedDecl *ND)> Filter) const;
-
- // Try to heuristically resolve the type of a possibly-dependent expression
- // `E`.
- const Type *resolveExprToType(const Expr *E) const;
- std::vector<const NamedDecl *> resolveExprToDecls(const Expr *E) const;
-
- // Helper function for HeuristicResolver::resolveDependentMember()
- // which takes a possibly-dependent type `T` and heuristically
- // resolves it to a CXXRecordDecl in which we can try name lookup.
- CXXRecordDecl *resolveTypeToRecordDecl(const Type *T) const;
-
- // This is a reimplementation of CXXRecordDecl::lookupDependentName()
- // so that the implementation can call into other HeuristicResolver helpers.
- // FIXME: Once HeuristicResolver is upstreamed to the clang libraries
- // (https://github.com/clangd/clangd/discussions/1662),
- // CXXRecordDecl::lookupDepenedentName() can be removed, and its call sites
- // can be modified to benefit from the more comprehensive heuristics offered
- // by HeuristicResolver instead.
- std::vector<const NamedDecl *> lookupDependentName(
- CXXRecordDecl *RD, DeclarationName Name,
- llvm::function_ref<bool(const NamedDecl *ND)> Filter) const;
- bool findOrdinaryMemberInDependentClasses(const CXXBaseSpecifier *Specifier,
- CXXBasePath &Path,
- DeclarationName Name) const;
};
} // namespace clangd
diff --git a/clang-tools-extra/clangd/unittests/FindTargetTests.cpp b/clang-tools-extra/clangd/unittests/FindTargetTests.cpp
index 29cff68cf03b2e..0af6036734ba53 100644
--- a/clang-tools-extra/clangd/unittests/FindTargetTests.cpp
+++ b/clang-tools-extra/clangd/unittests/FindTargetTests.cpp
@@ -1009,6 +1009,33 @@ TEST_F(TargetDeclTest, DependentTypes) {
)cpp";
EXPECT_DECLS("DependentTemplateSpecializationTypeLoc",
"template <typename> struct B");
+
+ // Dependent name with recursive definition. We don't expect a
+ // result, but we shouldn't get into a stack overflow either.
+ Code = R"cpp(
+ template <int N>
+ struct waldo {
+ typedef typename waldo<N - 1>::type::[[next]] type;
+ };
+ )cpp";
+ EXPECT_DECLS("DependentNameTypeLoc");
+
+ // Similar to above but using mutually recursive templates.
+ Code = R"cpp(
+ template <int N>
+ struct odd;
+
+ template <int N>
+ struct even {
+ using type = typename odd<N - 1>::type::next;
+ };
+
+ template <int N>
+ struct odd {
+ using type = typename even<N - 1>::type::[[next]];
+ };
+ )cpp";
+ EXPECT_DECLS("DependentNameTypeLoc");
}
TEST_F(TargetDeclTest, TypedefCascade) {
``````````
</details>
https://github.com/llvm/llvm-project/pull/84117
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