release/18.x: [clangd] [HeuristicResolver] Protect against infinite recursion on DependentNameTypes (#83542) #84117
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@llvm/pr-subscribers-clangd Author: None (llvmbot) ChangesBackport e6e53ca Requested by: @HighCommander4 Full diff: https://github.com/llvm/llvm-project/pull/84117.diff 3 Files Affected:
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) {
|
|
@llvm/pr-subscribers-clang-tools-extra Author: None (llvmbot) ChangesBackport e6e53ca Requested by: @HighCommander4 Full diff: https://github.com/llvm/llvm-project/pull/84117.diff 3 Files Affected:
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) {
|
|
(Does the backport need to be reviewed separately? Not sure what is the process these days.) |
zyn0217
approved these changes
Mar 15, 2024
There was a problem hiding this comment.
I think this merits a backport as we don't actually want this crash on some std libraries delays to 19.0.
(Does the backport need to be reviewed separately? Not sure what is the process these days.)
@HighCommander4 : Yes. And we shall ping our release manager @tstellar and hopefully we can make it in 18.2.
hokein
approved these changes
Mar 15, 2024
|
Oh, I saw PR #84436 just now. Do you think this needs a release note? |
There is an umbrella entry in the release notes for "Various stability improvements, e.g. crash fixes". I don't think it adds much value to list the crash fixes individually (unless maybe it's a particularly widely reported one like clangd/clangd#1384). |
Ah, although that sounds a bit unclear. :) |
I'm happy to take suggestions for better wording! |
…pendentNameTypes (llvm#83542) When resolving names inside templates that implement recursive compile-time functions (e.g. waldo<N>::type is defined in terms of waldo<N-1>::type), HeuristicResolver could get into an infinite recursion, specifically one where resolveDependentNameType() can be called recursively with the same DependentNameType*. To guard against this, HeuristicResolver tracks, for each external call into a HeuristicResolver function, the set of DependentNameTypes that it has seen, and bails if it sees the same DependentNameType again. To implement this, a helper class HeuristicResolverImpl is introduced to store state that persists for the duration of an external call into HeuristicResolver (but does not persist between such calls). Fixes clangd/clangd#1951 (cherry picked from commit e6e53ca)
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Backport e6e53ca
Requested by: @HighCommander4