Resolve member types for partial specializations (#562)

Author: lucic71

cpp2rust/converter/rules/registry.cpp

@@ -170,7 +170,7 @@ void addRule(clang::ASTContext &ctx, const std::string &dir,
     assert(llvm::isa<clang::VarDecl>(decl) &&
            "expression rule is neither a function nor a variable");
   }
-  auto keys = RuleKeys::GetExprKeys(ctx, decl);
+  auto keys = RuleKeys::GetExprKeys(*sema_, decl);
   assert(!keys.empty() && "expression rule has no key");
   for (const auto &key : keys) {
     exprs_.emplace(

cpp2rust/converter/rules/rule_keys.cpp

@@ -9,6 +9,8 @@
 #include <clang/Basic/OperatorKinds.h>
 #include <clang/Basic/SourceManager.h>
 #include <clang/Lex/Lexer.h>
+#include <clang/Sema/Sema.h>
+#include <clang/Sema/TemplateDeduction.h>
 #include <llvm/ADT/STLExtras.h>
 
 #include <cassert>
@@ -56,32 +58,51 @@ const clang::Decl *getParent(const clang::Decl *decl) {
   return nullptr;
 }
 
-std::vector<clang::QualType> resolveMemberType(clang::QualType type) {
+llvm::SmallVector<clang::CXXRecordDecl *>
+matchingDefinitions(clang::Sema &sema, clang::ClassTemplateDecl *tmpl,
+                    const clang::TemplateSpecializationType *spec) {
+  llvm::SmallVector<clang::ClassTemplatePartialSpecializationDecl *> partials;
+  tmpl->getPartialSpecializations(partials);
+  llvm::SmallVector<clang::CXXRecordDecl *> records;
+  for (auto partial : partials) {
+    RuleDecls::Trial trial(sema);
+    clang::sema::TemplateDeductionInfo info(partial->getLocation());
+    if (sema.DeduceTemplateArguments(partial, spec->template_arguments(),
+                                     info) ==
+            clang::TemplateDeductionResult::Success &&
+        !trial.failed()) {
+      records.push_back(partial);
+    }
+  }
+  if (records.empty()) {
+    records.push_back(tmpl->getTemplatedDecl());
+  }
+  return records;
+}
+
+std::vector<clang::QualType> resolveMemberType(clang::Sema &sema,
+                                               clang::QualType type) {
   auto member = type->getAs<clang::DependentNameType>();
   if (!member) {
     return {type};
   }
   auto qualifier = member->getQualifier().getAsType();
   assert(qualifier && "member type is not qualified by a type");
   std::vector<clang::QualType> resolved;
-  for (auto owner : resolveMemberType(clang::QualType(qualifier, 0))) {
+  for (auto owner : resolveMemberType(sema, clang::QualType(qualifier, 0))) {
     auto spec = owner->getAs<clang::TemplateSpecializationType>();
     auto tmpl = spec ? llvm::dyn_cast_or_null<clang::ClassTemplateDecl>(
                            spec->getTemplateName().getAsTemplateDecl())
                      : nullptr;
     assert(tmpl && "member type is not qualified by a class template");
-    llvm::SmallVector<clang::ClassTemplatePartialSpecializationDecl *> partials;
-    tmpl->getPartialSpecializations(partials);
-    llvm::SmallVector<clang::CXXRecordDecl *> records{tmpl->getTemplatedDecl()};
-    records.append(partials.begin(), partials.end());
-    for (auto record : records) {
+    for (auto record : matchingDefinitions(sema, tmpl, spec)) {
       if (!record->hasDefinition()) {
         continue;
       }
       for (auto decl :
            record->getDefinition()->lookup(member->getIdentifier())) {
         if (auto alias = llvm::dyn_cast<clang::TypedefNameDecl>(decl)) {
-          auto types = resolveMemberType(alias->getUnderlyingType());
+          auto types = resolveMemberType(sema, alias->getUnderlyingType());
           resolved.insert(resolved.end(), types.begin(), types.end());
         }
       }
@@ -198,8 +219,9 @@ std::optional<ExprKey> GetExprKey(clang::ASTContext &ctx,
   return std::nullopt;
 }
 
-std::vector<ExprKey> GetExprKeys(clang::ASTContext &ctx,
+std::vector<ExprKey> GetExprKeys(clang::Sema &sema,
                                  const clang::NamedDecl *rule) {
+  auto &ctx = sema.Context;
   if (auto var = llvm::dyn_cast<clang::VarDecl>(rule)) {
     auto key = GetExprKey(ctx, var->getInit());
     assert(key && "expression rule has no key");
@@ -210,7 +232,7 @@ std::vector<ExprKey> GetExprKeys(clang::ASTContext &ctx,
   if (auto construct =
           llvm::dyn_cast<clang::CXXUnresolvedConstructExpr>(returned)) {
     std::vector<ExprKey> keys;
-    for (auto type : resolveMemberType(construct->getTypeAsWritten())) {
+    for (auto type : resolveMemberType(sema, construct->getTypeAsWritten())) {
       if (type->getAs<clang::TemplateTypeParmType>()) {
         if (!llvm::is_contained(keys, ExprKey{kAnyConstructor})) {
           keys.push_back(kAnyConstructor);

cpp2rust/converter/rules/rule_keys.h

@@ -8,6 +8,7 @@
 #include <clang/AST/DeclarationName.h>
 #include <clang/AST/Expr.h>
 #include <clang/AST/Type.h>
+#include <clang/Sema/Sema.h>
 #include <llvm/ADT/Hashing.h>
 
 #include <compare>
@@ -46,7 +47,7 @@ inline const Constructor kAnyConstructor{nullptr};
 std::optional<ExprKey> GetExprKey(clang::ASTContext &ctx,
                                   const clang::Expr *use);
 
-std::vector<ExprKey> GetExprKeys(clang::ASTContext &ctx,
+std::vector<ExprKey> GetExprKeys(clang::Sema &sema,
                                  const clang::NamedDecl *rule);
 
 std::optional<ExprKey> GetDeclKey(const clang::NamedDecl *decl);

rules/vector/src.cpp

@@ -254,3 +254,9 @@ f116(std::vector<T1, T2> &o, typename std::vector<T1, T2>::const_iterator pos,
      std::initializer_list<T1> l) {
   return o.insert(pos, l);
 }
+
+template <typename T1>
+typename std::vector<bool, T1>::reference
+f117(const typename std::vector<bool, T1>::reference &a0) {
+  return typename std::vector<bool, T1>::reference(a0);
+}

rules/vector/tgt_unsafe.rs

@@ -249,3 +249,7 @@ unsafe fn f116<T1>(a0: &mut Vec<T1>, a1: UnsafeRandomAccessIterator<T1>, a2: Vec
     a0.splice(__off..__off, a2);
     UnsafeRandomAccessIterator::Vec(a0.as_mut_ptr().add(__off))
 }
+
+unsafe fn f117(a0: bool) -> bool {
+    a0
+}

tests/unit/out/refcount/simple_index.rs

@@ -13,6 +13,9 @@ pub fn main() {
 fn main_0() -> i32 {
     let v: Value<Vec<bool>> = Rc::new(RefCell::new(Vec::from([true])));
     assert!(({ (*v.borrow())[0_usize] } as bool));
+    let r: Value<bool> = Rc::new(RefCell::new({ (*v.borrow())[0_usize] }));
+    let copy: Value<bool> = Rc::new(RefCell::new((*r.borrow())));
+    assert!(((*copy.borrow()) as bool));
     return 0;
 }
 pub fn __cpp2rust_init_globals() {}

tests/unit/out/unsafe/simple_index.rs

@@ -15,6 +15,9 @@ pub fn main() {
 unsafe fn main_0() -> i32 {
     let mut v: Vec<bool> = Vec::from([true]);
     assert!((v[(0_usize)] as bool));
+    let mut r: bool = v[(0_usize)];
+    let mut copy: bool = r;
+    assert!((copy as bool));
     return 0;
 }
 pub unsafe fn __cpp2rust_init_globals() {}

tests/unit/simple_index.cpp

@@ -4,5 +4,8 @@
 int main() {
   std::vector<bool> v = {true};
   assert(v[0]);
+  std::vector<bool>::reference r = v[0];
+  std::vector<bool>::reference copy = r;
+  assert(copy);
   return 0;
 }