Add translation rules for variadic libc calls

cpp2rust/converter/converter.cpp

@@ -1524,6 +1524,11 @@ bool Converter::VisitCallExpr(clang::CallExpr *expr) {
   }
 
   if (Mapper::Contains(expr->getCallee())) {
+    if (Mapper::IsLibcPassthrough(GetCalleeOrExpr(expr))) {
+      ConvertGenericCallExpr(expr);
+      return false;
+    }
+
     auto **args = expr->getArgs();
     auto num_args = expr->getNumArgs();
     auto ctx = CollectPrvalueToLRefArgs(expr);
@@ -1598,20 +1603,20 @@ Converter::CallInfo Converter::CollectCallInfo(clang::CallExpr *expr) {
   using Kind = CallArg::Kind;
 
   CallInfo info;
-  info.callee = expr->getCallee();
+  info.expr = expr;
+  auto callee = GetCallee(expr);
   unsigned arg_begin = 0;
   if (auto op_call = llvm::dyn_cast<clang::CXXOperatorCallExpr>(expr)) {
     if (op_call->getOperator() == clang::OO_Call) {
-      info.callee = op_call->getArg(0);
       arg_begin = 1;
     }
   }
 
-  const auto *function =
-      expr->getCalleeDecl() ? expr->getCalleeDecl()->getAsFunction() : nullptr;
+  auto decl = expr->getCalleeDecl();
+  const auto *function = decl ? decl->getAsFunction() : nullptr;
   const clang::FunctionProtoType *proto = nullptr;
   if (!function) {
-    auto callee_ty = info.callee->getType().getDesugaredType(ctx_);
+    auto callee_ty = callee->getType().getDesugaredType(ctx_);
     if (auto ptr_ty = callee_ty->getAs<clang::PointerType>()) {
       proto = ptr_ty->getPointeeType()->getAs<clang::FunctionProtoType>();
     }
@@ -1624,6 +1629,7 @@ Converter::CallInfo Converter::CollectCallInfo(clang::CallExpr *expr) {
       function ? function->getNumParams() : proto->getNumParams();
   info.is_variadic = function ? function->isVariadic() : proto->isVariadic();
   info.is_fn_ptr_call = !function;
+  info.is_libc_passthrough = Mapper::IsLibcPassthrough(GetCalleeOrExpr(expr));
 
   for (unsigned i = 0; i < num_named_params && i < num_args; ++i) {
     auto *arg = expr->getArg(i + arg_begin);
@@ -1635,7 +1641,8 @@ Converter::CallInfo Converter::CollectCallInfo(clang::CallExpr *expr) {
                                : proto->getParamType(i),
         .expr = arg,
         .has_default = function && function->getParamDecl(i)->hasDefaultArg(),
-        .kind = IsLiteral(arg) ? Kind::Inline : Kind::Hoisted,
+        .kind = (IsLiteral(arg) || info.is_libc_passthrough) ? Kind::Inline
+                                                             : Kind::Hoisted,
     };
     bool is_materialize = clang::isa<clang::MaterializeTemporaryExpr>(arg);
     if (is_materialize && ca.param_type->isLValueReferenceType()) {
@@ -1691,7 +1698,9 @@ void Converter::EmitArgList(const CallInfo &info) {
   using Kind = CallArg::Kind;
   PushParen call_args(*this);
 
-  for (const auto &ca : info.args) {
+  for (unsigned i = 0; i < info.args.size(); i++) {
+    const auto &ca = info.args[i];
+
     if (ca.has_default) {
       StrCat("Some");
     }
@@ -1707,6 +1716,10 @@ void Converter::EmitArgList(const CallInfo &info) {
         break;
       case Kind::Inline:
         ConvertParamTy(ca.param_type, ca.expr);
+        if (info.is_libc_passthrough) {
+          StrCat(std::format(
+              "as {}", Mapper::GetParamType(GetCalleeOrExpr(info.expr), i)));
+        }
         break;
       }
     }
@@ -1715,14 +1728,19 @@ void Converter::EmitArgList(const CallInfo &info) {
   }
 
   if (info.is_variadic) {
-    StrCat(token::kRef);
-    PushBracket push(*this);
+    if (!info.is_libc_passthrough) {
+      StrCat(token::kRef);
+    }
+    PushBracket push(*this, !info.is_libc_passthrough);
     for (auto *arg : info.variadic_args) {
       {
         PushParen p(*this);
         ConvertVariadicArg(arg);
       }
-      StrCat(".into()", token::kComma);
+      if (!info.is_libc_passthrough) {
+        StrCat(".into()");
+      }
+      StrCat(token::kComma);
     }
   }
 }
@@ -1731,10 +1749,14 @@ void Converter::EmitCall(CallInfo &&info) {
   EmitHoistedArgs(info);
 
   if (info.is_fn_ptr_call) {
-    EmitFnPtrCall(info.callee);
+    EmitFnPtrCall(GetCallee(info.expr));
+  } else if (info.is_libc_passthrough) {
+    auto *direct_callee = info.expr->getDirectCallee();
+    assert(direct_callee);
+    StrCat("libc::", direct_callee->getName());
   } else {
     PushExprKind push(*this, ExprKind::Callee);
-    Convert(info.callee);
+    Convert(GetCallee(info.expr));
   }
 
   EmitArgList(info);

cpp2rust/converter/converter.h

@@ -242,9 +242,10 @@ class Converter : public clang::RecursiveASTVisitor<Converter> {
   struct CallInfo {
     std::vector<CallArg> args;
     std::vector<clang::Expr *> variadic_args;
-    clang::Expr *callee;
+    clang::CallExpr *expr;
     bool is_variadic;
     bool is_fn_ptr_call;
+    bool is_libc_passthrough;
   };
 
   CallInfo CollectCallInfo(clang::CallExpr *expr);

cpp2rust/converter/converter_lib.cpp

@@ -649,6 +649,15 @@ BuildUnifiedArgs(clang::Expr *expr, clang::Expr **args, unsigned num_args) {
   return all_args;
 }
 
+clang::Expr *GetCallee(clang::CallExpr *expr) {
+  if (auto op_call = clang::dyn_cast<clang::CXXOperatorCallExpr>(expr)) {
+    if (op_call->getOperator() == clang::OO_Call) {
+      return op_call->getArg(0);
+    }
+  }
+  return expr->getCallee();
+}
+
 clang::Expr *GetCalleeOrExpr(clang::Expr *expr) {
   if (auto *call = clang::dyn_cast<clang::CallExpr>(expr)) {
     return call->getCallee();

cpp2rust/converter/converter_lib.h

@@ -139,6 +139,8 @@ void ForEachTemplateArgument(
 
 clang::Expr *GetCallObject(clang::CallExpr *expr);
 
+clang::Expr *GetCallee(clang::CallExpr *expr);
+
 clang::Expr *GetCalleeOrExpr(clang::Expr *expr);
 
 bool HasReceiver(clang::Expr *expr);

cpp2rust/converter/mapper.cpp

@@ -588,6 +588,19 @@ const TranslationRule::ExprRule *GetExprRule(const clang::Expr *expr) {
   return search(expr);
 }
 
+bool IsLibcPassthrough(const clang::Expr *expr) {
+  const auto *tgt_ir = GetExprRule(expr);
+  if (tgt_ir == nullptr || !tgt_ir->body.empty() || !tgt_ir->is_extern) {
+    return false;
+  }
+  const auto *ref =
+      clang::dyn_cast<clang::DeclRefExpr>(expr->IgnoreParenImpCasts());
+  const auto *decl = ref != nullptr ? ref->getDecl() : nullptr;
+  return decl != nullptr &&
+         decl->getASTContext().getSourceManager().isInSystemHeader(
+             decl->getLocation());
+}
+
 std::string MapFunctionName(const clang::FunctionDecl *decl) {
   assert(decl);
   if (!IsUserDefinedDecl(decl) &&
@@ -804,6 +817,12 @@ std::string ToString(const clang::NamedDecl *decl) {
     }
     os << ToString(func_decl->getParamDecl(i)->getType());
   }
+  if (func_decl->isVariadic()) {
+    if (func_decl->getNumParams()) {
+      os << ", ";
+    }
+    os << "...";
+  }
   os << ')';
 
   if (const auto *method_decl =

cpp2rust/converter/mapper.h

@@ -30,6 +30,7 @@ bool Contains(const clang::Expr *expr);
 std::string Map(clang::QualType qual_type);
 std::string MapInitializer(clang::QualType qual_type);
 const TranslationRule::ExprRule *GetExprRule(const clang::Expr *expr);
+bool IsLibcPassthrough(const clang::Expr *expr);
 std::string MapFunctionName(const clang::FunctionDecl *decl);
 std::string InstantiateTemplate(const clang::Expr *expr, unsigned n);
 bool ReturnsPointer(const clang::Expr *expr);

cpp2rust/converter/translation_rule.cpp

@@ -98,11 +98,17 @@ ExprRule ParseExprRuleJSON(const llvm::json::Object &obj) {
     }
   }
 
-  if (auto *rt = obj.getObject("return_type"))
+  if (auto *rt = obj.getObject("return_type")) {
     ir.return_type = ParseTypeInfoJSON(*rt);
+  }
 
-  if (auto ms = obj.getBoolean("multi_statement"))
+  if (auto ms = obj.getBoolean("multi_statement")) {
     ir.multi_statement = *ms;
+  }
+
+  if (auto v = obj.getBoolean("is_extern")) {
+    ir.is_extern = *v;
+  }
 
   if (auto *generics = obj.getObject("generics")) {
     for (auto &[key, val] : *generics) {

cpp2rust/converter/translation_rule.h

@@ -70,6 +70,7 @@ struct ExprRule {
   std::vector<std::vector<std::string>> generics; // "T1" -> ["Ord", "Clone"]
   std::vector<BodyFragment> body;
   bool multi_statement = false;
+  bool is_extern = false;
 
   void dump() const;
   void validate(const std::string &name) const;

cpp2rust/cpp_rule_preprocessor.cpp

@@ -349,7 +349,10 @@ class Callback : public clang::ast_matchers::MatchFinder::MatchCallback {
   createTemplateArguments(clang::TemplateDecl *decl,
                           llvm::SmallVectorImpl<clang::TemplateArgument> &out) {
     for (clang::NamedDecl *param : *decl->getTemplateParameters()) {
-      if (llvm::isa<clang::TemplateTypeParmDecl>(param)) {
+      if (param->isTemplateParameterPack()) {
+        out.emplace_back(
+            clang::TemplateArgument::CreatePackCopy(sema_->Context, {}));
+      } else if (llvm::isa<clang::TemplateTypeParmDecl>(param)) {
         clang::RecordDecl *rdecl = createRecordDecl(param->getName());
         clang::QualType type =
             sema_->Context.getTagType(clang::ElaboratedTypeKeyword::None,
@@ -409,7 +412,14 @@ class Callback : public clang::ast_matchers::MatchFinder::MatchCallback {
                          clang::OverloadCandidateSet &candidates) {
     clang::LookupResult decls(*sema_, name, loc_,
                               clang::Sema::LookupOrdinaryName);
-    sema_->LookupQualifiedName(decls, sema_->getStdNamespace());
+    if (clang::NamespaceDecl *std_ns = sema_->getStdNamespace()) {
+      sema_->LookupQualifiedName(decls, std_ns);
+    }
+    if (decls.empty()) {
+      decls.clear();
+      sema_->LookupQualifiedName(decls,
+                                 sema_->Context.getTranslationUnitDecl());
+    }
     for (auto *ndecl : decls) {
       if (auto *candidate = createCandidate(ndecl, callArgs, explicitTArgs)) {
         sema_->AddOverloadCandidate(
@@ -573,6 +583,7 @@ class Callback : public clang::ast_matchers::MatchFinder::MatchCallback {
       cxxConstructorNameLookup(rule->getReturnType(), callArgs, candidates);
       break;
     case LookupKind::ADL:
+      regularNameLookup(callArgs, &explicitTArgs, name, candidates);
       adlLookup(callArgs, name, candidates);
       break;
     }

rule-preprocessor/src/ir.rs

@@ -57,6 +57,8 @@ pub struct FnIr {
     pub params: Option<BTreeMap<String, TypeInfo>>,
     #[serde(skip_serializing_if = "Option::is_none")]
     pub return_type: Option<TypeInfo>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub is_extern: Option<bool>,
 }
 
 impl FnIr {
@@ -104,7 +106,10 @@ impl FnIr {
             1,
             &format!("Rule {name} generics"),
         );
-        assert!(!self.body.is_empty(), "Rule {name}: body must not be empty");
+        assert!(
+            self.is_extern == Some(true) || !self.body.is_empty(),
+            "Rule {name}: body must not be empty"
+        );
     }
 }
 

rule-preprocessor/src/syntactic.rs

@@ -416,6 +416,13 @@ impl<'a> FnIrBuilder<'a> {
             .unwrap_or(Access::Read)
     }
 
+    fn is_extern(&self) -> bool {
+        self.fn_item
+            .syntax()
+            .ancestors()
+            .any(|a| a.kind() == SyntaxKind::EXTERN_BLOCK)
+    }
+
     fn returns_mut_ref(&self) -> bool {
         self.fn_item
             .ret_type()
@@ -517,6 +524,7 @@ impl<'a> FnIrBuilder<'a> {
             },
             multi_statement,
             body,
+            is_extern: self.is_extern().then_some(true),
         };
         ir.validate(&format!("{}:{}", path.display(), fn_name));
         ir

rules/builtin/src.c

@@ -0,0 +1,2 @@
+int f12(long a, long b, long *r) { return __builtin_mul_overflow(a, b, r); }
+int f13(long long a, long long b, long long *r) { return __builtin_mul_overflow(a, b, r); }

rules/builtin/tgt_refcount.rs

@@ -13,3 +13,13 @@ fn f10(a0: i64, a1: i64, a2: Ptr<i64>) -> bool {
     a2.write(val);
     ovf
 }
+fn f12(a0: i64, a1: i64, a2: Ptr<i64>) -> bool {
+    let (val, ovf) = a0.overflowing_mul(a1);
+    a2.write(val);
+    ovf
+}
+fn f13(a0: i64, a1: i64, a2: Ptr<i64>) -> bool {
+    let (val, ovf) = a0.overflowing_mul(a1);
+    a2.write(val);
+    ovf
+}

rules/builtin/tgt_unsafe.rs

@@ -39,3 +39,14 @@ unsafe fn f10(a0: i64, a1: i64, a2: *mut i64) -> bool {
 unsafe fn f11() {
     std::hint::spin_loop();
 }
+
+unsafe fn f12(a0: i64, a1: i64, a2: *mut i64) -> bool {
+    let (val, ovf) = a0.overflowing_mul(a1);
+    *a2 = val;
+    ovf
+}
+unsafe fn f13(a0: i64, a1: i64, a2: *mut i64) -> bool {
+    let (val, ovf) = a0.overflowing_mul(a1);
+    *a2 = val;
+    ovf
+}

rules/fcntl/src.cpp

@@ -0,0 +1,14 @@
+// Copyright (c) 2022-present INESC-ID.
+// Distributed under the MIT license that can be found in the LICENSE file.
+
+#include <fcntl.h>
+
+template <typename... Args>
+int f1(int a0, int a1, Args... args) {
+  return fcntl(a0, a1, args...);
+}
+
+template <typename... Args>
+int f2(const char *a0, int a1, Args... args) {
+  return open(a0, a1, args...);
+}

rules/fcntl/tgt_unsafe.rs

@@ -0,0 +1,7 @@
+// Copyright (c) 2022-present INESC-ID.
+// Distributed under the MIT license that can be found in the LICENSE file.
+
+unsafe extern "C" {
+    fn f1(a0: i32, a1: i32, ...) -> i32;
+    fn f2(a0: *const i8, a1: i32, ...) -> i32;
+}

rules/ioctl/src.cpp

@@ -0,0 +1,9 @@
+// Copyright (c) 2022-present INESC-ID.
+// Distributed under the MIT license that can be found in the LICENSE file.
+
+#include <sys/ioctl.h>
+
+template <typename... Args>
+int f1(int a0, unsigned long a1, Args... args) {
+  return ioctl(a0, a1, args...);
+}

rules/ioctl/tgt_unsafe.rs

@@ -0,0 +1,6 @@
+// Copyright (c) 2022-present INESC-ID.
+// Distributed under the MIT license that can be found in the LICENSE file.
+
+unsafe extern "C" {
+    fn f1(a0: i32, a1: u64, ...) -> i32;
+}

rules/src/modules.rs

@@ -40,6 +40,8 @@ pub mod deque_tgt_unsafe;
 pub mod dirent_tgt_unsafe;
 #[path = r#"../errno/tgt_unsafe.rs"#]
 pub mod errno_tgt_unsafe;
+#[path = r#"../fcntl/tgt_unsafe.rs"#]
+pub mod fcntl_tgt_unsafe;
 #[path = r#"../fnmatch/tgt_unsafe.rs"#]
 pub mod fnmatch_tgt_unsafe;
 #[path = r#"../fstream/tgt_refcount.rs"#]
@@ -50,6 +52,8 @@ pub mod fstream_tgt_unsafe;
 pub mod ifaddrs_tgt_unsafe;
 #[path = r#"../initializer_list/tgt_unsafe.rs"#]
 pub mod initializer_list_tgt_unsafe;
+#[path = r#"../ioctl/tgt_unsafe.rs"#]
+pub mod ioctl_tgt_unsafe;
 #[path = r#"../iomanip/tgt_unsafe.rs"#]
 pub mod iomanip_tgt_unsafe;
 #[path = r#"../iostream/tgt_refcount.rs"#]