Translate va_list references and pointers (#522)

Author: lucic71

cpp2rust/converter/converter.cpp

@@ -116,7 +116,7 @@ bool Converter::VisitRecoveryExpr(clang::RecoveryExpr *expr) {
 bool Converter::Convert(clang::QualType qual_type) {
   // Catch va_list before desugaring
   if (IsVaListType(qual_type)) {
-    StrCat("VaList");
+    StrCat("*const VaArg");
     return false;
   }
 
@@ -311,7 +311,7 @@ bool Converter::VisitPointerType(clang::PointerType *type) {
   }
 
   if (IsVaListType(clang::QualType(type, 0))) {
-    StrCat("VaList");
+    StrCat("*const VaArg");
     return false;
   }
 
@@ -480,7 +480,8 @@ void Converter::ConvertVaListVarDecl(clang::VarDecl *decl) {
     // va_list local variable
     StrCat(keyword::kLet);
   }
-  StrCat(keyword_mut_, GetNamedDeclAsString(decl), token::kColon, "VaList");
+  StrCat(keyword_mut_, GetNamedDeclAsString(decl), token::kColon,
+         "*const VaArg");
 }
 
 bool Converter::NeedsMut(const clang::VarDecl *decl, clang::QualType type,
@@ -1838,8 +1839,7 @@ void Converter::ConvertVariadicArg(clang::Expr *arg) {
 
 void Converter::ConvertVAArgCall(clang::CallExpr *expr) {
   if (IsBuiltinVaStart(expr)) {
-    StrCat(ToString(expr->getArg(0)->IgnoreImpCasts()),
-           "= VaList::new(__args)");
+    StrCat(ToString(expr->getArg(0)->IgnoreImpCasts()), "= __args.as_ptr()");
     return;
   }
   if (IsBuiltinVaEnd(expr)) {
@@ -4257,7 +4257,7 @@ std::string Converter::GetDefaultAsString(clang::QualType qual_type) {
 
   if (IsVaListType(qual_type)) {
     computed_expr_type_ = ComputedExprType::FreshValue;
-    return "VaList::default()";
+    return "::std::ptr::null()";
   }
 
   if (auto arr = GetArrayDefaultAsString(qual_type); !arr.empty()) {

cpp2rust/converter/models/converter_refcount.cpp

@@ -259,7 +259,7 @@ std::string ConverterRefCount::BoxValue(std::string &&str) const {
 bool ConverterRefCount::Convert(clang::QualType qual_type) {
   // Catch va_list before desugaring
   if (IsVaListType(qual_type)) {
-    StrCat(BoxType("VaList"));
+    StrCat(BoxType("Ptr<VaArg>"));
     return false;
   }
 
@@ -291,7 +291,7 @@ bool ConverterRefCount::VisitReferenceType(clang::ReferenceType *type) {
     PushConversionKind push(*this, ConversionKind::Unboxed);
     return Convert(ctx_.getPointerType(pointee_type));
   }
-  if (pointee_type->isArrayType()) {
+  if (pointee_type->isArrayType() && !IsVaListType(pointee_type)) {
     // A reference to an array decays straight to a pointer to its first
     // element, the same way a by-value array parameter would, instead of
     // going through a pointer to the whole boxed array.
@@ -325,7 +325,7 @@ bool ConverterRefCount::VisitPointerType(clang::PointerType *type) {
   }
 
   if (IsVaListType(clang::QualType(type, 0))) {
-    StrCat("VaList");
+    StrCat("Ptr<VaArg>");
     return false;
   }
 
@@ -335,10 +335,11 @@ bool ConverterRefCount::VisitPointerType(clang::PointerType *type) {
   }
 
   auto pointee_type = type->getPointeeType();
-  PushConversionKind push1(*this, ConversionKind::Ptr,
-                           !pointee_type->isArrayType());
+  bool pointee_is_array =
+      pointee_type->isArrayType() && !IsVaListType(pointee_type);
+  PushConversionKind push1(*this, ConversionKind::Ptr, !pointee_is_array);
   PushConversionKind push2(*this, ConversionKind::FullRefCount,
-                           pointee_type->isArrayType());
+                           pointee_is_array);
   if (pointee_type->isRecordType() &&
       abstract_structs_.contains(GetID(pointee_type->getAsRecordDecl()))) {
     StrCat("PtrDyn<dyn");
@@ -791,6 +792,10 @@ void ConverterRefCount::EmitFunctionPreamble(clang::FunctionDecl *decl) {
   // name_2)'. We want to get the parameters from the definition if possible,
   // i.e. name_2.
   PushConversionKind push(*this, ConversionKind::FullRefCount);
+  if (decl->isVariadic()) {
+    StrCat("let __args: Value<Box<[VaArg]>> = "
+           "Rc::new(RefCell::new(__args.into()));");
+  }
   auto params = decl->getDefinition() ? decl->getDefinition()->parameters()
                                       : decl->parameters();
   for (auto *param : params) {
@@ -853,7 +858,7 @@ void ConverterRefCount::ConvertVaListVarDecl(clang::VarDecl *decl) {
     StrCat(keyword::kLet);
   }
 
-  StrCat(GetNamedDeclAsString(decl), token::kColon, "Value<VaList>");
+  StrCat(GetNamedDeclAsString(decl), token::kColon, "Value<Ptr<VaArg>>");
 }
 
 bool ConverterRefCount::ConvertVarDeclSkipInit(clang::VarDecl *decl) {
@@ -1291,7 +1296,12 @@ void ConverterRefCount::ConvertPrintf(clang::CallExpr *expr) {
 }
 
 bool ConverterRefCount::VisitCallExpr(clang::CallExpr *expr) {
-  if (IsBuiltinVaStart(expr) || IsBuiltinVaEnd(expr) || IsBuiltinVaCopy(expr)) {
+  if (IsBuiltinVaStart(expr)) {
+    StrCat(ToString(expr->getArg(0)->IgnoreImpCasts()),
+           "= __args.as_pointer()");
+    return false;
+  }
+  if (IsBuiltinVaEnd(expr) || IsBuiltinVaCopy(expr)) {
     ConvertVAArgCall(expr);
     return false;
   }
@@ -2471,13 +2481,18 @@ bool ConverterRefCount::VisitVAArgExpr(clang::VAArgExpr *expr) {
   if (auto *cast = clang::dyn_cast<clang::ImplicitCastExpr>(va_list_expr)) {
     va_list_expr = cast->getSubExpr();
   }
-  StrCat(ConvertLValue(va_list_expr));
-  StrCat(".arg::<");
+  auto str = ConvertLValue(va_list_expr);
+  std::string arg_type;
   {
     PushConversionKind push(*this, ConversionKind::Unboxed);
-    StrCat(ToString(expr->getType()));
+    arg_type = ToString(expr->getType());
+  }
+  if (!pending_deref_.empty()) {
+    StrCat(pending_deref_.take(), ".with_mut(|__v| __v.arg::<", arg_type,
+           ">())");
+  } else {
+    StrCat(str, ".arg::<", arg_type, ">()");
   }
-  StrCat(">()");
   SetFreshType(expr->getType());
   return false;
 }
@@ -2529,7 +2544,7 @@ std::string ConverterRefCount::GetDefaultAsString(clang::QualType qual_type) {
 
   if (IsVaListType(qual_type)) {
     computed_expr_type_ = ComputedExprType::FreshValue;
-    return BoxValue("VaList::default()");
+    return BoxValue("Ptr::<VaArg>::default()");
   }
 
   if (auto arr = GetArrayDefaultAsString(qual_type); !arr.empty()) {

libcc2rs/src/va_args.rs

@@ -5,6 +5,8 @@ use std::any::Any;
 use std::ffi::c_void;
 use std::rc::Rc;
 
+use crate::inc::PrefixInc;
+use crate::rc::Ptr;
 use crate::void::AnyPtr;
 
 #[derive(Clone)]
@@ -52,21 +54,27 @@ impl<T: crate::reinterpret::ByteRepr + 'static> From<crate::rc::Ptr<T>> for VaAr
     }
 }
 
-#[derive(Clone, Copy, Default)]
-pub struct VaList<'a> {
-    args: &'a [VaArg],
-    pos: usize,
+impl crate::reinterpret::ByteRepr for VaArg {}
+
+pub trait VaArgs {
+    fn arg<T: VaArgGet>(&mut self) -> T;
 }
 
-impl<'a> VaList<'a> {
-    pub fn new(args: &'a [VaArg]) -> Self {
-        VaList { args, pos: 0 }
+impl VaArgs for Ptr<VaArg> {
+    fn arg<T: VaArgGet>(&mut self) -> T {
+        let val = self.with(T::get);
+        self.prefix_inc();
+        val
     }
+}
 
-    pub fn arg<T: VaArgGet>(&mut self) -> T {
-        let val = &self.args[self.pos];
-        self.pos += 1;
-        T::get(val)
+impl VaArgs for *const VaArg {
+    fn arg<T: VaArgGet>(&mut self) -> T {
+        unsafe {
+            let val = T::get(&**self);
+            *self = self.add(1);
+            val
+        }
     }
 }
 

tests/unit/out/refcount/va_arg_chain.rs

@@ -6,23 +6,24 @@ use std::io::prelude::*;
 use std::io::{Read, Seek, Write};
 use std::os::fd::AsFd;
 use std::rc::{Rc, Weak};
-pub fn extract_nth_0(mut n: i32, ap: VaList) -> i32 {
-    let ap: Value<VaList> = Rc::new(RefCell::new(ap));
+pub fn extract_nth_0(mut n: i32, ap: Ptr<VaArg>) -> i32 {
+    let ap: Value<Ptr<VaArg>> = Rc::new(RefCell::new(ap));
     let mut i: i32 = 0;
     'loop_: while (((i < n) as i32) != 0) {
         (*ap.borrow_mut()).arg::<i32>();
         i.postfix_inc();
     }
     return (*ap.borrow_mut()).arg::<i32>();
 }
-pub fn middle_layer_1(mut n: i32, ap: VaList) -> i32 {
-    let ap: Value<VaList> = Rc::new(RefCell::new(ap));
+pub fn middle_layer_1(mut n: i32, ap: Ptr<VaArg>) -> i32 {
+    let ap: Value<Ptr<VaArg>> = Rc::new(RefCell::new(ap));
     return ({ extract_nth_0(n, (*ap.borrow()).clone()) });
 }
 pub fn top_level_2(n: i32, __args: &[VaArg]) -> i32 {
+    let __args: Value<Box<[VaArg]>> = Rc::new(RefCell::new(__args.into()));
     let n: Value<i32> = Rc::new(RefCell::new(n));
-    let ap: Value<VaList> = Rc::new(RefCell::new(VaList::default()));
-    (*ap.borrow_mut()) = VaList::new(__args);
+    let ap: Value<Ptr<VaArg>> = Rc::new(RefCell::new(Ptr::<VaArg>::default()));
+    (*ap.borrow_mut()) = __args.as_pointer();
     let mut result: i32 = ({ middle_layer_1((*n.borrow()), (*ap.borrow()).clone()) });
     return result;
 }

tests/unit/out/refcount/va_arg_concat.rs

@@ -7,10 +7,11 @@ use std::io::{Read, Seek, Write};
 use std::os::fd::AsFd;
 use std::rc::{Rc, Weak};
 pub fn sum_ints_0(first: i32, __args: &[VaArg]) -> i32 {
+    let __args: Value<Box<[VaArg]>> = Rc::new(RefCell::new(__args.into()));
     let first: Value<i32> = Rc::new(RefCell::new(first));
-    let args: Value<VaList> = Rc::new(RefCell::new(VaList::default()));
+    let args: Value<Ptr<VaArg>> = Rc::new(RefCell::new(Ptr::<VaArg>::default()));
     let mut total: i32 = (*first.borrow());
-    (*args.borrow_mut()) = VaList::new(__args);
+    (*args.borrow_mut()) = __args.as_pointer();
     let mut val: i32 = 0_i32;
     'loop_: while (((({
         val = (*args.borrow_mut()).arg::<i32>();

tests/unit/out/refcount/va_arg_conditional.rs

@@ -7,10 +7,11 @@ use std::io::{Read, Seek, Write};
 use std::os::fd::AsFd;
 use std::rc::{Rc, Weak};
 pub fn conditional_log_0(mut verbose: i32, fmt: Ptr<i8>, __args: &[VaArg]) -> i32 {
+    let __args: Value<Box<[VaArg]>> = Rc::new(RefCell::new(__args.into()));
     let fmt: Value<Ptr<i8>> = Rc::new(RefCell::new(fmt));
     if (verbose != 0) {
-        let ap: Value<VaList> = Rc::new(RefCell::new(VaList::default()));
-        (*ap.borrow_mut()) = VaList::new(__args);
+        let ap: Value<Ptr<VaArg>> = Rc::new(RefCell::new(Ptr::<VaArg>::default()));
+        (*ap.borrow_mut()) = __args.as_pointer();
         let mut result: i32 = (*ap.borrow_mut()).arg::<i32>();
         return result;
     }

tests/unit/out/refcount/va_arg_copy.rs

@@ -7,10 +7,11 @@ use std::io::{Read, Seek, Write};
 use std::os::fd::AsFd;
 use std::rc::{Rc, Weak};
 pub fn sum_with_copy_0(count: i32, __args: &[VaArg]) -> i32 {
+    let __args: Value<Box<[VaArg]>> = Rc::new(RefCell::new(__args.into()));
     let count: Value<i32> = Rc::new(RefCell::new(count));
-    let ap: Value<VaList> = Rc::new(RefCell::new(VaList::default()));
-    let aq: Value<VaList> = Rc::new(RefCell::new(VaList::default()));
-    (*ap.borrow_mut()) = VaList::new(__args);
+    let ap: Value<Ptr<VaArg>> = Rc::new(RefCell::new(Ptr::<VaArg>::default()));
+    let aq: Value<Ptr<VaArg>> = Rc::new(RefCell::new(Ptr::<VaArg>::default()));
+    (*ap.borrow_mut()) = __args.as_pointer();
     (*aq.borrow_mut()) = (*ap.borrow_mut()).clone();
     let mut sum1: i32 = 0;
     let mut i: i32 = 0;

tests/unit/out/refcount/va_arg_fn_ptr.rs

@@ -16,17 +16,19 @@ pub fn add_2(mut a: i32, mut b: i32) -> i32 {
     return (a + b);
 }
 pub fn apply_unary_3(x: i32, __args: &[VaArg]) -> i32 {
+    let __args: Value<Box<[VaArg]>> = Rc::new(RefCell::new(__args.into()));
     let x: Value<i32> = Rc::new(RefCell::new(x));
-    let ap: Value<VaList> = Rc::new(RefCell::new(VaList::default()));
-    (*ap.borrow_mut()) = VaList::new(__args);
+    let ap: Value<Ptr<VaArg>> = Rc::new(RefCell::new(Ptr::<VaArg>::default()));
+    (*ap.borrow_mut()) = __args.as_pointer();
     let mut fn_: FnPtr<fn(i32) -> i32> = (*ap.borrow_mut()).arg::<FnPtr<fn(i32) -> i32>>();
     let mut result: i32 = ({ fn_.call((*x.borrow())) });
     return result;
 }
 pub fn apply_binary_4(mut a: i32, b: i32, __args: &[VaArg]) -> i32 {
+    let __args: Value<Box<[VaArg]>> = Rc::new(RefCell::new(__args.into()));
     let b: Value<i32> = Rc::new(RefCell::new(b));
-    let ap: Value<VaList> = Rc::new(RefCell::new(VaList::default()));
-    (*ap.borrow_mut()) = VaList::new(__args);
+    let ap: Value<Ptr<VaArg>> = Rc::new(RefCell::new(Ptr::<VaArg>::default()));
+    (*ap.borrow_mut()) = __args.as_pointer();
     let mut fn_: FnPtr<fn(i32, i32) -> i32> =
         (*ap.borrow_mut()).arg::<FnPtr<fn(i32, i32) -> i32>>();
     let mut result: i32 = ({ fn_.call(a, (*b.borrow())) });

tests/unit/out/refcount/va_arg_forward.rs

@@ -6,8 +6,8 @@ use std::io::prelude::*;
 use std::io::{Read, Seek, Write};
 use std::os::fd::AsFd;
 use std::rc::{Rc, Weak};
-pub fn inner_0(mut count: i32, ap: VaList) -> i32 {
-    let ap: Value<VaList> = Rc::new(RefCell::new(ap));
+pub fn inner_0(mut count: i32, ap: Ptr<VaArg>) -> i32 {
+    let ap: Value<Ptr<VaArg>> = Rc::new(RefCell::new(ap));
     let mut total: i32 = 0;
     let mut i: i32 = 0;
     'loop_: while (((i < count) as i32) != 0) {
@@ -17,9 +17,10 @@ pub fn inner_0(mut count: i32, ap: VaList) -> i32 {
     return total;
 }
 pub fn outer_1(count: i32, __args: &[VaArg]) -> i32 {
+    let __args: Value<Box<[VaArg]>> = Rc::new(RefCell::new(__args.into()));
     let count: Value<i32> = Rc::new(RefCell::new(count));
-    let ap: Value<VaList> = Rc::new(RefCell::new(VaList::default()));
-    (*ap.borrow_mut()) = VaList::new(__args);
+    let ap: Value<Ptr<VaArg>> = Rc::new(RefCell::new(Ptr::<VaArg>::default()));
+    (*ap.borrow_mut()) = __args.as_pointer();
     let mut result: i32 = ({ inner_0((*count.borrow()), (*ap.borrow()).clone()) });
     return result;
 }

tests/unit/out/refcount/va_arg_mixed_int_ptr.rs

@@ -7,9 +7,10 @@ use std::io::{Read, Seek, Write};
 use std::os::fd::AsFd;
 use std::rc::{Rc, Weak};
 pub fn mixed_args_0(count: i32, __args: &[VaArg]) -> i32 {
+    let __args: Value<Box<[VaArg]>> = Rc::new(RefCell::new(__args.into()));
     let count: Value<i32> = Rc::new(RefCell::new(count));
-    let ap: Value<VaList> = Rc::new(RefCell::new(VaList::default()));
-    (*ap.borrow_mut()) = VaList::new(__args);
+    let ap: Value<Ptr<VaArg>> = Rc::new(RefCell::new(Ptr::<VaArg>::default()));
+    (*ap.borrow_mut()) = __args.as_pointer();
     let mut total: i32 = 0;
     let mut i: i32 = 0;
     'loop_: while (((i < (*count.borrow())) as i32) != 0) {