cxgo: use unsafe.Add; resolves #34

gotranspile · Nov 14, 2021 · 874cdf3 · 874cdf3
1 parent 8d378a6
commit 874cdf3
Show file tree

Hide file tree

Showing 2 changed files with 32 additions and 33 deletions.
diff --git a/pointers.go b/pointers.go
@@ -705,19 +705,19 @@ func (e *PtrOffset) parts() (GoExpr, BinaryOp, GoExpr) {
 	if e.X.PtrType(nil).Elem() != nil {
 		x = call(unsafePtr(), x)
 	}
-	x = call(ident("uintptr"), x)
 	return x, op, y
 }
 
 func (e *PtrOffset) AsExpr() GoExpr {
 	x, tok, y := e.parts()
-	//if !VirtualPtrs {
-	x = &ast.BinaryExpr{
-		X: x, Op: tok.GoToken(), Y: y,
+	if tok != BinOpAdd {
+		y = &ast.UnaryExpr{Op: token.SUB, X: y}
 	}
+	x = call(ident("unsafe.Add"), x, y)
+	//if !VirtualPtrs {
 	to := e.toType()
-	if to.Elem() != nil {
-		x = call(unsafePtr(), x)
+	if to.Elem() == nil {
+		return x
 	}
 	return call(to.GoType(), x)
 	//}
@@ -801,13 +801,12 @@ func (e *PtrElemOffset) AsExpr() GoExpr {
 			Y:  call(ident("uintptr"), y),
 		}
 	}
-	x = &ast.BinaryExpr{
-		X:  call(ident("uintptr"), x),
-		Op: op.GoToken(),
-		Y:  y,
+	if op == BinOpSub {
+		y = &ast.UnaryExpr{Op: token.SUB, X: y}
 	}
-	if to.Elem() != nil {
-		x = call(unsafePtr(), x)
+	x = call(ident("unsafe.Add"), x, y)
+	if to.Elem() == nil {
+		return x
 	}
 	return call(to.GoType(), x)
 	//}
@@ -875,22 +874,22 @@ func (e *PtrVarOffset) AsExpr() GoExpr {
 	if e.X.PtrType(nil).Elem() != nil {
 		x = call(unsafePtr(), x)
 	}
+	if !e.Ind.CType(nil).Kind().IsInt() {
+		y = call(ident("uintptr"), y)
+	}
 	if mul != 1 {
 		y = &ast.BinaryExpr{
 			X:  intLit(mul),
 			Op: token.MUL,
-			Y:  call(ident("uintptr"), y),
+			Y:  y,
 		}
-	} else {
-		y = call(ident("uintptr"), y)
 	}
-	x = &ast.BinaryExpr{
-		X:  call(ident("uintptr"), x),
-		Op: op.GoToken(),
-		Y:  y,
+	if op == BinOpSub {
+		y = &ast.UnaryExpr{Op: token.SUB, X: y}
 	}
-	if to.Elem() != nil {
-		x = call(unsafePtr(), x)
+	x = call(ident("unsafe.Add"), x, y)
+	if to.Elem() == nil {
+		return x
 	}
 	return call(to.GoType(), x)
 	//}

diff --git a/pointers_test.go b/pointers_test.go
@@ -169,8 +169,8 @@ void foo() {
 		exp: `
 func foo() {
 	var a *byte
-	a = (*byte)(unsafe.Pointer(uintptr(unsafe.Pointer(a)) + 1))
-	a = (*byte)(unsafe.Pointer(uintptr(unsafe.Pointer(a)) - 1))
+	a = (*byte)(unsafe.Add(unsafe.Pointer(a), 1))
+	a = (*byte)(unsafe.Add(unsafe.Pointer(a), -1))
 }
 `,
 	},
@@ -192,10 +192,10 @@ func foo() {
 		a  int32 = 2
 		pa unsafe.Pointer
 	)
-	pa = unsafe.Pointer(uintptr(pa) + uintptr(a))
-	pa = unsafe.Pointer(uintptr(pa) + 3)
-	pa = unsafe.Pointer(uintptr(pa) + uintptr(a))
-	pa = unsafe.Pointer(uintptr(pa) + 5)
+	pa = unsafe.Add(pa, a)
+	pa = unsafe.Add(pa, 3)
+	pa = unsafe.Add(pa, a)
+	pa = unsafe.Add(pa, 5)
 }
 `,
 	},
@@ -329,10 +329,10 @@ func foo() {
 		a  int32 = 2
 		pa *int32
 	)
-	pa = (*int32)(unsafe.Pointer(uintptr(unsafe.Pointer(pa)) + unsafe.Sizeof(int32(0))*uintptr(a)))
-	pa = (*int32)(unsafe.Pointer(uintptr(unsafe.Pointer(pa)) + unsafe.Sizeof(int32(0))*3))
-	pa = (*int32)(unsafe.Pointer(uintptr(unsafe.Pointer(pa)) + unsafe.Sizeof(int32(0))*uintptr(a)))
-	pa = (*int32)(unsafe.Pointer(uintptr(unsafe.Pointer(pa)) + unsafe.Sizeof(int32(0))*5))
+	pa = (*int32)(unsafe.Add(unsafe.Pointer(pa), unsafe.Sizeof(int32(0))*uintptr(a)))
+	pa = (*int32)(unsafe.Add(unsafe.Pointer(pa), unsafe.Sizeof(int32(0))*3))
+	pa = (*int32)(unsafe.Add(unsafe.Pointer(pa), unsafe.Sizeof(int32(0))*uintptr(a)))
+	pa = (*int32)(unsafe.Add(unsafe.Pointer(pa), unsafe.Sizeof(int32(0))*5))
 }
 `,
 	},
@@ -621,7 +621,7 @@ func foo() {
 	*func() *int32 {
 		p := &a
 		x := *p
-		*p = (*int32)(unsafe.Pointer(uintptr(unsafe.Pointer(*p)) + unsafe.Sizeof(int32(0))*1))
+		*p = (*int32)(unsafe.Add(unsafe.Pointer(*p), unsafe.Sizeof(int32(0))*1))
 		return x
 	}() = b
 }
@@ -1117,7 +1117,7 @@ type A struct {
 
 func foo() {
 	var ptr *int32
-	ptr = (*int32)(unsafe.Pointer(uintptr(unsafe.Pointer(ptr)) + unsafe.Sizeof(int32(0))*(20*(unsafe.Sizeof(A{})/2))))
+	ptr = (*int32)(unsafe.Add(unsafe.Pointer(ptr), unsafe.Sizeof(int32(0))*(20*(unsafe.Sizeof(A{})/2))))
 }
 `,
 	},