Commit 77383f968d
Changed files (4)
src/translate_c.cpp
@@ -121,6 +121,7 @@ static int trans_stmt_extra(Context *c, TransScope *scope, const ZigClangStmt *s
TransScope **out_node_scope);
static TransScope *trans_stmt(Context *c, TransScope *scope, const ZigClangStmt *stmt, AstNode **out_node);
static AstNode *trans_expr(Context *c, ResultUsed result_used, TransScope *scope, const ZigClangExpr *expr, TransLRValue lrval);
+static AstNode *trans_type(Context *c, const ZigClangType *ty, ZigClangSourceLocation source_loc);
static AstNode *trans_qual_type(Context *c, ZigClangQualType qt, ZigClangSourceLocation source_loc);
static AstNode *trans_bool_expr(Context *c, ResultUsed result_used, TransScope *scope,
const ZigClangExpr *expr, TransLRValue lrval);
@@ -575,13 +576,6 @@ static bool is_c_void_type(AstNode *node) {
return (node->type == NodeTypeSymbol && buf_eql_str(node->data.symbol_expr.symbol, "c_void"));
}
-static bool expr_types_equal(Context *c, const ZigClangExpr *expr1, const ZigClangExpr *expr2) {
- ZigClangQualType t1 = get_expr_qual_type(c, expr1);
- ZigClangQualType t2 = get_expr_qual_type(c, expr2);
-
- return ZigClangQualType_eq(t1, t2);
-}
-
static bool qual_type_is_ptr(ZigClangQualType qt) {
const ZigClangType *ty = qual_type_canon(qt);
return ZigClangType_getTypeClass(ty) == ZigClangType_Pointer;
@@ -593,8 +587,7 @@ static const clang::FunctionProtoType *qual_type_get_fn_proto(ZigClangQualType q
if (ZigClangType_getTypeClass(ty) == ZigClangType_Pointer) {
*is_ptr = true;
- const clang::PointerType *pointer_ty = reinterpret_cast<const clang::PointerType*>(ty);
- ZigClangQualType child_qt = bitcast(pointer_ty->getPointeeType());
+ ZigClangQualType child_qt = ZigClangType_getPointeeType(ty);
ty = ZigClangQualType_getTypePtr(child_qt);
}
@@ -705,6 +698,36 @@ static bool qual_type_child_is_fn_proto(ZigClangQualType qt) {
return false;
}
+static AstNode* trans_c_ptr_cast(Context *c, ZigClangSourceLocation source_location, ZigClangQualType dest_type,
+ ZigClangQualType src_type, AstNode *expr)
+{
+ const ZigClangType *ty = ZigClangQualType_getTypePtr(dest_type);
+ const ZigClangQualType child_type = ZigClangType_getPointeeType(ty);
+
+ AstNode *dest_type_node = trans_type(c, ty, source_location);
+ AstNode *child_type_node = trans_qual_type(c, child_type, source_location);
+
+ // Implicit downcasting from higher to lower alignment values is forbidden,
+ // use @alignCast to side-step this problem
+ AstNode *ptrcast_node = trans_create_node_builtin_fn_call_str(c, "ptrCast");
+ ptrcast_node->data.fn_call_expr.params.append(dest_type_node);
+
+ if (ZigClangType_isVoidType(qual_type_canon(child_type))) {
+ // void has 1-byte alignment
+ ptrcast_node->data.fn_call_expr.params.append(expr);
+ } else {
+ AstNode *alignof_node = trans_create_node_builtin_fn_call_str(c, "alignOf");
+ alignof_node->data.fn_call_expr.params.append(child_type_node);
+ AstNode *aligncast_node = trans_create_node_builtin_fn_call_str(c, "alignCast");
+ aligncast_node->data.fn_call_expr.params.append(alignof_node);
+ aligncast_node->data.fn_call_expr.params.append(expr);
+
+ ptrcast_node->data.fn_call_expr.params.append(aligncast_node);
+ }
+
+ return ptrcast_node;
+}
+
static AstNode* trans_c_cast(Context *c, ZigClangSourceLocation source_location, ZigClangQualType dest_type,
ZigClangQualType src_type, AstNode *expr)
{
@@ -719,10 +742,7 @@ static AstNode* trans_c_cast(Context *c, ZigClangSourceLocation source_location,
return expr;
}
if (qual_type_is_ptr(dest_type) && qual_type_is_ptr(src_type)) {
- AstNode *ptr_cast_node = trans_create_node_builtin_fn_call_str(c, "ptrCast");
- ptr_cast_node->data.fn_call_expr.params.append(trans_qual_type(c, dest_type, source_location));
- ptr_cast_node->data.fn_call_expr.params.append(expr);
- return ptr_cast_node;
+ return trans_c_ptr_cast(c, source_location, dest_type, src_type, expr);
}
// TODO: maybe widen to increase size
// TODO: maybe bitcast to change sign
@@ -980,8 +1000,7 @@ static AstNode *trans_type(Context *c, const ZigClangType *ty, ZigClangSourceLoc
}
case ZigClangType_Pointer:
{
- const clang::PointerType *pointer_ty = reinterpret_cast<const clang::PointerType*>(ty);
- ZigClangQualType child_qt = bitcast(pointer_ty->getPointeeType());
+ ZigClangQualType child_qt = ZigClangType_getPointeeType(ty);
AstNode *child_node = trans_qual_type(c, child_qt, source_loc);
if (child_node == nullptr) {
emit_warning(c, source_loc, "pointer to unsupported type");
@@ -1889,16 +1908,10 @@ static AstNode *trans_implicit_cast_expr(Context *c, ResultUsed result_used, Tra
if (target_node == nullptr)
return nullptr;
- if (expr_types_equal(c, (const ZigClangExpr *)stmt, bitcast(stmt->getSubExpr()))) {
- return target_node;
- }
+ const ZigClangQualType dest_type = get_expr_qual_type(c, bitcast(stmt));
+ const ZigClangQualType src_type = get_expr_qual_type(c, bitcast(stmt->getSubExpr()));
- AstNode *dest_type_node = get_expr_type(c, (const ZigClangExpr *)stmt);
-
- AstNode *node = trans_create_node_builtin_fn_call_str(c, "ptrCast");
- node->data.fn_call_expr.params.append(dest_type_node);
- node->data.fn_call_expr.params.append(target_node);
- return maybe_suppress_result(c, result_used, node);
+ return trans_c_cast(c, bitcast(stmt->getBeginLoc()), dest_type, src_type, target_node);
}
case ZigClangCK_NullToPointer:
return trans_create_node_unsigned(c, 0);
src/zig_clang.cpp
@@ -870,6 +870,10 @@ ZigClangQualType ZigClangASTContext_getPointerType(const ZigClangASTContext* sel
return bitcast(reinterpret_cast<const clang::ASTContext *>(self)->getPointerType(bitcast(T)));
}
+unsigned ZigClangASTContext_getTypeAlign(const ZigClangASTContext* self, ZigClangQualType T) {
+ return reinterpret_cast<const clang::ASTContext *>(self)->getTypeAlign(bitcast(T));
+}
+
ZigClangASTContext *ZigClangASTUnit_getASTContext(ZigClangASTUnit *self) {
clang::ASTContext *result = &reinterpret_cast<clang::ASTUnit *>(self)->getASTContext();
return reinterpret_cast<ZigClangASTContext *>(result);
@@ -1030,6 +1034,11 @@ ZigClangTypeClass ZigClangType_getTypeClass(const ZigClangType *self) {
return (ZigClangTypeClass)tc;
}
+ZigClangQualType ZigClangType_getPointeeType(const ZigClangType *self) {
+ auto casted = reinterpret_cast<const clang::Type *>(self);
+ return bitcast(casted->getPointeeType());
+}
+
bool ZigClangType_isVoidType(const ZigClangType *self) {
auto casted = reinterpret_cast<const clang::Type *>(self);
return casted->isVoidType();
src/zig_clang.h
@@ -543,6 +543,7 @@ ZIG_EXTERN_C bool ZigClangQualType_isVolatileQualified(struct ZigClangQualType);
ZIG_EXTERN_C bool ZigClangQualType_isRestrictQualified(struct ZigClangQualType);
ZIG_EXTERN_C enum ZigClangTypeClass ZigClangType_getTypeClass(const struct ZigClangType *self);
+ZIG_EXTERN_C ZigClangQualType ZigClangType_getPointeeType(const ZigClangType *self);
ZIG_EXTERN_C bool ZigClangType_isVoidType(const struct ZigClangType *self);
ZIG_EXTERN_C const char *ZigClangType_getTypeClassName(const struct ZigClangType *self);
test/translate_c.zig
@@ -1334,7 +1334,7 @@ pub fn addCases(cases: *tests.TranslateCContext) void {
\\}
,
\\fn ptrcast(a: [*c]c_int) [*c]f32 {
- \\ return @ptrCast([*c]f32, a);
+ \\ return @ptrCast([*c]f32, @alignCast(@alignOf(f32), a));
\\}
);
@@ -1608,6 +1608,40 @@ pub fn addCases(cases: *tests.TranslateCContext) void {
\\}
);
+ cases.addC("pointer conversion with different alignment",
+ \\void test_ptr_cast() {
+ \\ void *p;
+ \\ {
+ \\ char *to_char = (char *)p;
+ \\ short *to_short = (short *)p;
+ \\ int *to_int = (int *)p;
+ \\ long long *to_longlong = (long long *)p;
+ \\ }
+ \\ {
+ \\ char *to_char = p;
+ \\ short *to_short = p;
+ \\ int *to_int = p;
+ \\ long long *to_longlong = p;
+ \\ }
+ \\}
+ ,
+ \\pub export fn test_ptr_cast() void {
+ \\ var p: ?*c_void = undefined;
+ \\ {
+ \\ var to_char: [*c]u8 = @ptrCast([*c]u8, @alignCast(@alignOf(u8), p));
+ \\ var to_short: [*c]c_short = @ptrCast([*c]c_short, @alignCast(@alignOf(c_short), p));
+ \\ var to_int: [*c]c_int = @ptrCast([*c]c_int, @alignCast(@alignOf(c_int), p));
+ \\ var to_longlong: [*c]c_longlong = @ptrCast([*c]c_longlong, @alignCast(@alignOf(c_longlong), p));
+ \\ }
+ \\ {
+ \\ var to_char: [*c]u8 = @ptrCast([*c]u8, @alignCast(@alignOf(u8), p));
+ \\ var to_short: [*c]c_short = @ptrCast([*c]c_short, @alignCast(@alignOf(c_short), p));
+ \\ var to_int: [*c]c_int = @ptrCast([*c]c_int, @alignCast(@alignOf(c_int), p));
+ \\ var to_longlong: [*c]c_longlong = @ptrCast([*c]c_longlong, @alignCast(@alignOf(c_longlong), p));
+ \\ }
+ \\}
+ );
+
// cases.add("empty array with initializer",
// "int a[4] = {};"
// ,