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Validate enum tag for extern enum

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The C specification mandates the enum to be compatible with signed char,
signed int or unsigned int.
This commit is contained in:
LemonBoy
2019-05-09 10:19:02 +02:00
parent 6cf7fb1177
commit 917bd4192d
1 changed files with 33 additions and 1 deletions
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34
src/analyze.cpp
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@@ -1908,6 +1908,30 @@ static Error resolve_union_type(CodeGen *g, ZigType *union_type) {
return ErrorNone;
}
static bool type_is_int_compatible(ZigType *t1, ZigType *t2) {
assert(t1->id == ZigTypeIdInt);
assert(t2->id == ZigTypeIdInt);
if (t1 == t2)
return true;
return (t1->data.integral.bit_count == t2->data.integral.bit_count &&
t1->data.integral.is_signed == t2->data.integral.is_signed);
}
static bool type_is_valid_extern_enum_tag(CodeGen *g, ZigType *ty) {
// According to the ANSI C standard:
// Each enumerated type shall be compatible with char, a signed integer
// type, or an unsigned integer type.
ZigType *c_uint_type = get_c_int_type(g, CIntTypeInt);
ZigType *c_int_type = get_c_int_type(g, CIntTypeInt);
ZigType *c_schar_type = g->builtin_types.entry_i8;
return (type_is_int_compatible(ty, c_schar_type) ||
type_is_int_compatible(ty, c_int_type) ||
type_is_int_compatible(ty, c_uint_type));
}
static Error resolve_enum_zero_bits(CodeGen *g, ZigType *enum_type) {
assert(enum_type->id == ZigTypeIdEnum);
@@ -1965,7 +1989,6 @@ static Error resolve_enum_zero_bits(CodeGen *g, ZigType *enum_type) {
enum_type->abi_size = tag_int_type->abi_size;
enum_type->abi_align = tag_int_type->abi_align;
// TODO: Are extern enums allowed to have an init_arg_expr?
if (decl_node->data.container_decl.init_arg_expr != nullptr) {
ZigType *wanted_tag_int_type = analyze_type_expr(g, scope, decl_node->data.container_decl.init_arg_expr);
if (type_is_invalid(wanted_tag_int_type)) {
@@ -1974,6 +1997,14 @@ static Error resolve_enum_zero_bits(CodeGen *g, ZigType *enum_type) {
enum_type->data.enumeration.is_invalid = true;
add_node_error(g, decl_node->data.container_decl.init_arg_expr,
buf_sprintf("expected integer, found '%s'", buf_ptr(&wanted_tag_int_type->name)));
} else if (enum_type->data.enumeration.layout == ContainerLayoutExtern &&
!type_is_valid_extern_enum_tag(g, wanted_tag_int_type)) {
enum_type->data.enumeration.is_invalid = true;
ErrorMsg *msg = add_node_error(g, decl_node->data.container_decl.init_arg_expr,
buf_sprintf("'%s' is not a valid tag type for an extern union",
buf_ptr(&wanted_tag_int_type->name)));
add_error_note(g, msg, decl_node->data.container_decl.init_arg_expr,
buf_sprintf("valid types are 'i8', 'c_int' and 'c_uint' or compatible types"));
} else if (wanted_tag_int_type->data.integral.is_signed) {
enum_type->data.enumeration.is_invalid = true;
add_node_error(g, decl_node->data.container_decl.init_arg_expr,
@@ -1987,6 +2018,7 @@ static Error resolve_enum_zero_bits(CodeGen *g, ZigType *enum_type) {
tag_int_type = wanted_tag_int_type;
}
}
enum_type->data.enumeration.tag_int_type = tag_int_type;
enum_type->size_in_bits = tag_int_type->size_in_bits;
enum_type->abi_size = tag_int_type->abi_size;