implement non-exhaustive enums

master
Vexu 2020-01-15 20:23:49 +02:00
parent 8d9d4a0658
commit 6fd0dddf18
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GPG Key ID: 59AEB8936E16A6AC
4 changed files with 97 additions and 35 deletions

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@ -1383,6 +1383,7 @@ struct ZigTypeEnum {
ContainerLayout layout;
ResolveStatus resolve_status;
bool non_exhaustive;
bool resolve_loop_flag;
};
@ -3665,6 +3666,7 @@ struct IrInstructionCheckSwitchProngs {
IrInstructionCheckSwitchProngsRange *ranges;
size_t range_count;
bool have_else_prong;
bool have_underscore_prong;
};
struct IrInstructionCheckStatementIsVoid {

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@ -2572,6 +2572,7 @@ static Error resolve_enum_zero_bits(CodeGen *g, ZigType *enum_type) {
enum_type->data.enumeration.src_field_count = field_count;
enum_type->data.enumeration.fields = allocate<TypeEnumField>(field_count);
enum_type->data.enumeration.fields_by_name.init(field_count);
enum_type->data.enumeration.non_exhaustive = false;
Scope *scope = &enum_type->data.enumeration.decls_scope->base;
@ -2648,6 +2649,21 @@ static Error resolve_enum_zero_bits(CodeGen *g, ZigType *enum_type) {
buf_sprintf("consider 'union(enum)' here"));
}
AstNode *tag_value = field_node->data.struct_field.value;
if (buf_eql_str(type_enum_field->name, "_")) {
if (field_i != field_count - 1) {
add_node_error(g, field_node, buf_sprintf("'_' field of non-exhaustive enum must be last"));
enum_type->data.enumeration.resolve_status = ResolveStatusInvalid;
}
if (tag_value != nullptr) {
add_node_error(g, field_node, buf_sprintf("value assigned to '_' field of non-exhaustive enum"));
enum_type->data.enumeration.resolve_status = ResolveStatusInvalid;
}
enum_type->data.enumeration.non_exhaustive = true;
continue;
}
auto field_entry = enum_type->data.enumeration.fields_by_name.put_unique(type_enum_field->name, type_enum_field);
if (field_entry != nullptr) {
ErrorMsg *msg = add_node_error(g, field_node,
@ -2657,8 +2673,6 @@ static Error resolve_enum_zero_bits(CodeGen *g, ZigType *enum_type) {
continue;
}
AstNode *tag_value = field_node->data.struct_field.value;
if (tag_value != nullptr) {
// A user-specified value is available
ZigValue *result = analyze_const_value(g, scope, tag_value, tag_int_type,

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@ -3356,7 +3356,7 @@ static LLVMValueRef ir_render_int_to_enum(CodeGen *g, IrExecutable *executable,
LLVMValueRef tag_int_value = gen_widen_or_shorten(g, ir_want_runtime_safety(g, &instruction->base),
instruction->target->value->type, tag_int_type, target_val);
if (ir_want_runtime_safety(g, &instruction->base) && wanted_type->data.enumeration.layout != ContainerLayoutExtern) {
if (ir_want_runtime_safety(g, &instruction->base) && !wanted_type->data.enumeration.non_exhaustive) {
LLVMBasicBlockRef bad_value_block = LLVMAppendBasicBlock(g->cur_fn_val, "BadValue");
LLVMBasicBlockRef ok_value_block = LLVMAppendBasicBlock(g->cur_fn_val, "OkValue");
size_t field_count = wanted_type->data.enumeration.src_field_count;

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@ -3451,7 +3451,7 @@ static IrInstruction *ir_build_err_to_int(IrBuilder *irb, Scope *scope, AstNode
static IrInstruction *ir_build_check_switch_prongs(IrBuilder *irb, Scope *scope, AstNode *source_node,
IrInstruction *target_value, IrInstructionCheckSwitchProngsRange *ranges, size_t range_count,
bool have_else_prong)
bool have_else_prong, bool have_underscore_prong)
{
IrInstructionCheckSwitchProngs *instruction = ir_build_instruction<IrInstructionCheckSwitchProngs>(
irb, scope, source_node);
@ -3459,6 +3459,7 @@ static IrInstruction *ir_build_check_switch_prongs(IrBuilder *irb, Scope *scope,
instruction->ranges = ranges;
instruction->range_count = range_count;
instruction->have_else_prong = have_else_prong;
instruction->have_underscore_prong = have_underscore_prong;
ir_ref_instruction(target_value, irb->current_basic_block);
for (size_t i = 0; i < range_count; i += 1) {
@ -8090,34 +8091,11 @@ static IrInstruction *ir_gen_switch_expr(IrBuilder *irb, Scope *scope, AstNode *
Scope *subexpr_scope = create_runtime_scope(irb->codegen, node, scope, is_comptime);
Scope *comptime_scope = create_comptime_scope(irb->codegen, node, scope);
AstNode *else_prong = nullptr;
AstNode *underscore_prong = nullptr;
for (size_t prong_i = 0; prong_i < prong_count; prong_i += 1) {
AstNode *prong_node = node->data.switch_expr.prongs.at(prong_i);
size_t prong_item_count = prong_node->data.switch_prong.items.length;
if (prong_item_count == 0) {
ResultLocPeer *this_peer_result_loc = create_peer_result(peer_parent);
if (else_prong) {
ErrorMsg *msg = add_node_error(irb->codegen, prong_node,
buf_sprintf("multiple else prongs in switch expression"));
add_error_note(irb->codegen, msg, else_prong,
buf_sprintf("previous else prong is here"));
return irb->codegen->invalid_instruction;
}
else_prong = prong_node;
IrBasicBlock *prev_block = irb->current_basic_block;
if (peer_parent->peers.length > 0) {
peer_parent->peers.last()->next_bb = else_block;
}
peer_parent->peers.append(this_peer_result_loc);
ir_set_cursor_at_end_and_append_block(irb, else_block);
if (!ir_gen_switch_prong_expr(irb, subexpr_scope, node, prong_node, end_block,
is_comptime, var_is_comptime, target_value_ptr, nullptr, 0, &incoming_blocks, &incoming_values,
&switch_else_var, LValNone, &this_peer_result_loc->base))
{
return irb->codegen->invalid_instruction;
}
ir_set_cursor_at_end(irb, prev_block);
} else if (prong_node->data.switch_prong.any_items_are_range) {
if (prong_node->data.switch_prong.any_items_are_range) {
ResultLocPeer *this_peer_result_loc = create_peer_result(peer_parent);
IrInstruction *ok_bit = nullptr;
@ -8195,6 +8173,59 @@ static IrInstruction *ir_gen_switch_expr(IrBuilder *irb, Scope *scope, AstNode *
}
ir_set_cursor_at_end_and_append_block(irb, range_block_no);
} else {
if (prong_item_count == 0) {
if (else_prong) {
ErrorMsg *msg = add_node_error(irb->codegen, prong_node,
buf_sprintf("multiple else prongs in switch expression"));
add_error_note(irb->codegen, msg, else_prong,
buf_sprintf("previous else prong is here"));
return irb->codegen->invalid_instruction;
}
else_prong = prong_node;
if (underscore_prong) {
ErrorMsg *msg = add_node_error(irb->codegen, prong_node,
buf_sprintf("else and '_' prong in switch expression"));
add_error_note(irb->codegen, msg, underscore_prong,
buf_sprintf("'_' prong is here"));
return irb->codegen->invalid_instruction;
}
} else if (prong_item_count == 1 &&
prong_node->data.switch_prong.items.at(0)->type == NodeTypeSymbol &&
buf_eql_str(prong_node->data.switch_prong.items.at(0)->data.symbol_expr.symbol, "_")) {
if (underscore_prong) {
ErrorMsg *msg = add_node_error(irb->codegen, prong_node,
buf_sprintf("multiple '_' prongs in switch expression"));
add_error_note(irb->codegen, msg, underscore_prong,
buf_sprintf("previous '_' prong is here"));
return irb->codegen->invalid_instruction;
}
underscore_prong = prong_node;
if (else_prong) {
ErrorMsg *msg = add_node_error(irb->codegen, prong_node,
buf_sprintf("else and '_' prong in switch expression"));
add_error_note(irb->codegen, msg, else_prong,
buf_sprintf("else prong is here"));
return irb->codegen->invalid_instruction;
}
} else {
continue;
}
ResultLocPeer *this_peer_result_loc = create_peer_result(peer_parent);
IrBasicBlock *prev_block = irb->current_basic_block;
if (peer_parent->peers.length > 0) {
peer_parent->peers.last()->next_bb = else_block;
}
peer_parent->peers.append(this_peer_result_loc);
ir_set_cursor_at_end_and_append_block(irb, else_block);
if (!ir_gen_switch_prong_expr(irb, subexpr_scope, node, prong_node, end_block,
is_comptime, var_is_comptime, target_value_ptr, nullptr, 0, &incoming_blocks, &incoming_values,
&switch_else_var, LValNone, &this_peer_result_loc->base))
{
return irb->codegen->invalid_instruction;
}
ir_set_cursor_at_end(irb, prev_block);
}
}
@ -8206,6 +8237,8 @@ static IrInstruction *ir_gen_switch_expr(IrBuilder *irb, Scope *scope, AstNode *
continue;
if (prong_node->data.switch_prong.any_items_are_range)
continue;
if (underscore_prong == prong_node)
continue;
ResultLocPeer *this_peer_result_loc = create_peer_result(peer_parent);
@ -8249,7 +8282,7 @@ static IrInstruction *ir_gen_switch_expr(IrBuilder *irb, Scope *scope, AstNode *
}
IrInstruction *switch_prongs_void = ir_build_check_switch_prongs(irb, scope, node, target_value,
check_ranges.items, check_ranges.length, else_prong != nullptr);
check_ranges.items, check_ranges.length, else_prong != nullptr, underscore_prong != nullptr);
IrInstruction *br_instruction;
if (cases.length == 0) {
@ -8269,7 +8302,7 @@ static IrInstruction *ir_gen_switch_expr(IrBuilder *irb, Scope *scope, AstNode *
peer_parent->peers.at(i)->base.source_instruction = peer_parent->base.source_instruction;
}
if (!else_prong) {
if (!else_prong && !underscore_prong) {
if (peer_parent->peers.length != 0) {
peer_parent->peers.last()->next_bb = else_block;
}
@ -12790,7 +12823,7 @@ static IrInstruction *ir_analyze_int_to_enum(IrAnalyze *ira, IrInstruction *sour
return ira->codegen->invalid_instruction;
TypeEnumField *field = find_enum_field_by_tag(wanted_type, &val->data.x_bigint);
if (field == nullptr && wanted_type->data.enumeration.layout != ContainerLayoutExtern) {
if (field == nullptr && !wanted_type->data.enumeration.non_exhaustive) {
Buf *val_buf = buf_alloc();
bigint_append_buf(val_buf, &val->data.x_bigint, 10);
ErrorMsg *msg = ir_add_error(ira, source_instr,
@ -26433,10 +26466,23 @@ static IrInstruction *ir_analyze_instruction_check_switch_prongs(IrAnalyze *ira,
bigint_incr(&field_index);
}
}
if (!instruction->have_else_prong) {
if (switch_type->data.enumeration.layout == ContainerLayoutExtern) {
if (switch_type->data.enumeration.non_exhaustive && instruction->have_underscore_prong) {
for (uint32_t i = 0; i < switch_type->data.enumeration.src_field_count; i += 1) {
TypeEnumField *enum_field = &switch_type->data.enumeration.fields[i];
if (buf_eql_str(enum_field->name, "_"))
continue;
auto entry = field_prev_uses.maybe_get(enum_field->value);
if (!entry) {
ir_add_error(ira, &instruction->base,
buf_sprintf("switch on an extern enum must have an else prong"));
buf_sprintf("enumeration value '%s.%s' not handled in switch", buf_ptr(&switch_type->name),
buf_ptr(enum_field->name)));
}
}
} else if (!instruction->have_else_prong) {
if (switch_type->data.enumeration.non_exhaustive) {
ir_add_error(ira, &instruction->base,
buf_sprintf("switch on non-exhaustive enum must include `else` or `_` prong"));
}
for (uint32_t i = 0; i < switch_type->data.enumeration.src_field_count; i += 1) {
TypeEnumField *enum_field = &switch_type->data.enumeration.fields[i];