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support variable in switch expression prongs 

See #43
master
Andrew Kelley 2016-02-04 17:21:08 -07:00
parent a4cba900e5
commit 093e0d1bb0
4 changed files with 105 additions and 36 deletions
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1
src/all_types.hpp
View File

@ -510,6 +510,7 @@ struct AstNodeSwitchProng {
// populated by semantic analyzer
BlockContext *block_context;
VariableTableEntry *var;
bool var_is_target_expr;
};
struct AstNodeSwitchRange {

19
src/analyze.cpp
View File

@ -4495,6 +4495,7 @@ static TypeTableEntry *analyze_switch_expr(CodeGen *g, ImportTableEntry *import,
AstNode *prong_node = node->data.switch_expr.prongs.at(prong_i);
TypeTableEntry *var_type;
bool var_is_target_expr;
if (prong_node->data.switch_prong.items.length == 0) {
if (else_prong) {
add_node_error(g, prong_node, buf_sprintf("multiple else prongs in switch expression"));
@ -4502,7 +4503,11 @@ static TypeTableEntry *analyze_switch_expr(CodeGen *g, ImportTableEntry *import,
else_prong = prong_node;
}
var_type = expr_type;
var_is_target_expr = true;
} else {
bool all_agree_on_var_type = true;
var_type = nullptr;
for (int item_i = 0; item_i < prong_node->data.switch_prong.items.length; item_i += 1) {
AstNode *item_node = prong_node->data.switch_prong.items.at(item_i);
if (item_node->type == NodeTypeSwitchRange) {
@ -4515,6 +4520,12 @@ static TypeTableEntry *analyze_switch_expr(CodeGen *g, ImportTableEntry *import,
TypeEnumField *type_enum_field = get_enum_field(expr_type, field_name);
if (type_enum_field) {
item_node->data.symbol_expr.enum_field = type_enum_field;
if (!var_type) {
var_type = type_enum_field->type_entry;
}
if (type_enum_field->type_entry != var_type) {
all_agree_on_var_type = false;
}
} else {
add_node_error(g, item_node,
buf_sprintf("enum '%s' has no field '%s'",
@ -4534,7 +4545,12 @@ static TypeTableEntry *analyze_switch_expr(CodeGen *g, ImportTableEntry *import,
}
}
}
var_type = expr_type;
if (!var_type || !all_agree_on_var_type) {
var_type = expr_type;
var_is_target_expr = true;
} else {
var_is_target_expr = false;
}
}
BlockContext *child_context = new_block_context(node, context);
@ -4546,6 +4562,7 @@ static TypeTableEntry *analyze_switch_expr(CodeGen *g, ImportTableEntry *import,
var_node->block_context = child_context;
prong_node->data.switch_prong.var = add_local_var(g, var_node, child_context, var_name,
var_type, true);
prong_node->data.switch_prong.var_is_target_expr = var_is_target_expr;
}
peer_types[prong_i] = analyze_expression(g, import, child_context, expected_type,

95
src/codegen.cpp
View File

@ -184,6 +184,15 @@ static LLVMValueRef get_int_overflow_fn(CodeGen *g, TypeTableEntry *type_entry,
return *fn;
}
static LLVMValueRef get_handle_value(CodeGen *g, AstNode *source_node, LLVMValueRef ptr, TypeTableEntry *type) {
if (handle_is_ptr(type)) {
return ptr;
} else {
add_debug_source_node(g, source_node);
return LLVMBuildLoad(g->builder, ptr, "");
}
}
static LLVMValueRef gen_builtin_fn_call_expr(CodeGen *g, AstNode *node) {
assert(node->type == NodeTypeFnCallExpr);
AstNode *fn_ref_expr = node->data.fn_call_expr.fn_ref_expr;
@ -1024,11 +1033,7 @@ static LLVMValueRef gen_prefix_op_expr(CodeGen *g, AstNode *node) {
if (type_has_bits(child_type)) {
LLVMValueRef child_val_ptr = LLVMBuildStructGEP(g->builder, expr_val, 1, "");
if (handle_is_ptr(child_type)) {
return child_val_ptr;
} else {
return LLVMBuildLoad(g->builder, child_val_ptr, "");
}
return get_handle_value(g, expr_node, child_val_ptr, child_type);
} else {
return nullptr;
}
@ -1073,11 +1078,7 @@ static LLVMValueRef gen_prefix_op_expr(CodeGen *g, AstNode *node) {
} else {
add_debug_source_node(g, node);
LLVMValueRef maybe_field_ptr = LLVMBuildStructGEP(g->builder, expr_val, 0, "");
if (handle_is_ptr(child_type)) {
return maybe_field_ptr;
} else {
return LLVMBuildLoad(g->builder, maybe_field_ptr, "");
}
return get_handle_value(g, node, maybe_field_ptr, child_type);
}
}
}
@ -1412,11 +1413,7 @@ static LLVMValueRef gen_unwrap_maybe(CodeGen *g, AstNode *node, LLVMValueRef may
} else {
add_debug_source_node(g, node);
LLVMValueRef maybe_field_ptr = LLVMBuildStructGEP(g->builder, maybe_struct_ref, 0, "");
if (handle_is_ptr(child_type)) {
return maybe_field_ptr;
} else {
return LLVMBuildLoad(g->builder, maybe_field_ptr, "");
}
return get_handle_value(g, node, maybe_field_ptr, child_type);
}
}
@ -1580,12 +1577,7 @@ static LLVMValueRef gen_unwrap_err_expr(CodeGen *g, AstNode *node) {
return nullptr;
}
LLVMValueRef child_val_ptr = LLVMBuildStructGEP(g->builder, expr_val, 1, "");
LLVMValueRef child_val;
if (handle_is_ptr(child_type)) {
child_val = child_val_ptr;
} else {
child_val = LLVMBuildLoad(g->builder, child_val_ptr, "");
}
LLVMValueRef child_val = get_handle_value(g, node, child_val_ptr, child_type);
if (!have_end_block) {
return child_val;
@ -1667,11 +1659,7 @@ static LLVMValueRef gen_return_expr(CodeGen *g, AstNode *node) {
if (type_has_bits(child_type)) {
add_debug_source_node(g, node);
LLVMValueRef val_ptr = LLVMBuildStructGEP(g->builder, value, 1, "");
if (handle_is_ptr(child_type)) {
return val_ptr;
} else {
return LLVMBuildLoad(g->builder, val_ptr, "");
}
return get_handle_value(g, node, val_ptr, child_type);
} else {
return nullptr;
}
@ -2294,12 +2282,7 @@ static LLVMValueRef gen_symbol(CodeGen *g, AstNode *node) {
return nullptr;
} else if (variable->is_ptr) {
assert(variable->value_ref);
if (handle_is_ptr(variable->type)) {
return variable->value_ref;
} else {
add_debug_source_node(g, node);
return LLVMBuildLoad(g->builder, variable->value_ref, "");
}
return get_handle_value(g, node, variable->value_ref, variable->type);
} else {
return variable->value_ref;
}
@ -2347,6 +2330,8 @@ static LLVMValueRef gen_switch_expr(CodeGen *g, AstNode *node) {
AstNode *else_prong = nullptr;
for (int prong_i = 0; prong_i < prong_count; prong_i += 1) {
AstNode *prong_node = node->data.switch_expr.prongs.at(prong_i);
VariableTableEntry *prong_var = prong_node->data.switch_prong.var;
LLVMBasicBlockRef prong_block;
if (prong_node->data.switch_prong.items.length == 0) {
assert(!else_prong);
@ -2354,8 +2339,12 @@ static LLVMValueRef gen_switch_expr(CodeGen *g, AstNode *node) {
prong_block = else_block;
} else {
prong_block = LLVMAppendBasicBlock(g->cur_fn->fn_value, "SwitchProng");
for (int item_i = 0; item_i < prong_node->data.switch_prong.items.length; item_i += 1) {
int prong_item_count = prong_node->data.switch_prong.items.length;
bool make_item_blocks = prong_var && prong_item_count > 1;
for (int item_i = 0; item_i < prong_item_count; item_i += 1) {
AstNode *item_node = prong_node->data.switch_prong.items.at(item_i);
assert(item_node->type != NodeTypeSwitchRange);
LLVMValueRef val;
if (target_type->id == TypeTableEntryIdEnum) {
@ -2364,14 +2353,50 @@ static LLVMValueRef gen_switch_expr(CodeGen *g, AstNode *node) {
assert(enum_field);
val = LLVMConstInt(target_type->data.enumeration.tag_type->type_ref,
enum_field->value, false);
if (prong_var && type_has_bits(prong_var->type)) {
LLVMBasicBlockRef item_block;
if (make_item_blocks) {
item_block = LLVMAppendBasicBlock(g->cur_fn->fn_value, "SwitchProngItem");
LLVMAddCase(switch_instr, val, item_block);
LLVMPositionBuilderAtEnd(g->builder, item_block);
} else {
LLVMAddCase(switch_instr, val, prong_block);
LLVMPositionBuilderAtEnd(g->builder, prong_block);
}
AstNode *var_node = prong_node->data.switch_prong.var_symbol;
add_debug_source_node(g, var_node);
if (prong_node->data.switch_prong.var_is_target_expr) {
gen_assign_raw(g, var_node, BinOpTypeAssign,
prong_var->value_ref, target_value, prong_var->type, target_type);
} else if (target_type->id == TypeTableEntryIdEnum) {
assert(type_has_bits(enum_field->type_entry));
LLVMValueRef union_field_ptr = LLVMBuildStructGEP(g->builder, target_value_handle,
1, "");
LLVMValueRef bitcasted_union_field_ptr = LLVMBuildBitCast(g->builder, union_field_ptr,
LLVMPointerType(enum_field->type_entry->type_ref, 0), "");
LLVMValueRef handle_val = get_handle_value(g, var_node, bitcasted_union_field_ptr,
enum_field->type_entry);
gen_assign_raw(g, var_node, BinOpTypeAssign,
prong_var->value_ref, handle_val, prong_var->type, enum_field->type_entry);
}
if (make_item_blocks) {
LLVMBuildBr(g->builder, prong_block);
}
} else {
LLVMAddCase(switch_instr, val, prong_block);
}
} else {
assert(get_resolved_expr(item_node)->const_val.ok);
val = gen_expr(g, item_node);
LLVMAddCase(switch_instr, val, prong_block);
}
LLVMAddCase(switch_instr, val, prong_block);
}
}
assert(!prong_node->data.switch_prong.var_symbol);
LLVMPositionBuilderAtEnd(g->builder, prong_block);
AstNode *prong_expr = prong_node->data.switch_prong.expr;
LLVMValueRef prong_val = gen_expr(g, prong_expr);

26
test/self_hosted.zig
View File

@ -147,3 +147,29 @@ enum SwitchStatmentFoo {
C,
D,
}
#attribute("test")
fn switch_prong_with_var() {
switch_prong_with_var_fn(SwitchProngWithVarEnum.One(13));
switch_prong_with_var_fn(SwitchProngWithVarEnum.Two(13.0));
switch_prong_with_var_fn(SwitchProngWithVarEnum.Meh);
}
enum SwitchProngWithVarEnum {
One: i32,
Two: f32,
Meh,
}
fn switch_prong_with_var_fn(a: SwitchProngWithVarEnum) {
switch(a) {
One => |x| {
if (x != 13) unreachable{};
},
Two => |x| {
if (x != 13.0) unreachable{};
},
Meh => |x| {
const v: void = x;
},
}
}