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implement %defer and ?defer

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see #110
This commit is contained in:
Andrew Kelley
2016-02-06 16:36:49 -07:00
parent 34a7e6fdb3
commit 65a03c5859
4 changed files with 113 additions and 47 deletions
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68
src/codegen.cpp
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@@ -483,6 +483,7 @@ static LLVMValueRef gen_cast_expr(CodeGen *g, AstNode *node) {
}
case CastOpPureErrorWrap:
assert(wanted_type->id == TypeTableEntryIdErrorUnion);
if (!type_has_bits(wanted_type->data.error.child_type)) {
return expr_val;
} else {
@@ -1593,18 +1594,48 @@ static LLVMValueRef gen_unwrap_err_expr(CodeGen *g, AstNode *node) {
return phi;
}
static void gen_defers_for_block(CodeGen *g, BlockContext *inner_block, BlockContext *outer_block) {
static void gen_defers_for_block(CodeGen *g, BlockContext *inner_block, BlockContext *outer_block,
bool gen_error_defers, bool gen_maybe_defers)
{
while (inner_block != outer_block) {
if (inner_block->node->type == NodeTypeDefer) {
if (inner_block->node->type == NodeTypeDefer &&
((inner_block->node->data.defer.kind == ReturnKindUnconditional) ||
(gen_error_defers && inner_block->node->data.defer.kind == ReturnKindError) ||
(gen_maybe_defers && inner_block->node->data.defer.kind == ReturnKindMaybe)))
{
gen_expr(g, inner_block->node->data.defer.expr);
}
inner_block = inner_block->parent;
}
}
static LLVMValueRef gen_return(CodeGen *g, AstNode *source_node, LLVMValueRef value) {
gen_defers_for_block(g, source_node->block_context,
source_node->block_context->fn_entry->fn_def_node->block_context);
static int get_conditional_defer_count(BlockContext *inner_block, BlockContext *outer_block) {
int result = 0;
while (inner_block != outer_block) {
if (inner_block->node->type == NodeTypeDefer &&
(inner_block->node->data.defer.kind == ReturnKindError ||
inner_block->node->data.defer.kind == ReturnKindMaybe))
{
result += 1;
}
inner_block = inner_block->parent;
}
return result;
}
static LLVMValueRef gen_return(CodeGen *g, AstNode *source_node, LLVMValueRef value, ReturnKnowledge rk) {
BlockContext *defer_inner_block = source_node->block_context;
BlockContext *defer_outer_block = source_node->block_context->fn_entry->fn_def_node->block_context;
if (rk == ReturnKnowledgeUnknown) {
if (get_conditional_defer_count(defer_inner_block, defer_outer_block) > 0) {
// generate branching code that checks the return value and generates defers
// if the return value is error
zig_panic("TODO");
}
} else if (rk != ReturnKnowledgeSkipDefers) {
gen_defers_for_block(g, defer_inner_block, defer_outer_block,
rk == ReturnKnowledgeKnownError, rk == ReturnKnowledgeKnownNull);
}
TypeTableEntry *return_type = g->cur_fn->type_entry->data.fn.fn_type_id.return_type;
if (handle_is_ptr(return_type)) {
@@ -1628,7 +1659,23 @@ static LLVMValueRef gen_return_expr(CodeGen *g, AstNode *node) {
switch (node->data.return_expr.kind) {
case ReturnKindUnconditional:
{
return gen_return(g, node, value);
Expr *expr = get_resolved_expr(param_node);
if (expr->const_val.ok) {
if (value_type->id == TypeTableEntryIdErrorUnion) {
if (expr->const_val.data.x_err.err) {
expr->return_knowledge = ReturnKnowledgeKnownError;
} else {
expr->return_knowledge = ReturnKnowledgeKnownNonError;
}
} else if (value_type->id == TypeTableEntryIdMaybe) {
if (expr->const_val.data.x_maybe) {
expr->return_knowledge = ReturnKnowledgeKnownNonNull;
} else {
expr->return_knowledge = ReturnKnowledgeKnownNull;
}
}
}
return gen_return(g, node, value, expr->return_knowledge);
}
case ReturnKindError:
{
@@ -1653,7 +1700,7 @@ static LLVMValueRef gen_return_expr(CodeGen *g, AstNode *node) {
LLVMPositionBuilderAtEnd(g->builder, return_block);
TypeTableEntry *return_type = g->cur_fn->type_entry->data.fn.fn_type_id.return_type;
if (return_type->id == TypeTableEntryIdPureError) {
gen_return(g, node, err_val);
gen_return(g, node, err_val, ReturnKnowledgeKnownError);
} else if (return_type->id == TypeTableEntryIdErrorUnion) {
if (type_has_bits(return_type->data.error.child_type)) {
assert(g->cur_ret_ptr);
@@ -1663,7 +1710,7 @@ static LLVMValueRef gen_return_expr(CodeGen *g, AstNode *node) {
LLVMBuildStore(g->builder, err_val, tag_ptr);
LLVMBuildRetVoid(g->builder);
} else {
gen_return(g, node, err_val);
gen_return(g, node, err_val, ReturnKnowledgeKnownError);
}
} else {
zig_unreachable();
@@ -1834,10 +1881,11 @@ static LLVMValueRef gen_block(CodeGen *g, AstNode *block_node, TypeTableEntry *i
return nullptr;
}
gen_defers_for_block(g, block_node->data.block.nested_block, block_node->data.block.child_block);
gen_defers_for_block(g, block_node->data.block.nested_block, block_node->data.block.child_block,
false, false);
if (implicit_return_type) {
return gen_return(g, block_node, return_value);
return gen_return(g, block_node, return_value, ReturnKnowledgeSkipDefers);
} else {
return return_value;
}