remove ?return and ?defer

closes #309
This commit is contained in:
Andrew Kelley 2017-04-21 15:08:03 -04:00
parent bee1ae68ef
commit d5346d7a80
8 changed files with 19 additions and 114 deletions

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@ -85,9 +85,9 @@ ForExpression(body) = "for" "(" Expression ")" option("|" option("*") Symbol opt
BoolOrExpression = BoolAndExpression "or" BoolOrExpression | BoolAndExpression
ReturnExpression = option("%" | "?") "return" option(Expression)
ReturnExpression = option("%") "return" option(Expression)
Defer(body) = option("%" | "?") "defer" body
Defer(body) = option("%") "defer" body
IfExpression(body) = IfVarExpression(body) | IfBoolExpression(body)

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@ -11,8 +11,6 @@
libc.
* **cat** - implementation of the `cat` UNIX utility in Zig, with no dependency
on libc.
## Work-In-Progress Examples
* **shared_library** - demonstration of building a shared library and generating
a header file and documentation for interop with C code.
a header file for interop with C code.
* **mix_o_files** - how to mix .zig and .c files together as object files

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@ -408,7 +408,6 @@ struct AstNodeBlock {
enum ReturnKind {
ReturnKindUnconditional,
ReturnKindMaybe,
ReturnKindError,
};

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@ -92,7 +92,6 @@ static const char *return_string(ReturnKind kind) {
switch (kind) {
case ReturnKindUnconditional: return "return";
case ReturnKindError: return "%return";
case ReturnKindMaybe: return "?return";
}
zig_unreachable();
}
@ -101,7 +100,6 @@ static const char *defer_string(ReturnKind kind) {
switch (kind) {
case ReturnKindUnconditional: return "defer";
case ReturnKindError: return "%defer";
case ReturnKindMaybe: return "?defer";
}
zig_unreachable();
}

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@ -3091,7 +3091,6 @@ static IrInstruction *ir_instruction_get_dep(IrInstruction *instruction, size_t
static void ir_count_defers(IrBuilder *irb, Scope *inner_scope, Scope *outer_scope, size_t *results) {
results[ReturnKindUnconditional] = 0;
results[ReturnKindError] = 0;
results[ReturnKindMaybe] = 0;
while (inner_scope != outer_scope) {
assert(inner_scope);
@ -3111,9 +3110,7 @@ static IrInstruction *ir_mark_gen(IrInstruction *instruction) {
return instruction;
}
static bool ir_gen_defers_for_block(IrBuilder *irb, Scope *inner_scope, Scope *outer_scope,
bool gen_error_defers, bool gen_maybe_defers)
{
static bool ir_gen_defers_for_block(IrBuilder *irb, Scope *inner_scope, Scope *outer_scope, bool gen_error_defers) {
Scope *scope = inner_scope;
while (scope != outer_scope) {
if (!scope)
@ -3124,8 +3121,7 @@ static bool ir_gen_defers_for_block(IrBuilder *irb, Scope *inner_scope, Scope *o
assert(defer_node->type == NodeTypeDefer);
ReturnKind defer_kind = defer_node->data.defer.kind;
if (defer_kind == ReturnKindUnconditional ||
(gen_error_defers && defer_kind == ReturnKindError) ||
(gen_maybe_defers && defer_kind == ReturnKindMaybe))
(gen_error_defers && defer_kind == ReturnKindError))
{
AstNode *defer_expr_node = defer_node->data.defer.expr;
ir_gen_node(irb, defer_expr_node, defer_node->data.defer.expr_scope);
@ -3188,7 +3184,7 @@ static IrInstruction *ir_gen_return(IrBuilder *irb, Scope *scope, AstNode *node,
return_value = ir_build_const_void(irb, scope, node);
}
size_t defer_counts[3];
size_t defer_counts[2];
ir_count_defers(irb, scope, outer_scope, defer_counts);
if (defer_counts[ReturnKindError] > 0) {
IrBasicBlock *err_block = ir_build_basic_block(irb, scope, "ErrRetErr");
@ -3206,37 +3202,15 @@ static IrInstruction *ir_gen_return(IrBuilder *irb, Scope *scope, AstNode *node,
ir_mark_gen(ir_build_cond_br(irb, scope, node, is_err, err_block, ok_block, is_comptime));
ir_set_cursor_at_end(irb, err_block);
ir_gen_defers_for_block(irb, scope, outer_scope, true, false);
ir_gen_defers_for_block(irb, scope, outer_scope, true);
ir_build_return(irb, scope, node, return_value);
ir_set_cursor_at_end(irb, ok_block);
ir_gen_defers_for_block(irb, scope, outer_scope, false, false);
return ir_build_return(irb, scope, node, return_value);
} else if (defer_counts[ReturnKindMaybe] > 0) {
IrBasicBlock *null_block = ir_build_basic_block(irb, scope, "MaybeRetNull");
IrBasicBlock *ok_block = ir_build_basic_block(irb, scope, "MaybeRetOk");
IrInstruction *is_non_null = ir_build_test_nonnull(irb, scope, node, return_value);
IrInstruction *is_comptime;
if (ir_should_inline(irb->exec, scope)) {
is_comptime = ir_build_const_bool(irb, scope, node, true);
} else {
is_comptime = ir_build_test_comptime(irb, scope, node, is_non_null);
}
ir_mark_gen(ir_build_cond_br(irb, scope, node, is_non_null, ok_block, null_block, is_comptime));
ir_set_cursor_at_end(irb, null_block);
ir_gen_defers_for_block(irb, scope, outer_scope, false, true);
ir_build_return(irb, scope, node, return_value);
ir_set_cursor_at_end(irb, ok_block);
ir_gen_defers_for_block(irb, scope, outer_scope, false, false);
ir_gen_defers_for_block(irb, scope, outer_scope, false);
return ir_build_return(irb, scope, node, return_value);
} else {
// generate unconditional defers
ir_gen_defers_for_block(irb, scope, outer_scope, false, false);
ir_gen_defers_for_block(irb, scope, outer_scope, false);
return ir_build_return(irb, scope, node, return_value);
}
}
@ -3255,7 +3229,7 @@ static IrInstruction *ir_gen_return(IrBuilder *irb, Scope *scope, AstNode *node,
ir_mark_gen(ir_build_cond_br(irb, scope, node, is_err_val, return_block, continue_block, is_comptime));
ir_set_cursor_at_end(irb, return_block);
ir_gen_defers_for_block(irb, scope, outer_scope, true, false);
ir_gen_defers_for_block(irb, scope, outer_scope, true);
IrInstruction *err_val = ir_build_unwrap_err_code(irb, scope, node, err_union_ptr);
ir_build_return(irb, scope, node, err_val);
@ -3266,32 +3240,6 @@ static IrInstruction *ir_gen_return(IrBuilder *irb, Scope *scope, AstNode *node,
else
return ir_build_load_ptr(irb, scope, node, unwrapped_ptr);
}
case ReturnKindMaybe:
{
assert(expr_node);
IrInstruction *maybe_val_ptr = ir_gen_node_extra(irb, expr_node, scope, LVAL_PTR);
if (maybe_val_ptr == irb->codegen->invalid_instruction)
return irb->codegen->invalid_instruction;
IrInstruction *maybe_val = ir_build_load_ptr(irb, scope, node, maybe_val_ptr);
IrInstruction *is_non_null = ir_build_test_nonnull(irb, scope, node, maybe_val);
IrBasicBlock *return_block = ir_build_basic_block(irb, scope, "MaybeRetReturn");
IrBasicBlock *continue_block = ir_build_basic_block(irb, scope, "MaybeRetContinue");
IrInstruction *is_comptime = ir_build_const_bool(irb, scope, node, ir_should_inline(irb->exec, scope));
ir_mark_gen(ir_build_cond_br(irb, scope, node, is_non_null, continue_block, return_block, is_comptime));
ir_set_cursor_at_end(irb, return_block);
ir_gen_defers_for_block(irb, scope, outer_scope, false, true);
IrInstruction *null = ir_build_const_null(irb, scope, node);
ir_build_return(irb, scope, node, null);
ir_set_cursor_at_end(irb, continue_block);
IrInstruction *unwrapped_ptr = ir_build_unwrap_maybe(irb, scope, node, maybe_val_ptr, false);
if (lval.is_ptr)
return unwrapped_ptr;
else
return ir_build_load_ptr(irb, scope, node, unwrapped_ptr);
}
}
zig_unreachable();
}
@ -3490,7 +3438,7 @@ static IrInstruction *ir_gen_block(IrBuilder *irb, Scope *parent_scope, AstNode
return_value = ir_mark_gen(ir_build_const_void(irb, child_scope, block_node));
}
ir_gen_defers_for_block(irb, child_scope, outer_block_scope, false, false);
ir_gen_defers_for_block(irb, child_scope, outer_block_scope, false);
}
assert(return_value != nullptr);
@ -5420,7 +5368,7 @@ static IrInstruction *ir_gen_break(IrBuilder *irb, Scope *scope, AstNode *node)
}
IrBasicBlock *dest_block = loop_stack_item->break_block;
ir_gen_defers_for_block(irb, scope, dest_block->scope, false, false);
ir_gen_defers_for_block(irb, scope, dest_block->scope, false);
return ir_build_br(irb, scope, node, dest_block, is_comptime);
}
@ -5443,7 +5391,7 @@ static IrInstruction *ir_gen_continue(IrBuilder *irb, Scope *scope, AstNode *nod
}
IrBasicBlock *dest_block = loop_stack_item->continue_block;
ir_gen_defers_for_block(irb, scope, dest_block->scope, false, false);
ir_gen_defers_for_block(irb, scope, dest_block->scope, false);
return ir_build_br(irb, scope, node, dest_block, is_comptime);
}
@ -5784,7 +5732,7 @@ static bool ir_goto_pass2(IrBuilder *irb) {
IrInstruction *is_comptime = ir_build_const_bool(irb, goto_item->scope, source_node,
ir_should_inline(irb->exec, goto_item->scope) || source_node->data.goto_expr.is_inline);
if (!ir_gen_defers_for_block(irb, goto_item->scope, label->bb->scope, false, false)) {
if (!ir_gen_defers_for_block(irb, goto_item->scope, label->bb->scope, false)) {
add_node_error(irb->codegen, source_node,
buf_sprintf("no label in scope named '%s'", buf_ptr(label_name)));
return false;

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@ -1483,7 +1483,7 @@ static AstNode *ast_parse_if_expr(ParseContext *pc, size_t *token_index, bool ma
}
/*
ReturnExpression : option("%" | "?") "return" option(Expression)
ReturnExpression : option("%") "return" option(Expression)
*/
static AstNode *ast_parse_return_expr(ParseContext *pc, size_t *token_index) {
Token *token = &pc->tokens->at(*token_index);
@ -1500,15 +1500,6 @@ static AstNode *ast_parse_return_expr(ParseContext *pc, size_t *token_index) {
} else {
return nullptr;
}
} else if (token->id == TokenIdMaybe) {
Token *next_token = &pc->tokens->at(*token_index + 1);
if (next_token->id == TokenIdKeywordReturn) {
kind = ReturnKindMaybe;
node_type = NodeTypeReturnExpr;
*token_index += 2;
} else {
return nullptr;
}
} else if (token->id == TokenIdKeywordReturn) {
kind = ReturnKindUnconditional;
node_type = NodeTypeReturnExpr;
@ -1525,7 +1516,7 @@ static AstNode *ast_parse_return_expr(ParseContext *pc, size_t *token_index) {
}
/*
Defer(body) = option("%" | "?") "defer" body
Defer(body) = option("%") "defer" body
*/
static AstNode *ast_parse_defer_expr(ParseContext *pc, size_t *token_index) {
Token *token = &pc->tokens->at(*token_index);
@ -1542,15 +1533,6 @@ static AstNode *ast_parse_defer_expr(ParseContext *pc, size_t *token_index) {
} else {
return nullptr;
}
} else if (token->id == TokenIdMaybe) {
Token *next_token = &pc->tokens->at(*token_index + 1);
if (next_token->id == TokenIdKeywordDefer) {
kind = ReturnKindMaybe;
node_type = NodeTypeDefer;
*token_index += 2;
} else {
return nullptr;
}
} else if (token->id == TokenIdKeywordDefer) {
kind = ReturnKindUnconditional;
node_type = NodeTypeDefer;

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@ -13,14 +13,6 @@ fn runSomeErrorDefers(x: bool) -> %bool {
return if (x) x else error.FalseNotAllowed;
}
fn runSomeMaybeDefers(x: bool) -> ?bool {
index = 0;
defer {result[index] = 'a'; index += 1;};
?defer {result[index] = 'b'; index += 1;};
defer {result[index] = 'c'; index += 1;};
return if (x) x else null;
}
test "mixingNormalAndErrorDefers" {
assert(%%runSomeErrorDefers(true));
assert(result[0] == 'c');
@ -35,15 +27,3 @@ test "mixingNormalAndErrorDefers" {
assert(result[1] == 'b');
assert(result[2] == 'a');
}
test "mixingNormalAndMaybeDefers" {
assert(??runSomeMaybeDefers(true));
assert(result[0] == 'c');
assert(result[1] == 'a');
const ok = runSomeMaybeDefers(false) ?? true;
assert(ok);
assert(result[0] == 'c');
assert(result[1] == 'b');
assert(result[2] == 'a');
}

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@ -42,7 +42,7 @@ test "rhsMaybeUnwrapReturn" {
}
test "maybeReturn" {
test "maybe return" {
maybeReturnImpl();
comptime maybeReturnImpl();
}
@ -54,7 +54,7 @@ fn maybeReturnImpl() {
}
fn foo(x: ?i32) -> ?bool {
const value = ?return x;
const value = x ?? return null;
return value > 1234;
}