implement %% prefix operator

See #23

also make undefined constants use llvm undef value
This commit is contained in:
Andrew Kelley 2016-01-25 15:45:05 -07:00
parent c0dc0ca6c9
commit deb3586884
9 changed files with 54 additions and 20 deletions

View File

@ -48,8 +48,8 @@ compromises backward compatibility.
### Current Status
* Have a look in the example/ folder to see some code examples.
* Basic language features available such as loops, inline assembly,
expressions, literals, functions, importing, structs, tagged unions.
* Most language features are available, but many edge cases and errors are
not yet implemented.
* Linux x86_64 is supported.
* Building for the native target is supported.
* Optimized machine code that Zig produces is indistinguishable from

View File

@ -137,7 +137,7 @@ ContainerInitBody : list(StructLiteralField, ",") | list(Expression, ",")
StructLiteralField : "." "Symbol" "=" Expression
PrefixOp : "!" | "-" | "~" | "*" | ("&" option("const")) | "?" | "%"
PrefixOp : "!" | "-" | "~" | "*" | ("&" option("const")) | "?" | "%" | "%%"
PrimaryExpression : "Number" | "String" | "CharLiteral" | KeywordLiteral | GroupedExpression | GotoExpression | BlockExpression | "Symbol" | ("@" "Symbol" FnCallExpression) | ArrayType | AsmExpression | ("error" "." "Symbol")
@ -154,7 +154,7 @@ KeywordLiteral : "true" | "false" | "null" | "break" | "continue" | "undefined"
```
x() x[] x.y
!x -x ~x *x &x ?x %x
!x -x ~x *x &x ?x %x %%x
x{}
* / %
+ -

View File

@ -5,7 +5,6 @@ import "std.zig";
// Things to do to make this work:
// * var args printing
// * defer
// * %% binary operator
// * %% prefix operator
// * cast err type to string
// * string equality
@ -21,7 +20,7 @@ pub fn main(args: [][]u8) %void => {
return usage(exe);
} else {
var is: InputStream;
is.open(arg, OpenReadOnly) %% (err) => {
is.open(arg, OpenReadOnly) %% |err| {
%%stderr.print("Unable to open file: {}", ([]u8])(err));
return err;
}
@ -45,7 +44,7 @@ fn cat_stream(is: InputStream) %void => {
var buf: [1024 * 4]u8;
while (true) {
const bytes_read = is.read(buf) %% (err) => {
const bytes_read = is.read(buf) %% |err| {
%%stderr.print("Unable to read from stream: {}", ([]u8)(err));
return err;
}
@ -54,7 +53,7 @@ fn cat_stream(is: InputStream) %void => {
break;
}
stdout.write(buf[0...bytes_read]) %% (err) => {
stdout.write(buf[0...bytes_read]) %% |err| {
%%stderr.print("Unable to write to stdout: {}", ([]u8)(err));
return err;
}

View File

@ -4,35 +4,35 @@ import "std.zig";
import "rand.zig";
pub fn main(args: [][]u8) %void => {
stderr.print_str("Welcome to the Guess Number Game in Zig.\n");
%%stderr.print_str("Welcome to the Guess Number Game in Zig.\n");
var seed : u32;
const seed_bytes = (&u8)(&seed)[0...4];
os_get_random_bytes(seed_bytes) %% unreachable{};
%%os_get_random_bytes(seed_bytes);
var rand = rand_new(seed);
const answer = rand.range_u64(0, 100) + 1;
while (true) {
stderr.print_str("\nGuess a number between 1 and 100: ");
%%stderr.print_str("\nGuess a number between 1 and 100: ");
var line_buf : [20]u8;
const line_len = stdin.read(line_buf) %% |err| {
stderr.print_str("Unable to read from stdin.\n");
%%stderr.print_str("Unable to read from stdin.\n");
return err;
};
const guess = parse_u64(line_buf[0...line_len - 1], 10) %% {
stderr.print_str("Invalid number.\n");
%%stderr.print_str("Invalid number.\n");
continue;
};
if (guess > answer) {
stderr.print_str("Guess lower.\n");
%%stderr.print_str("Guess lower.\n");
} else if (guess < answer) {
stderr.print_str("Guess higher.\n");
%%stderr.print_str("Guess higher.\n");
} else {
stderr.print_str("You win!\n");
%%stderr.print_str("You win!\n");
return;
}
}

View File

@ -405,6 +405,7 @@ enum PrefixOp {
PrefixOpDereference,
PrefixOpMaybe,
PrefixOpError,
PrefixOpUnwrapError,
};
struct AstNodePrefixOpExpr {

View File

@ -3656,6 +3656,20 @@ static TypeTableEntry *analyze_prefix_op_expr(CodeGen *g, ImportTableEntry *impo
}
}
case PrefixOpUnwrapError:
{
TypeTableEntry *type_entry = analyze_expression(g, import, context, nullptr, expr_node);
if (type_entry->id == TypeTableEntryIdInvalid) {
return type_entry;
} else if (type_entry->id == TypeTableEntryIdErrorUnion) {
return type_entry->data.error.child_type;
} else {
add_node_error(g, expr_node,
buf_sprintf("expected error type, got '%s'", buf_ptr(&type_entry->name)));
return g->builtin_types.entry_invalid;
}
}
}
zig_unreachable();
}

View File

@ -833,6 +833,24 @@ static LLVMValueRef gen_prefix_op_expr(CodeGen *g, AstNode *node) {
{
zig_panic("TODO codegen PrefixOpError");
}
case PrefixOpUnwrapError:
{
LLVMValueRef expr_val = gen_expr(g, expr_node);
TypeTableEntry *expr_type = get_expr_type(expr_node);
assert(expr_type->id == TypeTableEntryIdErrorUnion);
TypeTableEntry *child_type = expr_type->data.error.child_type;
// TODO in debug mode, put a panic here if the error is not 0
if (child_type->size_in_bits > 0) {
LLVMValueRef child_val_ptr = LLVMBuildStructGEP(g->builder, expr_val, 1, "");
if (handle_is_ptr(child_type)) {
return child_val_ptr;
} else {
return expr_val;
}
} else {
return nullptr;
}
}
}
zig_unreachable();
}
@ -2219,7 +2237,7 @@ static LLVMValueRef gen_const_val(CodeGen *g, TypeTableEntry *type_entry, ConstE
assert(const_val->ok);
if (const_val->undef) {
return LLVMConstNull(type_entry->type_ref);
return LLVMGetUndef(type_entry->type_ref);
}
if (type_entry->id == TypeTableEntryIdInt) {

View File

@ -64,6 +64,7 @@ static const char *prefix_op_str(PrefixOp prefix_op) {
case PrefixOpDereference: return "*";
case PrefixOpMaybe: return "?";
case PrefixOpError: return "%";
case PrefixOpUnwrapError: return "%%";
}
zig_unreachable();
}
@ -1664,6 +1665,7 @@ static PrefixOp tok_to_prefix_op(Token *token) {
case TokenIdStar: return PrefixOpDereference;
case TokenIdMaybe: return PrefixOpMaybe;
case TokenIdPercent: return PrefixOpError;
case TokenIdPercentPercent: return PrefixOpUnwrapError;
case TokenIdBoolAnd: return PrefixOpAddressOf;
default: return PrefixOpInvalid;
}

View File

@ -3,9 +3,9 @@ import "syscall.zig";
// The compiler treats this file special by implicitly importing the function `main`
// from the root source file.
var argc: isize;
var argv: &&u8;
var env: &&u8;
var argc: isize = undefined;
var argv: &&u8 = undefined;
var env: &&u8 = undefined;
#attribute("naked")
export fn _start() unreachable => {