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add zeroes value

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This commit is contained in:
Andrew Kelley 2016-08-08 20:43:38 -07:00
parent 0d5ecc4312
commit 2ed949a6ae
11 changed files with 101 additions and 16 deletions
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2
doc/langref.md
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@ -151,7 +151,7 @@ GotoExpression = "goto" Symbol
GroupedExpression = "(" Expression ")"
KeywordLiteral = "true" | "false" | "null" | "break" | "continue" | "undefined" | "error" | "type"
KeywordLiteral = "true" | "false" | "null" | "break" | "continue" | "undefined" | "zeroes" | "error" | "type"
```
## Operator Precedence

23
src/all_types.hpp
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@ -62,11 +62,18 @@ struct ConstErrValue {
ConstExprValue *payload;
};
struct ConstExprValue {
bool ok; // true if constant expression evalution worked
bool depends_on_compile_var;
bool undef;
enum ConstValSpecial {
ConstValSpecialOther,
ConstValSpecialUndef,
ConstValSpecialZeroes,
};
struct ConstExprValue {
bool ok;
bool depends_on_compile_var;
ConstValSpecial special;
// populated if val_type == ConstValTypeOk
union {
BigNum x_bignum;
bool x_bool;
@ -167,6 +174,7 @@ enum NodeType {
NodeTypeBoolLiteral,
NodeTypeNullLiteral,
NodeTypeUndefinedLiteral,
NodeTypeZeroesLiteral,
NodeTypeIfBoolExpr,
NodeTypeIfVarExpr,
NodeTypeWhileExpr,
@ -694,6 +702,12 @@ struct AstNodeUndefinedLiteral {
Expr resolved_expr;
};
struct AstNodeZeroesLiteral {
// populated by semantic analyzer
StructValExprCodeGen resolved_struct_val_expr;
Expr resolved_expr;
};
struct AstNodeSymbolExpr {
Buf *symbol;
@ -791,6 +805,7 @@ struct AstNode {
AstNodeStructValueField struct_val_field;
AstNodeNullLiteral null_literal;
AstNodeUndefinedLiteral undefined_literal;
AstNodeZeroesLiteral zeroes_literal;
AstNodeSymbolExpr symbol_expr;
AstNodeBoolLiteral bool_literal;
AstNodeBreakExpr break_expr;

25
src/analyze.cpp
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@ -90,6 +90,7 @@ static AstNode *first_executing_node(AstNode *node) {
case NodeTypeBoolLiteral:
case NodeTypeNullLiteral:
case NodeTypeUndefinedLiteral:
case NodeTypeZeroesLiteral:
case NodeTypeIfBoolExpr:
case NodeTypeIfVarExpr:
case NodeTypeLabel:
@ -1849,6 +1850,7 @@ static void resolve_top_level_decl(CodeGen *g, AstNode *node, bool pointer_only)
case NodeTypeBoolLiteral:
case NodeTypeNullLiteral:
case NodeTypeUndefinedLiteral:
case NodeTypeZeroesLiteral:
case NodeTypeSymbol:
case NodeTypePrefixOpExpr:
case NodeTypeIfBoolExpr:
@ -3937,7 +3939,19 @@ static TypeTableEntry *analyze_undefined_literal_expr(CodeGen *g, ImportTableEnt
ConstExprValue *const_val = &expr->const_val;
const_val->ok = true;
const_val->undef = true;
const_val->special = ConstValSpecialUndef;
return expected_type ? expected_type : g->builtin_types.entry_undef;
}
static TypeTableEntry *analyze_zeroes_literal_expr(CodeGen *g, ImportTableEntry *import, BlockContext *context,
TypeTableEntry *expected_type, AstNode *node)
{
Expr *expr = get_resolved_expr(node);
ConstExprValue *const_val = &expr->const_val;
const_val->ok = true;
const_val->special = ConstValSpecialZeroes;
return expected_type ? expected_type : g->builtin_types.entry_undef;
}
@ -4252,7 +4266,7 @@ static TypeTableEntry *analyze_if_bool_expr(CodeGen *g, ImportTableEntry *import
}
ConstExprValue *cond_val = &get_resolved_expr(*cond)->const_val;
if (cond_val->undef) {
if (cond_val->special == ConstValSpecialUndef) {
add_node_error(g, first_executing_node(*cond), buf_sprintf("branch on undefined value"));
return cond_type;
}
@ -6504,6 +6518,9 @@ static TypeTableEntry *analyze_expression_pointer_only(CodeGen *g, ImportTableEn
case NodeTypeUndefinedLiteral:
return_type = analyze_undefined_literal_expr(g, import, context, expected_type, node);
break;
case NodeTypeZeroesLiteral:
return_type = analyze_zeroes_literal_expr(g, import, context, expected_type, node);
break;
case NodeTypeSymbol:
return_type = analyze_symbol_expr(g, import, context, expected_type, node, pointer_only);
break;
@ -6771,6 +6788,7 @@ static void scan_decls(CodeGen *g, ImportTableEntry *import, BlockContext *conte
case NodeTypeBoolLiteral:
case NodeTypeNullLiteral:
case NodeTypeUndefinedLiteral:
case NodeTypeZeroesLiteral:
case NodeTypeSymbol:
case NodeTypePrefixOpExpr:
case NodeTypeIfBoolExpr:
@ -7029,6 +7047,8 @@ Expr *get_resolved_expr(AstNode *node) {
return &node->data.null_literal.resolved_expr;
case NodeTypeUndefinedLiteral:
return &node->data.undefined_literal.resolved_expr;
case NodeTypeZeroesLiteral:
return &node->data.zeroes_literal.resolved_expr;
case NodeTypeGoto:
return &node->data.goto_expr.resolved_expr;
case NodeTypeBreak:
@ -7111,6 +7131,7 @@ static TopLevelDecl *get_as_top_level_decl(AstNode *node) {
case NodeTypeBoolLiteral:
case NodeTypeNullLiteral:
case NodeTypeUndefinedLiteral:
case NodeTypeZeroesLiteral:
case NodeTypeLabel:
case NodeTypeGoto:
case NodeTypeBreak:

4
src/ast_render.cpp
View File

@ -171,6 +171,8 @@ static const char *node_type_str(NodeType node_type) {
return "NullLiteral";
case NodeTypeUndefinedLiteral:
return "UndefinedLiteral";
case NodeTypeZeroesLiteral:
return "ZeroesLiteral";
case NodeTypeIfBoolExpr:
return "IfBoolExpr";
case NodeTypeIfVarExpr:
@ -591,6 +593,8 @@ static void render_node(AstRender *ar, AstNode *node) {
zig_panic("TODO");
case NodeTypeUndefinedLiteral:
zig_panic("TODO");
case NodeTypeZeroesLiteral:
zig_panic("TODO");
case NodeTypeIfBoolExpr:
zig_panic("TODO");
case NodeTypeIfVarExpr:

22
src/codegen.cpp
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@ -3141,11 +3141,15 @@ static LLVMValueRef gen_var_decl_raw(CodeGen *g, AstNode *source_node, AstNodeVa
}
bool have_init_expr = false;
bool want_zeroes = false;
if (var_decl->expr) {
ConstExprValue *const_val = &get_resolved_expr(var_decl->expr)->const_val;
if (!const_val->ok || !const_val->undef) {
if (!const_val->ok || const_val->special == ConstValSpecialOther) {
have_init_expr = true;
}
if (const_val->ok && const_val->special == ConstValSpecialZeroes) {
want_zeroes = true;
}
}
if (have_init_expr) {
TypeTableEntry *expr_type = get_expr_type(var_decl->expr);
@ -3204,7 +3208,8 @@ static LLVMValueRef gen_var_decl_raw(CodeGen *g, AstNode *source_node, AstNodeVa
}
}
}
if (!ignore_uninit && want_debug_safety(g, source_node)) {
bool want_safe = want_debug_safety(g, source_node);
if (!ignore_uninit && (want_safe || want_zeroes)) {
TypeTableEntry *usize = g->builtin_types.entry_usize;
uint64_t size_bytes = LLVMStoreSizeOfType(g->target_data_ref, variable->type->type_ref);
uint64_t align_bytes = get_memcpy_align(g, variable->type);
@ -3212,7 +3217,7 @@ static LLVMValueRef gen_var_decl_raw(CodeGen *g, AstNode *source_node, AstNodeVa
// memset uninitialized memory to 0xa
set_debug_source_node(g, source_node);
LLVMTypeRef ptr_u8 = LLVMPointerType(LLVMInt8Type(), 0);
LLVMValueRef fill_char = LLVMConstInt(LLVMInt8Type(), 0xaa, false);
LLVMValueRef fill_char = LLVMConstInt(LLVMInt8Type(), want_zeroes ? 0x00 : 0xaa, false);
LLVMValueRef dest_ptr = LLVMBuildBitCast(g->builder, variable->value_ref, ptr_u8, "");
LLVMValueRef byte_count = LLVMConstInt(usize->type_ref, size_bytes, false);
LLVMValueRef align_in_bytes = LLVMConstInt(LLVMInt32Type(), align_bytes, false);
@ -3535,6 +3540,7 @@ static LLVMValueRef gen_expr(CodeGen *g, AstNode *node) {
case NodeTypeCharLiteral:
case NodeTypeNullLiteral:
case NodeTypeUndefinedLiteral:
case NodeTypeZeroesLiteral:
case NodeTypeErrorType:
case NodeTypeTypeLiteral:
case NodeTypeArrayType:
@ -3562,8 +3568,14 @@ static LLVMValueRef gen_expr(CodeGen *g, AstNode *node) {
static LLVMValueRef gen_const_val(CodeGen *g, TypeTableEntry *type_entry, ConstExprValue *const_val) {
assert(const_val->ok);
if (const_val->undef) {
return LLVMGetUndef(type_entry->type_ref);
switch (const_val->special) {
case ConstValSpecialUndef:
return LLVMGetUndef(type_entry->type_ref);
case ConstValSpecialZeroes:
return LLVMConstNull(type_entry->type_ref);
case ConstValSpecialOther:
break;
}
switch (type_entry->id) {

7
src/eval.cpp
View File

@ -545,7 +545,7 @@ void eval_const_expr_implicit_cast(CastOp cast_op,
ConstExprValue *const_val, TypeTableEntry *new_type)
{
const_val->depends_on_compile_var = other_val->depends_on_compile_var;
const_val->undef = other_val->undef;
const_val->special = other_val->special;
assert(other_val != const_val);
switch (cast_op) {
@ -572,7 +572,7 @@ void eval_const_expr_implicit_cast(CastOp cast_op,
const_val->data.x_ptr.ptr = ptr_val;
const_val->data.x_ptr.len = 1;
const_val->ok = true;
const_val->undef = other_val->undef;
const_val->special = other_val->special;
const_val->depends_on_compile_var = other_val->depends_on_compile_var;
} else {
zig_panic("TODO");
@ -608,7 +608,7 @@ void eval_const_expr_implicit_cast(CastOp cast_op,
const_val->data.x_maybe = ptr_parent;
const_val->ok = true;
const_val->undef = other_val->undef;
const_val->special = other_val->special;
const_val->depends_on_compile_var = other_val->depends_on_compile_var;
} else {
zig_panic("TODO");
@ -1277,6 +1277,7 @@ static bool eval_expr(EvalFn *ef, AstNode *node, ConstExprValue *out) {
case NodeTypeSliceExpr:
case NodeTypeNullLiteral:
case NodeTypeUndefinedLiteral:
case NodeTypeZeroesLiteral:
case NodeTypeIfVarExpr:
case NodeTypeSwitchExpr:
case NodeTypeSwitchProng:

12
src/parser.cpp
View File

@ -606,7 +606,7 @@ static AstNode *ast_parse_asm_expr(ParseContext *pc, int *token_index, bool mand
/*
PrimaryExpression = "Number" | "String" | "CharLiteral" | KeywordLiteral | GroupedExpression | GotoExpression | BlockExpression | "Symbol" | ("@" "Symbol" FnCallExpression) | ArrayType | FnProto | AsmExpression | ("error" "." "Symbol")
KeywordLiteral = "true" | "false" | "null" | "break" | "continue" | "undefined" | "error" | "type"
KeywordLiteral = "true" | "false" | "null" | "break" | "continue" | "undefined" | "zeroes" | "error" | "type"
*/
static AstNode *ast_parse_primary_expr(ParseContext *pc, int *token_index, bool mandatory) {
Token *token = &pc->tokens->at(*token_index);
@ -654,6 +654,10 @@ static AstNode *ast_parse_primary_expr(ParseContext *pc, int *token_index, bool
AstNode *node = ast_create_node(pc, NodeTypeUndefinedLiteral, token);
*token_index += 1;
return node;
} else if (token->id == TokenIdKeywordZeroes) {
AstNode *node = ast_create_node(pc, NodeTypeZeroesLiteral, token);
*token_index += 1;
return node;
} else if (token->id == TokenIdKeywordType) {
AstNode *node = ast_create_node(pc, NodeTypeTypeLiteral, token);
*token_index += 1;
@ -2539,6 +2543,9 @@ void ast_visit_node_children(AstNode *node, void (*visit)(AstNode **, void *cont
case NodeTypeUndefinedLiteral:
// none
break;
case NodeTypeZeroesLiteral:
// none
break;
case NodeTypeIfBoolExpr:
visit_field(&node->data.if_bool_expr.condition, visit, context);
visit_field(&node->data.if_bool_expr.then_block, visit, context);
@ -2813,6 +2820,9 @@ AstNode *ast_clone_subtree_special(AstNode *old_node, uint32_t *next_node_index,
case NodeTypeUndefinedLiteral:
// none
break;
case NodeTypeZeroesLiteral:
// none
break;
case NodeTypeIfBoolExpr:
clone_subtree_field(&new_node->data.if_bool_expr.condition, old_node->data.if_bool_expr.condition, next_node_index);
clone_subtree_field(&new_node->data.if_bool_expr.then_block, old_node->data.if_bool_expr.then_block, next_node_index);

2
src/tokenizer.cpp
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@ -137,6 +137,7 @@ static const struct ZigKeyword zig_keywords[] = {
{"var", TokenIdKeywordVar},
{"volatile", TokenIdKeywordVolatile},
{"while", TokenIdKeywordWhile},
{"zeroes", TokenIdKeywordZeroes},
};
bool is_zig_keyword(Buf *buf) {
@ -1467,6 +1468,7 @@ const char * token_name(TokenId id) {
case TokenIdKeywordNoAlias: return "noalias";
case TokenIdKeywordSwitch: return "switch";
case TokenIdKeywordUndefined: return "undefined";
case TokenIdKeywordZeroes: return "zeroes";
case TokenIdKeywordError: return "error";
case TokenIdKeywordType: return "type";
case TokenIdKeywordInline: return "inline";

1
src/tokenizer.hpp
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@ -40,6 +40,7 @@ enum TokenId {
TokenIdKeywordNoAlias,
TokenIdKeywordSwitch,
TokenIdKeywordUndefined,
TokenIdKeywordZeroes,
TokenIdKeywordError,
TokenIdKeywordType,
TokenIdKeywordInline,

18
test/cases/zeroes.zig Normal file
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@ -0,0 +1,18 @@
const assert = @import("std").debug.assert;
struct Foo {
a: f32,
b: i32,
c: bool,
d: ?i32,
}
#attribute("test")
fn initializing_a_struct_with_zeroes() {
const foo: Foo = zeroes;
assert(foo.a == 0.0);
assert(foo.b == 0);
assert(foo.c == false);
assert(if (const x ?= foo.d) false else true);
}

1
test/self_hosted.zig
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@ -4,6 +4,7 @@ const str = std.str;
const cstr = std.cstr;
const other = @import("other.zig");
const cases_return_type_type = @import("cases/return_type_type.zig");
const test_zeroes = @import("cases/zeroes.zig");
// normal comment
/// this is a documentation comment