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add labeled loops, labeled break, labeled continue. remove goto

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closes #346
closes #630

regression: translate-c can no longer translate switch statements.
after #629 we can ressurect and modify the code to utilize arbitrarily
returning from blocks.
This commit is contained in:
Andrew Kelley
2017-12-20 22:55:24 -05:00
parent d686113bd2
commit 8bc523219c
15 changed files with 345 additions and 694 deletions
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203
src/parser.cpp
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@@ -632,27 +632,6 @@ static AstNode *ast_parse_asm_expr(ParseContext *pc, size_t *token_index, bool m
return node;
}
/*
GotoExpression = "goto" Symbol
*/
static AstNode *ast_parse_goto_expr(ParseContext *pc, size_t *token_index, bool mandatory) {
Token *goto_token = &pc->tokens->at(*token_index);
if (goto_token->id == TokenIdKeywordGoto) {
*token_index += 1;
} else if (mandatory) {
ast_expect_token(pc, goto_token, TokenIdKeywordGoto);
zig_unreachable();
} else {
return nullptr;
}
AstNode *node = ast_create_node(pc, NodeTypeGoto, goto_token);
Token *dest_symbol = ast_eat_token(pc, token_index, TokenIdSymbol);
node->data.goto_expr.name = token_buf(dest_symbol);
return node;
}
/*
CompTimeExpression(body) = "comptime" body
*/
@@ -676,8 +655,8 @@ static AstNode *ast_parse_comptime_expr(ParseContext *pc, size_t *token_index, b
}
/*
PrimaryExpression = Integer | Float | String | CharLiteral | KeywordLiteral | GroupedExpression | GotoExpression | BlockExpression(BlockOrExpression) | Symbol | ("@" Symbol FnCallExpression) | ArrayType | FnProto | AsmExpression | ("error" "." Symbol) | ContainerDecl
KeywordLiteral = "true" | "false" | "null" | "continue" | "undefined" | "error" | "this" | "unreachable"
PrimaryExpression = Integer | Float | String | CharLiteral | KeywordLiteral | GroupedExpression | BlockExpression(BlockOrExpression) | Symbol | ("@" Symbol FnCallExpression) | ArrayType | FnProto | AsmExpression | ("error" "." Symbol) | ContainerDecl | ("continue" option(":" Symbol))
KeywordLiteral = "true" | "false" | "null" | "undefined" | "error" | "this" | "unreachable"
*/
static AstNode *ast_parse_primary_expr(ParseContext *pc, size_t *token_index, bool mandatory) {
Token *token = &pc->tokens->at(*token_index);
@@ -721,6 +700,12 @@ static AstNode *ast_parse_primary_expr(ParseContext *pc, size_t *token_index, bo
} else if (token->id == TokenIdKeywordContinue) {
AstNode *node = ast_create_node(pc, NodeTypeContinue, token);
*token_index += 1;
Token *maybe_colon_token = &pc->tokens->at(*token_index);
if (maybe_colon_token->id == TokenIdColon) {
*token_index += 1;
Token *name = ast_eat_token(pc, token_index, TokenIdSymbol);
node->data.continue_expr.name = token_buf(name);
}
return node;
} else if (token->id == TokenIdKeywordUndefined) {
AstNode *node = ast_create_node(pc, NodeTypeUndefinedLiteral, token);
@@ -770,10 +755,6 @@ static AstNode *ast_parse_primary_expr(ParseContext *pc, size_t *token_index, bo
return node;
}
AstNode *goto_node = ast_parse_goto_expr(pc, token_index, false);
if (goto_node)
return goto_node;
AstNode *grouped_expr_node = ast_parse_grouped_expr(pc, token_index, false);
if (grouped_expr_node) {
return grouped_expr_node;
@@ -1488,7 +1469,7 @@ static AstNode *ast_parse_return_expr(ParseContext *pc, size_t *token_index) {
}
/*
BreakExpression : "break" option(Expression)
BreakExpression = "break" option(":" Symbol) option(Expression)
*/
static AstNode *ast_parse_break_expr(ParseContext *pc, size_t *token_index) {
Token *token = &pc->tokens->at(*token_index);
@@ -1498,8 +1479,15 @@ static AstNode *ast_parse_break_expr(ParseContext *pc, size_t *token_index) {
} else {
return nullptr;
}
AstNode *node = ast_create_node(pc, NodeTypeBreak, token);
Token *maybe_colon_token = &pc->tokens->at(*token_index);
if (maybe_colon_token->id == TokenIdColon) {
*token_index += 1;
Token *name = ast_eat_token(pc, token_index, TokenIdSymbol);
node->data.break_expr.name = token_buf(name);
}
node->data.break_expr.expr = ast_parse_expression(pc, token_index, false);
return node;
@@ -1678,35 +1666,53 @@ static AstNode *ast_parse_bool_or_expr(ParseContext *pc, size_t *token_index, bo
}
/*
WhileExpression(body) = option("inline") "while" "(" Expression ")" option("|" option("*") Symbol "|") option(":" "(" Expression ")") body option("else" option("|" Symbol "|") BlockExpression(body))
WhileExpression(body) = option(Symbol ":") option("inline") "while" "(" Expression ")" option("|" option("*") Symbol "|") option(":" "(" Expression ")") body option("else" option("|" Symbol "|") BlockExpression(body))
*/
static AstNode *ast_parse_while_expr(ParseContext *pc, size_t *token_index, bool mandatory) {
Token *first_token = &pc->tokens->at(*token_index);
Token *while_token;
size_t orig_token_index = *token_index;
bool is_inline;
if (first_token->id == TokenIdKeywordInline) {
while_token = &pc->tokens->at(*token_index + 1);
if (while_token->id == TokenIdKeywordWhile) {
is_inline = true;
*token_index += 2;
Token *name_token = nullptr;
Token *token = &pc->tokens->at(*token_index);
if (token->id == TokenIdSymbol) {
*token_index += 1;
Token *colon_token = &pc->tokens->at(*token_index);
if (colon_token->id == TokenIdColon) {
*token_index += 1;
name_token = token;
token = &pc->tokens->at(*token_index);
} else if (mandatory) {
ast_expect_token(pc, while_token, TokenIdKeywordWhile);
ast_expect_token(pc, colon_token, TokenIdColon);
zig_unreachable();
} else {
*token_index = orig_token_index;
return nullptr;
}
} else if (first_token->id == TokenIdKeywordWhile) {
while_token = first_token;
is_inline = false;
}
bool is_inline = false;
if (token->id == TokenIdKeywordInline) {
is_inline = true;
*token_index += 1;
token = &pc->tokens->at(*token_index);
}
Token *while_token;
if (token->id == TokenIdKeywordWhile) {
while_token = token;
*token_index += 1;
} else if (mandatory) {
ast_expect_token(pc, first_token, TokenIdKeywordWhile);
ast_expect_token(pc, token, TokenIdKeywordWhile);
zig_unreachable();
} else {
*token_index = orig_token_index;
return nullptr;
}
AstNode *node = ast_create_node(pc, NodeTypeWhileExpr, while_token);
if (name_token != nullptr) {
node->data.while_expr.name = token_buf(name_token);
}
node->data.while_expr.is_inline = is_inline;
ast_eat_token(pc, token_index, TokenIdLParen);
@@ -1766,36 +1772,53 @@ static AstNode *ast_parse_symbol(ParseContext *pc, size_t *token_index) {
}
/*
ForExpression(body) = option("inline") "for" "(" Expression ")" option("|" option("*") Symbol option("," Symbol) "|") body option("else" BlockExpression(body))
ForExpression(body) = option(Symbol ":") option("inline") "for" "(" Expression ")" option("|" option("*") Symbol option("," Symbol) "|") body option("else" BlockExpression(body))
*/
static AstNode *ast_parse_for_expr(ParseContext *pc, size_t *token_index, bool mandatory) {
Token *first_token = &pc->tokens->at(*token_index);
Token *for_token;
size_t orig_token_index = *token_index;
bool is_inline;
if (first_token->id == TokenIdKeywordInline) {
is_inline = true;
for_token = &pc->tokens->at(*token_index + 1);
if (for_token->id == TokenIdKeywordFor) {
*token_index += 2;
Token *name_token = nullptr;
Token *token = &pc->tokens->at(*token_index);
if (token->id == TokenIdSymbol) {
*token_index += 1;
Token *colon_token = &pc->tokens->at(*token_index);
if (colon_token->id == TokenIdColon) {
*token_index += 1;
name_token = token;
token = &pc->tokens->at(*token_index);
} else if (mandatory) {
ast_expect_token(pc, first_token, TokenIdKeywordFor);
ast_expect_token(pc, colon_token, TokenIdColon);
zig_unreachable();
} else {
*token_index = orig_token_index;
return nullptr;
}
} else if (first_token->id == TokenIdKeywordFor) {
for_token = first_token;
is_inline = false;
}
bool is_inline = false;
if (token->id == TokenIdKeywordInline) {
is_inline = true;
*token_index += 1;
token = &pc->tokens->at(*token_index);
}
Token *for_token;
if (token->id == TokenIdKeywordFor) {
for_token = token;
*token_index += 1;
} else if (mandatory) {
ast_expect_token(pc, first_token, TokenIdKeywordFor);
ast_expect_token(pc, token, TokenIdKeywordFor);
zig_unreachable();
} else {
*token_index = orig_token_index;
return nullptr;
}
AstNode *node = ast_create_node(pc, NodeTypeForExpr, for_token);
if (name_token != nullptr) {
node->data.for_expr.name = token_buf(name_token);
}
node->data.for_expr.is_inline = is_inline;
ast_eat_token(pc, token_index, TokenIdLParen);
@@ -2125,32 +2148,6 @@ static AstNode *ast_parse_expression(ParseContext *pc, size_t *token_index, bool
/*
Label: token(Symbol) token(Colon)
*/
static AstNode *ast_parse_label(ParseContext *pc, size_t *token_index, bool mandatory) {
Token *symbol_token = &pc->tokens->at(*token_index);
if (symbol_token->id != TokenIdSymbol) {
if (mandatory) {
ast_expect_token(pc, symbol_token, TokenIdSymbol);
} else {
return nullptr;
}
}
Token *colon_token = &pc->tokens->at(*token_index + 1);
if (colon_token->id != TokenIdColon) {
if (mandatory) {
ast_expect_token(pc, colon_token, TokenIdColon);
} else {
return nullptr;
}
}
*token_index += 2;
AstNode *node = ast_create_node(pc, NodeTypeLabel, symbol_token);
node->data.label.name = token_buf(symbol_token);
return node;
}
static bool statement_terminates_without_semicolon(AstNode *node) {
switch (node->type) {
case NodeTypeIfBoolExpr:
@@ -2175,7 +2172,6 @@ static bool statement_terminates_without_semicolon(AstNode *node) {
return node->data.defer.expr->type == NodeTypeBlock;
case NodeTypeSwitchExpr:
case NodeTypeBlock:
case NodeTypeLabel:
return true;
default:
return false;
@@ -2183,27 +2179,48 @@ static bool statement_terminates_without_semicolon(AstNode *node) {
}
/*
Block = "{" many(Statement) option(Expression) "}"
Block = option(Symbol ":") "{" many(Statement) option(Expression) "}"
Statement = Label | VariableDeclaration ";" | Defer(Block) | Defer(Expression) ";" | BlockExpression(Block) | Expression ";" | ";" | ExportDecl
*/
static AstNode *ast_parse_block(ParseContext *pc, size_t *token_index, bool mandatory) {
size_t orig_token_index = *token_index;
Token *name_token = nullptr;
Token *last_token = &pc->tokens->at(*token_index);
if (last_token->id == TokenIdSymbol) {
*token_index += 1;
Token *colon_token = &pc->tokens->at(*token_index);
if (colon_token->id == TokenIdColon) {
*token_index += 1;
name_token = last_token;
last_token = &pc->tokens->at(*token_index);
} else if (mandatory) {
ast_expect_token(pc, colon_token, TokenIdColon);
zig_unreachable();
} else {
*token_index = orig_token_index;
return nullptr;
}
}
if (last_token->id != TokenIdLBrace) {
if (mandatory) {
ast_expect_token(pc, last_token, TokenIdLBrace);
} else {
*token_index = orig_token_index;
return nullptr;
}
}
*token_index += 1;
AstNode *node = ast_create_node(pc, NodeTypeBlock, last_token);
if (name_token != nullptr) {
node->data.block.name = token_buf(name_token);
}
for (;;) {
AstNode *statement_node = ast_parse_label(pc, token_index, false);
if (!statement_node)
statement_node = ast_parse_local_var_decl(pc, token_index);
AstNode *statement_node = ast_parse_local_var_decl(pc, token_index);
if (!statement_node)
statement_node = ast_parse_defer_expr(pc, token_index);
if (!statement_node)
@@ -2225,9 +2242,7 @@ static AstNode *ast_parse_block(ParseContext *pc, size_t *token_index, bool mand
}
}
node->data.block.last_statement_is_result_expression = statement_node && !(
statement_node->type == NodeTypeLabel ||
statement_node->type == NodeTypeDefer);
node->data.block.last_statement_is_result_expression = statement_node && statement_node->type != NodeTypeDefer;
last_token = &pc->tokens->at(*token_index);
if (last_token->id == TokenIdRBrace) {
@@ -2860,12 +2875,6 @@ void ast_visit_node_children(AstNode *node, void (*visit)(AstNode **, void *cont
visit_field(&node->data.switch_range.start, visit, context);
visit_field(&node->data.switch_range.end, visit, context);
break;
case NodeTypeLabel:
// none
break;
case NodeTypeGoto:
// none
break;
case NodeTypeCompTime:
visit_field(&node->data.comptime_expr.expr, visit, context);
break;