Commit 356424916c
Changed files (4)
src/all_types.hpp
@@ -410,10 +410,8 @@ struct AstNodeParamDecl {
};
struct AstNodeBlock {
- // the final statement is the returned expression.
- // if there are no statements, the returned expression is void.
- // the final statement is never a label.
ZigList<AstNode *> statements;
+ bool last_statement_is_result_expression;
};
enum ReturnKind {
src/ast_render.cpp
@@ -464,8 +464,10 @@ static void render_node_extra(AstRender *ar, AstNode *node, bool grouped) {
}
print_indent(ar);
render_node_grouped(ar, statement);
- if (i != node->data.block.statements.length - 1)
+ if (!(i == node->data.block.statements.length - 1 &&
+ node->data.block.last_statement_is_result_expression)) {
fprintf(ar->f, ";");
+ }
fprintf(ar->f, "\n");
}
ar->indent -= ar->indent_size;
src/ir.cpp
@@ -3378,6 +3378,7 @@ static IrInstruction *ir_gen_block(IrBuilder *irb, Scope *parent_scope, AstNode
// a label is an entry point
is_continuation_unreachable = false;
+ return_value = nullptr;
continue;
}
@@ -3406,7 +3407,8 @@ static IrInstruction *ir_gen_block(IrBuilder *irb, Scope *parent_scope, AstNode
child_scope = decl_var_instruction->var->child_scope;
} else {
// label, defer, variable declaration will never be the last statement
- if (i == block_node->data.block.statements.length - 1) {
+ if (block_node->data.block.last_statement_is_result_expression &&
+ i == block_node->data.block.statements.length - 1) {
// this is the result value statement
return_value = statement_value;
} else {
@@ -3422,13 +3424,18 @@ static IrInstruction *ir_gen_block(IrBuilder *irb, Scope *parent_scope, AstNode
}
}
- assert(return_value != nullptr);
-
if (!is_continuation_unreachable) {
// control flow falls out of block
+
+ if (!block_node->data.block.last_statement_is_result_expression) {
+ assert(return_value == nullptr);
+ 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);
}
+ assert(return_value != nullptr);
return return_value;
}
src/parser.cpp
@@ -1882,36 +1882,6 @@ static AstNode *ast_parse_switch_expr(ParseContext *pc, size_t *token_index, boo
}
}
-static bool statement_has_block_body(AstNode *node) {
- switch (node->type) {
- case NodeTypeIfBoolExpr:
- if (node->data.if_bool_expr.else_node)
- return statement_has_block_body(node->data.if_bool_expr.else_node);
- return node->data.if_bool_expr.then_block->type == NodeTypeBlock;
- case NodeTypeIfVarExpr:
- if (node->data.if_var_expr.else_node)
- return statement_has_block_body(node->data.if_var_expr.else_node);
- return node->data.if_var_expr.then_block->type == NodeTypeBlock;
- case NodeTypeTryExpr:
- if (node->data.try_expr.else_node)
- return statement_has_block_body(node->data.try_expr.else_node);
- return node->data.try_expr.then_node->type == NodeTypeBlock;
- case NodeTypeWhileExpr:
- return node->data.while_expr.body->type == NodeTypeBlock;
- case NodeTypeForExpr:
- return node->data.for_expr.body->type == NodeTypeBlock;
- case NodeTypeSwitchExpr:
- case NodeTypeBlock:
- return true;
- case NodeTypeCompTime:
- return node->data.comptime_expr.expr->type == NodeTypeBlock;
- case NodeTypeDefer:
- return node->data.defer.expr->type == NodeTypeBlock;
- default:
- return false;
- }
-}
-
/*
BlockExpression(body) = Block | IfExpression(body) | TryExpression(body) | WhileExpression(body) | ForExpression(body) | SwitchExpression | CompTimeExpression(body)
*/
@@ -2124,9 +2094,35 @@ static AstNode *ast_parse_label(ParseContext *pc, size_t *token_index, bool mand
return node;
}
-static AstNode *ast_create_void_expr(ParseContext *pc, Token *token) {
- AstNode *node = ast_create_node(pc, NodeTypeBlock, token);
- return node;
+static bool statement_terminates_without_semicolon(AstNode *node) {
+ switch (node->type) {
+ case NodeTypeIfBoolExpr:
+ if (node->data.if_bool_expr.else_node)
+ return statement_terminates_without_semicolon(node->data.if_bool_expr.else_node);
+ return node->data.if_bool_expr.then_block->type == NodeTypeBlock;
+ case NodeTypeIfVarExpr:
+ if (node->data.if_var_expr.else_node)
+ return statement_terminates_without_semicolon(node->data.if_var_expr.else_node);
+ return node->data.if_var_expr.then_block->type == NodeTypeBlock;
+ case NodeTypeTryExpr:
+ if (node->data.try_expr.else_node)
+ return statement_terminates_without_semicolon(node->data.try_expr.else_node);
+ return node->data.try_expr.then_node->type == NodeTypeBlock;
+ case NodeTypeWhileExpr:
+ return node->data.while_expr.body->type == NodeTypeBlock;
+ case NodeTypeForExpr:
+ return node->data.for_expr.body->type == NodeTypeBlock;
+ case NodeTypeCompTime:
+ return node->data.comptime_expr.expr->type == NodeTypeBlock;
+ case NodeTypeDefer:
+ return node->data.defer.expr->type == NodeTypeBlock;
+ case NodeTypeSwitchExpr:
+ case NodeTypeBlock:
+ case NodeTypeLabel:
+ return true;
+ default:
+ return false;
+ }
}
/*
@@ -2149,56 +2145,36 @@ static AstNode *ast_parse_block(ParseContext *pc, size_t *token_index, bool mand
for (;;) {
AstNode *statement_node = ast_parse_label(pc, token_index, false);
- bool need_implicit_final_void_statement = false;
+ if (!statement_node)
+ statement_node = ast_parse_variable_declaration_expr(pc, token_index, false, VisibModPrivate);
+ if (!statement_node)
+ statement_node = ast_parse_defer_expr(pc, token_index);
+ if (!statement_node)
+ statement_node = ast_parse_block_expr(pc, token_index, false);
+ if (!statement_node)
+ statement_node = ast_parse_expression(pc, token_index, false);
+
bool semicolon_expected = true;
if (statement_node) {
- // label
- semicolon_expected = false;
- // if a label is the last thing in a block, add a void statement.
- need_implicit_final_void_statement = true;
- } else {
- statement_node = ast_parse_variable_declaration_expr(pc, token_index, false, VisibModPrivate);
- if (!statement_node) {
- statement_node = ast_parse_defer_expr(pc, token_index);
- if (statement_node) {
- // defer
- if (statement_has_block_body(statement_node)) {
- // don't let defer be the last statement in a block
- need_implicit_final_void_statement = true;
- semicolon_expected = false;
- } else {
- // defer without a block body requires a semicolon
- Token *token = &pc->tokens->at(*token_index);
- ast_expect_token(pc, token, TokenIdSemicolon);
- }
- } else {
- statement_node = ast_parse_block_expr(pc, token_index, false);
- if (statement_node) {
- // block expr
- if (statement_has_block_body(statement_node))
- semicolon_expected = false;
- } else {
- statement_node = ast_parse_expression(pc, token_index, false);
- if (!statement_node) {
- // no statement.
- // final semicolon means add a void statement.
- need_implicit_final_void_statement = true;
- }
- }
+ node->data.block.statements.append(statement_node);
+ if (statement_terminates_without_semicolon(statement_node)) {
+ semicolon_expected = false;
+ } else {
+ if (statement_node->type == NodeTypeDefer) {
+ // defer without a block body requires a semicolon
+ Token *token = &pc->tokens->at(*token_index);
+ ast_expect_token(pc, token, TokenIdSemicolon);
}
}
}
- if (statement_node)
- node->data.block.statements.append(statement_node);
+
+ node->data.block.last_statement_is_result_expression = statement_node && !(
+ statement_node->type == NodeTypeLabel ||
+ statement_node->type == NodeTypeDefer);
last_token = &pc->tokens->at(*token_index);
if (last_token->id == TokenIdRBrace) {
*token_index += 1;
-
- if (node->data.block.statements.length > 0 && need_implicit_final_void_statement) {
- node->data.block.statements.append(ast_create_void_expr(pc, last_token));
- }
-
return node;
} else if (!semicolon_expected) {
continue;