diff options
Diffstat (limited to 'src/parser')
| -rw-r--r-- | src/parser/ast.c | 8 | ||||
| -rw-r--r-- | src/parser/ast.h | 4 | ||||
| -rw-r--r-- | src/parser/parser.c | 81 |
3 files changed, 88 insertions, 5 deletions
diff --git a/src/parser/ast.c b/src/parser/ast.c index a387533..9c78d1f 100644 --- a/src/parser/ast.c +++ b/src/parser/ast.c @@ -26,7 +26,7 @@ void free_expr(struct Expr* expr) free(expr); } -static void free_statement(struct Statement* statement) +void free_statement(struct Statement* statement) { switch (statement->kind) { @@ -36,8 +36,12 @@ static void free_statement(struct Statement* statement) case STATEMENT_IF: free_expr(statement->branch.left); free_expr(statement->branch.right); - free_statement(statement->branch.body); + for (size_t i = 0; i < statement->branch.body_count; i += 1) + free_statement(&statement->branch.body[i]); free(statement->branch.body); + for (size_t i = 0; i < statement->branch.else_count; i += 1) + free_statement(&statement->branch.else_body[i]); + free(statement->branch.else_body); break; case STATEMENT_CALL: for (size_t i = 0; i < statement->call.arg_count; i += 1) diff --git a/src/parser/ast.h b/src/parser/ast.h index c439747..75d0bdd 100644 --- a/src/parser/ast.h +++ b/src/parser/ast.h @@ -135,6 +135,9 @@ struct IfStatement struct Token comparison; struct Expr* right; struct Statement* body; + size_t body_count; + struct Statement* else_body; + size_t else_count; }; struct CallStatement @@ -230,3 +233,4 @@ void add_statement(struct ProcDecl* proc, struct Statement statement); void add_proc(struct Program* program, struct ProcDecl decl); void free_expr(struct Expr* expr); +void free_statement(struct Statement* statement); diff --git a/src/parser/parser.c b/src/parser/parser.c index a83c3c4..ebf07c7 100644 --- a/src/parser/parser.c +++ b/src/parser/parser.c @@ -215,7 +215,7 @@ static bool is_assign_op(enum TokenType type) static struct Expr* alloc_expr(enum ExprKind kind) { - struct Expr* expr = malloc(sizeof(struct Expr)); + struct Expr* expr = malloc(sizeof(*expr)); if (expr != NULL) expr->kind = kind; return expr; @@ -390,6 +390,66 @@ error: static bool parse_statement(struct Parser* parser, struct Statement* out); +// A branch body is either a braced block or a single bare statement, always +// returned as a list so codegen and freeing treat both the same way. +static bool parse_block(struct Parser* parser, struct Statement** out_body, size_t* out_count) +{ + if (!match_token(parser, TOKEN_LEFT_BRACE)) + { + struct Statement* body = malloc(sizeof(*body)); + if (body == NULL) + return false; + + if (!parse_statement(parser, body)) + { + free(body); + return false; + } + + *out_body = body; + *out_count = 1; + return true; + } + + struct Statement* body = NULL; + size_t count = 0; + size_t capacity = 0; + + while (!check(parser, TOKEN_RIGHT_BRACE)) + { + if (check(parser, TOKEN_EOF)) + { + error_at(parser, parser->current, "unterminated block"); + goto error; + } + + if (count == capacity) + { + size_t grown_capacity = capacity == 0 ? 4 : capacity * 2; + struct Statement* grown = realloc(body, grown_capacity * sizeof(*grown)); + if (grown == NULL) + goto error; + body = grown; + capacity = grown_capacity; + } + + if (!parse_statement(parser, &body[count])) + goto error; + count += 1; + } + advance_parser(parser); + + *out_body = body; + *out_count = count; + return true; + +error: + for (size_t i = 0; i < count; i += 1) + free_statement(&body[i]); + free(body); + return false; +} + static bool parse_if(struct Parser* parser, struct Statement* out) { struct Expr* left = parse_expression(parser); @@ -412,9 +472,21 @@ static bool parse_if(struct Parser* parser, struct Statement* out) return false; } - struct Statement* body = malloc(sizeof(struct Statement)); - if (!parse_statement(parser, body)) + struct Statement* body; + size_t body_count; + if (!parse_block(parser, &body, &body_count)) + { + free_expr(left); + free_expr(right); + return false; + } + + struct Statement* else_body = NULL; + size_t else_count = 0; + if (match_token(parser, TOKEN_ELSE) && !parse_block(parser, &else_body, &else_count)) { + for (size_t i = 0; i < body_count; i += 1) + free_statement(&body[i]); free(body); free_expr(left); free_expr(right); @@ -426,6 +498,9 @@ static bool parse_if(struct Parser* parser, struct Statement* out) out->branch.comparison = comparison; out->branch.right = right; out->branch.body = body; + out->branch.body_count = body_count; + out->branch.else_body = else_body; + out->branch.else_count = else_count; return true; } |
