harec

commit 05d4c2825e41ad0c7113aa8c39032e4d9d6aa975
parent 725964bae88bcea1307f627f50682fc537af72bb
Author: Drew DeVault <sir@cmpwn.com>
Date:   Tue, 23 Feb 2021 08:50:41 -0500

parse: implement error propagation

Diffstat:
M
include/ast.h
 | 
5
+++++
M
include/expr.h
 | 
1
+
M
include/lex.h
 | 
1
+
M
src/check.c
 | 
2
++
M
src/eval.c
 | 
1
+
M
src/gen.c
 | 
2
++
M
src/lex.c
 | 
4
++++
M
src/main.c
 | 
2
--
M
src/parse.c
 | 
10
++++++++--

9 files changed, 24 insertions(+), 4 deletions(-)
diff --git a/include/ast.h b/include/ast.h
@@ -265,6 +265,10 @@ struct ast_expression_measure {
 	};
 };
 
+struct ast_expression_propagate {
+	struct ast_expression *value;
+};
+
 struct ast_expression_return {
 	struct ast_expression *value;
 };
@@ -344,6 +348,7 @@ struct ast_expression {
 		struct ast_expression_list list;
 		struct ast_expression_match match;
 		struct ast_expression_measure measure;
+		struct ast_expression_propagate propagate;
 		struct ast_expression_return _return;
 		struct ast_expression_slice slice;
 		struct ast_expression_struct _struct;
diff --git a/include/expr.h b/include/expr.h
@@ -28,6 +28,7 @@ enum expr_type {
 	EXPR_LIST,
 	EXPR_MATCH,
 	EXPR_MEASURE,
+	EXPR_PROPAGATE,
 	EXPR_RETURN,
 	EXPR_SLICE,
 	EXPR_STRUCT,
diff --git a/include/lex.h b/include/lex.h
@@ -106,6 +106,7 @@ enum lexical_token {
 	T_PLUS,
 	T_PLUSEQ,
 	T_PLUSPLUS,
+	T_QUESTION,
 	T_RBRACE,
 	T_RBRACKET,
 	T_RPAREN,
diff --git a/src/check.c b/src/check.c
@@ -2042,6 +2042,8 @@ check_expression(struct context *ctx,
 	case EXPR_MEASURE:
 		check_expr_measure(ctx, aexpr, expr, hint);
 		break;
+	case EXPR_PROPAGATE:
+		assert(0); // TODO
 	case EXPR_RETURN:
 		check_expr_return(ctx, aexpr, expr, hint);
 		break;
diff --git a/src/eval.c b/src/eval.c
@@ -545,6 +545,7 @@ eval_expr(struct context *ctx, struct expression *in, struct expression *out)
 	case EXPR_IF:
 	case EXPR_LIST:
 	case EXPR_MATCH:
+	case EXPR_PROPAGATE:
 	case EXPR_RETURN:
 	case EXPR_SWITCH:
 		// Excluded from translation-compatible subset
diff --git a/src/gen.c b/src/gen.c
@@ -2570,6 +2570,8 @@ gen_expression(struct gen_context *ctx,
 	case EXPR_MEASURE:
 		gen_expr_measure(ctx, expr, out);
 		break;
+	case EXPR_PROPAGATE:
+		assert(0); // TODO
 	case EXPR_RETURN:
 		gen_expr_return(ctx, expr, out);
 		break;
diff --git a/src/lex.c b/src/lex.c
@@ -114,6 +114,7 @@ static const char *tokens[] = {
 	[T_PLUS] = "+",
 	[T_PLUSEQ] = "+=",
 	[T_PLUSPLUS] = "++",
+	[T_QUESTION] = "?",
 	[T_RBRACE] = "}",
 	[T_RBRACKET] = "]",
 	[T_RPAREN] = ")",
@@ -897,6 +898,9 @@ _lex(struct lexer *lexer, struct token *out)
 	case ';':
 		out->token = T_SEMICOLON;
 		break;
+	case '?':
+		out->token = T_QUESTION;
+		break;
 	default:
 		out->token = T_ERROR;
 		break;
diff --git a/src/main.c b/src/main.c
@@ -6,7 +6,6 @@
 #include <unistd.h>
 #include "ast.h"
 #include "check.h"
-#include "dump.h"
 #include "emit.h"
 #include "gen.h"
 #include "lex.h"
@@ -140,7 +139,6 @@ main(int argc, char *argv[])
 	builtin_types_init();
 	check(&ts, tags, &aunit, &unit);
 	if (stage == STAGE_CHECK) {
-		dump_unit(&unit);
 		return 0;
 	}
 
diff --git a/src/parse.c b/src/parse.c
@@ -1386,6 +1386,7 @@ parse_postfix_expression(struct lexer *lexer, struct ast_expression *lvalue)
 		lvalue = parse_plain_expression(lexer);
 	}
 
+	struct ast_expression *exp;
 	switch (lex(lexer, &tok)) {
 	case T_LPAREN:
 		unlex(lexer, &tok);
@@ -1393,8 +1394,7 @@ parse_postfix_expression(struct lexer *lexer, struct ast_expression *lvalue)
 		break;
 	case T_DOT:
 		trenter(TR_PARSE, "field-access");
-		struct ast_expression *exp =
-			mkexpr(&lexer->loc);
+		exp = mkexpr(&lexer->loc);
 		exp->type = EXPR_ACCESS;
 
 		switch (lex(lexer, &tok)) {
@@ -1420,6 +1420,12 @@ parse_postfix_expression(struct lexer *lexer, struct ast_expression *lvalue)
 		unlex(lexer, &tok);
 		lvalue = parse_index_slice_expression(lexer, lvalue);
 		break;
+	case T_QUESTION:
+		exp = mkexpr(&lexer->loc);
+		exp->type = EXPR_PROPAGATE;
+		exp->propagate.value = lvalue;
+		lvalue = exp;
+		break;
 	default:
 		unlex(lexer, &tok);
 		return lvalue;