From 957d77141f56714e9f4551c8d49e6658ff778ce7 Mon Sep 17 00:00:00 2001
From: David Phillips <david@sighup.nz>
Date: Wed, 1 Aug 2018 02:04:47 +1200
Subject: Add line area/span indication to error messages

---
 Makefile    |  2 +-
 common.h    |  4 ++++
 lexer.c     |  3 +++
 lexer.h     |  1 +
 parser.c    | 42 +++++++++++++++++++++++++++++++++++++++---
 parser.h    |  2 +-
 simulator.c | 19 +++++++++++++++----
 7 files changed, 64 insertions(+), 9 deletions(-)

diff --git a/Makefile b/Makefile
index bdfcc72..5ba9cc6 100644
--- a/Makefile
+++ b/Makefile
@@ -2,7 +2,7 @@ CFLAGS += -std=c99 -D_XOPEN_SOURCE=500 -D_POSIX_C_SOURCE=200809L -Wall -Wextra
 
 all: simulator
 
-simulator: simulator.o gate.o logic.o lexer.o parser.o
+simulator: simulator.o common.o gate.o logic.o lexer.o parser.o
 
 .PHONY: test
 test: all
diff --git a/common.h b/common.h
index e5c0ab4..5a6977d 100644
--- a/common.h
+++ b/common.h
@@ -1,6 +1,10 @@
 #ifndef COMMON_H
 #define COMMON_H
 
+#include <stdio.h>
+#include <stddef.h>
+
+void indicate_file_area(FILE *fd, size_t line, size_t column, size_t span);
 #define MIN(a, b) (((a) < (b)) ? (a) : (b))
 
 #endif
diff --git a/lexer.c b/lexer.c
index 40dfd67..a8b7716 100644
--- a/lexer.c
+++ b/lexer.c
@@ -138,6 +138,7 @@ lex_alphanum(void) {
 	t.value[i] = '\0';
 
 	column_number += i;
+	t.span = i;
 
 	if (i == 0) {
 		emit_error("Expected alphanumeric, got '%c'\n", buf[i]);
@@ -163,6 +164,7 @@ lex_eol(void) {
 
 	t.type = TOK_EOL;
 	t.loc = get_current_loc();
+	t.span = 1;
 
 	expect('\n');
 
@@ -175,6 +177,7 @@ lex_colon(void) {
 
 	t.type = TOK_COLON;
 	t.loc = get_current_loc();
+	t.span = 1;
 
 	expect(':');
 
diff --git a/lexer.h b/lexer.h
index 542dd2c..2e27ffa 100644
--- a/lexer.h
+++ b/lexer.h
@@ -25,6 +25,7 @@ struct token {
 	enum TOKEN_TYPE type;
 	struct location loc;
 	char value[MAX_IDENT_LENGTH];
+	size_t span;
 	struct token *next;
 };
 
diff --git a/parser.c b/parser.c
index c577105..987f26d 100644
--- a/parser.c
+++ b/parser.c
@@ -10,6 +10,7 @@
 #include "gate.h"
 
 
+static FILE* fd;
 static struct token *cursor;
 
 #ifdef emit_error
@@ -18,7 +19,8 @@ static struct token *cursor;
 #endif /* ifdef emit_error */
 
 #define emit_error(...) fprintf(stderr, "Error (%zd,%zd): ", cursor->loc.line, cursor->loc.column);\
-                        fprintf(stderr, __VA_ARGS__)
+                        fprintf(stderr, __VA_ARGS__);\
+                        indicate_file_area(fd, cursor->loc.line, cursor->loc.column, cursor->span)
 
 
 //static struct op_lookup uop_handlers[] = {
@@ -54,10 +56,44 @@ expect(enum TOKEN_TYPE e) {
 	return 0;
 }
 
+static void
+kerchunk() {
+	cursor = cursor->next;
+}
 
 int
-parse(struct token *t) {
+parse(FILE *f, struct token *t) {
+	char *token_desc = "(internal error)";
+	fd = f;
 	cursor = t;
-	expect(TOK_MODULE);
+
+	if (expect(TOK_MODULE)) {
+		return 1;
+	}
+	kerchunk();
+
+	if (expect(TOK_IDENT)) {
+		return 1;
+	}
+	emit_error("Debug: module is named %s\n", cursor->value);
+	kerchunk();
+
+	if (expect(TOK_EOL)) {
+		return 1;
+	}
+	kerchunk();
+
+	while (cursor) {
+		switch(cursor->type) {
+			case TOK_EOL:
+				kerchunk();
+				break;
+			/* FIXME implement everything */
+			default:
+				token_desc = get_token_description(cursor->type);
+				emit_error("Unexpected %s\n", token_desc);
+				return 1;
+		}
+	}
 	return 0;
 }
diff --git a/parser.h b/parser.h
index cf5c3b0..1446650 100644
--- a/parser.h
+++ b/parser.h
@@ -1 +1 @@
-int parse(struct token *);
+int parse(FILE*, struct token *);
diff --git a/simulator.c b/simulator.c
index 4f99c4f..bbea893 100644
--- a/simulator.c
+++ b/simulator.c
@@ -7,13 +7,24 @@
 #include "parser.h"
 
 int main(int argc, char **argv) {
-	(void)argc;
-	(void)argv;
+	FILE *fd = NULL;
+
+	if (argc != 2) {
+		fprintf(stderr, "Syntax: %s file.hence\n", argv[0]);
+		return 1;
+	}
 
 //	gate_init();
 
-	struct token *tok = lex_file(stdin);
-	int p = parse(tok);
+	fd = fopen(argv[1], "r");
+	
+	if (!fd) {
+		perror("fopen");
+		return 1;
+	}
+
+	struct token *tok = lex_file(fd);
+	int p = parse(fd, tok);
 
 //	gate_set_input("a", LOGIC_LOW);
 //	gate_set_input("b", LOGIC_LOW);
-- 
cgit v1.1