error: improved error reporting for parsers

it will now report the line and the approximate position of the error.

4 files changed, 117 insertions, 38 deletions

diff --git a/src/error.c b/src/error.c
index ad4e3f4..d3d045d 100644
--- a/src/error.c
+++ b/src/error.c
@@ -50,26 +50,54 @@ blogc_error_parser(blogc_error_type_t type, const char *src, size_t src_len,
     char *msg = b_strdup_vprintf(format, ap);
     va_end(ap);
 
-    b_string_t *str = b_string_new();
-    while (current < src_len) {
-        char c = src[current];
-
-        if (c == '\r' || c == '\n')
+    size_t lineno = 1;
+    size_t linestart = 0;
+    size_t lineend = 0;
+    size_t pos = 1;
+
+    for (size_t i = 0; i < src_len; i++) {
+        char c = src[i];
+        if (i < current) {
+            if ((i + 1) < src_len) {
+                if ((c == '\n' && src[i + 1] == '\r') ||
+                    (c == '\r' && src[i + 1] == '\n'))
+                {
+                    lineno++;
+                    pos = 1;
+                    c = src[++i];
+                    if ((i + 1) < src_len)
+                        linestart = i + 1;
+                    continue;
+                }
+            }
+            if (c == '\n' || c == '\r') {
+                lineno++;
+                pos = 1;
+                if ((i + 1) < src_len)
+                    linestart = i + 1;
+                continue;
+            }
+            pos++;
+        }
+        else if (c == '\n' || c == '\r') {
+            lineend = i;
             break;
+        }
+    }
 
-        b_string_append_c(str, c);
+    if (lineend <= linestart && src_len >= linestart)
+        lineend = src_len;
 
-        current++;
-    }
-    char *line = b_string_free(str, false);
+    char *line = b_strndup(src + linestart, lineend - linestart);
 
     blogc_error_t *rv = NULL;
 
-    if (strlen(line) == 0)  // "near to" message isn't useful if line is empty
+    if (line[0] == '\0')  // "near" message isn't useful if line is empty
         rv = blogc_error_new(type, msg);
     else
         rv = blogc_error_new_printf(type,
-            "%s\nError occurred near to '%s'", msg, line);
+            "%s\nError occurred near line %d, position %d: %s", msg, lineno,
+            pos, line);
 
     free(msg);
     free(line);
diff --git a/tests/check_error.c b/tests/check_error.c
index 68f287a..17e1c40 100644
--- a/tests/check_error.c
+++ b/tests/check_error.c
@@ -48,7 +48,28 @@ test_error_parser(void **state)
     blogc_error_t *error = blogc_error_parser(1, a, strlen(a), 11, "asd %d", 10);
     assert_non_null(error);
     assert_int_equal(error->type, 1);
-    assert_string_equal(error->msg, "asd 10\nError occurred near to 'hunda'");
+    assert_string_equal(error->msg,
+        "asd 10\nError occurred near line 3, position 2: chunda");
+    blogc_error_free(error);
+    a = "bola\nguda\nchunda";
+    error = blogc_error_parser(1, a, strlen(a), 11, "asd %d", 10);
+    assert_non_null(error);
+    assert_int_equal(error->type, 1);
+    assert_string_equal(error->msg,
+        "asd 10\nError occurred near line 3, position 2: chunda");
+    blogc_error_free(error);
+    a = "bola\nguda\nchunda";
+    error = blogc_error_parser(1, a, strlen(a), 0, "asd %d", 10);
+    assert_non_null(error);
+    assert_int_equal(error->type, 1);
+    assert_string_equal(error->msg,
+        "asd 10\nError occurred near line 1, position 1: bola");
+    blogc_error_free(error);
+    a = "";
+    error = blogc_error_parser(1, a, strlen(a), 0, "asd %d", 10);
+    assert_non_null(error);
+    assert_int_equal(error->type, 1);
+    assert_string_equal(error->msg, "asd 10");
     blogc_error_free(error);
 }
 
@@ -60,7 +81,22 @@ test_error_parser_crlf(void **state)
     blogc_error_t *error = blogc_error_parser(1, a, strlen(a), 13, "asd %d", 10);
     assert_non_null(error);
     assert_int_equal(error->type, 1);
-    assert_string_equal(error->msg, "asd 10\nError occurred near to 'hunda'");
+    assert_string_equal(error->msg,
+        "asd 10\nError occurred near line 3, position 2: chunda");
+    blogc_error_free(error);
+    a = "bola\r\nguda\r\nchunda";
+    error = blogc_error_parser(1, a, strlen(a), 13, "asd %d", 10);
+    assert_non_null(error);
+    assert_int_equal(error->type, 1);
+    assert_string_equal(error->msg,
+        "asd 10\nError occurred near line 3, position 2: chunda");
+    blogc_error_free(error);
+    a = "bola\r\nguda\r\nchunda";
+    error = blogc_error_parser(1, a, strlen(a), 0, "asd %d", 10);
+    assert_non_null(error);
+    assert_int_equal(error->type, 1);
+    assert_string_equal(error->msg,
+        "asd 10\nError occurred near line 1, position 1: bola");
     blogc_error_free(error);
 }
 
diff --git a/tests/check_source_parser.c b/tests/check_source_parser.c
index 810786b..4d8518e 100644
--- a/tests/check_source_parser.c
+++ b/tests/check_source_parser.c
@@ -183,7 +183,7 @@ test_source_parse_config_invalid_key(void **state)
     assert_int_equal(err->type, BLOGC_ERROR_SOURCE_PARSER);
     assert_string_equal(err->msg,
         "Can't find a configuration key or the content separator.\n"
-        "Error occurred near to 'bola: guda'");
+        "Error occurred near line 1, position 1: bola: guda");
     blogc_error_free(err);
     b_trie_free(source);
 }
@@ -199,7 +199,7 @@ test_source_parse_config_no_key(void **state)
     assert_int_equal(err->type, BLOGC_ERROR_SOURCE_PARSER);
     assert_string_equal(err->msg,
         "Invalid configuration key.\n"
-        "Error occurred near to 'a'");
+        "Error occurred near line 1, position 4: BOLa");
     blogc_error_free(err);
     b_trie_free(source);
 }
@@ -214,7 +214,8 @@ test_source_parse_config_no_key2(void **state)
     assert_non_null(err);
     assert_int_equal(err->type, BLOGC_ERROR_SOURCE_PARSER);
     assert_string_equal(err->msg,
-        "Your last configuration key is missing ':' and the value");
+        "Your last configuration key is missing ':' and the value\n"
+        "Error occurred near line 1, position 5: BOLA");
     blogc_error_free(err);
     b_trie_free(source);
 }
@@ -230,7 +231,8 @@ test_source_parse_config_no_value(void **state)
     assert_non_null(err);
     assert_int_equal(err->type, BLOGC_ERROR_SOURCE_PARSER);
     assert_string_equal(err->msg,
-        "Configuration value not provided for 'BOLA'.");
+        "Configuration value not provided for 'BOLA'.\n"
+        "Error occurred near line 1, position 6: BOLA:");
     blogc_error_free(err);
     b_trie_free(source);
 }
@@ -246,7 +248,8 @@ test_source_parse_config_no_value2(void **state)
     assert_non_null(err);
     assert_int_equal(err->type, BLOGC_ERROR_SOURCE_PARSER);
     assert_string_equal(err->msg,
-        "Configuration value not provided for 'BOLA'.");
+        "Configuration value not provided for 'BOLA'.\n"
+        "Error occurred near line 1, position 6: BOLA:");
     blogc_error_free(err);
     b_trie_free(source);
 }
@@ -449,7 +452,8 @@ test_source_parse_config_value_no_line_ending(void **state)
     assert_non_null(err);
     assert_int_equal(err->type, BLOGC_ERROR_SOURCE_PARSER);
     assert_string_equal(err->msg,
-        "No line ending after the configuration value for 'BOLA'.");
+        "No line ending after the configuration value for 'BOLA'.\n"
+        "Error occurred near line 1, position 10: BOLA: asd");
     blogc_error_free(err);
     b_trie_free(source);
 }
@@ -466,7 +470,7 @@ test_source_parse_invalid_separator(void **state)
     assert_int_equal(err->type, BLOGC_ERROR_SOURCE_PARSER);
     assert_string_equal(err->msg,
         "Invalid content separator. Must be more than one '-' characters.\n"
-        "Error occurred near to '#'");
+        "Error occurred near line 2, position 4: ---#");
     blogc_error_free(err);
     b_trie_free(source);
 }
diff --git a/tests/check_template_parser.c b/tests/check_template_parser.c
index df5dc4c..94f669b 100644
--- a/tests/check_template_parser.c
+++ b/tests/check_template_parser.c
@@ -359,7 +359,7 @@ test_template_parse_invalid_block_start(void **state)
     assert_int_equal(err->type, BLOGC_ERROR_TEMPLATE_PARSER);
     assert_string_equal(err->msg,
         "Invalid statement syntax. Must begin with lowercase letter.\n"
-        "Error occurred near to 'ASD %}'");
+        "Error occurred near line 1, position 4: {% ASD %}");
     blogc_error_free(err);
 }
 
@@ -377,7 +377,7 @@ test_template_parse_invalid_block_nested(void **state)
     assert_int_equal(err->type, BLOGC_ERROR_TEMPLATE_PARSER);
     assert_string_equal(err->msg,
         "Blocks can't be nested.\n"
-        "Error occurred near to ' listing %}'");
+        "Error occurred near line 2, position 9: {% block listing %}");
     blogc_error_free(err);
 }
 
@@ -393,7 +393,7 @@ test_template_parse_invalid_block_not_open(void **state)
     assert_int_equal(err->type, BLOGC_ERROR_TEMPLATE_PARSER);
     assert_string_equal(err->msg,
         "'endblock' statement without an open 'block' statement.\n"
-        "Error occurred near to ' %}'");
+        "Error occurred near line 1, position 12: {% endblock %}");
     blogc_error_free(err);
 }
 
@@ -409,7 +409,8 @@ test_template_parse_invalid_endif_not_open(void **state)
     assert_int_equal(err->type, BLOGC_ERROR_TEMPLATE_PARSER);
     assert_string_equal(err->msg,
         "'endif' statement without an open 'ifdef' or 'ifndef' statement.\n"
-        "Error occurred near to ' %}{% endblock %}'");
+        "Error occurred near line 1, position 28: "
+        "{% block listing %}{% endif %}{% endblock %}");
     blogc_error_free(err);
 }
 
@@ -425,7 +426,8 @@ test_template_parse_invalid_block_name(void **state)
     assert_int_equal(err->type, BLOGC_ERROR_TEMPLATE_PARSER);
     assert_string_equal(err->msg,
         "Invalid statement type: Allowed types are: 'block', 'endblock', 'ifdef', "
-        "'ifndef' and 'endif'.\nError occurred near to ' %}'");
+        "'ifndef' and 'endif'.\n"
+        "Error occurred near line 1, position 10: {% chunda %}");
     blogc_error_free(err);
 }
 
@@ -441,7 +443,7 @@ test_template_parse_invalid_block_type_start(void **state)
     assert_int_equal(err->type, BLOGC_ERROR_TEMPLATE_PARSER);
     assert_string_equal(err->msg,
         "Invalid block syntax. Must begin with lowercase letter.\n"
-        "Error occurred near to 'ENTRY %}'");
+        "Error occurred near line 1, position 10: {% block ENTRY %}");
     blogc_error_free(err);
 }
 
@@ -457,7 +459,7 @@ test_template_parse_invalid_block_type(void **state)
     assert_int_equal(err->type, BLOGC_ERROR_TEMPLATE_PARSER);
     assert_string_equal(err->msg,
         "Invalid block type. Allowed types are: 'entry', 'listing' and 'listing_once'.\n"
-        "Error occurred near to ' %}'");
+        "Error occurred near line 1, position 16: {% block chunda %}");
     blogc_error_free(err);
 }
 
@@ -473,7 +475,8 @@ test_template_parse_invalid_ifdef_start(void **state)
     assert_int_equal(err->type, BLOGC_ERROR_TEMPLATE_PARSER);
     assert_string_equal(err->msg,
         "Invalid variable name. Must begin with uppercase letter.\n"
-        "Error occurred near to 'guda %}'");
+        "Error occurred near line 1, position 27: "
+        "{% block entry %}{% ifdef guda %}");
     blogc_error_free(err);
 }
 
@@ -489,7 +492,8 @@ test_template_parse_invalid_ifdef_variable(void **state)
     assert_int_equal(err->type, BLOGC_ERROR_TEMPLATE_PARSER);
     assert_string_equal(err->msg,
         "Invalid variable name. Must be uppercase letter, number or '_'.\n"
-        "Error occurred near to 'oLA %}'");
+        "Error occurred near line 1, position 28: "
+        "{% block entry %}{% ifdef BoLA %}");
     blogc_error_free(err);
 }
 
@@ -505,7 +509,8 @@ test_template_parse_invalid_if_operator(void **state)
     assert_int_equal(err->type, BLOGC_ERROR_TEMPLATE_PARSER);
     assert_string_equal(err->msg,
         "Invalid 'if' operator. Must be '<', '>', '<=', '>=', '==' or '!='.\n"
-        "Error occurred near to '= \"asd\" %}'");
+        "Error occurred near line 1, position 29: "
+        "{% block entry %}{% if BOLA = \"asd\" %}");
     blogc_error_free(err);
 }
 
@@ -521,7 +526,8 @@ test_template_parse_invalid_if_operand(void **state)
     assert_int_equal(err->type, BLOGC_ERROR_TEMPLATE_PARSER);
     assert_string_equal(err->msg,
         "Invalid 'if' operand. Must be double-quoted static string.\n"
-        "Error occurred near to 'asd %}'");
+        "Error occurred near line 1, position 32: "
+        "{% block entry %}{% if BOLA == asd %}");
     blogc_error_free(err);
 }
 
@@ -537,7 +543,8 @@ test_template_parse_invalid_if_operand2(void **state)
     assert_int_equal(err->type, BLOGC_ERROR_TEMPLATE_PARSER);
     assert_string_equal(err->msg,
         "Found an open double-quoted string.\n"
-        "Error occurred near to '\"asd %}'");
+        "Error occurred near line 1, position 32: "
+        "{% block entry %}{% if BOLA == \"asd %}");
     blogc_error_free(err);
 }
 
@@ -553,7 +560,7 @@ test_template_parse_invalid_block_end(void **state)
     assert_int_equal(err->type, BLOGC_ERROR_TEMPLATE_PARSER);
     assert_string_equal(err->msg,
         "Invalid statement syntax. Must end with '%}'.\n"
-        "Error occurred near to '}}'");
+        "Error occurred near line 1, position 16: {% block entry }}");
     blogc_error_free(err);
 }
 
@@ -569,7 +576,8 @@ test_template_parse_invalid_variable_name(void **state)
     assert_int_equal(err->type, BLOGC_ERROR_TEMPLATE_PARSER);
     assert_string_equal(err->msg,
         "Invalid variable name. Must begin with uppercase letter.\n"
-        "Error occurred near to 'bola }}{% endblock %}'");
+        "Error occurred near line 1, position 21: "
+        "{% block entry %}{{ bola }}{% endblock %}");
     blogc_error_free(err);
 }
 
@@ -585,7 +593,8 @@ test_template_parse_invalid_variable_name2(void **state)
     assert_int_equal(err->type, BLOGC_ERROR_TEMPLATE_PARSER);
     assert_string_equal(err->msg,
         "Invalid variable name. Must be uppercase letter, number or '_'.\n"
-        "Error occurred near to 'ola }}{% endblock %}'");
+        "Error occurred near line 1, position 22: "
+        "{% block entry %}{{ Bola }}{% endblock %}");
     blogc_error_free(err);
 }
 
@@ -601,7 +610,8 @@ test_template_parse_invalid_variable_end(void **state)
     assert_int_equal(err->type, BLOGC_ERROR_TEMPLATE_PARSER);
     assert_string_equal(err->msg,
         "Invalid statement syntax. Must end with '}}'.\n"
-        "Error occurred near to '%}{% endblock %}'");
+        "Error occurred near line 1, position 26: "
+        "{% block entry %}{{ BOLA %}{% endblock %}");
     blogc_error_free(err);
 }
 
@@ -617,7 +627,7 @@ test_template_parse_invalid_close(void **state)
     assert_int_equal(err->type, BLOGC_ERROR_TEMPLATE_PARSER);
     assert_string_equal(err->msg,
         "Invalid statement syntax. Must end with '}'.\n"
-        "Error occurred near to '%'");
+        "Error occurred near line 1, position 17: {% block entry %%");
     blogc_error_free(err);
 }
 
@@ -633,7 +643,8 @@ test_template_parse_invalid_close2(void **state)
     assert_int_equal(err->type, BLOGC_ERROR_TEMPLATE_PARSER);
     assert_string_equal(err->msg,
         "Invalid statement syntax. Must end with '}'.\n"
-        "Error occurred near to '%{% endblock %}'");
+        "Error occurred near line 1, position 27: "
+        "{% block entry %}{{ BOLA }%{% endblock %}");
     blogc_error_free(err);
 }