Change output format for line+col.

CHANGELOG.md

@@ -1,6 +1,11 @@
 # Changelog
 All notable changes to this project will be documented in this file.
 
+## Unreleased - ???
+- Fix bug where a buffer overflow could be confused with an out of memory error.
+- Change error output to `file:line:column: message`. Column is in bytes - tabs
+  are considered to have width 1 (instead of 8).
+
 ## 1.14.2 - 2021-01-23
 - Allow `JANET_PROFILE` env variable to load a profile before loading the repl.
 - Update `tracev` macro to allow `def` and `var` inside to work as expected.

src/boot/boot.janet

@@ -2054,30 +2054,31 @@
   (def [line col] (:where p))
   (eprint
     (if ec "\e[31m" "")
-    "parse error in "
     where
-    " around line "
-    (string line)
-    ", column "
-    (string col)
-    ": "
+    ":"
+    line
+    ":"
+    col
+    ": parse error: "
     (:error p)
     (if ec "\e[0m" ""))
   (eflush))
 
 (defn bad-compile
   "Default handler for a compile error."
-  [msg macrof where]
+  [msg macrof where line col]
   (def ec (dyn :err-color))
+  (eprin
+    (if ec "\e[31m" "")
+    where
+    ":"
+    line
+    ":"
+    col
+    ": compile error: ")
   (if macrof
-    (debug/stacktrace macrof (string msg " while compiling " where))
-    (eprint
-      (if ec "\e[31m" "")
-      "compile error: "
-      msg
-      " while compiling "
-      where
-      (if ec "\e[0m" "")))
+    (debug/stacktrace macrof msg)
+    (eprint msg (if ec "\e[0m" "")))
   (eflush))
 
 (defn curenv
@@ -2130,7 +2131,7 @@
   (default guard :ydt)
 
   # Evaluate 1 source form in a protected manner
-  (defn eval1 [source]
+  (defn eval1 [source &opt l c]
     (def source (if expand (expand source) source))
     (var good true)
     (var resumeval nil)
@@ -2143,11 +2144,7 @@
             (do
               (set good false)
               (def {:error err :line line :column column :fiber errf} res)
-              (def msg
-                (if (<= 0 line)
-                  (string err " on line " line ", column " column)
-                  err))
-              (on-compile-error msg errf where))))
+              (on-compile-error err errf where (or line l) (or column c)))))
         guard))
     (fiber/setenv f env)
     (while (fiber/can-resume? f)
@@ -2175,6 +2172,10 @@
     (fiber/setenv f env)
     (resume f))
 
+  (defn produce []
+    (def tup (p-produce p true))
+    [(in tup 0) ;(tuple/sourcemap tup)])
+
   # Loop
   (def buf @"")
   (var parser-not-done true)
@@ -2196,7 +2197,7 @@
         (while (> len pindex)
           (+= pindex (p-consume p buf pindex))
           (while (p-has-more p)
-            (eval1 (p-produce p))
+            (eval1 ;(produce))
             (if (env :exit) (break)))
           (when (= (p-status p) :error)
             (parse-err p where)
@@ -2205,7 +2206,7 @@
   # Check final parser state
   (unless (env :exit)
     (while (p-has-more p)
-      (eval1 (p-produce p))
+      (eval1 ;(produce))
       (if (env :exit) (break)))
     (when (= (p-status p) :error)
       (parse-err p where)))
@@ -2450,9 +2451,9 @@
     (def [line col] (:where x))
     (def pe (string (:error x) " in " y " around line " line ", column " col))
     (set exit-error pe))
-  (defn bc [&opt x y z]
+  (defn bc [&opt x y z a b]
     (when exit
-      (bad-compile x y z)
+      (bad-compile x y z a b)
       (os/exit 1))
     (put env :exit true)
     (def ce (string x " while compiling " z))

src/core/compile.c

@@ -872,8 +872,12 @@ static Janet cfun(int32_t argc, Janet *argv) {
     } else {
         JanetTable *t = janet_table(4);
         janet_table_put(t, janet_ckeywordv("error"), janet_wrap_string(res.error));
-        janet_table_put(t, janet_ckeywordv("line"), janet_wrap_integer(res.error_mapping.line));
-        janet_table_put(t, janet_ckeywordv("column"), janet_wrap_integer(res.error_mapping.column));
+        if (res.error_mapping.line > 0) {
+            janet_table_put(t, janet_ckeywordv("line"), janet_wrap_integer(res.error_mapping.line));
+        }
+        if (res.error_mapping.column > 0) {
+            janet_table_put(t, janet_ckeywordv("column"), janet_wrap_integer(res.error_mapping.column));
+        }
         if (res.macrofiber) {
             janet_table_put(t, janet_ckeywordv("fiber"), janet_wrap_fiber(res.macrofiber));
         }

src/core/parse.c

@@ -175,7 +175,14 @@ static void popstate(JanetParser *p, Janet val) {
         if (newtop->flags & PFLAG_CONTAINER) {
             newtop->argn++;
             /* Keep track of number of values in the root state */
-            if (p->statecount == 1) p->pending++;
+            if (p->statecount == 1) {
+                p->pending++;
+                /* Root items are always wrapped in a tuple for source map info. */
+                const Janet *tup = janet_tuple_n(&val, 1);
+                janet_tuple_sm_line(tup) = (int32_t) top.line;
+                janet_tuple_sm_column(tup) = (int32_t) top.column;
+                val = janet_wrap_tuple(tup);
+            }
             push_arg(p, val);
             return;
         } else if (newtop->flags & PFLAG_READERMAC) {
@@ -730,6 +737,19 @@ const char *janet_parser_error(JanetParser *parser) {
 }
 
 Janet janet_parser_produce(JanetParser *parser) {
+    Janet ret;
+    size_t i;
+    if (parser->pending == 0) return janet_wrap_nil();
+    ret = janet_unwrap_tuple(parser->args[0])[0];
+    for (i = 1; i < parser->argcount; i++) {
+        parser->args[i - 1] = parser->args[i];
+    }
+    parser->pending--;
+    parser->argcount--;
+    return ret;
+}
+
+Janet janet_parser_produce_wrapped(JanetParser *parser) {
     Janet ret;
     size_t i;
     if (parser->pending == 0) return janet_wrap_nil();
@@ -980,9 +1000,13 @@ static Janet cfun_parse_error(int32_t argc, Janet *argv) {
 }
 
 static Janet cfun_parse_produce(int32_t argc, Janet *argv) {
-    janet_fixarity(argc, 1);
+    janet_arity(argc, 1, 2);
     JanetParser *p = janet_getabstract(argv, 0, &janet_parser_type);
-    return janet_parser_produce(p);
+    if (argc == 2 && janet_truthy(argv[1])) {
+        return janet_parser_produce_wrapped(p);
+    } else {
+        return janet_parser_produce(p);
+    }
 }
 
 static Janet cfun_parse_flush(int32_t argc, Janet *argv) {
@@ -1217,10 +1241,12 @@ static const JanetReg parse_cfuns[] = {
     },
     {
         "parser/produce", cfun_parse_produce,
-        JDOC("(parser/produce parser)\n\n"
+        JDOC("(parser/produce parser &opt wrap)\n\n"
              "Dequeue the next value in the parse queue. Will return nil if "
              "no parsed values are in the queue, otherwise will dequeue the "
-             "next value.")
+             "next value. If `wrap` is truthy, will return a 1-element tuple that "
+             "wraps the result. This tuple can be used for source-mapping "
+             "purposes.")
     },
     {
         "parser/consume", cfun_parse_consume,

src/include/janet.h

@@ -1367,6 +1367,7 @@ JANET_API void janet_parser_deinit(JanetParser *parser);
 JANET_API void janet_parser_consume(JanetParser *parser, uint8_t c);
 JANET_API enum JanetParserStatus janet_parser_status(JanetParser *parser);
 JANET_API Janet janet_parser_produce(JanetParser *parser);
+JANET_API Janet janet_parser_produce_wrapped(JanetParser *parser);
 JANET_API const char *janet_parser_error(JanetParser *parser);
 JANET_API void janet_parser_flush(JanetParser *parser);
 JANET_API void janet_parser_eof(JanetParser *parser);