error: new flag ERR_HERE

ERR_HERE is used to mark messages of the form "... here" so that we
can emit sane output to the list file with filename and line number,
instead of a nonsensical "here" which could point almost anywhere.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>

asm/labels.c

@@ -506,8 +506,7 @@ void define_label(const char *label, int32_t segment,
 
             src_get(&saved_line, &saved_fname);
             src_set(lptr->defn.def_line, lptr->defn.def_file);
-            nasm_note("label `%s' originally defined here",
-                      lptr->defn.label);
+            nasm_notef(ERR_HERE, "label `%s' originally defined", lptr->defn.label);
             src_set(saved_line, saved_fname);
         } else if (pass0 > 1 && lptr->defn.type != LBL_SPECIAL) {
             /*

asm/listing.c

@@ -324,12 +324,16 @@ static void list_downlevel(int type)
     }
 }
 
-static void list_error(int severity, const char *pfx, const char *msg)
+static void list_error(int severity, const char *fmt, ...)
 {
+    va_list ap;
+
     if (!listfp)
 	return;
 
-    snprintf(listerror, sizeof listerror, "%s%s", pfx, msg);
+    va_start(ap, fmt);
+    vsnprintf(listerror, sizeof listerror, fmt, ap);
+    va_end(ap);
 
     if ((severity & ERR_MASK) >= ERR_FATAL)
 	list_emit();

asm/listing.h

@@ -96,7 +96,7 @@ struct lfmt {
     /*
      * Called on a warning or error, with the error message.
      */
-    void (*error)(int severity, const char *pfx, const char *msg);
+    void printf_func(2, 3) (*error)(int severity, const char *fmt, ...);
 
     /*
      * Update the current offset.  Used to give the listing generator

asm/nasm.c

@@ -1767,6 +1767,8 @@ static bool skip_this_pass(int severity)
 static void nasm_verror_asm(int severity, const char *fmt, va_list args)
 {
     char msg[1024];
+    char warnsuf[64];
+    char linestr[64];
     const char *pfx;
     bool warn_is_err = warning_is_error(severity);
     bool warn_is_other = WARN_IDX(severity) == ERR_WARN_OTHER;
@@ -1786,8 +1788,6 @@ static void nasm_verror_asm(int severity, const char *fmt, va_list args)
             lineno = 0;
         }
     }
-    if (!currentfile)
-        currentfile = "nasm";
 
     switch (severity & (ERR_MASK|ERR_NO_SEVERITY)) {
     case ERR_NOTE:
@@ -1816,23 +1816,35 @@ static void nasm_verror_asm(int severity, const char *fmt, va_list args)
         break;
     }
 
-    vsnprintf(msg, sizeof msg - 64, fmt, args);
+    /*
+     * For a debug/warning/note event, if ERR_HERE is set don't
+     * output anything if there is no current filename available
+     */
+    if (!currentfile && (severity & ERR_HERE) &&
+        ((severity & ERR_MASK) < ERR_WARNING ||
+         (is_valid_warning(severity) && !warn_is_err)))
+        return;
+
+
+    vsnprintf(msg, sizeof msg, fmt, args);
+    *warnsuf = 0;
     if (is_valid_warning(severity) && (warn_is_err || !warn_is_other)) {
-        char *p = strchr(msg, '\0');
-	snprintf(p, 64, " [-w+%s%s]",
+	snprintf(warnsuf, sizeof warnsuf, " [-w+%s%s]",
                  warn_is_err ? "error=" : "",
                  warnings[WARN_IDX(severity)].name);
     }
 
+    *linestr = 0;
+    if (lineno) {
+        snprintf(linestr, sizeof linestr, "%s%"PRId32"%s",
+                 errfmt->beforeline, lineno, errfmt->afterline);
+    }
+
     if (!skip_this_pass(severity)) {
-        if (!lineno) {
-            fprintf(error_file, "%s%s%s%s\n",
-                    currentfile, errfmt->beforemsg, pfx, msg);
-        } else {
-            fprintf(error_file, "%s%s%"PRId32"%s%s%s%s\n",
-                    currentfile, errfmt->beforeline, lineno,
-                    errfmt->afterline, errfmt->beforemsg, pfx, msg);
-        }
+        fprintf(error_file, "%s%s%s%s%s%s%s\n",
+                currentfile ? currentfile : "nasm",
+                linestr, errfmt->beforemsg, pfx, msg,
+                (severity & ERR_HERE) ? " here" : "", warnsuf);
     }
 
     /* Are we recursing from error_list_macros? */
@@ -1843,7 +1855,19 @@ static void nasm_verror_asm(int severity, const char *fmt, va_list args)
      * Don't suppress this with skip_this_pass(), or we don't get
      * pass1 or preprocessor warnings in the list file
      */
-    lfmt->error(severity, pfx, msg);
+    if (severity & ERR_HERE) {
+        if (lineno)
+            lfmt->error(severity, "%s%s at %s:%"PRId32"%s",
+                        pfx, msg, currentfile, lineno, warnsuf);
+        else if (currentfile)
+            lfmt->error(severity, "%s%s in file %s%s",
+                        pfx, msg, currentfile, warnsuf);
+        else
+            lfmt->error(severity, "%s%s in unknown location%s",
+                        pfx, msg, warnsuf);
+    } else {
+        lfmt->error(severity, "%s%s%s", pfx, msg, warnsuf);
+    }
 
     if (skip_this_pass(severity))
         return;

asm/preproc.c

@@ -5329,22 +5329,21 @@ static void pp_list_one_macro(MMacro *m, int severity)
 
     if (m->name && !m->nolist) {
 	src_set(m->xline + m->lineno, m->fname);
-	nasm_error(severity, "... from macro `%s' defined here", m->name);
+	nasm_error(severity, "... from macro `%s' defined", m->name);
     }
 }
 
 static void pp_error_list_macros(int severity)
 {
-    int32_t saved_line;
-    const char *saved_fname = NULL;
+    struct src_location saved;
 
-    severity |= ERR_PP_LISTMACRO | ERR_NO_SEVERITY;
-    src_get(&saved_line, &saved_fname);
+    severity |= ERR_PP_LISTMACRO | ERR_NO_SEVERITY | ERR_HERE;
+    saved = src_where();
 
     if (istk)
         pp_list_one_macro(istk->mstk, severity);
 
-    src_set(saved_line, saved_fname);
+    src_update(saved);
 }
 
 const struct preproc_ops nasmpp = {

include/error.h

@@ -83,6 +83,7 @@ static inline vefunc nasm_set_verror(vefunc ve)
 						 * and dump core for reference */
 #define ERR_MASK		0x00000007	/* mask off the above codes */
 #define ERR_NOFILE		0x00000010	/* don't give source file name/line */
+#define ERR_HERE		0x00000020      /* point to a specific source location */
 #define ERR_USAGE		0x00000040	/* print a usage message */
 #define ERR_PASS1		0x00000080	/* only print this error on pass one */
 #define ERR_PASS2		0x00000100	/* only print this error on pass one */