Show the expanded macro stack when displaying diagnostics

It can be hard to find errors inside potentially nested macros.
Show the mmacro expansion stack when printing diagnostics.
Note that a list file doesn't help for errors that are detected
before the code-generation pass.

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

nasm.c

@@ -128,7 +128,7 @@ static struct RAA *offsets;
 static struct SAA *forwrefs;    /* keep track of forward references */
 static const struct forwrefinfo *forwref;
 
-static struct preproc_ops *preproc;
+static const struct preproc_ops *preproc;
 
 #define OP_NORMAL           (1u << 0)
 #define OP_PREPROCESS       (1u << 1)
@@ -1876,12 +1876,11 @@ static void nasm_verror_gnu(int severity, const char *fmt, va_list ap)
         return;
 
     if (!(severity & ERR_NOFILE))
-        src_get(&lineno, &currentfile);
+	src_get(&lineno, &currentfile);
 
     if (!skip_this_pass(severity)) {
 	if (currentfile) {
 	    fprintf(error_file, "%s:%"PRId32": ", currentfile, lineno);
-	    nasm_free(currentfile);
 	} else {
 	    fputs("nasm: ", error_file);
 	}
@@ -2002,7 +2001,7 @@ static void nasm_verror_common(int severity, const char *fmt, va_list args)
     }
 
     vsnprintf(msg, sizeof msg - 64, fmt, args);
-    if (severity & ERR_WARN_MASK) {
+    if ((severity & (ERR_WARN_MASK|ERR_PP_LISTMACRO)) == ERR_WARN_MASK) {
 	char *p = strchr(msg, '\0');
 	snprintf(p, 64, " [-w+%s]", warnings[WARN_IDX(severity)].name);
     }
@@ -2010,6 +2009,10 @@ static void nasm_verror_common(int severity, const char *fmt, va_list args)
     if (!skip_this_pass(severity))
 	fprintf(error_file, "%s%s\n", pfx, msg);
 
+    /* Are we recursing from error_list_macros? */
+    if (severity & ERR_PP_LISTMACRO)
+	return;
+
     /*
      * Don't suppress this with skip_this_pass(), or we don't get
      * pass1 or preprocessor warnings in the list file
@@ -2020,6 +2023,8 @@ static void nasm_verror_common(int severity, const char *fmt, va_list args)
     if (severity & ERR_USAGE)
         want_usage = true;
 
+    preproc->error_list_macros(severity);
+
     switch (severity & ERR_MASK) {
     case ERR_DEBUG:
         /* no further action, by definition */

nasm.h

@@ -342,10 +342,13 @@ struct preproc_ops {
 
     /* Include path from command line */
     void (*include_path)(char *path);
+
+    /* Unwind the macro stack when printing an error message */
+    void (*error_list_macros)(int severity);
 };
 
-extern struct preproc_ops nasmpp;
-extern struct preproc_ops preproc_nop;
+extern const struct preproc_ops nasmpp;
+extern const struct preproc_ops preproc_nop;
 
 /*
  * Some lexical properties of the NASM source language, included

nasmlib.c

@@ -570,6 +570,12 @@ int32_t src_set_linnum(int32_t newline)
     return oldline;
 }
 
+/* This returns a pointer, not a copy, to the current fname */
+const char *src_get_fname(void)
+{
+    return file_name;
+}
+
 int32_t src_get_linnum(void)
 {
     return line_number;

nasmlib.h

@@ -107,6 +107,7 @@ static inline vefunc nasm_set_verror(vefunc ve)
 
 #define ERR_NO_SEVERITY 0x00000100      /* suppress printing severity */
 #define ERR_PP_PRECOND	0x00000200	/* for preprocessor use */
+#define ERR_PP_LISTMACRO 0x00000400	/* from preproc->error_list_macros() */
 
 /*
  * These codes define specific types of suppressible warning.
@@ -392,6 +393,7 @@ int bsi(const char *string, const char **array, int size);
 int bsii(const char *string, const char **array, int size);
 
 char *src_set_fname(char *newname);
+const char *src_get_fname(void);
 int32_t src_set_linnum(int32_t newline);
 int32_t src_get_linnum(void);
 /*

preproc-nop.c

@@ -1,6 +1,6 @@
 /* ----------------------------------------------------------------------- *
  *
- *   Copyright 1996-2012 The NASM Authors - All Rights Reserved
+ *   Copyright 1996-2016 The NASM Authors - All Rights Reserved
  *   See the file AUTHORS included with the NASM distribution for
  *   the specific copyright holders.
  *
@@ -170,7 +170,12 @@ static void nop_include_path(char *path)
     (void)path;
 }
 
-struct preproc_ops preproc_nop = {
+static void nop_error_list_macros(int severity)
+{
+    (void)severity;
+}
+
+const struct preproc_ops preproc_nop = {
     nop_reset,
     nop_getline,
     nop_cleanup,
@@ -178,5 +183,6 @@ struct preproc_ops preproc_nop = {
     nop_pre_define,
     nop_pre_undefine,
     nop_pre_include,
-    nop_include_path
+    nop_include_path,
+    nop_error_list_macros,
 };

preproc.c

@@ -155,6 +155,9 @@ struct MMacro {
     uint64_t unique;
     int lineno;                 /* Current line number on expansion */
     uint64_t condcnt;           /* number of if blocks... */
+
+    char *fname;		/* File where defined */
+    int32_t xline;		/* First line in macro */
 };
 
 
@@ -625,6 +628,7 @@ static void free_mmacro(MMacro * m)
     free_tlist(m->dlist);
     nasm_free(m->defaults);
     free_llist(m->expansion);
+    nasm_free(m->fname);
     nasm_free(m);
 }
 
@@ -2738,7 +2742,7 @@ issue_error:
                   pp_directives[i]);
             return DIRECTIVE_FOUND;
         }
-        defining = nasm_malloc(sizeof(MMacro));
+        defining = nasm_zalloc(sizeof(MMacro));
         defining->max_depth =
             (i == PP_RMACRO) || (i == PP_IRMACRO) ? DEADMAN_LIMIT : 0;
         defining->casesense = (i == PP_MACRO) || (i == PP_RMACRO);
@@ -2748,6 +2752,8 @@ issue_error:
             return DIRECTIVE_FOUND;
         }
 
+	src_get(&defining->xline, &defining->fname);
+
         mmac = (MMacro *) hash_findix(&mmacros, defining->name);
         while (mmac) {
             if (!strcmp(mmac->name, defining->name) &&
@@ -5011,7 +5017,7 @@ static char *pp_getline(void)
                 /* only set line and file name if there's a next node */
                 if (i->next) {
                     src_set_linnum(i->lineno);
-                    nasm_free(src_set_fname(nasm_strdup(i->fname)));
+                    src_set_fname(nasm_strdup(i->fname));
                 }
                 istk = i->next;
                 lfmt->downlevel(LIST_INCLUDE);
@@ -5237,7 +5243,29 @@ static void make_tok_num(Token * tok, int64_t val)
     tok->type = TOK_NUMBER;
 }
 
-struct preproc_ops nasmpp = {
+static void pp_error_list_macros(int severity)
+{
+    MMacro *m;
+    int32_t saved_line;
+    const char *saved_fname = NULL;
+
+    severity |= ERR_PP_LISTMACRO | ERR_NO_SEVERITY;
+    saved_line = src_get_linnum();
+    saved_fname = src_get_fname();
+
+    list_for_each(m, istk->mstk) {
+	if (m->name && !m->nolist) {
+	    src_set_linnum(m->xline + m->lineno);
+	    src_set_fname(m->fname);
+	    nasm_error(severity, "from macro `%s' defined here", m->name);
+	}
+    }
+
+    src_set_fname((char *)saved_fname);
+    src_set_linnum(saved_line);
+}
+
+const struct preproc_ops nasmpp = {
     pp_reset,
     pp_getline,
     pp_cleanup,
@@ -5245,5 +5273,6 @@ struct preproc_ops nasmpp = {
     pp_pre_define,
     pp_pre_undefine,
     pp_pre_include,
-    pp_include_path
+    pp_include_path,
+    pp_error_list_macros,
 };

test/macroerr.asm

@@ -0,0 +1,11 @@
+%include "macroerr.inc"
+
+%macro bluttan 1
+	mov eax,%1
+%endmacro
+
+	bluttan ptr
+	blej ptr
+	dd ptr, ptr
+	
+ptr:

test/macroerr.inc

@@ -0,0 +1,3 @@
+%macro blej 1
+	mov eax,%1
+%endmacro