Defer debug format search until after command line parsing

Avoid funnies with ordering of debug format selection by deferring
debug format search until after command line processing.  Also permit
the -gformat syntax used by many C compilers.

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

4 files changed, 28 insertions, 17 deletions

diff --git a/nasm.c b/nasm.c
index 7a699ef6..fc26bba7 100644
--- a/nasm.c
+++ b/nasm.c
@@ -85,7 +85,9 @@ static void nasm_verror_vc(int severity, const char *fmt, va_list args);
 static void nasm_verror_common(int severity, const char *fmt, va_list args);
 static void usage(void);
 
-static int using_debug_info, opt_verbose_info;
+static bool using_debug_info, opt_verbose_info;
+static const char *debug_format;
+
 bool tasm_compatible_mode = false;
 int pass0, passn;
 int globalrel = 0;
@@ -356,11 +358,21 @@ int main(int argc, char **argv)
         return 1;
     }
 
-    /* If debugging info is disabled, suppress any debug calls */
-    if (!using_debug_info)
+    if (!using_debug_info) {
+        /* No debug info, redirect to the null backend (empty stubs) */
         dfmt = &null_debug_form;
-    else if (!dfmt)
+    } else if (!debug_format) {
+        /* Default debug format for this backend */
 	dfmt = ofmt->default_dfmt;
+    } else {
+        dfmt = dfmt_find(ofmt, debug_format);
+        if (!dfmt) {
+            nasm_fatal(ERR_NOFILE | ERR_USAGE,
+                       "unrecognized debug format `%s' for"
+                       " output format `%s'",
+                       debug_format, ofmt->shortname);
+        }
+    }
 
     if (ofmt->stdmac)
         preproc->extra_stdmac(ofmt->stdmac);
@@ -666,7 +678,6 @@ static bool process_arg(char *p, char *q)
                            "unrecognised output format `%s' - "
                            "use -hf for a list", param);
             }
-	    dfmt = NULL;
             break;
 
         case 'O':       /* Optimization level */
@@ -744,14 +755,8 @@ static bool process_arg(char *p, char *q)
             break;
 
         case 'F':       /* specify debug format */
-            dfmt = dfmt_find(ofmt, param);
-            if (!dfmt) {
-                nasm_fatal(ERR_NOFILE | ERR_USAGE,
-                           "unrecognized debug format `%s' for"
-                           " output format `%s'",
-                           param, ofmt->shortname);
-            }
             using_debug_info = true;
+            debug_format = param;
             break;
 
         case 'X':       /* specify error reporting format */
@@ -767,6 +772,8 @@ static bool process_arg(char *p, char *q)
 
         case 'g':
             using_debug_info = true;
+            if (p[2])
+                debug_format = nasm_skip_spaces(p + 2);
             break;
 
         case 'h':
@@ -775,8 +782,7 @@ static bool process_arg(char *p, char *q)
                  "[-l listfile]\n"
                  "            [options...] [--] filename\n"
                  "    or nasm -v (or --v) for version info\n\n"
-                 "    -t          assemble in SciTech TASM compatible mode\n"
-                 "    -g          generate debug information in selected format\n");
+                 "    -t          assemble in SciTech TASM compatible mode\n");
             printf
                 ("    -E (or -e)  preprocess only (writes output to stdout by default)\n"
                  "    -a          don't preprocess (assemble only)\n"
@@ -789,7 +795,9 @@ static bool process_arg(char *p, char *q)
                  "    -MP         emit phony target\n\n"
                  "    -Z<file>    redirect error messages to file\n"
                  "    -s          redirect error messages to stdout\n\n"
+                 "    -g          generate debugging information\n\n"
                  "    -F format   select a debugging format\n\n"
+                 "    -gformat    same as -g -F format\n\n"
                  "    -o outfile  write output to an outfile\n\n"
                  "    -f format   select an output format\n\n"
                  "    -l listfile write listing to a listfile\n\n"
diff --git a/nasm.txt b/nasm.txt
index 55f9a05b..a28202f9 100644
--- a/nasm.txt
+++ b/nasm.txt
@@ -47,7 +47,10 @@ OPTIONS
 	formats, use the *-y* option (for example *-felf -y*).
 
 *-g*::
-	Causes *nasm* to generate debug information in selected format.
+	Causes *nasm* to generate debug information.
+
+*-g*'format'::
+	Equivalent to **-g -F**__ format__.
 
 *-h*::
 	Causes *nasm* to exit immediately, after giving a summary of its
diff --git a/output/outform.c b/output/outform.c
index 3d70e2a9..17744bb2 100644
--- a/output/outform.c
+++ b/output/outform.c
@@ -72,7 +72,7 @@ struct ofmt *ofmt_find(char *name, struct ofmt_alias **ofmt_alias)
     return NULL;
 }
 
-struct dfmt *dfmt_find(struct ofmt *ofmt, char *name)
+struct dfmt *dfmt_find(struct ofmt *ofmt, const char *name)
 {
     struct dfmt **dfp, *df;
 
diff --git a/output/outform.h b/output/outform.h
index f52a112a..e34ef752 100644
--- a/output/outform.h
+++ b/output/outform.h
@@ -371,7 +371,7 @@ static struct ofmt_alias ofmt_aliases[] = {
 #endif /* BUILD_DRIVERS_ARRAY */
 
 struct ofmt *ofmt_find(char *name, struct ofmt_alias **ofmt_alias);
-struct dfmt *dfmt_find(struct ofmt *, char *);
+struct dfmt *dfmt_find(struct ofmt *, const char *);
 void ofmt_list(struct ofmt *, FILE *);
 void dfmt_list(struct ofmt *ofmt, FILE * fp);
 extern struct dfmt null_debug_form;