Don't fclose() the output in the backend

We fopen() the output file in common code but fclose() it in the
backend.  This is bad for a variety of reasons:

1. it is generally an awkward interface to change ownership.
2. we should use ferror() to test for write errors, and that is
   better done in common code.
3. it requires more code.
4. we still need to fclose() in common code during error handing.

Thus, move the fclose() of the output out of the backends, and add
fflush() so we can test ferror() on output.

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

1 files changed, 11 insertions, 8 deletions

diff --git a/nasm.c b/nasm.c
index d1cd4659..53e1c72b 100644
--- a/nasm.c
+++ b/nasm.c
@@ -431,6 +431,7 @@ int main(int argc, char **argv)
                 fclose(ofile);
             if (ofile && terminate_after_phase)
                 remove(outname);
+	    ofile = NULL;
         }
         break;
 
@@ -466,16 +467,17 @@ int main(int argc, char **argv)
             if (!terminate_after_phase) {
                 ofmt->cleanup(using_debug_info);
                 cleanup_labels();
-            } else {
-                /*
-                 * Despite earlier comments, we need this fclose.
-                 * The object output drivers only fclose on cleanup,
-                 * and we just skipped that.
-                 */
-                fclose (ofile);
+		fflush(ofile);
+		if (ferror(ofile)) {
+		    report_error(ERR_NONFATAL|ERR_NOFILE,
+				 "write error on output file `%s'", outname);
+		}
+	    }
 
+	    fclose(ofile);
+	    if (ofile && terminate_after_phase)
                 remove(outname);
-            }
+	    ofile = NULL;
         }
         break;
     }
@@ -1961,6 +1963,7 @@ static void report_error_common(int severity, const char *fmt,
         if (ofile) {
             fclose(ofile);
             remove(outname);
+	    ofile = NULL;
         }
         if (want_usage)
             usage();