listing: make it possible to flush the listing output after every line

Add the -Lw option to flush the list file after every line
output. This is handy for debugging if nasm hangs.

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

2 files changed, 7 insertions, 1 deletions

diff --git a/asm/listing.c b/asm/listing.c
index 3101a258..9b101ff4 100644
--- a/asm/listing.c
+++ b/asm/listing.c
@@ -148,6 +148,8 @@ static void list_cleanup(void)
 
 static void list_init(const char *fname)
 {
+    enum file_flags flags = NF_TEXT;
+
     if (listfp)
         list_cleanup();
 
@@ -156,7 +158,10 @@ static void list_init(const char *fname)
 	return;
     }
 
-    listfp = nasm_open_write(fname, NF_TEXT);
+    if (list_option('w'))
+        flags |= NF_IOLBF;
+
+    listfp = nasm_open_write(fname, flags);
     if (!listfp) {
         nasm_nonfatal("unable to open listing file `%s'", fname);
         return;
diff --git a/asm/nasm.c b/asm/nasm.c
index 07a360b2..a30831dc 100644
--- a/asm/nasm.c
+++ b/asm/nasm.c
@@ -2067,6 +2067,7 @@ static void help(FILE *out)
         "       -Lm        show multi-line macro calls with expanded parmeters\n"
         "       -Lp        output a list file every pass, in case of errors\n"
         "       -Ls        show all single-line macro definitions\n"
+        "       -Lw        flush the output after every line\n"
         "       -L+        enable all listing options (very verbose!)\n"
         "\n"
         "    -Oflags...    optimize opcodes, immediates and branch offsets\n"