From dc374ed7e2e772850db2e32f536280506ee459ca Mon Sep 17 00:00:00 2001
From: Ivan Maidanski <ivmai@mail.ru>
Date: Tue, 13 Nov 2012 08:04:41 +0400
Subject: [PATCH] Code refactoring of GC_X_printf to improve extensibility

* misc.c (GC_DEFAULT_STDOUT_FD, GC_DEFAULT_STDERR_FD): New macro.
* misc.c (GC_stdout, GC_stderr, GC_log): Use GC_DEFAULT_STDOUT_FD and
GC_DEFAULT_STDERR_FD (only if not OS2, MACOS, Win32).
* misc.c (GC_PRINTF_IMPL): Replace with GC_PRINTF_FILLBUF (move out
"buf" array definition, move out WRITE call, remove "f" and "f_name"
arguments, add "buf" argument, use sizeof(buf)-1 instead of BUFSZ.
* misc.c (GC_printf, GC_err_printf, GC_log_printf): Declare and use
"buf" array; replace GC_PRINTF_IMPL with GC_PRINTF_FILLBUF.
* misc.c (GC_printf, GC_log_printf): Call WRITE to output "buf"
content.
* misc.c (GC_err_printf): Call GC_err_puts to output "buf" content.
* misc.c (GC_default_warn_proc): Add TODO item.
---
 misc.c | 41 ++++++++++++++++++++++++++---------------
 1 file changed, 26 insertions(+), 15 deletions(-)

diff --git a/misc.c b/misc.c
index fb56bf39..c5117967 100644
--- a/misc.c
+++ b/misc.c
@@ -746,10 +746,13 @@ STATIC void GC_exit_check(void)
 # define maybe_install_looping_handler()
 #endif
 
+#define GC_DEFAULT_STDOUT_FD 1
+#define GC_DEFAULT_STDERR_FD 2
+
 #if !defined(OS2) && !defined(MACOS) && !defined(MSWIN32) && !defined(MSWINCE)
-  STATIC int GC_stdout = 1;
-  STATIC int GC_stderr = 2;
-  STATIC int GC_log = 2; /* stderr */
+  STATIC int GC_stdout = GC_DEFAULT_STDOUT_FD;
+  STATIC int GC_stderr = GC_DEFAULT_STDERR_FD;
+  STATIC int GC_log = GC_DEFAULT_STDERR_FD;
 #endif
 
 STATIC word GC_parse_mem_size_arg(const char *str)
@@ -1455,37 +1458,44 @@ GC_API void GC_CALL GC_enable_incremental(void)
 /* Floating point arguments and formats should be avoided, since FP       */
 /* conversion is more likely to allocate memory.                          */
 /* Assumes that no more than BUFSZ-1 characters are written at once.      */
-#define GC_PRINTF_IMPL(f, f_name, format) { \
+#define GC_PRINTF_FILLBUF(buf, format) { \
           va_list args; \
-          char buf[BUFSZ + 1]; \
           va_start(args, format); \
-          buf[BUFSZ] = 0x15; \
-          (void)vsnprintf(buf, BUFSZ, format, args); \
+          (buf)[sizeof(buf) - 1] = 0x15; /* guard */ \
+          (void)vsnprintf(buf, sizeof(buf) - 1, format, args); \
           va_end(args); \
-          if (buf[BUFSZ] != 0x15) \
+          if ((buf)[sizeof(buf) - 1] != 0x15) \
             ABORT("GC_printf clobbered stack"); \
-          if (WRITE(f, buf, strlen(buf)) < 0) \
-            ABORT("write to " f_name " failed"); \
         }
 
 void GC_printf(const char *format, ...)
 {
-    if (GC_quiet) return;
+    char buf[BUFSZ + 1];
 
-    GC_PRINTF_IMPL(GC_stdout, "stdout", format);
+    if (!GC_quiet) {
+      GC_PRINTF_FILLBUF(buf, format);
+      if (WRITE(GC_stdout, buf, strlen(buf)) < 0)
+        ABORT("write to stdout failed");
+    }
 }
 
 void GC_err_printf(const char *format, ...)
 {
-    GC_PRINTF_IMPL(GC_stderr, "stderr", format);
+    char buf[BUFSZ + 1];
+
+    GC_PRINTF_FILLBUF(buf, format);
+    GC_err_puts(buf);
 }
 
 void GC_log_printf(const char *format, ...)
 {
-    GC_PRINTF_IMPL(GC_log, "log", format);
+    char buf[BUFSZ + 1];
+
+    GC_PRINTF_FILLBUF(buf, format);
+    if (WRITE(GC_log, buf, strlen(buf)) < 0)
+      ABORT("write to GC log failed");
 }
 
-/* This is equivalent to GC_err_printf("%s",s). */
 void GC_err_puts(const char *s)
 {
     if (WRITE(GC_stderr, s, strlen(s)) < 0) ABORT("write to stderr failed");
@@ -1493,6 +1503,7 @@ void GC_err_puts(const char *s)
 
 STATIC void GC_CALLBACK GC_default_warn_proc(char *msg, GC_word arg)
 {
+    /* TODO: Add assertion on arg comply with msg (format).     */
     GC_err_printf(msg, arg);
 }
 
-- 
2.40.0