[PATCH 4/5] implement error_errno and warning_errno

[Luke Dashjr <luke-jr+git@utopios.org>]

This allows for easier conversion of code that currently does a (fatal)
die_errno to a safer error (which can be ignored), or perhaps even warning
status.

Signed-off-by: Luke Dashjr <luke-jr+git@utopios.org>
---
 git-compat-util.h |    2 +
 usage.c           |   66 ++++++++++++++++++++++++-----------------------------
 2 files changed, 32 insertions(+), 36 deletions(-)

diff --git a/git-compat-util.h b/git-compat-util.h
index 9f941e4..25d4c1e 100644
--- a/git-compat-util.h
+++ b/git-compat-util.h
@@ -181,7 +181,9 @@ extern void usage(const char *err) NORETURN;
 extern void die(const char *err, ...) NORETURN __attribute__((format (printf, 1, 2)));
 extern void die_errno(const char *err, ...) NORETURN __attribute__((format (printf, 1, 2)));
 extern int error(const char *err, ...) __attribute__((format (printf, 1, 2)));
+extern int error_errno(const char *err, ...) __attribute__((format (printf, 1, 2)));
 extern void warning(const char *err, ...) __attribute__((format (printf, 1, 2)));
+extern void warning_errno(const char *err, ...) __attribute__((format (printf, 1, 2)));
 
 extern void set_die_routine(void (*routine)(const char *err, va_list params) NORETURN);
 
diff --git a/usage.c b/usage.c
index b6aea45..dce90dc 100644
--- a/usage.c
+++ b/usage.c
@@ -39,7 +39,7 @@ static void warn_builtin(const char *warn, va_list params)
 static void (*usage_routine)(const char *err) NORETURN = usage_builtin;
 static void (*die_routine)(const char *err, va_list params) NORETURN = die_builtin;
 static void (*error_routine)(const char *err, va_list params) = error_builtin;
-static void (*warn_routine)(const char *err, va_list params) = warn_builtin;
+static void (*warning_routine)(const char *err, va_list params) = warn_builtin;
 
 void set_die_routine(void (*routine)(const char *err, va_list params) NORETURN)
 {
@@ -51,19 +51,8 @@ void usage(const char *err)
 	usage_routine(err);
 }
 
-void die(const char *err, ...)
+static void _e_errno(const char *fmt, char *fmt_with_err, size_t sizeof_fmt_with_err)
 {
-	va_list params;
-
-	va_start(params, err);
-	die_routine(err, params);
-	va_end(params);
-}
-
-void die_errno(const char *fmt, ...)
-{
-	va_list params;
-	char fmt_with_err[1024];
 	char str_error[256], *err;
 	int i, j;
 
@@ -81,28 +70,33 @@ void die_errno(const char *fmt, ...)
 		}
 	}
 	str_error[j] = 0;
-	snprintf(fmt_with_err, sizeof(fmt_with_err), "%s: %s", fmt, str_error);
-
-	va_start(params, fmt);
-	die_routine(fmt_with_err, params);
-	va_end(params);
-}
-
-int error(const char *err, ...)
-{
-	va_list params;
-
-	va_start(params, err);
-	error_routine(err, params);
-	va_end(params);
-	return -1;
+	snprintf(fmt_with_err, sizeof_fmt_with_err, "%s: %s", fmt, str_error);
 }
 
-void warning(const char *warn, ...)
-{
-	va_list params;
-
-	va_start(params, warn);
-	warn_routine(warn, params);
-	va_end(params);
-}
+#define BUILD_E(RTYPE, NAME, CODE)  \
+RTYPE NAME(const char *err, ...)  \
+{  \
+	va_list params;  \
+  \
+	va_start(params, err);  \
+	NAME ## _routine(err, params);  \
+	va_end(params);  \
+	CODE  \
+}  \
+  \
+RTYPE NAME ## _errno(const char *fmt, ...)  \
+{  \
+	va_list params;  \
+	static char fmt_with_err[1024];  \
+  \
+	va_start(params, fmt);  \
+	_e_errno(fmt, fmt_with_err, sizeof(fmt_with_err));  \
+	NAME ## _routine(fmt_with_err, params);  \
+	va_end(params);  \
+	CODE  \
+}  \
+// END OF BUILD_E MACRO
+
+BUILD_E(void, die, )
+BUILD_E(int, error, return -1;)
+BUILD_E(void, warning, )
-- 
1.6.3.3