Documentation/hooks: add pre-auto-gc hook

diff --git a/usage.c b/usage.c
index 52c2e960560531b62a28a8a716e531093fd5e8a7..a5fc4ec5fae66823266862fa0254474696c220e6 100644 (file)
--- a/usage.c
+++ b/usage.c
@@ -7,9 +7,9 @@
 
 static void report(const char *prefix, const char *err, va_list params)
 {
-       fputs(prefix, stderr);
-       vfprintf(stderr, err, params);
-       fputs("\n", stderr);
+       char msg[256];
+       vsnprintf(msg, sizeof(msg), err, params);
+       fprintf(stderr, "%s%s\n", prefix, msg);
 }
 
 static NORETURN void usage_builtin(const char *err)
@@ -29,12 +29,17 @@ static void error_builtin(const char *err, va_list params)
        report("error: ", err, params);
 }
 
+static void warn_builtin(const char *warn, va_list params)
+{
+       report("warning: ", warn, params);
+}
 
 /* If we are in a dlopen()ed .so write to a global variable would segfault
  * (ugh), so keep things static. */
 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;
 
 void set_usage_routine(void (*routine)(const char *err) NORETURN)
 {
@@ -51,6 +56,11 @@ void set_error_routine(void (*routine)(const char *err, va_list params))
        error_routine = routine;
 }
 
+void set_warn_routine(void (*routine)(const char *warn, va_list params))
+{
+       warn_routine = routine;
+}
+
 
 void usage(const char *err)
 {
@@ -75,3 +85,12 @@ int error(const char *err, ...)
        va_end(params);
        return -1;
 }
+
+void warning(const char *warn, ...)
+{
+       va_list params;
+
+       va_start(params, warn);
+       warn_routine(warn, params);
+       va_end(params);
+}