[RFC v5 003/126] error: rename errp to errp_in where it is IN-argument

[Vladimir Sementsov-Ogievskiy]

Error **errp is almost always OUT-argument: it's assumed to be NULL, or
pointer to NULL-initialized pointer, or pointer to error_abort or
error_fatal, for callee to report error.

But very few functions instead get Error **errp as IN-argument:
it's assumed to be set (or, maybe, NULL), and callee should clean it,
or add some information.

In such cases, rename errp to errp_in.

This patch updates only error API functions. There still a few
functions with errp-in semantics, they will be updated in further
commits.

Signed-off-by: Vladimir Sementsov-Ogievskiy <address@hidden>
---
 include/qapi/error.h |  8 ++++----
 util/error.c         | 30 +++++++++++++++---------------
 2 files changed, 19 insertions(+), 19 deletions(-)

diff --git a/include/qapi/error.h b/include/qapi/error.h
index 3f95141a01..12532bdf69 100644
--- a/include/qapi/error.h
+++ b/include/qapi/error.h
@@ -233,13 +233,13 @@ void error_propagate_prepend(Error **dst_errp, Error 
*local_err,
  * Prepend some text to @errp's human-readable error message.
  * The text is made by formatting @fmt, @ap like vprintf().
  */
-void error_vprepend(Error **errp, const char *fmt, va_list ap);
+void error_vprepend(Error **errp_in, const char *fmt, va_list ap);
 
 /*
  * Prepend some text to @errp's human-readable error message.
  * The text is made by formatting @fmt, ... like printf().
  */
-void error_prepend(Error **errp, const char *fmt, ...)
+void error_prepend(Error **errp_in, const char *fmt, ...)
     GCC_FMT_ATTR(2, 3);
 
 /*
@@ -256,7 +256,7 @@ void error_prepend(Error **errp, const char *fmt, ...)
  * May be called multiple times.  The resulting hint should end with a
  * newline.
  */
-void error_append_hint(Error **errp, const char *fmt, ...)
+void error_append_hint(Error **errp_in, const char *fmt, ...)
     GCC_FMT_ATTR(2, 3);
 
 /*
@@ -283,7 +283,7 @@ void error_free(Error *err);
 /*
  * Convenience function to assert that *@errp is set, then silently free it.
  */
-void error_free_or_abort(Error **errp);
+void error_free_or_abort(Error **errp_in);
 
 /*
  * Convenience function to warn_report() and free @err.
diff --git a/util/error.c b/util/error.c
index d4532ce318..275586faa8 100644
--- a/util/error.c
+++ b/util/error.c
@@ -121,41 +121,41 @@ void error_setg_file_open_internal(Error **errp,
                               "Could not open '%s'", filename);
 }
 
-void error_vprepend(Error **errp, const char *fmt, va_list ap)
+void error_vprepend(Error **errp_in, const char *fmt, va_list ap)
 {
     GString *newmsg;
 
-    if (!errp) {
+    if (!errp_in) {
         return;
     }
 
     newmsg = g_string_new(NULL);
     g_string_vprintf(newmsg, fmt, ap);
-    g_string_append(newmsg, (*errp)->msg);
-    g_free((*errp)->msg);
-    (*errp)->msg = g_string_free(newmsg, 0);
+    g_string_append(newmsg, (*errp_in)->msg);
+    g_free((*errp_in)->msg);
+    (*errp_in)->msg = g_string_free(newmsg, 0);
 }
 
-void error_prepend(Error **errp, const char *fmt, ...)
+void error_prepend(Error **errp_in, const char *fmt, ...)
 {
     va_list ap;
 
     va_start(ap, fmt);
-    error_vprepend(errp, fmt, ap);
+    error_vprepend(errp_in, fmt, ap);
     va_end(ap);
 }
 
-void error_append_hint(Error **errp, const char *fmt, ...)
+void error_append_hint(Error **errp_in, const char *fmt, ...)
 {
     va_list ap;
     int saved_errno = errno;
     Error *err;
 
-    if (!errp) {
+    if (!errp_in) {
         return;
     }
-    err = *errp;
-    assert(err && errp != &error_abort && errp != &error_fatal);
+    err = *errp_in;
+    assert(err && errp_in != &error_abort && errp_in != &error_fatal);
 
     if (!err->hint) {
         err->hint = g_string_new(NULL);
@@ -271,11 +271,11 @@ void error_free(Error *err)
     }
 }
 
-void error_free_or_abort(Error **errp)
+void error_free_or_abort(Error **errp_in)
 {
-    assert(errp && *errp);
-    error_free(*errp);
-    *errp = NULL;
+    assert(errp_in && *errp_in);
+    error_free(*errp_in);
+    *errp_in = NULL;
 }
 
 void error_propagate(Error **dst_errp, Error *local_err)
-- 
2.21.0