[Qemu-devel] [PATCH 03/14] qerror: drop qerror_abort()

[Luiz Capitulino <lcapitulino@redhat.com>]

Previously, developers had to create error dicts manually and also enter
the matching desc table entry. Thus, qerro_abort() was added to help
catching bad error dicts.

Today, all that stuff is generated automatically which makes the chance
of a bad generated dict quite low.

Also, qerror_abort() would... _abort_ on a bad error dict!

This commit maintains the same verification logic on the error object
but drops the abort() in favor of reporting UndefinedError for bad dicts
(and also print a debug message to stderr).

Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
---
 qerror.c | 83 +++++++++++++++++++++++++++++++++++-----------------------------
 1 file changed, 46 insertions(+), 37 deletions(-)

diff --git a/qerror.c b/qerror.c
index d428b52..74b3659 100644
--- a/qerror.c
+++ b/qerror.c
@@ -38,55 +38,50 @@ static QError *qerror_new(void)
     return qerr;
 }
 
-static void GCC_FMT_ATTR(2, 3) qerror_abort(const QError *qerr,
-                                            const char *fmt, ...)
-{
-    va_list ap;
-
-    fprintf(stderr, "qerror: bad call in function '%s':\n", qerr->func);
-    fprintf(stderr, "qerror: -> ");
-
-    va_start(ap, fmt);
-    vfprintf(stderr, fmt, ap);
-    va_end(ap);
-
-    fprintf(stderr, "\nqerror: call at %s:%d\n", qerr->file, qerr->linenr);
-    abort();
-}
-
-static void GCC_FMT_ATTR(2, 0) qerror_set_data(QError *qerr,
-                                               const char *fmt, va_list *va)
+static QDict *error_object_from_fmt(const char *fmt, va_list *va)
 {
     QObject *obj;
+    QDict *ret;
 
     obj = qobject_from_jsonv(fmt, va);
     if (!obj) {
-        qerror_abort(qerr, "invalid format '%s'", fmt);
+        fprintf(stderr, "invalid json in error dict '%s'\n", fmt);
+        return NULL;
     }
     if (qobject_type(obj) != QTYPE_QDICT) {
-        qerror_abort(qerr, "error format is not a QDict '%s'", fmt);
+        fprintf(stderr, "error is not a dict '%s'\n", fmt);
+        goto out_free;
     }
 
-    qerr->error = qobject_to_qdict(obj);
-
-    obj = qdict_get(qerr->error, "class");
+    ret = qobject_to_qdict(obj);
+    obj = qdict_get(ret, "class");
     if (!obj) {
-        qerror_abort(qerr, "missing 'class' key in '%s'", fmt);
+        fprintf(stderr, "missing 'class' key in '%s'\n", fmt);
+        goto out_free;
     }
     if (qobject_type(obj) != QTYPE_QSTRING) {
-        qerror_abort(qerr, "'class' key value should be a QString");
+        fprintf(stderr, "'class' key value should be a string in '%s'\n", fmt);
+        goto out_free;
     }
-    
-    obj = qdict_get(qerr->error, "data");
+
+    obj = qdict_get(ret, "data");
     if (!obj) {
-        qerror_abort(qerr, "missing 'data' key in '%s'", fmt);
+        fprintf(stderr, "missing 'data' key in '%s'\n", fmt);
+        goto out_free;
     }
     if (qobject_type(obj) != QTYPE_QDICT) {
-        qerror_abort(qerr, "'data' key value should be a QDICT");
+        fprintf(stderr, "'data' key value should be a dict in '%s'\n", fmt);
+        goto out_free;
     }
+
+    return ret;
+
+out_free:
+    qobject_decref(obj);
+    return NULL;
 }
 
-static void qerror_set_desc(QError *qerr, const char *fmt)
+static const QErrorStringTable *error_get_desc(const char *fmt)
 {
     int i;
 
@@ -94,12 +89,17 @@ static void qerror_set_desc(QError *qerr, const char *fmt)
 
     for (i = 0; qerror_table[i].error_fmt; i++) {
         if (strcmp(qerror_table[i].error_fmt, fmt) == 0) {
-            qerr->entry = &qerror_table[i];
-            return;
+            return &qerror_table[i];
         }
     }
 
-    qerror_abort(qerr, "error format '%s' not found", fmt);
+    fprintf(stderr, "error format '%s' not found\n", fmt);
+    return NULL;
+}
+
+static QDict *build_error_no_arg(const char *fmt)
+{
+    return qobject_to_qdict(qobject_from_jsonv(fmt, NULL));
 }
 
 /**
@@ -127,13 +127,22 @@ static QError *qerror_from_info(const char *file, int linenr, const char *func,
     qerr->file = file;
     qerr->func = func;
 
-    if (!fmt) {
-        qerror_abort(qerr, "QDict not specified");
+    qerr->error = error_object_from_fmt(fmt, va);
+    if (!qerr->error) {
+        goto bad_err;
+    }
+
+    qerr->entry = error_get_desc(fmt);
+    if (!qerr->entry) {
+        QDECREF(qerr->error);
+        goto bad_err;
     }
 
-    qerror_set_data(qerr, fmt, va);
-    qerror_set_desc(qerr, fmt);
+    return qerr;
 
+bad_err:
+    qerr->error = build_error_no_arg(QERR_UNDEFINED_ERROR);
+    qerr->entry = error_get_desc(QERR_UNDEFINED_ERROR);
     return qerr;
 }
 
-- 
1.7.11.2.249.g31c7954.dirty