[PATCH-for-5.0 01/12] scripts/coccinelle: Add script to catch missing error_propagate() calls

[Philippe Mathieu-Daudé]

In some places in we put an error into a local Error*, but forget
to check for failure and pass it back to the caller.
Add a Coccinelle patch to catch automatically add the missing code.

Inspired-by: Peter Maydell <address@hidden>
Signed-off-by: Philippe Mathieu-Daudé <address@hidden>
---
 ...ect_property_missing_error_propagate.cocci | 58 +++++++++++++++++++
 1 file changed, 58 insertions(+)
 create mode 100644 
scripts/coccinelle/object_property_missing_error_propagate.cocci

diff --git a/scripts/coccinelle/object_property_missing_error_propagate.cocci 
b/scripts/coccinelle/object_property_missing_error_propagate.cocci
new file mode 100644
index 0000000000..104e345273
--- /dev/null
+++ b/scripts/coccinelle/object_property_missing_error_propagate.cocci
@@ -0,0 +1,58 @@
+// Add missing error-propagation code
+//
+// Copyright: (C) 2020 Philippe Mathieu-Daudé.
+// This work is licensed under the terms of the GNU GPLv2 or later.
+//
+// spatch \
+//  --macro-file scripts/cocci-macro-file.h --include-headers \
+//  --sp-file scripts/coccinelle/object_property_missing_error_propagate.cocci 
\
+//  --keep-comments --smpl-spacing --in-place --dir hw
+//
+// Inspired by https://www.mail-archive.com/address@hidden/msg691638.html
+
+@match exists@
+typedef Error;
+Error *err;
+identifier func, errp;
+identifier object_property_set_type1 =~ "^object_property_set_.*";
+identifier object_property_set_type2 =~ "^object_property_set_.*";
+expression obj;
+@@
+void func(..., Error **errp)
+{
+ <+...
+ object_property_set_type1(obj, ..., &err);
+ ... when != err
+ object_property_set_type2(obj, ..., &err);
+ ...+>
+}
+
+@@
+Error *match.err;
+identifier match.errp;
+identifier match.object_property_set_type1;
+expression match.obj;
+@@
+ object_property_set_type1(obj, ..., &err);
++if (err) {
++    error_propagate(errp, err);
++    return;
++}
+
+@manual depends on never match@
+Error *err;
+identifier object_property_set_type1 =~ "^object_property_set_.*";
+identifier object_property_set_type2 =~ "^object_property_set_.*";
+position p;
+@@
+ object_property_set_type1@p(..., &err);
+ ... when != err
+ object_property_set_type2(..., &err);
+
+@script:python@
+f << manual.object_property_set_type1;
+p << manual.p;
+@@
+print("[[manual check required: "
+      "error_propagate() might be missing in {}() {}:{}:{}]]".format(
+            f, p[0].file, p[0].line, p[0].column))
-- 
2.21.1