In some places in we put an error into a local Error*, but forget to use it. Add a Coccinelle patch to find such cases and report them.
Inspired-by: Peter Maydell <peter.mayd...@linaro.org> Signed-off-by: Philippe Mathieu-Daudé <f4...@amsat.org> --- .../find-missing-error_propagate.cocci | 53 +++++++++++++++++++ MAINTAINERS | 1 + 2 files changed, 54 insertions(+) create mode 100644 scripts/coccinelle/find-missing-error_propagate.cocci diff --git a/scripts/coccinelle/find-missing-error_propagate.cocci b/scripts/coccinelle/find-missing-error_propagate.cocci new file mode 100644 index 0000000000..8b75b37b64 --- /dev/null +++ b/scripts/coccinelle/find-missing-error_propagate.cocci @@ -0,0 +1,53 @@ +// Find places likely missing error-propagation code, but code is too +// complex for automatic transformation, so manual analysis is required. +// +// 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/find-missing-error_propagate.cocci +// +// Inspired by https://www.mail-archive.com/qemu-devel@nongnu.org/msg691638.html + + +// First match two subsequent calls using local Error* +// in function provided a Error** argument +// +@discard_func_with_errp_argument@ +typedef Error; +Error *local_err; +identifier func, errp, errfunc1, errfunc2; +@@ +void func(..., Error **errp) +{ + <+... + errfunc1(..., &local_err); + ... when != local_err // local_err is not used between the calls + errfunc2(..., &local_err); + ...+> +} + + +// Again, match two subsequent calls using local Error* +// but ignoring within functions provided a Error** argument +// +@manual depends on never discard_func_with_errp_argument@ +Error *local_err; +identifier errfunc1, errfunc2; +position p; +@@ + errfunc1@p(..., &local_err); + ... when != local_err + errfunc2(..., &local_err); + + +// As it is likely too complex to transform, report the hit +// +@script:python@ +f << manual.errfunc1; +p << manual.p; +@@ +print("[[manual check required: " + "error_propagate() might be missing in {}() {}:{}:{}]]".format( + f, p[0].file, p[0].line, p[0].column)) diff --git a/MAINTAINERS b/MAINTAINERS index ae71a0a4b0..29d29461f3 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -2057,6 +2057,7 @@ F: scripts/coccinelle/add-missing-error_propagate.cocci F: scripts/coccinelle/err-bad-newline.cocci F: scripts/coccinelle/error-use-after-free.cocci F: scripts/coccinelle/error_propagate_null.cocci +F: scripts/coccinelle/find-missing-error_propagate.cocci F: scripts/coccinelle/remove_local_err.cocci F: scripts/coccinelle/simplify-init-realize-error_propagate.cocci F: scripts/coccinelle/use-error_abort-in-instance_init.cocci -- 2.21.1
