disable ubsan null checks with gcc

[oliverlee]

Use of GCC with UBSan and the null, returns-nonnull-attribute,
nonnull-attribute checks will cause the compiler to reject valid code
due to use of the underlying GCC option -fno-delete-null-pointer-checks.

This commit patches rules_cc to disable these checks if a GCC compiler
is used with the ubsan feature.

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67762#c2
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71962

This change is needed by #89.

Change-Id: Ic0e5224850d8478aa92806a8f21248e979acce04

[codecov-commenter]

Codecov Report

Merging #93 (d1c8b2e) into master (199bc3e) will not change coverage.
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@@           Coverage Diff           @@
##           master      #93   +/-   ##
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  Coverage   98.82%   98.82%           
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  Files          11       11           
  Lines         255      255           
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  Hits          252      252           
  Misses          3        3           

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[garymm]

Ugh. I hate carrying patches. OK for now I guess.

[oliverlee]

do you want to merge this before #89?

…

On Thu, Sep 28, 2023, 11:41 Gary Miguel ***@***.***> wrote: ***@***.**** approved this pull request. Ugh. I hate carrying patches. OK for now I guess. ------------------------------ In WORKSPACE.bazel <#93 (comment)>: > +# +# The patched cc_* rules adds the sanitize feature disable flags in `copts` only +# for GCC + UBSan builds. As these are set in `user_compile_flags`, these +# options follow `-fsanitize=undefined` when present. +# +# https://bazel.build/rules/lib/toplevel/cc_common#parameters_5 +# +http_archive( + name = "rules_cc", + patch_args = ["-p1"], + patches = ["//toolchain:rules_cc-gcc-ubsan-no-sanitize-null.patch"], + #sha256 = "2037875b9a4456dce4a79d112a8ae885bbc4aad968e6587dca6e64f3a0900cdx", + sha256 = "2037875b9a4456dce4a79d112a8ae885bbc4aad968e6587dca6e64f3a0900cdf", + strip_prefix = "rules_cc-0.0.9", + urls = ["https://github.com/bazelbuild/rules_cc/releases/download/0.0.9/rules_cc-0.0.9.tar.gz"], + #patches = ["//:third_party/google_benchmark.patch"], remove ------------------------------ In WORKSPACE.bazel <#93 (comment)>: > +# (bootlin_toolchain below) as the sanitize feature disable flags will precede +# `-fsanitize=undefined` from `--features=ubsan` and thus be ignored. +# +# https://clang.llvm.org/docs/UndefinedBehaviorSanitizer.html#id3 +# +# The patched cc_* rules adds the sanitize feature disable flags in `copts` only +# for GCC + UBSan builds. As these are set in `user_compile_flags`, these +# options follow `-fsanitize=undefined` when present. +# +# https://bazel.build/rules/lib/toplevel/cc_common#parameters_5 +# +http_archive( + name = "rules_cc", + patch_args = ["-p1"], + patches = ["//toolchain:rules_cc-gcc-ubsan-no-sanitize-null.patch"], + #sha256 = "2037875b9a4456dce4a79d112a8ae885bbc4aad968e6587dca6e64f3a0900cdx", remove ------------------------------ In toolchain/rules_cc-gcc-ubsan-no-sanitize-null.patch <#93 (comment)>: > @@ -0,0 +1,50 @@ +diff --git a/cc/defs.bzl b/cc/defs.bzl +index a3acac7..53ee96e 100644 +--- a/cc/defs.bzl ++++ b/cc/defs.bzl +@@ -46,6 +46,18 @@ def _add_tags(attrs, is_binary = False): + + return attrs + ++def _gcc_no_sanitize_null(attrs): ++ attrs["copts"] = ( ++ attrs.get("copts") or [] + get() takes a default as an optional second arg: attrs.get("copts", []) — Reply to this email directly, view it on GitHub <#93 (review)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AAWT4J3FIN7YF7KZUIQITB3X4XAFHANCNFSM6AAAAAA5ISS56A> . You are receiving this because you authored the thread.Message ID: ***@***.***>