From: Josh Steadmon <steadmon@google.com>
To: Andrzej Hunt via GitGitGadget <gitgitgadget@gmail.com>
Cc: git@vger.kernel.org, Andrzej Hunt <andrzej@ahunt.org>,
Andrzej Hunt <ajrhunt@google.com>
Subject: Re: [PATCH v3] Makefile: update 'make fuzz-all' docs to reflect modern clang
Date: Wed, 10 Mar 2021 10:52:39 -0800 [thread overview]
Message-ID: <YEkVdx6PugLSX2UF@google.com> (raw)
In-Reply-To: <pull.889.v3.git.1615223682911.gitgitgadget@gmail.com>
On 2021.03.08 17:14, Andrzej Hunt via GitGitGadget wrote:
> From: Andrzej Hunt <ajrhunt@google.com>
>
> Clang no longer produces a libFuzzer.a. Instead, you can include
> libFuzzer by using -fsanitize=fuzzer. Therefore we should use that in
> the example command for building fuzzers.
>
> We also add -fsanitize=fuzzer-no-link to the CFLAGS to ensure that all
> the required instrumentation is added when compiling git [1], and remove
> -fsanitize-coverage=trace-pc-guard as it is deprecated.
>
> I happen to have tested with LLVM 11 - however -fsanitize=fuzzer appears
> to work in a wide range of reasonably modern clangs.
>
> (On my system: what used to be libFuzzer.a now lives under the following
> path, which is tricky albeit not impossible for a novice such as myself
> to find:
> /usr/lib64/clang/11.0.0/lib/linux/libclang_rt.fuzzer-x86_64.a )
>
> [1] https://releases.llvm.org/11.0.0/docs/LibFuzzer.html#fuzzer-usage
>
> Signed-off-by: Andrzej Hunt <ajrhunt@google.com>
> ---
> Update 'make fuzz-all' docs to reflect modern clang
>
> This version of the patch fixes the commit message as per Junio's
> feedback. Thank you!
>
> Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-889%2Fahunt%2Ffuzz-docs-v3
> Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-889/ahunt/fuzz-docs-v3
> Pull-Request: https://github.com/gitgitgadget/git/pull/889
>
> Range-diff vs v2:
>
> 1: f5b5a11966ca ! 1: bc0d8b615410 Update 'make fuzz-all' docs to reflect modern clang
> @@ Metadata
> Author: Andrzej Hunt <ajrhunt@google.com>
>
> ## Commit message ##
> - Update 'make fuzz-all' docs to reflect modern clang
> + Makefile: update 'make fuzz-all' docs to reflect modern clang
>
> - Clang no longer produces a libFuzzer.a, instead you can include
> - libFuzzer by using -fsanitize=fuzzer. Therefore we should use
> - that in the example command for building fuzzers.
> + Clang no longer produces a libFuzzer.a. Instead, you can include
> + libFuzzer by using -fsanitize=fuzzer. Therefore we should use that in
> + the example command for building fuzzers.
>
> - We also add -fsanitize=fuzzer-no-link to ensure that all the required
> - instrumentation is added when compiling git [1], and remove
> + We also add -fsanitize=fuzzer-no-link to the CFLAGS to ensure that all
> + the required instrumentation is added when compiling git [1], and remove
> -fsanitize-coverage=trace-pc-guard as it is deprecated.
>
> - I happen to have tested with LLVM 11 - however -fsanitize=fuzzer appears to
> - work in a wide range of reasonably modern clangs.
> + I happen to have tested with LLVM 11 - however -fsanitize=fuzzer appears
> + to work in a wide range of reasonably modern clangs.
>
> - (On my system: what used to be libFuzzer.a now lives under the following path,
> - which is tricky albeit not impossible for a novice such as myself to find:
> + (On my system: what used to be libFuzzer.a now lives under the following
> + path, which is tricky albeit not impossible for a novice such as myself
> + to find:
> /usr/lib64/clang/11.0.0/lib/linux/libclang_rt.fuzzer-x86_64.a )
>
> [1] https://releases.llvm.org/11.0.0/docs/LibFuzzer.html#fuzzer-usage
>
>
> Makefile | 6 +++---
> 1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/Makefile b/Makefile
> index dfb0f1000fa3..f3dc2178324e 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -3299,11 +3299,11 @@ cover_db_html: cover_db
> # are not necessarily appropriate for general builds, and that vary greatly
> # depending on the compiler version used.
> #
> -# An example command to build against libFuzzer from LLVM 4.0.0:
> +# An example command to build against libFuzzer from LLVM 11.0.0:
> #
> # make CC=clang CXX=clang++ \
> -# CFLAGS="-fsanitize-coverage=trace-pc-guard -fsanitize=address" \
> -# LIB_FUZZING_ENGINE=/usr/lib/llvm-4.0/lib/libFuzzer.a \
> +# CFLAGS="-fsanitize=fuzzer-no-link,address" \
> +# LIB_FUZZING_ENGINE="-fsanitize=fuzzer" \
> # fuzz-all
> #
> FUZZ_CXXFLAGS ?= $(CFLAGS)
>
> base-commit: be7935ed8bff19f481b033d0d242c5d5f239ed50
> --
> gitgitgadget
This version looks good to me, although you may also want to make the
changes Junio suggested regarding LIB_FUZZING_ENGINE.
Thanks!
prev parent reply other threads:[~2021-03-10 18:53 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-02-28 12:22 [PATCH] Update 'make fuzz-all' docs to reflect modern clang Andrzej Hunt via GitGitGadget
2021-03-01 22:39 ` Josh Steadmon
2021-03-04 15:26 ` Andrzej Hunt
2021-03-04 15:28 ` [PATCH v2] " Andrzej Hunt via GitGitGadget
2021-03-04 22:48 ` Junio C Hamano
2021-03-08 17:05 ` Andrzej Hunt
2021-03-08 18:28 ` Junio C Hamano
2021-03-10 18:50 ` Josh Steadmon
2021-03-08 17:14 ` [PATCH v3] Makefile: update " Andrzej Hunt via GitGitGadget
2021-03-10 18:52 ` Josh Steadmon [this message]
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