Re: [PATCH v2 00/12] fsmonitor: Implement fsmonitor for Linux

From: Glen Choo <chooglen@google.com>
To: Eric DeCosta via GitGitGadget <gitgitgadget@gmail.com>,
	git@vger.kernel.org
Cc: "Eric Sunshine" <sunshine@sunshineco.com>,
	"Ævar Arnfjörð Bjarmason" <avarab@gmail.com>,
	"Eric DeCosta" <edecosta@mathworks.com>
Subject: Re: [PATCH v2 00/12] fsmonitor: Implement fsmonitor for Linux
Date: Mon, 17 Oct 2022 15:14:04 -0700	[thread overview]
Message-ID: <kl6l7d0yyu6r.fsf@chooglen-macbookpro.roam.corp.google.com> (raw)
In-Reply-To: <pull.1352.v2.git.git.1665783944.gitgitgadget@gmail.com>

At $DAYJOB, we observed that this topic breaks MacOS builds with sha1dc:

  $ make NO_APPLE_COMMON_CRYPTO=1 DC_SHA1=1 NO_OPENSSL=1 compat/fsmonitor/fsm-ipc-darwin.o  

      CC compat/fsmonitor/fsm-ipc-darwin.o
    compat/fsmonitor/fsm-ipc-darwin.c:13:2: error: unknown type name 'SHA_CTX'; did you mean 'SHA1_CTX'?
            SHA_CTX sha1ctx;
            ^~~~~~~
            SHA1_CTX
    ./sha1dc/sha1.h:55:3: note: 'SHA1_CTX' declared here
    } SHA1_CTX;
      ^
    compat/fsmonitor/fsm-ipc-darwin.c:16:21: error: use of undeclared identifier 'SHA_DIGEST_LENGTH'
            unsigned char hash[SHA_DIGEST_LENGTH];
                              ^
    compat/fsmonitor/fsm-ipc-darwin.c:31:2: error: implicit declaration of function 'SHA1_Init' is invalid in C99 [-Werror,-Wimplicit-function-declaration]
            SHA1_Init(&sha1ctx);
            ^
    compat/fsmonitor/fsm-ipc-darwin.c:31:2: note: did you mean 'SHA1DCInit'?
    ./sha1dc/sha1.h:58:6: note: 'SHA1DCInit' declared here
    void SHA1DCInit(SHA1_CTX*);
        ^
    compat/fsmonitor/fsm-ipc-darwin.c:32:2: error: implicit declaration of function 'SHA1_Update' is invalid in C99 [-Werror,-Wimplicit-function-declaration]
            SHA1_Update(&sha1ctx, r->worktree, strlen(r->worktree));
            ^
    compat/fsmonitor/fsm-ipc-darwin.c:32:2: note: did you mean 'SHA1DCUpdate'?
    ./sha1dc/sha1.h:96:6: note: 'SHA1DCUpdate' declared here
    void SHA1DCUpdate(SHA1_CTX*, const char*, size_t);
        ^
    compat/fsmonitor/fsm-ipc-darwin.c:33:2: error: implicit declaration of function 'SHA1_Final' is invalid in C99 [-Werror,-Wimplicit-function-declaration]
            SHA1_Final(hash, &sha1ctx);
            ^
    compat/fsmonitor/fsm-ipc-darwin.c:33:2: note: did you mean 'SHA1DCFinal'?
    ./sha1dc/sha1.h:100:6: note: 'SHA1DCFinal' declared here
    int  SHA1DCFinal(unsigned char[20], SHA1_CTX*);
        ^
    5 errors generated.
    make: *** [compat/fsmonitor/fsm-ipc-darwin.o] Error 1

Without NO_OPENSSL, this still fails, but with slightly different error
messages.

  $ make NO_APPLE_COMMON_CRYPTO=1 DC_SHA1=1 compat/fsmonitor/fsm-ipc-darwin.o

        CC compat/fsmonitor/fsm-ipc-darwin.o
    compat/fsmonitor/fsm-ipc-darwin.c:31:2: error: 'SHA1_Init' is deprecated [-Werror,-Wdeprecated-declarations]
            SHA1_Init(&sha1ctx);
            ^
    /opt/local/include/openssl/sha.h:49:1: note: 'SHA1_Init' has been explicitly marked deprecated here
    OSSL_DEPRECATEDIN_3_0 int SHA1_Init(SHA_CTX *c);
    ^
    /opt/local/include/openssl/macros.h:182:49: note: expanded from macro 'OSSL_DEPRECATEDIN_3_0'
    #   define OSSL_DEPRECATEDIN_3_0                OSSL_DEPRECATED(3.0)
                                                    ^
    /opt/local/include/openssl/macros.h:62:52: note: expanded from macro 'OSSL_DEPRECATED'
    #     define OSSL_DEPRECATED(since) __attribute__((deprecated))
                                                      ^
    compat/fsmonitor/fsm-ipc-darwin.c:32:2: error: 'SHA1_Update' is deprecated [-Werror,-Wdeprecated-declarations]
            SHA1_Update(&sha1ctx, r->worktree, strlen(r->worktree));
            ^
    /opt/local/include/openssl/sha.h:50:1: note: 'SHA1_Update' has been explicitly marked deprecated here
    OSSL_DEPRECATEDIN_3_0 int SHA1_Update(SHA_CTX *c, const void *data, size_t len);
    ^
    /opt/local/include/openssl/macros.h:182:49: note: expanded from macro 'OSSL_DEPRECATEDIN_3_0'
    #   define OSSL_DEPRECATEDIN_3_0                OSSL_DEPRECATED(3.0)
                                                    ^
    /opt/local/include/openssl/macros.h:62:52: note: expanded from macro 'OSSL_DEPRECATED'
    #     define OSSL_DEPRECATED(since) __attribute__((deprecated))
                                                      ^
    compat/fsmonitor/fsm-ipc-darwin.c:33:2: error: 'SHA1_Final' is deprecated [-Werror,-Wdeprecated-declarations]
            SHA1_Final(hash, &sha1ctx);
            ^
    /opt/local/include/openssl/sha.h:51:1: note: 'SHA1_Final' has been explicitly marked deprecated here
    OSSL_DEPRECATEDIN_3_0 int SHA1_Final(unsigned char *md, SHA_CTX *c);
    ^
    /opt/local/include/openssl/macros.h:182:49: note: expanded from macro 'OSSL_DEPRECATEDIN_3_0'
    #   define OSSL_DEPRECATEDIN_3_0                OSSL_DEPRECATED(3.0)
                                                    ^
    /opt/local/include/openssl/macros.h:62:52: note: expanded from macro 'OSSL_DEPRECATED'
    #     define OSSL_DEPRECATED(since) __attribute__((deprecated))
                                                      ^
    3 errors generated.
    make: *** [compat/fsmonitor/fsm-ipc-darwin.o] Error 1

"Eric DeCosta via GitGitGadget" <gitgitgadget@gmail.com> writes:

> Goal is to deliver fsmonitor for Linux that is on par with fsmonitor for
> Windows and Mac OS.
>
> This patch set builds upon previous work for done for Windows and Mac OS
> (first 6 patches) to implement a fsmonitor back-end for Linux based on the
> Linux inotify API. inotify differs significantly from the equivalent Windows
> and Mac OS APIs in that a watch must be registered for every directory of
> interest (rather than a singular watch at the root of the directory tree)
> and special care must be taken to handle directory renames correctly.
>
> More information about inotify:
> https://man7.org/linux/man-pages/man7/inotify.7.html
>
> v1 differs from v0:
>
>  * Code review feedback
>  * Update how and which code can be shared between Mac OS and Linux
>  * Increase polling frequency to every 1ms (matches Mac OS)
>  * Updates to t7527 to improve test stability
>