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Title: On macOS Sierra, warning: implicit declaration of function 'getentropy'
Type: compile error Stage: resolved
Components: Build, macOS Versions: Python 3.7, Python 3.6, Python 3.5, Python 2.7
Status: closed Resolution: fixed
Dependencies: Superseder:
Assigned To: Nosy List:, ned.deily, python-dev, ronaldoussoren
Priority: normal Keywords: patch

Created on 2016-11-12 19:30 by, last changed 2022-04-11 14:58 by admin. This issue is now closed.

File name Uploaded Description Edit
getentropy.patch, 2016-11-12 19:30 review
Pull Requests
URL Status Linked Edit
PR 552 closed dstufft, 2017-03-31 16:36
Messages (3)
msg280669 - (view) Author: Gareth Rees ( * (Python triager) Date: 2016-11-12 19:30
On macOS Sierra (OSX 10.12.1):

    $ ./configure --with-pydebug && make
    [... lots of output omitted ...]
    gcc -c -Wno-unused-result -Wsign-compare -g -O0 -Wall -Wstrict-prototypes    -std=c99 -Wextra -Wno-unused-result -Wno-unused-parameter -Wno-missing-field-initializers   -I. -I./Include    -DPy_BUILD_CORE -o Python/random.o Python/random.c
    Python/random.c:97:19: warning: implicit declaration of function 'getentropy' is
          invalid in C99 [-Wimplicit-function-declaration]
                res = getentropy(buffer, len);
    1 warning generated.

This is because OSX 10.12.1 has getentropy() but does not have
getrandom(). You can see this in pyconfig.h:

    /* Define to 1 if you have the `getentropy' function. */
    #define HAVE_GETENTROPY 1

    /* Define to 1 if the getrandom() function is available */
    /* #undef HAVE_GETRANDOM */

and this means that in Python/random.c the header <sys/random.h> is
not included:

    #  ifdef HAVE_GETRANDOM
    #    include <sys/random.h>
    #  elif defined(HAVE_GETRANDOM_SYSCALL)
    #    include <sys/syscall.h>
    #  endif

It's necessary include <sys/random.h> if either HAVE_GETRANDOM or
msg280672 - (view) Author: Roundup Robot (python-dev) (Python triager) Date: 2016-11-12 21:40
New changeset 828251c2bccf by Ned Deily in branch '2.7':
Issue #28676: Prevent missing 'getentropy' declaration warning on macOS.

New changeset 0efd48d4c47c by Ned Deily in branch '3.5':
Issue #28676: Prevent missing 'getentropy' declaration warning on macOS.

New changeset e2faa8a22b69 by Ned Deily in branch '3.6':
Issue #28676: merge from 3.5

New changeset b31a7efd8b31 by Ned Deily in branch 'default':
Issue #28676: merge from 3.6
msg280674 - (view) Author: Ned Deily (ned.deily) * (Python committer) Date: 2016-11-12 21:43
Thanks for the patch, Gareth!  Pushed for release in 2.7.13, 3.5.3, 3.6.0b4, and 3.7.0.
Date User Action Args
2022-04-11 14:58:39adminsetgithub: 72862
2017-03-31 16:36:38dstufftsetpull_requests: + pull_request1105
2016-11-12 21:43:39ned.deilysetstatus: open -> closed
versions: + Python 2.7, Python 3.5, Python 3.6
messages: + msg280674

resolution: fixed
stage: resolved
2016-11-12 21:40:41python-devsetnosy: + python-dev
messages: + msg280672
2016-11-12 19:30:20gdr@garethrees.orgcreate