Deprecated function warning getenv()- unsafe

[mubinskt]

Module:

Description

The inline.h file uses a function called getenv() which results into a warning 'deprecated function'.
https://learn.microsoft.com/en-us/cpp/error-messages/compiler-warnings/compiler-warning-level-3-c4996?f1url=%3FappId%3DDev16IDEF1%26l%3DEN-US%26k%3Dk(C4996)%26rd%3Dtrue&view=msvc-170

link to a discussion on the topic
https://stackoverflow.com/questions/48568707/getenv-function-may-be-unsafe-really

Steps to Reproduce

Rebuild in a MFC Windows application referring perl files.

Expected behavior

Warning resolved

Perl configuration

# perl -V output goes here

This is perl 5, version 32, subversion 1 (v5.32.1) built for MSWin32-x64-multi-thread

Copyright 1987-2021, Larry Wall

Perl may be copied only under the terms of either the Artistic License or the
GNU General Public License, which may be found in the Perl 5 source kit.

Complete documentation for Perl, including FAQ lists, should be found on
this system using "man perl" or "perldoc perl".  If you have access to the
Internet, point your browser at http://www.perl.org/, the Perl Home Page.

[demerphq]

The latest version of the code includes an extensive discussion of the implications of this function and whether we consider it unsafe. TLDR: we now use mutex locks to prevent it being used in a way which is unsafe, and we copy its results immediately to a new buffer. Provided only perl code itself is being used to access the environment, this should be fine and the warning can be ignored.

https://github.com/Perl/perl5/blob/blead/inline.h#L3285

[tonycoz]

What options are the object file being built with?

In particular I think you need at least -DMULTIPLICITY -DPERL_IMPLICIT_SYS, assuming your perl was built with them.

See the result of perl -V:ccflags to see if perl was built with them. Some of the other definitions from ccflags may also be needed.

For a default build of perl for Win32 a call to getenv() calls PerlEnv_getenv() which ends up calling win32_getenv() in win32/win32.c which uses GetEnvironmentVariableA() to fetch the value.

[tonycoz]

perl -V output goes here

This is perl 5, version 32, subversion 1 (v5.32.1) built for MSWin32-x64-multi-thread

This is the perl -v (lower case v) output, not the perl -V (upper-case V) output. Please supply the second.