[MacPorts] #71356: New linker in Command Line Tools 16 not working with fortran BLOCK DATA

[MacPorts]

#71356: New linker in Command Line Tools 16 not working with fortran BLOCK DATA
----------------------+--------------------
 Reporter:  luillo76  |      Owner:  (none)
     Type:  defect    |     Status:  new
 Priority:  Normal    |  Milestone:
Component:  ports     |    Version:
 Keywords:            |       Port:  gcc
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 Hello,

 We've encountered a critical issue with the new linker of CLT16 (version
 16.1.0.0.1.1729049160) that prevents proper initialization of BLOCK DATA
 in Fortran code.
 This affects software built with the Macports-provided GNU gcc13 compiler.

 BLOCK DATA are used to initialize global variables, and its failure to
 initialize those variables leads to a program crash.

 The current workaround is using the `-ld_classic` linker option. However,
 this option is deprecated and will be removed in a future release, as
 described in the Xcode release note
 [https://developer.apple.com/documentation/xcode-release-notes/xcode-16
 -release-notes#Linking].

 I've attached a minimal example that reproduces the problem using GNU
 gcc13 with the following instructions:


 {{{
 gfortran -c bd.f
 gfortran -c main.f

 ar rv libtest.a bd.o main.o

 gfortran -ld_classic -o good.x -L. libtest.a
 gfortran -o bad.x -L. libtest.a
 }}}

 Running the two programs, one can see that the BLOCK DATA are not
 initialised without the option `ld_classic`,


 {{{
 $ > ./good.x
    3.7273802569289098        2.8083922366048202
 $ > ./bad.x
    0.0000000000000000        0.0000000000000000
 }}}


 I'm not sure if this is directly related to Macports, but I suspect it
 might be connected to how Macports builds GCC. Has anyone else encountered
 this issue? Are there any known workarounds within the Macports
 environment?

 Thanks.

-- 
Ticket URL: <https://trac.macports.org/ticket/71356>
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