ROOT 6.25/01 with clang: several warnings for 'REMOVE_THIS_NOW' [-Wunknown-attributes] during root compilation

[talismanbrandi]

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ROOT Version: 6.25/01
Platform: Darwin 20.5.0 (OS Big Sur)
Compiler: Apple clang 12.0.5

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These warnings were discussed and removed previously: ROOT 6.23/01 with GCC 10: Too many warnings

They seem to have come back in 6.25/01. I am installing from the git repo using the tag 6-25-01 and these appear while compiling root with cmake (specifying only the install prefix).

In file included from /Users/ayanpaul/opt/packages/root/core/macosx/src/TMacOSXSystem.mm:18:
/Users/ayanpaul/opt/packages/root/core/foundation/inc/TError.h:42:38: warning: unknown attribute 'REMOVE_THIS_NOW' ignored [-Wunknown-attributes]
R__EXTERN TVirtualMutex *gErrorMutex R__DEPRECATED(6,26, "ROOT stopped exporting gErrorMutex.");
                                     ^
/Users/ayanpaul/opt/packages/root/core/foundation/inc/ROOT/RConfig.hxx:523:3: note: expanded from macro 'R__DEPRECATED'
  _R__JOIN3_(_R__DEPRECATED_,MAJOR,MINOR)("will be removed in ROOT v" #MAJOR "." #MINOR ": " REASON)
  ^
/Users/ayanpaul/opt/packages/root/core/foundation/inc/ROOT/RConfig.hxx:454:30: note: expanded from macro '_R__JOIN3_'
#   define _R__JOIN3_(F,X,Y) _NAME3_(F,X,Y)
                             ^
/Users/ayanpaul/opt/packages/root/core/foundation/inc/ROOT/RConfig.hxx:436:39: note: expanded from macro '_NAME3_'
#   define _NAME3_(name1,name2,name3) name1##name2##name3
                                      ^
<scratch space>:51:1: note: expanded from here
_R__DEPRECATED_626
^
/Users/ayanpaul/opt/packages/root/core/foundation/inc/ROOT/RConfig.hxx:510:37: note: expanded from macro '_R__DEPRECATED_626'
# define _R__DEPRECATED_626(REASON) _R_DEPRECATED_REMOVE_NOW(REASON)
                                    ^
/Users/ayanpaul/opt/packages/root/core/foundation/inc/ROOT/RConfig.hxx:482:57: note: expanded from macro '_R_DEPRECATED_REMOVE_NOW'
#define _R_DEPRECATED_REMOVE_NOW(REASON) __attribute__((REMOVE_THIS_NOW))
                                                        ^
1 warning generated.

Thanks!

[eguiraud]

Hi @talismanbrandi,
welcome to the ROOT forum and thank you for your report, we will fix this in the next tag.

I think you can either:

• use latest master instead of the v6.25.01 tag
• use the latest stable release rather than a development release, i.e. 6.24.02 at the time of writing

Cheers,
Enrico

[jalopezg]

Hi @talismanbrandi,

To complement @eguiraud’s reply, since a few weeks the latest stable ROOT version can be obtained by checking out the latest-stable branch, i.e.

$ git clone -b latest-stable https://github.com/root-project/root
# or this, if you already have a local clone
$ git checkout latest-stable

I would recommend checking out the current master only if you want to have bleeding-edge ROOT.

Cheers,
J.

[talismanbrandi]

Thanks a lot @eguiraud and @jalopezg !