workaround mangle collision between decltype(Rf_error) and decltype(Rf_warning)

[bkietz]

I also cleaned up the signatures of detail:: functions, hopefully it's more readable

[romainfrancois]

I'm still getting the same problem on my current branch of arrow:

==> R CMD INSTALL --preclean --no-multiarch --with-keep.source r

* installing to library ‘/Users/romainfrancois/.R/library/4.0’
*** Generating code with data-raw/codegen.R
* installing *source* package ‘arrow’ ...
** using staged installation
Warning messages:
1: package ‘decor’ was built under R version 4.0.2 
2: package ‘vctrs’ was built under R version 4.0.2 
*** > 378 functions decorated with [[arrow|s3::export]]
*** > generated file `src/arrowExports.cpp`
*** > generated file `R/arrowExports.R`
*** Arrow C++ libraries found via pkg-config
PKG_CFLAGS=-DNDEBUG -I/usr/local/Cellar/apache-arrow/HEAD-81d3f26/include -DARROW_R_WITH_ARROW
PKG_LIBS=-L/usr/local/Cellar/apache-arrow/HEAD-81d3f26/lib -larrow_dataset -lparquet -larrow
clang++ -mmacosx-version-min=10.13 -std=gnu++11 -I"/Library/Frameworks/R.framework/Resources/include" -DNDEBUG -DNDEBUG -I/usr/local/Cellar/apache-arrow/HEAD-81d3f26/include -DARROW_R_WITH_ARROW -I'/Users/romainfrancois/.R/library/4.0/cpp11/include' -I/usr/local/include   -fPIC  -Wall -O3 -Wall -Wimplicit-int-float-conversion -c array.cpp -o array.o
** libs
In file included from array.cpp:18:
In file included from ././arrow_types.h:22:
In file included from ././arrow_cpp11.h:37:
In file included from /Users/romainfrancois/.R/library/4.0/cpp11/include/cpp11.hpp:5:
In file included from /Users/romainfrancois/.R/library/4.0/cpp11/include/cpp11/as.hpp:9:
/Users/romainfrancois/.R/library/4.0/cpp11/include/cpp11/protect.hpp:240:58: error: definition with same mangled name '_ZNK5cpp117protect8functionIFvPKczEEclIJRS3_EEEDTclclL_ZNSt3__17declvalIPS4_EEDTclsr3std3__1E9__declvalIT_ELi0EEEvEEspclsr3stdE7declvalIOT_EEEEDpSE_' as another definition
    decltype(std::declval<F*>()(std::declval<A&&>()...)) operator()(A&&... a) const {
                                                         ^
/Users/romainfrancois/.R/library/4.0/cpp11/include/cpp11/protect.hpp:240:58: note: previous definition is here
1 error generated.
make: *** [array.o] Error 1
ERROR: compilation failed for package ‘arrow’
* removing ‘/Users/romainfrancois/.R/library/4.0/arrow’
* restoring previous ‘/Users/romainfrancois/.R/library/4.0/arrow’

Exited with status 1.

[romainfrancois]

Minor comments, but not really fixing the issue

[jimhester]

If the code prior to #71 works on clang and the current code works on gcc one approach would be to ifdef them?

don't really enjoy playing compiler whack-a-mole though :(

[bkietz]

@jimhester if we can add a test with a minimal reproducer for the compilation failure I'd personally be comfortable adding the #ifdef and trying to golf it out in a follow up. @romainfrancois is working on one

[romainfrancois]

cpp11::cpp_source(code = '
#include <cpp11.hpp>

[[cpp11::register]]
std::string fun() {
  cpp11::stop("b");
  cpp11::warning("c");
}
', quiet = FALSE)
#> clang++ -mmacosx-version-min=10.13 -std=gnu++11 -I"/Library/Frameworks/R.framework/Resources/include" -DNDEBUG -I/Users/romainfrancois/.R/library/4.0/cpp11/include  -I/usr/local/include   -fPIC  -Wall -O3 -Wall -Wimplicit-int-float-conversion -c /private/var/folders/4b/hn4fq98s6810s4ccv2f9hm2h0000gn/T/RtmpnWGTon/file16a78559d98cd/src/code_0.cpp -o /private/var/folders/4b/hn4fq98s6810s4ccv2f9hm2h0000gn/T/RtmpnWGTon/file16a78559d98cd/src/code_0.o
#> In file included from /private/var/folders/4b/hn4fq98s6810s4ccv2f9hm2h0000gn/T/RtmpnWGTon/file16a78559d98cd/src/code_0.cpp:2:
#> In file included from /Users/romainfrancois/.R/library/4.0/cpp11/include/cpp11.hpp:5:
#> In file included from /Users/romainfrancois/.R/library/4.0/cpp11/include/cpp11/as.hpp:9:
#> /Users/romainfrancois/.R/library/4.0/cpp11/include/cpp11/protect.hpp:240:58: error: definition with same mangled name '_ZNK5cpp117protect8functionIFvPKczEEclIJRS3_EEEDTclclL_ZNSt3__17declvalIPS4_EEDTclsr3std3__1E9__declvalIT_ELi0EEEvEEspclsr3stdE7declvalIOT_EEEEDpSE_' as another definition
#>     decltype(std::declval<F*>()(std::declval<A&&>()...)) operator()(A&&... a) const {
#>                                                          ^
#> /Users/romainfrancois/.R/library/4.0/cpp11/include/cpp11/protect.hpp:240:58: note: previous definition is here
#> 1 error generated.
#> make: *** [/private/var/folders/4b/hn4fq98s6810s4ccv2f9hm2h0000gn/T/RtmpnWGTon/file16a78559d98cd/src/code_0.o] Error 1
#> Error in dyn.load(shared_lib, local = TRUE, now = TRUE): unable to load shared object '/var/folders/4b/hn4fq98s6810s4ccv2f9hm2h0000gn/T//RtmpnWGTon/file16a78559d98cd/src/code_0.so':
#>   dlopen(/var/folders/4b/hn4fq98s6810s4ccv2f9hm2h0000gn/T//RtmpnWGTon/file16a78559d98cd/src/code_0.so, 6): image not found

^{Created on 2020-08-10 by the reprex package (v0.3.0.9001)}

[jimhester]

So is the ifdef solution the best option to go forward with this?

[bkietz]

I'm looking at Romain's reproducer. I'll either find a fix today or revert to #ifdefs

[bkietz]

@romainfrancois PTAL

[romainfrancois]

This does fix the issue with the reprex and I can compile arrow#cpp11.

Thanks @bkietz

In terms of style, I'm just wondering if this should rather be safe_noreturn[Rf_error] but I guess this is ok as not supposed to be used by code outside of cpp11.

[bkietz]

@romainfrancois it is internal, so we can rewrite as safe_noreturn anytime