clang complains about "no newline at end of file" in Rcpp/utils/tinyformat.h

[Enchufa2]

I see this when I compile my package with clang. Also here, among other things:

/data/gannet/ripley/R/packages/tests-clang-SAN/Rcpp.Rcheck/Rcpp/include/Rcpp/utils/tinyformat.h:1046:32: warning: no newline at end of file [-Wnewline-eof]
#endif // TINYFORMAT_H_INCLUDED

If the comment is required, a newline should appease clang.

[eddelbuettel]

Clang version? Exact invocation command?

[Enchufa2]

Sorry, in my system, clang 3.9.1, default version shipped with Fedora 25:

ccache clang++ -Qunused-arguments -I/usr/include/R -DNDEBUG -DBOOST_NO_LONG_LONG -I/usr/local/include -I"/home/xxx/R/x86_64-redhat-linux-gnu-library/3.3/Rcpp/include" -I"/home/xxx/R/x86_64-redhat-linux-gnu-library/3.3/BH/include"   -fpic  -O2 -g -pipe -Wall -Werror=format-security -Wp,-D_FORTIFY_SOURCE=2 -fexceptions -fstack-protector-strong --param=ssp-buffer-size=4 -grecord-gcc-switches -specs=/usr/lib/rpm/redhat/redhat-hardened-cc1 -m64 -mtune=generic  -pedantic -Wno-long-long -c policy.cpp -o policy.o
In file included from RcppExports.cpp:4:
In file included from /home/xxx/R/x86_64-redhat-linux-gnu-library/3.3/Rcpp/include/Rcpp.h:27:
In file included from /home/xxx/R/x86_64-redhat-linux-gnu-library/3.3/Rcpp/include/RcppCommon.h:70:
/home/xxx/R/x86_64-redhat-linux-gnu-library/3.3/Rcpp/include/Rcpp/utils/tinyformat.h:1046:32: warning: no newline at end of file [-Wnewline-eof]
#endif // TINYFORMAT_H_INCLUDED

The link points to CRAN's clang-UBSAN checks.

[eddelbuettel]

I cannot reproduce it, though I can generate pages of other warnings :-/

clang++-3.8 and clang++-3.9 on Ubuntu.

[eddelbuettel]

NOW I get it, using `-Wno-conversion -pedantic'.

[Enchufa2]

It seems that this is a warning in some versions of C++ only: see comments here and here.

[coatless]

What is an appropriate battery of compile flags to run against?

[eddelbuettel]

Well @krlmlr helped to get rid of a few of the (easier) conversion warnings so now -Wall -Wextra -pedantic works, now we have some harder ones (in the: need to make sure we don't accidentally pick a wrong variable conversions) left.

My (current) default (for g++) is

CXXFLAGS += -O3 -Wall -pipe -Wno-unused -pedantic -Wextra -Wno-deprecated-declarations

but I few more commented-out lines in there. For clang++ I used

CC=ccache clang-3.9 -Qunused-arguments 
CXX=ccache clang++-3.9 -Qunused-arguments  
CXXFLAGS=-Wall -O3 -Wno-conversion -pedantic