[Rd] new warnings when compiling cmplxblas.f

[Toby Hocking]

Hi all, I am observing the following warnings which are new (at least on my
system, ubuntu 18.04 with gfortran 10.1) when compiling the new release,
R-4.2.1 (make command).

$ ./configure --prefix=$HOME --enable-lto
...
$ make
...
make[4]: Entering directory '/home/tdhock/R/R-4.2.1/src/extra/blas'
gfortran -fno-optimize-sibling-calls -fpic  -g -O2 -mtune=native -Wall
-pedantic -flto -c blas.f -o blas.o
gfortran -fno-optimize-sibling-calls -fpic  -g -O2 -mtune=native -Wall
-pedantic -flto -c cmplxblas.f -o cmplxblas.o
cmplxblas.f:2:21:

    2 |       double complex z,zz
      |                     1
Warning: GNU Extension: DOUBLE COMPLEX at (1)
...
cmplxblas.f:4808:26:

 4808 |                   RTEMP = RTEMP + DCONJG( A( L, J ) )*A( L, J )
      |                          1
Warning: Possible change of value in conversion from COMPLEX(8) to REAL(8)
at (1) [-Wconversion]
gcc -shared -fopenmp -g -O2 -Wall -pedantic -mtune=native -flto -fpic
 -L/home/tdhock/lib64 -o libRblas.so blas.o  cmplxblas.o -lgfortran -lm
-lquadmath
#gcc-ar -cr libRblas.so blas.o  cmplxblas.o
make[4]: Leaving directory '/home/tdhock/R/R-4.2.1/src/extra/blas'
...
$ gfortran --version
GNU Fortran (GCC) 10.1.0
Copyright (C) 2020 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

Above was the result when using the following in config.site:
RANLIB=gcc-ranlib
AR=gcc-ar
CXXFLAGS="-g -O2 -Wall -pedantic -mtune=native -Wno-ignored-attributes
-Wno-deprecated-declarations -Wno-parentheses"
FFLAGS="-g -O2 -mtune=native -Wall -pedantic"
CFLAGS="-g -O2 -Wall -pedantic -mtune=native"
LDFLAGS="-L$HOME/lib64"

	[[alternative HTML version deleted]]