CC_FOR_BUILD 宏定义问题

说明

        编译indent-2.2.12出错

/indent-2.2.12/man'
o texinfo2man ./texinfo2man.c
make[2]: o: Command not found
make[2]: [Makefile:546: texinfo2man] Error 127 (ignored)
./texinfo2man ./indent.1.in ./../doc/indent.texi > indent.1
/bin/sh: ./texinfo2man: No such file or directory
make[2]: *** [Makefile:549: indent.1] Error 127
make[2]: Leaving directory '/3thrdparty/indent-2.2.12/man'
make[1]: *** [Makefile:455: all-recursive] Error 1
make[1]: Leaving directory '/3thrdparty/indent-2.2.12'
make: *** [Makefile:393: all] Error 2

排查man/Makefile编译文件

$(CC_FOR_BUILD) -o $@ ${srcdir}/texinfo2man.c

无法识别CC_FOR_BUILD

解决该问题，可以通过修改宏定义

$(CC) -o $@ ${srcdir}/texinfo2man.c

引申

autoconf cached variables (CC_FOR_BUILD)，搜索autoconf脚本没有搜索到任何的信息

文件夹目录下config/config.guess中对CC_FOR_BUILD进行了详细的说明

# CC_FOR_BUILD -- compiler used by this script. Note that the use of a
# compiler to aid in system detection is discouraged as it requires
# temporary files to be created and, as you can see below, it is a
# headache to deal with in a portable fashion.

# Historically, `CC_FOR_BUILD' used to be named `HOST_CC'. We still
# use `HOST_CC' if defined, but it is deprecated.

在其他的开源中定义了该宏定义

secp256k1/build-aux/m4/ax_prog_cc_for_build.m4

This macro searches for a C compiler that generates native executables,
#   that is a C compiler that surely is not a cross-compiler. This can be
#   useful if you have to generate source code at compile-time like for
#   example GCC does.
#
#   The macro sets the CC_FOR_BUILD and CPP_FOR_BUILD macros to anything
#   needed to compile or link (CC_FOR_BUILD) and preprocess (CPP_FOR_BUILD).
#   The value of these variables can be overridden by the user by specifying
#   a compiler with an environment variable (like you do for standard CC).

config.guess这里对宏定义进行了赋值

set_cc_for_build='
trap "exitcode=\$?; (rm -f \$tmpfiles 2>/dev/null; rmdir \$tmp 2>/dev/null) && exit \$exitcode" 0 ;
trap "rm -f \$tmpfiles 2>/dev/null; rmdir \$tmp 2>/dev/null; exit 1" 1 2 13 15 ;
: ${TMPDIR=/tmp} ;
 { tmp=`(umask 077 && mktemp -d "$TMPDIR/cgXXXXXX") 2>/dev/null` && test -n "$tmp" && test -d "$tmp" ; } ||
 { test -n "$RANDOM" && tmp=$TMPDIR/cg$$-$RANDOM && (umask 077 && mkdir $tmp) ; } ||
 { tmp=$TMPDIR/cg-$$ && (umask 077 && mkdir $tmp) && echo "Warning: creating insecure temp directory" >&2 ; } ||
 { echo "$me: cannot create a temporary directory in $TMPDIR" >&2 ; exit 1 ; } ;
dummy=$tmp/dummy ;
tmpfiles="$dummy.c $dummy.o $dummy.rel $dummy" ;
case $CC_FOR_BUILD,$HOST_CC,$CC in
 ,,)    echo "int x;" > $dummy.c ;
 for c in cc gcc c89 c99 ; do
   if ($c -c -o $dummy.o $dummy.c) >/dev/null 2>&1 ; then
      CC_FOR_BUILD="$c"; break ;
   fi ;
 done ;
 if test x"$CC_FOR_BUILD" = x ; then
   CC_FOR_BUILD=no_compiler_found ;
 fi
 ;;
 ,,*)   CC_FOR_BUILD=$CC ;;
 ,*,*)  CC_FOR_BUILD=$HOST_CC ;;
esac ; set_cc_for_build= ;'