fixinc.math

来自「GCC编译器源代码」· MATH 代码 · 共 54 行

#! /bin/sh
# Fix struct exception in /usr/include/math.h.
#
# We expect several systems which did not need fixincludes in the past
# to need to fix just math.h.  So we created a separate fixinc.math
# script to fix just that problem.
# See README-fixinc for more information.

# Directory containing the original header files.
# (This was named INCLUDES, but that conflicts with a name in Makefile.in.)
INPUT=${2-${INPUT-/usr/include}}

# Directory in which to store the results.
LIB=${1?"fixincludes: output directory not specified"}

# Make sure it exists.
if [ ! -d $LIB ]; then
  mkdir $LIB || exit 1
fi

echo Building fixed headers in ${LIB}

# Some math.h files define struct exception, which conflicts with
# the class exception defined in the C++ file std/stdexcept.h.  We
# redefine it to __math_exception.  This is not a great fix, but I
# haven't been able to think of anything better.
file=math.h
if [ -r $INPUT/$file ]; then
  echo Checking $INPUT/$file
  if grep 'struct exception' $INPUT/$file >/dev/null
  then
    echo Fixed $file
    rm -f $LIB/$file
    cat <<'__EOF__' >$LIB/$file
#ifndef _MATH_H_WRAPPER
#ifdef __cplusplus
# define exception __math_exception
#endif
#include_next <math.h>
#ifdef __cplusplus
# undef exception
#endif
#define _MATH_H_WRAPPER
#endif /* _MATH_H_WRAPPER */
__EOF__
    # Define _MATH_H_WRAPPER at the end of the wrapper, not the start,
    # so that if #include_next gets another instance of the wrapper,
    # this will follow the #include_next chain until we arrive at
    # the real <math.h>.
    chmod a+r $LIB/$file
  fi
fi
exit 0