AM_PROG_AS (automake 1.5) conflicts with libtool 1.3.5

[Rob Leslie]

The definition of AM_PROG_AS:

  AC_DEFUN([AM_PROG_AS],
  [# By default we simply use the C compiler to build assembly code.
  AC_REQUIRE([AC_PROG_CC])
  : ${AS='$(CC)'}
  # Set ASFLAGS if not already set.
  : ${ASFLAGS='$(CFLAGS)'}
  AC_SUBST(AS)
  AC_SUBST(ASFLAGS)])

causes problems with libtool, which subsequently contains:

  #! /bin/sh
  # ...

  AS="$(CC)"

causing the program `CC' to be run in a subshell with no arguments, and
assigning the empty string to the shell variable AS. (A symptom of this is the
message "CC: No input files" or perhaps another error message during
compilation depending whether a command named CC exists.)

Perhaps the definition should use ${CC} instead, which is valid in both
makefiles and shell scripts?

Or is this a bug in libtool?

Cheers,

-- 
Rob Leslie
address@hidden