Re: Bug in gnulib-tools prevents bison from bootstrapping

[Bruno Haible]

Eric Blake wrote:
> Since forking external programs matters most on cygwin and mingw ...

Also on AIX, HP-UX, IRIX, OSF/1, Solaris, one can avoid spawning 'cat':
by using the 'print -r' trick from libtool.m4.


2007-06-23  Bruno Haible  <address@hidden>

        * gnulib-tool (echo): Add a speedier workaround for ksh.
        * tests/test-echo.sh: Likewise.

*** gnulib-tool 23 Jun 2007 10:14:04 -0000      1.238
--- gnulib-tool 23 Jun 2007 11:16:22 -0000
***************
*** 431,438 ****
  # - for bash >= 2.0: define echo to a function that uses the printf built-in.
  # - for bash < 2.0: define echo to a function that uses cat of a here 
document.
  # - for zsh: turn sh-emulation on.
  # - for ksh: alias echo to a function that uses cat of a here document.
! # - for Solaris /bin/sh: respawn using /bin/ksh and rely on the ksh 
workaround.
  # - otherwise: respawn using /bin/sh and rely on the workarounds.
  # When respawning, we pass --no-reexec as first argument, so as to avoid
  # turning this script into a fork bomb in unlucky situations.
--- 431,440 ----
  # - for bash >= 2.0: define echo to a function that uses the printf built-in.
  # - for bash < 2.0: define echo to a function that uses cat of a here 
document.
  # - for zsh: turn sh-emulation on.
+ # - for ksh: alias echo to 'print -r'.
  # - for ksh: alias echo to a function that uses cat of a here document.
! # - for Solaris /bin/sh and OSF/1 /bin/sh: respawn using /bin/ksh and rely on
! #   the ksh workaround.
  # - otherwise: respawn using /bin/sh and rely on the workarounds.
  # When respawning, we pass --no-reexec as first argument, so as to avoid
  # turning this script into a fork bomb in unlucky situations.
***************
*** 487,492 ****
--- 489,512 ----
     && (emulate sh) >/dev/null 2>&1; then
    emulate sh
  fi
+ # For ksh: alias echo to 'print -r'.
+ if test -z "$have_echo" \
+    && (type print) >/dev/null 2>&1; then
+   # A 'print' command exists.
+   if type print 2>/dev/null | grep / > /dev/null; then
+     :
+   else
+     # 'print' is a shell built-in.
+     if (print -r '\told' | grep told > /dev/null) 2>/dev/null; then
+       # 'print' is the ksh shell built-in.
+       alias echo='print -r'
+     fi
+   fi
+ fi
+ if test -z "$have_echo" \
+    && echo '\t' | grep t > /dev/null; then
+   have_echo=yes
+ fi
  # For ksh: alias echo to a function that uses cat of a here document.
  # The ksh manual page says:
  #   "Aliasing is performed when scripts are read, not while they are executed.
*** tests/test-echo.sh  23 Jun 2007 10:14:04 -0000      1.3
--- tests/test-echo.sh  23 Jun 2007 11:16:22 -0000
***************
*** 36,43 ****
  # - for bash >= 2.0: define echo to a function that uses the printf built-in.
  # - for bash < 2.0: define echo to a function that uses cat of a here 
document.
  # - for zsh: turn sh-emulation on.
  # - for ksh: alias echo to a function that uses cat of a here document.
! # - for Solaris /bin/sh: respawn using /bin/ksh and rely on the ksh 
workaround.
  # - otherwise: respawn using /bin/sh and rely on the workarounds.
  # When respawning, we pass --no-reexec as first argument, so as to avoid
  # turning this script into a fork bomb in unlucky situations.
--- 36,45 ----
  # - for bash >= 2.0: define echo to a function that uses the printf built-in.
  # - for bash < 2.0: define echo to a function that uses cat of a here 
document.
  # - for zsh: turn sh-emulation on.
+ # - for ksh: alias echo to 'print -r'.
  # - for ksh: alias echo to a function that uses cat of a here document.
! # - for Solaris /bin/sh and OSF/1 /bin/sh: respawn using /bin/ksh and rely on
! #   the ksh workaround.
  # - otherwise: respawn using /bin/sh and rely on the workarounds.
  # When respawning, we pass --no-reexec as first argument, so as to avoid
  # turning this script into a fork bomb in unlucky situations.
***************
*** 92,97 ****
--- 94,117 ----
     && (emulate sh) >/dev/null 2>&1; then
    emulate sh
  fi
+ # For ksh: alias echo to 'print -r'.
+ if test -z "$have_echo" \
+    && (type print) >/dev/null 2>&1; then
+   # A 'print' command exists.
+   if type print 2>/dev/null | grep / > /dev/null; then
+     :
+   else
+     # 'print' is a shell built-in.
+     if (print -r '\told' | grep told > /dev/null) 2>/dev/null; then
+       # 'print' is the ksh shell built-in.
+       alias echo='print -r'
+     fi
+   fi
+ fi
+ if test -z "$have_echo" \
+    && echo '\t' | grep t > /dev/null; then
+   have_echo=yes
+ fi
  # For ksh: alias echo to a function that uses cat of a here document.
  # The ksh manual page says:
  #   "Aliasing is performed when scripts are read, not while they are executed.