Warn on naked cross-tool names, add macros to detect target tools

[Bonzini]

For target tools, it makes no sense to me to have naked names, so I am
already looking for prefixed names only.  Ok to apply?

2004-03-16  Paolo Bonzini  <address@hidden>

        * lib/autoconf/programs.m4 (AC_PATH_TOOL, AC_CHECK_TOOL,
        AC_CHECK_TOOLS): Warn if a cross-tool is found without
        a prefix.
        (AC_PATH_TARGET_TOOL, AC_CHECK_TARGET_TOOL,
        AC_CHECK_TARGET_TOOLS): New macros.
        * doc/autoconf.texi (Generic Programs): Document
        (AC_PATH_TARGET_TOOL, AC_CHECK_TARGET_TOOL,
        AC_CHECK_TARGET_TOOLS, and warn for future changes
        in the behavior of AC_PATH_TOOL, AC_CHECK_TOOL and
        AC_CHECK_TOOLS.
        * tests/mktests.sh: Do not generate tests for the
        new macros.

Index: autoconf.texi
===================================================================
RCS file: /cvsroot/autoconf/autoconf/doc/autoconf.texi,v
retrieving revision 1.803
diff -u -r1.803 autoconf.texi
--- autoconf.texi       15 Mar 2004 22:00:06 -0000      1.803
+++ autoconf.texi       16 Mar 2004 10:07:26 -0000
@@ -3438,6 +3438,26 @@
 is not changed.  Calls @code{AC_SUBST} for @var{variable}.
 @end defmac
 
address@hidden AC_CHECK_TARGET_TOOL (@var{variable}, @var{prog-to-check-for}, 
@ovar{value-if-not-found}, @ovar{path})
address@hidden
+Like @code{AC_CHECK_PROG}, but first looks for @var{prog-to-check-for}
+with a prefix of the target type as determined by
address@hidden, followed by a dash (@pxref{Canonicalizing}).
+For example, if the user runs @samp{configure --target=i386-gnu}, then
+this call:
address@hidden
+AC_CHECK_TARGET_TOOL(RANLIB, ranlib, :)
address@hidden example
address@hidden
+sets @code{RANLIB} to @file{i386-gnu-ranlib} if that program exists in
address@hidden, or otherwise to @samp{ranlib} if that program exists in
address@hidden, or to @samp{:} if neither program exists.
+This macro is rarely needed, because the host and the target are usually
+the same (the notable difference being compilers, assemblers and linkers).
+When building a cross-compiler this macro will @emph{not}
+accept program names that are not prefixed with the host type.
address@hidden defmac
+
 @defmac AC_CHECK_TOOL (@var{variable}, @var{prog-to-check-for}, 
@ovar{value-if-not-found}, @ovar{path})
 @acindex{CHECK_TOOL}
 Like @code{AC_CHECK_PROG}, but first looks for @var{prog-to-check-for}
@@ -3452,6 +3472,23 @@
 sets @code{RANLIB} to @file{i386-gnu-ranlib} if that program exists in
 @code{PATH}, or otherwise to @samp{ranlib} if that program exists in
 @code{PATH}, or to @samp{:} if neither program exists.
+
+In the future, when cross-compiling this macro will @emph{not}
+accept program names that are not prefixed with the host type.
address@hidden defmac
+
address@hidden AC_CHECK_TARGET_TOOLS (@var{variable}, @var{progs-to-check-for}, 
@ovar{value-if-not-found}, @ovar{path})
address@hidden
+Like @code{AC_CHECK_TARGET_TOOL}, each of the tools in the list
address@hidden are checked with a prefix of the target type as
+determined by @code{AC_CANONICAL_TARGET}, followed by a dash
+(@pxref{Canonicalizing}).  If none of the tools can be found with a
+prefix, and if the build and target types are equal, then the first one
+without a prefix is used.  If a tool is found, set @var{variable} to
+the name of that program.  If none of the tools in the list are found,
+set @var{variable} to @var{value-if-not-found}; if @var{value-if-not-found}
+is not specified, the value of @var{variable} is not changed.  Calls
address@hidden for @var{variable}.
 @end defmac
 
 @defmac AC_CHECK_TOOLS (@var{variable}, @var{progs-to-check-for}, 
@ovar{value-if-not-found}, @ovar{path})
@@ -3465,6 +3502,9 @@
 the list are found, set @var{variable} to @var{value-if-not-found}; if
 @var{value-if-not-found} is not specified, the value of @var{variable}
 is not changed.  Calls @code{AC_SUBST} for @var{variable}.
+
+In the future, when cross-compiling this macro will @emph{not}
+accept program names that are not prefixed with the host type.
 @end defmac
 
 @defmac AC_PATH_PROG (@var{variable}, @var{prog-to-check-for}, 
@ovar{value-if-not-found}, @ovar{path})
@@ -3480,10 +3520,19 @@
 found.
 @end defmac
 
address@hidden AC_PATH_TARGET_TOOL (@var{variable}, @var{prog-to-check-for}, 
@ovar{value-if-not-found}, @ovar{path})
address@hidden
+Like @code{AC_CHECK_TARGET_TOOL}, but set @var{variable} to the entire
+path of the program if it is found.
address@hidden defmac
+
 @defmac AC_PATH_TOOL (@var{variable}, @var{prog-to-check-for}, 
@ovar{value-if-not-found}, @ovar{path})
 @acindex{PATH_TOOL}
 Like @code{AC_CHECK_TOOL}, but set @var{variable} to the entire
 path of the program if it is found.
+
+In the future, when cross-compiling this macro will @emph{not}
+accept program names that are not prefixed with the host type.
 @end defmac
 
 
Index: programs.m4
===================================================================
RCS file: /cvsroot/autoconf/autoconf/lib/autoconf/programs.m4,v
retrieving revision 1.21
diff -u -F^AC_DEFUN -r1.21 programs.m4
--- programs.m4 30 Jan 2004 14:21:36 -0000      1.21
+++ programs.m4 16 Mar 2004 10:15:19 -0000
@@ -197,8 +197,17 @@ AC_DEFUN([AC_PATH_TOOL],
 fi
 if test -z "$ac_cv_path_$1"; then
   ac_pt_$1=$$1
-  AC_PATH_PROG([ac_pt_$1], [$2], [$3], [$4])
-  $1=$ac_pt_$1
+  AC_PATH_PROG([ac_pt_$1], [$2], [], [$4])
+  if test "x$ac_pt_$1" = x; then
+    $1="$3"
+  else
+    if test "$build" != "$host"; then
+      AC_MSG_WARN([In the future, Autoconf will not detect cross-tools
+whose name does not start with the host triplet.  If you think this
+configuration is useful to you, please write to address@hidden)
+    fi
+    $1=$ac_pt_$1
+  fi
 else
   $1="$ac_cv_path_$1"
 fi
@@ -214,8 +223,17 @@ AC_DEFUN([AC_CHECK_TOOL],
 fi
 if test -z "$ac_cv_prog_$1"; then
   ac_ct_$1=$$1
-  AC_CHECK_PROG([ac_ct_$1], [$2], [$2], [$3], [$4])
-  $1=$ac_ct_$1
+  AC_CHECK_PROG([ac_ct_$1], [$2], [$2], [], [$4])
+  if test "x$ac_ct_$1" = x; then
+    $1="$3"
+  else
+    if test "$build" != "$host"; then
+      AC_MSG_WARN([In the future, Autoconf will not detect cross-tools
+whose name does not start with the host triplet.  If you think this
+configuration is useful to you, please write to address@hidden)
+    fi
+    $1=$ac_ct_$1
+  fi
 else
   $1="$ac_cv_prog_$1"
 fi
@@ -240,10 +258,86 @@ AC_DEFUN([AC_CHECK_TOOLS],
 fi
 if test -z "$$1"; then
   ac_ct_$1=$$1
-  AC_CHECK_PROGS([ac_ct_$1], [$2], [$3], [$4])
-  $1=$ac_ct_$1
+  AC_CHECK_PROGS([ac_ct_$1], [$2], [], [$4])
+  if test "x$ac_ct_$1" = x; then
+    $1="$3"
+  else
+    if test "$build" != "$host"; then
+      AC_MSG_WARN([In the future, Autoconf will not detect cross-tools
+whose name does not start with the host triplet.  If you think this
+configuration is useful to you, please write to address@hidden)
+    fi
+    $1=$ac_ct_$1
+  fi
 fi
 ])# AC_CHECK_TOOLS
+
+
+# AC_PATH_TARGET_TOOL(VARIABLE, PROG-TO-CHECK-FOR, [VALUE-IF-NOT-FOUND], 
[PATH])
+# -----------------------------------------------------------------------
+# (Use different variables $1 and ac_pt_$1 so that cache vars don't conflict.)
+AC_DEFUN([AC_PATH_TARGET_TOOL],
+[AC_BEFORE([$0], [AC_CANONICAL_TARGET])dnl
+AC_PATH_PROG([$1], [$target_alias-$2], , [$4])
+if test -z "$ac_cv_path_$1"; then
+  if test "$build" = "$target"; then
+    ac_pt_$1=$$1
+    AC_PATH_PROG([ac_pt_$1], [$2], [$3], [$4])
+    $1=$ac_pt_$1
+  else
+    $1="$3"
+  fi
+else
+  $1="$ac_cv_path_$1"
+fi
+])# AC_PATH_TARGET_TOOL
+
+
+# AC_CHECK_TARGET_TOOL(VARIABLE, PROG-TO-CHECK-FOR, [VALUE-IF-NOT-FOUND], 
[PATH])
+# ------------------------------------------------------------------------
+# (Use different variables $1 and ac_ct_$1 so that cache vars don't conflict.)
+AC_DEFUN([AC_CHECK_TARGET_TOOL],
+[AC_BEFORE([$0], [AC_CANONICAL_TARGET])dnl
+AC_CHECK_PROG([$1], [$target_alias-$2], [$target_alias-$2], , [$4])
+if test -z "$ac_cv_prog_$1"; then
+  if test "$build" = "$target"; then
+    ac_ct_$1=$$1
+    AC_CHECK_PROG([ac_ct_$1], [$2], [$2], [$3], [$4])
+    $1=ac_ct_$1
+  else
+    $1="$3"
+  fi
+else
+  $1="$ac_cv_prog_$1"
+fi
+])# AC_CHECK_TARGET_TOOL
+
+
+# AC_CHECK_TARGET_TOOLS(VARIABLE, PROGS-TO-CHECK-FOR, [VALUE-IF-NOT-FOUND],
+#                      [PATH])
+# ------------------------------------------------------------------
+# Check for each tool in PROGS-TO-CHECK-FOR with the cross prefix. If
+# none can be found with a cross prefix, then use the first one that
+# was found without the cross prefix.
+AC_DEFUN([AC_CHECK_TARGET_TOOLS],
+[AC_BEFORE([$0], [AC_CANONICAL_TARGET])dnl
+for ac_prog in $2
+do
+  AC_CHECK_PROG([$1],
+               [$target_alias-$ac_prog], [$target_alias-$ac_prog],,
+               [$4])
+  test -n "$$1" && break
+done
+if test -z "$$1"; then
+  if test "$build" = "$target"; then
+    ac_ct_$1=$$1
+    AC_CHECK_PROGS([ac_ct_$1], [$2], [$3], [$4])
+    $1=$ac_ct_$1
+  else
+    $1="$3"
+  fi
+fi
+])# AC_CHECK_TARGET_TOOLS
 
 
 
Index: mktests.sh
===================================================================
RCS file: /cvsroot/autoconf/autoconf/tests/mktests.sh,v
retrieving revision 1.39
diff -u -r1.39 mktests.sh
--- mktests.sh  15 Mar 2004 22:00:06 -0000      1.39
+++ mktests.sh  16 Mar 2004 11:08:31 -0000
@@ -131,7 +131,7 @@
 #
 ac_exclude_list='^AC_ARG_VAR$
 ^AC_CANONICALIZE|AC_PREFIX_PROGRAM|AC_PREREQ$
-^AC_CHECK_(ALIGNOF|DECL|FILE|FUNC|HEADER|LIB|MEMBER|PROG|SIZEOF|TOOL|TYPE)S?$
+^AC_CHECK_(ALIGNOF|DECL|FILE|FUNC|HEADER|LIB|MEMBER|PROG|SIZEOF|.*TOOL|TYPE)S?$
 ^AC_CONFIG
 ^AC_(F77|FC)_FUNC$
 ^AC_FC_(FUNC|FREEFORM|SRCEXT)$