[Qemu-devel] Stop using "which" in ./configure

["Loïc Minier" <lool@dooz.org>]

[-- Attachment #1: Type: text/plain, Size: 408 bytes --]

        Hi

 Following the thread on the sdl-config patch, please find attached a
 patch to add a couple of portable shell functions which allow testing
 whehter a command/builtin is available and to find the full pathname of
 an executable in the PATH.  This also replaces all uses of "which" in
 ./configure.  (This should be applied on top of the sdl-config patch.)

   Thanks,
-- 
Loïc Minier

[-- Attachment #2: 0001-Add-and-use-has-and-path_of-funcs.patch --]
[-- Type: text/x-diff, Size: 4257 bytes --]

>From 815ca36e9b3e2c56040d7fc7709c95d600ed6496 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Lo=C3=AFc=20Minier?= <lool@dooz.org>
Date: Tue, 19 Jan 2010 11:05:00 +0100
Subject: [PATCH] Add and use has() and path_of() funcs

Add has() and path_of() funcs and use them across configure; has()
will test whether a command or builtin is available; path_of() will
search the PATH for executables and return the full pathname if found.
---
 configure |   57 ++++++++++++++++++++++++++++++++++++++++++++++++---------
 1 files changed, 48 insertions(+), 9 deletions(-)

diff --git a/configure b/configure
index baa2800..8d67b9c 100755
--- a/configure
+++ b/configure
@@ -27,6 +27,47 @@ compile_prog() {
   $cc $QEMU_CFLAGS $local_cflags -o $TMPE $TMPC $LDFLAGS $local_ldflags > /dev/null 2> /dev/null
 }
 
+# check whether a command is available to this shell (may be either an
+# executable or a builtin)
+has() {
+    local_command="$1"
+    type "$local_command" >/dev/null
+}
+
+# search for an executable in PATH
+path_of() {
+    local_command="$1"
+    local_path="$PATH"
+    local_dir=""
+    # absolute path?
+    if [ "${local_command#*/}" != "$local_command" ]; then
+        if [ -x "$local_command" ] && [ ! -d "$local_command" ]; then
+            echo "$local_command"
+            return 0
+        fi
+    fi
+    if [ -z "$local_path" ] || [ -z "$local_command" ]; then
+        return 1
+    fi
+    while :; do
+        local_dir="${local_path%%:*}"
+        if [ "${local_path#*:}" = "$local_path" ]; then
+            # last loop
+            local_path=""
+        else
+            local_path="${local_path#*:}"
+        fi
+        if [ -x "$local_dir/$local_command" ] && [ ! -d "$local_dir/$local_command" ]; then
+            echo "$local_dir/$local_command"
+            return 0
+        fi
+        if [ -z "$local_path" ]; then
+            # not found
+            return 1
+        fi
+    done
+}
+
 # default parameters
 cpu=""
 prefix=""
@@ -763,7 +804,7 @@ fi
 # Solaris specific configure tool chain decisions
 #
 if test "$solaris" = "yes" ; then
-  solinst=`which $install 2> /dev/null | /usr/bin/grep -v "no $install in"`
+  solinst=`path_of $install`
   if test -z "$solinst" ; then
     echo "Solaris install program not found. Use --install=/usr/ucb/install or"
     echo "install fileutils from www.blastwave.org using pkg-get -i fileutils"
@@ -776,7 +817,7 @@ if test "$solaris" = "yes" ; then
     echo "using pkg-get -i fileutils, or use --install=/usr/ucb/install"
     exit 1
   fi
-  sol_ar=`which ar 2> /dev/null | /usr/bin/grep -v "no ar in"`
+  sol_ar=`path_of ar`
   if test -z "$sol_ar" ; then
     echo "Error: No path includes ar"
     if test -f /usr/ccs/bin/ar ; then
@@ -969,7 +1010,7 @@ fi
 # pkgconfig probe
 
 pkgconfig="${cross_prefix}pkg-config"
-if ! test -x "$(which $pkgconfig 2>/dev/null)"; then
+if ! has $pkgconfig; then
   # likely not cross compiling, or hope for the best
   pkgconfig=pkg-config
 fi
@@ -977,7 +1018,7 @@ fi
 ##########################################
 # Sparse probe
 if test "$sparse" != "no" ; then
-  if test -x "$(which cgcc 2>/dev/null)"; then
+  if has cgcc; then
     sparse=yes
   else
     if test "$sparse" = "yes" ; then
@@ -993,7 +1034,7 @@ fi
 if $pkgconfig sdl --modversion >/dev/null 2>&1; then
   sdlconfig="$pkgconfig sdl"
   _sdlversion=`$sdlconfig --modversion 2>/dev/null | sed 's/[^0-9]//g'`
-elif which sdl-config >/dev/null 2>&1; then
+elif has sdl-config; then
   sdlconfig='sdl-config'
   _sdlversion=`$sdlconfig --version | sed 's/[^0-9]//g'`
 else
@@ -1424,8 +1465,7 @@ EOF
     fi
   else
     if test "$kvm" = "yes" ; then
-      if [ -x "`which awk 2>/dev/null`" ] && \
-         [ -x "`which grep 2>/dev/null`" ]; then
+      if has awk && has grep; then
         kvmerr=`LANG=C $cc $QEMU_CFLAGS -o $TMPE $kvm_cflags $TMPC 2>&1 \
 	| grep "error: " \
 	| awk -F "error: " '{if (NR>1) printf(", "); printf("%s",$2);}'`
@@ -1694,8 +1734,7 @@ fi
 
 # Check if tools are available to build documentation.
 if test "$docs" != "no" ; then
-  if test -x "`which texi2html 2>/dev/null`" -a \
-          -x "`which pod2man 2>/dev/null`" ; then
+  if has texi2html && has pod2man; then
     docs=yes
   else
     if test "$docs" = "yes" ; then
-- 
1.6.5