qemu-iotests: convert `pwd` and $(pwd) to $PWD

POSIX requires $PWD to be reliable, and we expect all
shells used by qemu scripts to be relatively close to
POSIX.  Thus, it is smarter to avoid forking the pwd
executable for something that is already available in
the environment.

So replace it with the following:

sed -i 's/\(`pwd`\|\$(pwd)\)/$PWD/g' $(git grep -l pwd)

Then delete a pointless line assigning PWD to itself.

Cc: kwolf@redhat.com
Cc: mreitz@redhat.com
Cc: eblake@redhat.com
Suggested-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Mao Zhongyi <maozhongyi@cmss.chinamobile.com>
Message-Id: <20181024094051.4470-2-maozhongyi@cmss.chinamobile.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
[eblake: touch up commit message, reorder series, tweak a couple more files]
Signed-off-by: Eric Blake <eblake@redhat.com>

6 files changed, 7 insertions, 9 deletions

diff --git a/configure b/configure
index 5b1d83ea26..0a3c6a72c3 100755
--- a/configure
+++ b/configure
@@ -878,7 +878,7 @@ Linux)
   vhost_crypto="yes"
   vhost_scsi="yes"
   vhost_vsock="yes"
-  QEMU_INCLUDES="-I\$(SRC_PATH)/linux-headers -I$(pwd)/linux-headers $QEMU_INCLUDES"
+  QEMU_INCLUDES="-I\$(SRC_PATH)/linux-headers -I$PWD/linux-headers $QEMU_INCLUDES"
   supported_os="yes"
   libudev="yes"
 ;;
diff --git a/scripts/coccinelle/tcg_gen_extract.cocci b/scripts/coccinelle/tcg_gen_extract.cocci
index 81e66a35ae..c10c863482 100644
--- a/scripts/coccinelle/tcg_gen_extract.cocci
+++ b/scripts/coccinelle/tcg_gen_extract.cocci
@@ -17,7 +17,7 @@
 //     --keep-comments --in-place \
 //     --use-gitgrep --dir target
 //
-// $ docker run --rm -v `pwd`:`pwd` -w `pwd` philmd/coccinelle \
+// $ docker run --rm -v $PWD:$PWD -w $PWD philmd/coccinelle \
 //     --macro-file scripts/cocci-macro-file.h \
 //     --sp-file scripts/coccinelle/tcg_gen_extract.cocci \
 //     --keep-comments --in-place \
diff --git a/tests/check-block.sh b/tests/check-block.sh
index c3de3789c4..f3d12fd602 100755
--- a/tests/check-block.sh
+++ b/tests/check-block.sh
@@ -5,9 +5,9 @@ if [ "$#" -ne 0 ]; then
     FORMAT_LIST="$@"
 fi
 
-export QEMU_PROG="$(pwd)/x86_64-softmmu/qemu-system-x86_64"
-export QEMU_IMG_PROG="$(pwd)/qemu-img"
-export QEMU_IO_PROG="$(pwd)/qemu-io"
+export QEMU_PROG="$PWD/x86_64-softmmu/qemu-system-x86_64"
+export QEMU_IMG_PROG="$PWD/qemu-img"
+export QEMU_IO_PROG="$PWD/qemu-io"
 
 if [ ! -x $QEMU_PROG ]; then
     echo "'make check-block' requires qemu-system-x86_64"
diff --git a/tests/qemu-iotests/check b/tests/qemu-iotests/check
index aa94c6c7ea..b37713277d 100755
--- a/tests/qemu-iotests/check
+++ b/tests/qemu-iotests/check
@@ -99,7 +99,7 @@ set_prog_path()
 }
 
 if [ -z "$TEST_DIR" ]; then
-        TEST_DIR=`pwd`/scratch
+        TEST_DIR=$PWD/scratch
 fi
 
 if [ ! -e "$TEST_DIR" ]; then
diff --git a/tests/qemu-iotests/common.config b/tests/qemu-iotests/common.config
index 102aa6878a..3cda0fe569 100644
--- a/tests/qemu-iotests/common.config
+++ b/tests/qemu-iotests/common.config
@@ -25,8 +25,6 @@ HOSTOS=`uname -s`
 arch=`uname -m`
 [[ "$arch" =~ "ppc64" ]] && qemu_arch=ppc64 || qemu_arch="$arch"
 
-export PWD=`pwd`
-
 # make sure we have a standard umask
 umask 022
 
diff --git a/tests/qemu-iotests/common.rc b/tests/qemu-iotests/common.rc
index 70ca65b49b..e15e7a7c8e 100644
--- a/tests/qemu-iotests/common.rc
+++ b/tests/qemu-iotests/common.rc
@@ -160,7 +160,7 @@ fi
 ORIG_TEST_IMG="$TEST_IMG"
 
 if [ -z "$TEST_DIR" ]; then
-        TEST_DIR=`pwd`/scratch
+        TEST_DIR=$PWD/scratch
 fi
 
 QEMU_TEST_DIR="${TEST_DIR}"