configure: remove --with-git= option

The scenario for which --with-git= was introduced was to use a SOCKS proxy
such as tsocks.  However, this was back in 2017 when QEMU's submodules
used the git:// protocol, and it is not as important when using the
"smart HTTP" backend; for example, neither "meson subprojects download"
nor scripts/checkpatch.pl obey the GIT environment variable.

So remove the knob, but test for the presence of git in the configure and
git-submodule.sh scripts, and suggest using --with-git-submodules=validate
+ a manual invocation of git-submodule.sh when git does not work.  Hopefully
in the future the GIT environment variable will be supported by Meson.

Reviewed-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Makefile

@@ -53,7 +53,7 @@ Makefile: .git-submodule-status
 git-submodule-update:
 ifneq ($(GIT_SUBMODULES_ACTION),ignore)
 	$(call quiet-command, \
-		(GIT="$(GIT)" "$(SRC_PATH)/scripts/git-submodule.sh" $(GIT_SUBMODULES_ACTION) $(GIT_SUBMODULES)), \
+		(GIT=git "$(SRC_PATH)/scripts/git-submodule.sh" $(GIT_SUBMODULES_ACTION) $(GIT_SUBMODULES)), \
 		"GIT","$(GIT_SUBMODULES)")
 endif
 

configure

@@ -751,8 +751,6 @@ for opt do
   ;;
   --enable-fdt=*) fdt="$optarg"
   ;;
-  --with-git=*) git="$optarg"
-  ;;
   --with-git-submodules=*)
       git_submodules_action="$optarg"
   ;;
@@ -791,7 +789,7 @@ fi
 
 case $git_submodules_action in
     update|validate)
-        if test ! -e "$source_path/.git"; then
+        if test ! -e "$source_path/.git" || ! has git; then
             echo "ERROR: cannot $git_submodules_action git submodules without .git"
             exit 1
         fi
@@ -892,7 +890,6 @@ Advanced options (experts only):
   --python=PYTHON          use specified python [$python]
   --ninja=NINJA            use specified ninja [$ninja]
   --smbd=SMBD              use specified smbd [$smbd]
-  --with-git=GIT           use specified git [$git]
   --with-git-submodules=update   update git submodules (default if .git dir exists)
   --with-git-submodules=validate fail if git submodules are not up to date
   --with-git-submodules=ignore   do not update or check git submodules (default if no .git dir)
@@ -1699,7 +1696,7 @@ fi
 #######################################
 # generate config-host.mak
 
-if ! (GIT="$git" "$source_path/scripts/git-submodule.sh" "$git_submodules_action" "$git_submodules"); then
+if ! (GIT=git "$source_path/scripts/git-submodule.sh" "$git_submodules_action" "$git_submodules"); then
     exit 1
 fi
 
@@ -1709,7 +1706,6 @@ echo "# Automatically generated by configure - do not modify" > $config_host_mak
 echo >> $config_host_mak
 
 echo all: >> $config_host_mak
-echo "GIT=$git" >> $config_host_mak
 echo "GIT_SUBMODULES=$git_submodules" >> $config_host_mak
 echo "GIT_SUBMODULES_ACTION=$git_submodules_action" >> $config_host_mak
 

meson.build

@@ -4011,7 +4011,6 @@ summary(summary_info, bool_yn: true, section: 'Directories')
 
 # Host binaries
 summary_info = {}
-summary_info += {'git':               config_host['GIT']}
 summary_info += {'python':            '@0@ (version: @1@)'.format(python.full_path(), python.language_version())}
 summary_info += {'sphinx-build':      sphinx_build}
 if config_host.has_key('HAVE_GDB_BIN')

scripts/ci/org.centos/stream/8/x86_64/configure

@@ -29,14 +29,12 @@
 --extra-cflags="-O2 -g -pipe -Wall -Werror=format-security -Wp,-D_FORTIFY_SOURCE=2 -Wp,-D_GLIBCXX_ASSERTIONS -fexceptions -fstack-protector-strong -grecord-gcc-switches -specs=/usr/lib/rpm/redhat/redhat-hardened-cc1 -specs=/usr/lib/rpm/redhat/redhat-annobin-cc1 -m64 -mtune=generic -fasynchronous-unwind-tables -fstack-clash-protection -fcf-protection" \
 --with-suffix="qemu-kvm" \
 --firmwarepath=/usr/share/qemu-firmware \
---with-git=meson \
 --with-git-submodules=update \
 --target-list="x86_64-softmmu" \
 --block-drv-rw-whitelist="qcow2,raw,file,host_device,nbd,iscsi,rbd,blkdebug,luks,null-co,nvme,copy-on-read,throttle,gluster" \
 --audio-drv-list="" \
 --block-drv-ro-whitelist="vmdk,vhdx,vpc,https,ssh" \
 --with-coroutine=ucontext \
---with-git=git \
 --tls-priority=@QEMU,SYSTEM \
 --disable-attr \
 --disable-auth-pam \

scripts/git-submodule.sh

@@ -12,7 +12,7 @@ maybe_modules="$@"
 # if --with-git-submodules=ignore, do nothing
 test "$command" = "ignore" && exit 0
 
-test -z "$GIT" && GIT=git
+test -z "$GIT" && GIT=$(command -v git)
 
 cd "$(dirname "$0")/.."
 
@@ -21,19 +21,14 @@ update_error() {
     echo
     echo "Unable to automatically checkout GIT submodules '$modules'."
     echo "If you require use of an alternative GIT binary (for example to"
-    echo "enable use of a transparent proxy), then please specify it by"
-    echo "running configure by with the '--with-git' argument. e.g."
-    echo
-    echo " $ ./configure --with-git='tsocks git'"
-    echo
-    echo "Alternatively you may disable automatic GIT submodule checkout"
-    echo "with:"
+    echo "enable use of a transparent proxy), please disable automatic"
+    echo "GIT submodule checkout with:"
     echo
     echo " $ ./configure --with-git-submodules=validate"
     echo
     echo "and then manually update submodules prior to running make, with:"
     echo
-    echo " $ scripts/git-submodule.sh update $modules"
+    echo " $ GIT='tsocks git' scripts/git-submodule.sh update $modules"
     echo
     exit 1
 }
@@ -57,6 +52,12 @@ then
     exit 1
 fi
 
+if test -n "$maybe_modules" && test -z "$GIT"
+then
+    echo "$0: unexpectedly called with submodules but git binary not found"
+    exit 1
+fi
+
 modules=""
 for m in $maybe_modules
 do