[PATCH] Makefile: Let the 'help' target list the helper targets

[Philippe Mathieu-Daudé]

List the name of the helper targets when calling 'make help',
along with the tool targets:

  $ make help
  [...]

  Helper targets:
    fsdev/virtfs-proxy-helper      - Build virtfs-proxy-helper
    scsi/qemu-pr-helper            - Build qemu-pr-helper
    qemu-bridge-helper             - Build qemu-bridge-helper
    vhost-user-gpu                 - Build vhost-user-gpu
    virtiofsd                      - Build virtiofsd

  Tools targets:
    qemu-ga                        - Build qemu-ga tool
    qemu-keymap                    - Build qemu-keymap tool
    elf2dmp                        - Build elf2dmp tool
    ivshmem-client                 - Build ivshmem-client tool
    ivshmem-server                 - Build ivshmem-server tool
    qemu-nbd                       - Build qemu-nbd tool
    qemu-storage-daemon            - Build qemu-storage-daemon tool
    qemu-img                       - Build qemu-img tool
    qemu-io                        - Build qemu-io tool
    qemu-edid                      - Build qemu-edid tool

Signed-off-by: Philippe Mathieu-Daudé <address@hidden>
---
 configure | 5 +++--
 Makefile  | 9 +++++++--
 2 files changed, 10 insertions(+), 4 deletions(-)

diff --git a/configure b/configure
index 23b5e93752..caf880c38e 100755
--- a/configure
+++ b/configure
@@ -6374,7 +6374,7 @@ if test "$softmmu" = yes ; then
   if test "$linux" = yes; then
     if test "$virtfs" != no && test "$cap_ng" = yes && test "$attr" = yes ; 
then
       virtfs=yes
-      tools="$tools fsdev/virtfs-proxy-helper\$(EXESUF)"
+      helpers="$helpers fsdev/virtfs-proxy-helper\$(EXESUF)"
     else
       if test "$virtfs" = yes; then
         error_exit "VirtFS requires libcap-ng devel and libattr devel"
@@ -6389,7 +6389,7 @@ if test "$softmmu" = yes ; then
       fi
       mpath=no
     fi
-    tools="$tools scsi/qemu-pr-helper\$(EXESUF)"
+    helpers="$helpers scsi/qemu-pr-helper\$(EXESUF)"
   else
     if test "$virtfs" = yes; then
       error_exit "VirtFS is supported only on Linux"
@@ -7630,6 +7630,7 @@ else
   QEMU_INCLUDES="-iquote \$(SRC_PATH)/tcg/\$(ARCH) $QEMU_INCLUDES"
 fi
 
+echo "HELPERS=$helpers" >> $config_host_mak
 echo "TOOLS=$tools" >> $config_host_mak
 echo "ROMS=$roms" >> $config_host_mak
 echo "MAKE=$make" >> $config_host_mak
diff --git a/Makefile b/Makefile
index 8a9113e666..021a0cd491 100644
--- a/Makefile
+++ b/Makefile
@@ -336,9 +336,9 @@ $(call set-vpath, $(SRC_PATH))
 LIBS+=-lz $(LIBS_TOOLS)
 
 vhost-user-json-y =
-HELPERS-y =
+HELPERS-y = $(HELPERS)
 
-HELPERS-$(call land,$(CONFIG_SOFTMMU),$(CONFIG_LINUX)) = 
qemu-bridge-helper$(EXESUF)
+HELPERS-$(call land,$(CONFIG_SOFTMMU),$(CONFIG_LINUX)) += 
qemu-bridge-helper$(EXESUF)
 
 ifeq ($(CONFIG_LINUX)$(CONFIG_VIRGL)$(CONFIG_GBM)$(CONFIG_TOOLS),yyyy)
 HELPERS-y += vhost-user-gpu$(EXESUF)
@@ -1255,6 +1255,11 @@ endif
                $(foreach t, $(TARGET_DIRS), \
                $(call print-help-run,$(t)/all,Build for $(t));) \
                echo '')
+       @$(if $(HELPERS-y), \
+               echo 'Helper targets:'; \
+               $(foreach t, $(HELPERS-y), \
+               $(call print-help-run,$(t),Build $(shell basename $(t)));) \
+               echo '')
        @$(if $(TOOLS), \
                echo 'Tools targets:'; \
                $(foreach t, $(TOOLS), \
-- 
2.21.1