build: rework verbosity level selection

V=99 and V=1 are now deprecated in favor of a new verbosity class system,
though the old flags are still supported.
You can set the V variable on the command line (or OPENWRT_VERBOSE in the
environment) to one or more of the following characters:

- s: stdout+stderr (equal to the old V=99)
- c: commands (for build systems that suppress commands by default, e.g. kbuild)
- w: warnings/errors only (equal to the old V=1)

SVN-Revision: 31484

include/verbose.mk

@@ -5,16 +5,23 @@
 # See /LICENSE for more information.
 #
 
-ifeq ($(NO_TRACE_MAKE),)
-NO_TRACE_MAKE := $(MAKE) V=99
-export NO_TRACE_MAKE
-endif
-
-ifndef KBUILD_VERBOSE
-  KBUILD_VERBOSE:=0
+ifndef OPENWRT_VERBOSE
+  OPENWRT_VERBOSE:=
 endif
 ifeq ("$(origin V)", "command line")
-  KBUILD_VERBOSE:=$(V)
+  OPENWRT_VERBOSE:=$(V)
+endif
+
+ifeq ($(OPENWRT_VERBOSE),1)
+  OPENWRT_VERBOSE:=w
+endif
+ifeq ($(OPENWRT_VERBOSE),99)
+  OPENWRT_VERBOSE:=s
+endif
+
+ifeq ($(NO_TRACE_MAKE),)
+NO_TRACE_MAKE := $(MAKE) V=$(subst w,s,$(OPENWRT_VERBOSE))
+export NO_TRACE_MAKE
 endif
 
 ifeq ($(IS_TTY),1)
@@ -24,7 +31,7 @@ ifeq ($(IS_TTY),1)
   endif
 endif
 
-ifneq ($(KBUILD_VERBOSE),99)
+ifeq ($(findstring s,$(OPENWRT_VERBOSE)),)
   define MESSAGE
 	printf "$(_Y)%s$(_N)\n" "$(1)" >&8
   endef
@@ -40,13 +47,9 @@ ifneq ($(KBUILD_VERBOSE),99)
     ))
     SUBMAKE=$(MAKE)
   else
-    ifeq ($(KBUILD_VERBOSE),0)
-      SILENT:=>/dev/null 2>&1
-    else
-      SILENT:=
-    endif
+    SILENT:=>/dev/null $(if $(findstring w,$(OPENWRT_VERBOSE)),,2>&1)
     export QUIET:=1
-    SUBMAKE=cmd() { $(SILENT) $(MAKE) -s $$* < /dev/null || { echo "make $$*: build failed. Please re-run make with V=99 to see what's going on"; false; } } 8>&1 9>&2; cmd
+    SUBMAKE=cmd() { $(SILENT) $(MAKE) -s $$* < /dev/null || { echo "make $$*: build failed. Please re-run make with V=s to see what's going on"; false; } } 8>&1 9>&2; cmd
   endif
 
   .SILENT: $(MAKECMDGOALS)