Make internal $V flag to store @ when pretty printing

Verbosity flag ($V variable) let the user decide if he want to see nice
small messages ($V empty) or the standard make output displaying the raw
commands as they are executed ($V non-empty).

Now the meaning of this flag is reversed (and stores "@" when non-empty)
to let the Makefile writer to easily silence commands dependending on the
verbosity flag. When writing a rule, just prepend $V to each action you
want to conditionally silence depending on the verbosity flag.

diff --git a/Lib.mak b/Lib.mak
index 7d82101df2dd08b14402ed4b034c7bc92f7c9e80..ce5449914729d8b53a51f7e9cc0a005a5cd4095a 100644 (file)
--- a/Lib.mak
+++ b/Lib.mak
@@ -7,9 +7,13 @@ Lib.mak.included := 1
 # T should be the path to the top-level directory.
 # C should be the path to the current directory.
 
-# Verbosity flag (empty show nice messages, 1 be verbose)
+# Verbosity flag (empty show nice messages, non-empty use make messages)
+# When used internal, $V expand to @ is nice messages should be printed, this
+# way it's easy to add $V in front of commands that should be silenced when
+# displaying the nice messages.
+override V := $(if $V,,@)
 # honour make -s flag
-override V := $(if $(findstring s,$(MAKEFLAGS)),1,$V)
+override V := $(if $(findstring s,$(MAKEFLAGS)),,$V)
 
 # Flavor (variant), should be one of "dbg", "opt" or "cov"
 F ?= opt
@@ -70,16 +74,16 @@ find_objects = $(patsubst $T/%.$1,$O/%.o,$(shell find $T/$C -name '*.$1'))
 abbr = $(addprefix $(shell echo $R | sed 's|/\?\([^/]\+\)/\?|../|g'),\
                $(subst $T,.,$(patsubst $T/%,%,$1)))
 
-# Execute a command printing a nice message if $V is empty
+# Execute a command printing a nice message if $V is @.
 # The first argument is mandatory and it's the command to execute. The second
 # and third arguments are optional and are the target name and command name to
 # pretty print.
-vexec = $(if $V,,\
+vexec = $(if $V,\
                echo '   $(notdir $(if $3,$(strip $3),$(firstword $1))) \
                                $(call abbr,$(if $2,$(strip $2),$@))' ; )$1
 
-# Same as vexec but it silence the echo command (prepending a @).
-exec = $(if $V,,@)$(call vexec,$1,$2,$3)
+# Same as vexec but it silence the echo command (prepending a @ if $V).
+exec = $V$(call vexec,$1,$2,$3)
 
 # Compile a source file to an object, generating pre-compiled headers and
 # dependencies. The pre-compiled headers are generated only if the system
@@ -89,7 +93,7 @@ exec = $(if $V,,@)$(call vexec,$1,$2,$3)
 # variables from a rule.
 define compile
 $(if $(GCH),\
-@if test -f $O/$*.d; then \
+$Vif test -f $O/$*.d; then \
        tmp=`mktemp`; \
        h=`awk -F: '!$$0 {f = 1} $$0 && f {print $$1}' $O/$*.d`; \
        grep -h '^#include <' $(call abbr,$<) $$h | sort -u > "$$tmp"; \
@@ -233,7 +237,7 @@ setup_build_dir__ := $(shell \
        test -L $D/last || ln -s $F $D/last )
 
 # Print any generated message (if verbose)
-$(if $V,,$(if $(setup_build_dir__), \
+$(if $V,$(if $(setup_build_dir__), \
        $(info !! Something changed: $(setup_build_dir__) \
                        re-building affected files...)))