[bg] silent: simplify by taking advantage of GNU make semantics

In particular, taking advantage of the fact that, in GNU make, command
line override of variables is propagated to recursive make invocations.

This change offers us a small but nice size reduction bot in Automake's
code and in the generated Makefiles.  It also improves the API to define
custom silent "tags", by turning it from:

    pkg_verbose = $(pkg_verbose_$(V))
    pkg_verbose_ = $(pkg_verbose_$(AM_DEFAULT_V))
    pkg_verbose_0 = @echo PKG-GEN $@;

to the slightly clearer:

    pkg_verbose = $(pkg_verbose/$(V))
    pkg_verbose/1 =
    pkg_verbose/0 = @echo PKG-GEN $@;

* NG-NEWS: Update.
* doc/automake-ng.texi (Automake Silent Rules): Update w.r.t. the
API for user-defined silent rules.
* automake.in: Simplify, by removing the indirections involving
$(AM_DEFAULT_VERBOSITY); some other changes and simplifications.
(verbose_private_var): Delete, its calls from &define_verbose_var
deleted (and those were its only calls).
* lib/am/header-vars.am: Define '$(V)' to 0 if it's not already
defined.
* m4/silent.m4: Initialize and AC_SUBST the variable 'V' directly,
instead of of the indirect 'AM_DEFAULT_VERBOSITY'.  Do not set nor
AC_SUBST the variable 'AM_BACKSLASH', it's not used anymore (and
hasn't been since out overhauling and simplification of the compile
rules).
* GNUmakefile: Simplify a little.
* t/silent6.sh, t/silent-configsite.sh: Adjust.

Signed-off-by: Stefano Lattarini <stefano.lattarini@gmail.com>

diff --git a/GNUmakefile b/GNUmakefile
index a6ba2f99c936dff8519eb2f573b694e84ab5a8f1..d814dfe41ac676ece5f7b981a0e0c74a994b02d3 100644 (file)
--- a/GNUmakefile
+++ b/GNUmakefile
@@ -35,8 +35,7 @@ endif
 # To allow bootstrapping also in an unconfigured tree.
 srcdir ?= .
 am__cd ?= CDPATH=. && unset CDPATH && cd
-AM_DEFAULT_VERBOSITY ?= 0
-V ?= $(AM_DEFAULT_VERBOSITY)
+V ?= 0
 
 ifeq ($(V),0)
   AM_V_BOOTSTRAP = @echo "  BOOTSTRAP";

diff --git a/NG-NEWS b/NG-NEWS
index 16d0074882dd491ba45b3f837d4da1f973b818b0..7776ed9371c6e20852b4352ab7498d00c514face 100644 (file)
--- a/NG-NEWS
+++ b/NG-NEWS
@@ -25,18 +25,23 @@ Automatic dependency tracking support
 Silent rules
 ============
 
-* The silent-rules support unconditionally assumes that nested variables
-  expansion are supported.  Accordingly, the AC_SUBST'd variables '@AM_V@'
-  and'@AM_DEFAULT_V@' have been removed, so that instead of using
-  something like:
-
-    pkg_verbose = $(pkg_verbose_@AM_V@)
-    pkg_verbose_ = $(pkg_verbose_@AM_DEFAULT_V@)
-
-  you should simply use:
-
-    pkg_verbose = $(pkg_verbose_$(V))
-    pkg_verbose_ = $(pkg_verbose_$(AM_DEFAULT_VERBOSITY))
+* The silent rules support has been simplified to take advantage
+  of more GNU make features.  Among other things, the AC_SUBST'd
+  variables '@AM_V@' and'@AM_DEFAULT_V@' have been removed.  Now,
+  when defining uses custom silent rules, you should do something
+  like:
+
+      # Modern correct way.
+      pkg_verbose = $(pkg_verbose/$(V))
+      pkg_verbose/0 = @echo PKG-GEN $@;
+      pkg_verbose/1 =
+
+  while the old idiom would have been something like:
+
+      # Old obsolete way, won't work anymore.
+      pkg_verbose = $(pkg_verbose_@AM_V@)
+      pkg_verbose_ = $(pkg_verbose_@AM_DEFAULT_V@)
+      pkg_verbose_0 = @echo PKG-GEN $@;
 
 
 Warnings and diagnostic

diff --git a/automake.in b/automake.in
index c3a9848da3948cb5715179fb1f2635aef0064d26..12224e8ba1c71ec9363810244653bc2d9d3f57e8 100644 (file)
--- a/automake.in
+++ b/automake.in
@@ -1119,15 +1119,6 @@ sub verbose_var ($)
     return 'AM_V_' . $name;
 }
 
-# verbose_private_var (NAME)
-# --------------------------
-# The naming policy for the private variables for silent rules.
-sub verbose_private_var ($)
-{
-    my ($name) = @_;
-    return 'am__v_' . $name;
-}
-
 # define_verbose_var (NAME, VAL-IF-SILENT, [VAL-IF-VERBOSE])
 # ----------------------------------------------------------
 # For  silent rules, setup VAR and dispatcher, to expand to
@@ -1138,19 +1129,13 @@ sub define_verbose_var ($$;$)
     my ($name, $silent_val, $verbose_val) = @_;
     $verbose_val = '' unless defined $verbose_val;
     my $var = verbose_var ($name);
-    my $pvar = verbose_private_var ($name);
-    my $silent_var = $pvar . '_0';
-    my $verbose_var = $pvar . '_1';
-    define_variable ($var, INTERNAL,
-                     '$(' . $pvar . '_$(V))');
-    define_variable ($pvar . '_', INTERNAL,
-                     '$(' . $pvar . '_$(AM_DEFAULT_VERBOSITY))');
-    Automake::Variable::define ($silent_var, VAR_AUTOMAKE, '', TRUE,
+    define_variable ($var, INTERNAL, "\$($var/\$V)");
+    Automake::Variable::define ("$var/0", VAR_AUTOMAKE, '', TRUE,
                                 $silent_val, '', INTERNAL)
-      if (! vardef ($silent_var, TRUE));
-    Automake::Variable::define ($verbose_var, VAR_AUTOMAKE, '', TRUE,
+      if (! vardef ("$var/0", TRUE));
+    Automake::Variable::define ("$var/1", VAR_AUTOMAKE, '', TRUE,
                                 $verbose_val, '', INTERNAL)
-      if (! vardef ($verbose_var, TRUE));
+      if (! vardef ("$var/1", TRUE));
 }
 
 # Above should not be needed in the general automake code.

diff --git a/doc/automake-ng.texi b/doc/automake-ng.texi
index d0132104354610f2fcc9fed08ca8bf0dddcc781c..23749b58a684fc7e12973a96f7b1457df85f26f3 100644 (file)
--- a/doc/automake-ng.texi
+++ b/doc/automake-ng.texi
@@ -10783,9 +10783,9 @@ The following snippet shows how you would define your own equivalent of
 @code{AM_V_GEN}:
 
 @example
-pkg_verbose = $(pkg_verbose_$(V))
-pkg_verbose_ = $(pkg_verbose_$(AM_DEFAULT_VERBOSITY))
-pkg_verbose_0 = @@echo PKG-GEN $@@;
+pkg_verbose = $(pkg_verbose/$(V))
+pkg_verbose/1 =
+pkg_verbose/0 = @@echo PKG-GEN $@@;
 
 foo: foo.in
         $(pkg_verbose)cp $(srcdir)/foo.in $@@

diff --git a/lib/am/header-vars.am b/lib/am/header-vars.am
index c4f14d0181e2ff35347ce93b87a749fc58c63455..636713b9b7c425a3529023f90349754ef8ae1e92 100644 (file)
--- a/lib/am/header-vars.am
+++ b/lib/am/header-vars.am
@@ -60,6 +60,12 @@ ifdef SUBDIRS
   endif
 endif
 
+# Be verbose by deafault.  Yes, we really want $(V) to be overridable
+# from the environment, both for simplicity and for consistency with
+# mainline Automake.
+# FIXME: maybe normalize/sanitize $(V)?
+V ?= 0
+
 am__mkdir = test -d $1 || $(MKDIR_P) $1
 
 # In a recipe, ensure the given directory exists, creating it if

diff --git a/m4/silent.m4 b/m4/silent.m4
index 3929793049515b0865a60a729294cf63f036902d..7f4d4b4a47ac9cb88a22c0987a75ddfd72d2f599 100644 (file)
--- a/m4/silent.m4
+++ b/m4/silent.m4
@@ -21,12 +21,8 @@ AS_HELP_STRING(
   [verbose build output (undo: "make V=0")])dnl
 ])
 case $enable_silent_rules in @%:@ (((
-  yes) AM_DEFAULT_VERBOSITY=0;;
-   no) AM_DEFAULT_VERBOSITY=1;;
-    *) AM_DEFAULT_VERBOSITY=m4_if([$1], [yes], [0], [1]);;
+  yes) V=0;;
+   no) V=1;;
+    *) V=m4_if([$1], [yes], [0], [1]);;
 esac
-AC_SUBST([AM_DEFAULT_VERBOSITY])dnl
-AM_BACKSLASH='\'
-AC_SUBST([AM_BACKSLASH])dnl
-_AM_SUBST_NOTMAKE([AM_BACKSLASH])dnl
-])
+AC_SUBST([V])])

diff --git a/t/silent-configsite.sh b/t/silent-configsite.sh
index d8c2b3322a9ff2244e3eb923d45e2e4f9a19f985..a31fb2a6401c4e2ffc5cc46501d00d7cb6888f5f 100755 (executable)
--- a/t/silent-configsite.sh
+++ b/t/silent-configsite.sh
@@ -28,9 +28,9 @@ EOF
 cat > Makefile.am <<'EOF'
 .PHONY: test-silent test-nosilent
 test-silent:
-       test x'$(AM_DEFAULT_VERBOSITY)' = x'0'
+       $(AM_V_P); test $$? -eq 1
 test-nosilent:
-       test x'$(AM_DEFAULT_VERBOSITY)' = x'1'
+       $(AM_V_P); test $$? -eq 0
 EOF
 
 unset enable_silent_rules || :

diff --git a/t/silent6.sh b/t/silent6.sh
index 0fc36650968d8f28ea06715b0a887a31bef8df0d..8d3a3260d43cd9d503ada14bb71af4e45288003f 100755 (executable)
--- a/t/silent6.sh
+++ b/t/silent6.sh
@@ -30,9 +30,9 @@ echo SUBDIRS = sub > Makefile.am
 
 mkdir sub
 cat > sub/Makefile.am <<'EOF'
-my_verbose = $(my_verbose_$(V))
-my_verbose_ = $(my_verbose_$(AM_DEFAULT_VERBOSITY))
-my_verbose_0 = @echo " XGEN    $@";
+my_verbose = $(my_verbose/$(V))
+my_verbose/0 = @echo " XGEN    $@";
+my_verbose/1 =
 
 all-local: foo gen-headers