From: Stefano Lattarini <stefano.lattarini@gmail.com>
Date: Mon, 18 Jun 2012 09:33:00 +0000 (+0200)
Subject: [bg] silent: simplify by taking advantage of GNU make semantics
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=f50cba3f2f04c4b4adb7b6843a56b4ee524f5bf9;p=thirdparty%2Fautomake.git

[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 a6ba2f99c..d814dfe41 100644
--- 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 16d007488..7776ed937 100644
--- 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 c3a9848da..12224e8ba 100644
--- 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 d01321043..23749b58a 100644
--- 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 c4f14d018..636713b9b 100644
--- 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 392979304..7f4d4b4a4 100644
--- 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([$1], [yes], [0], [1]);;
 esac
-AC_SUBST([AM_DEFAULT_VERBOSITY])dnl
-AM_BACKSLASH='\'
-AC_SUBST([AM_BACKSLASH])dnl
-_AM_SUBST_NOTMAKE([AM_BACKSLASH])dnl
-])
+AC_SUBST([V])])
diff --git a/t/silent-configsite.sh b/t/silent-configsite.sh
index d8c2b3322..a31fb2a64 100755
--- a/t/silent-configsite.sh
+++ b/t/silent-configsite.sh
@@ -28,9 +28,9 @@ EOF
 cat > Makefile.am <<'EOF'
 .PHONY: test-silent test-nosilent
 test-silent:
-	test x'$(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 0fc366509..8d3a3260d 100755
--- 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