Use automake’s silent-rules mode if available, for quieter build output

With automake 1.11, this gives us Linux kernel–style silent output
that makes warnings more obvious:

  GEN    userinput.pb.cc
  CXX    userinput.pb.o
  AR     libmoshprotos.a
  CXXLD  mosh-client

(Use ‘make V=1’ for the traditional verbose output.)

Signed-off-by: Anders Kaseorg <andersk@mit.edu>

configure.ac

@@ -4,6 +4,7 @@
 AC_PREREQ([2.65])
 AC_INIT([mosh], [0.96a], [mosh-devel@mit.edu])
 AM_INIT_AUTOMAKE([-Wall -Werror foreign])
+m4_ifdef([AM_SILENT_RULES], [AM_SILENT_RULES([yes])])
 AC_CONFIG_SRCDIR([src/frontend/mosh-client.cc])
 AC_CONFIG_MACRO_DIR([m4])
 AC_CONFIG_HEADERS([config.h])

debian/rules

@@ -14,4 +14,5 @@
 
 override_dh_auto_configure:
 	dh_auto_configure -- \
+		--disable-silent-rules \
 		--enable-compile-warnings=error

src/protobufs/Makefile.am

@@ -7,7 +7,7 @@ AM_CXXFLAGS = $(WARNING_CXXFLAGS) -fno-default-inline -pipe
 SUFFIXES = .proto .pb.cc
 
 .proto.pb.cc:
-	$(PROTOC) --cpp_out=$(builddir) -I$(srcdir) $<
+	$(AM_V_GEN)$(PROTOC) --cpp_out=$(builddir) -I$(srcdir) $<
 
 noinst_LIBRARIES = libmoshprotos.a