Make warning CXXFLAGS configurable

This turns off -Werror by default except in the Debian package.
-Werror is inherently unportable and breaks things on OS X.  While it
can cause problems in Debian too, this is at least a little better.

It also turns off -pedantic in src/protobufs, because apparently
protoc output doesn’t compile with -pedantic on all platforms.

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

configure.ac

@@ -12,6 +12,33 @@ AC_CONFIG_HEADERS([config.h])
 AC_PROG_CXX
 AC_PROG_RANLIB
 
+WARNING_CXXFLAGS=""
+PICKY_CXXFLAGS=""
+AC_ARG_ENABLE([compile-warnings],
+  [AS_HELP_STRING([--enable-compile-warnings@<:@=no/yes/maximum/error],
+     [Turn on compiler warnings])],
+  [case "$enableval" in
+     no)
+       ;;
+     '' | yes)
+       WARNING_CXXFLAGS="-Wall"
+       ;;
+     maximum)
+       WARNING_CXXFLAGS="-Wall"
+       PICKY_CXXFLAGS="-Wextra -pedantic -Wno-long-long -Weffc++"
+       ;;
+     error)
+       WARNING_CXXFLAGS="-Wall -Werror"
+       PICKY_CXXFLAGS="-Wextra -pedantic -Wno-long-long -Weffc++"
+       ;;
+     *)
+       AC_MSG_ERROR([Unknown argument '$enableval' to --enable-compile-warnings])
+       ;;
+   esac],
+  [WARNING_CXXFLAGS="-Wall"])
+AC_SUBST([WARNING_CXXFLAGS])
+AC_SUBST([PICKY_CXXFLAGS])
+
 # Checks for libraries.
 AC_SEARCH_LIBS([utempter_remove_added_record], [utempter], , [AC_MSG_ERROR([Unable to find libutempter.])])
 AC_SEARCH_LIBS([compress], [z], , [AC_MSG_ERROR([Unable to find zlib.])])

debian/control

@@ -2,7 +2,7 @@ Source: mosh
 Section: net
 Priority: optional
 Maintainer: Keith Winstein <keithw@mit.edu>
-Build-Depends: debhelper (>= 7.0.0), autotools-dev, protobuf-compiler, libprotobuf-dev, dh-autoreconf, pkg-config, libutempter-dev, libboost-dev, zlib1g-dev
+Build-Depends: debhelper (>= 7.0.50), autotools-dev, protobuf-compiler, libprotobuf-dev, dh-autoreconf, pkg-config, libutempter-dev, libboost-dev, zlib1g-dev
 Standards-Version: 3.9.3
 Homepage: http://mosh.mit.edu
 Vcs-Git: git://github.com/keithw/mosh.git

debian/rules

@@ -11,3 +11,7 @@
 
 %:
 	dh $@ --with autoreconf
+
+override_dh_auto_configure:
+	dh_auto_configure -- \
+		--enable-compile-warnings=error

src/crypto/Makefile.am

@@ -1,4 +1,4 @@
-AM_CXXFLAGS = -pedantic -Wno-long-long -Werror -Wall -Wextra -Weffc++ -fno-default-inline -pipe
+AM_CXXFLAGS = $(WARNING_CXXFLAGS) $(PICKY_CXXFLAGS) -fno-default-inline -pipe
 
 noinst_LIBRARIES = libmoshcrypto.a
 

src/examples/Makefile.am

@@ -1,4 +1,4 @@
-AM_CXXFLAGS = -pedantic -Wno-long-long -Werror -Wall -Wextra -Weffc++ -fno-default-inline -pipe
+AM_CXXFLAGS = $(WARNING_CXXFLAGS) $(PICKY_CXXFLAGS) -fno-default-inline -pipe
 
 noinst_PROGRAMS = encrypt decrypt ntester parse termemu
 

src/frontend/Makefile.am

@@ -1,5 +1,5 @@
 AM_CPPFLAGS = -I$(srcdir)/../statesync -I$(srcdir)/../terminal -I$(srcdir)/../network -I$(srcdir)/../crypto -I$(builddir)/../protobufs -I$(srcdir)/../util
-AM_CXXFLAGS = -pedantic -Wno-long-long -Werror -Wall -Wextra -Weffc++ -fno-default-inline -pipe
+AM_CXXFLAGS = $(WARNING_CXXFLAGS) $(PICKY_CXXFLAGS) -fno-default-inline -pipe
 LIBS = $(protobuf_LIBS)
 LDADD = ../crypto/libmoshcrypto.a ../network/libmoshnetwork.a ../statesync/libmoshstatesync.a ../terminal/libmoshterminal.a ../util/libmoshutil.a ../protobufs/libmoshprotos.a -lutil -lrt -lm -lutempter
 

src/network/Makefile.am

@@ -1,5 +1,5 @@
 AM_CPPFLAGS = -I$(srcdir)/../util -I$(srcdir)/../crypto -I$(builddir)/../protobufs
-AM_CXXFLAGS = -pedantic -Wno-long-long -Werror -Wall -Wextra -Weffc++ -fno-default-inline -pipe
+AM_CXXFLAGS = $(WARNING_CXXFLAGS) $(PICKY_CXXFLAGS) -fno-default-inline -pipe
 
 noinst_LIBRARIES = libmoshnetwork.a
 

src/protobufs/Makefile.am

@@ -2,7 +2,7 @@ source = userinput.proto hostinput.proto transportinstruction.proto
 
 PROTOC = protoc
 AM_CPPFLAGS = $(protobuf_CFLAGS)
-AM_CXXFLAGS = -pedantic -Wno-long-long -Werror -Wall -fno-default-inline -pipe
+AM_CXXFLAGS = $(WARNING_CXXFLAGS) -fno-default-inline -pipe
 
 SUFFIXES = .proto .pb.cc
 

src/statesync/Makefile.am

@@ -1,5 +1,5 @@
 AM_CPPFLAGS = -I$(srcdir)/../terminal -I$(builddir)/../protobufs
-AM_CXXFLAGS = -pedantic -Wno-long-long -Werror -Wall -Wextra -Weffc++ -fno-default-inline -pipe
+AM_CXXFLAGS = $(WARNING_CXXFLAGS) $(PICKY_CXXFLAGS) -fno-default-inline -pipe
 
 noinst_LIBRARIES = libmoshstatesync.a
 

src/terminal/Makefile.am

@@ -1,5 +1,5 @@
 AM_CPPFLAGS = -I$(srcdir)/../util
-AM_CXXFLAGS = -pedantic -Wno-long-long -Werror -Wall -Wextra -Weffc++ -fno-default-inline -pipe
+AM_CXXFLAGS = $(WARNING_CXXFLAGS) $(PICKY_CXXFLAGS) -fno-default-inline -pipe
 
 noinst_LIBRARIES = libmoshterminal.a
 

src/util/Makefile.am

@@ -1,4 +1,4 @@
-AM_CXXFLAGS = -pedantic -Wno-long-long -Werror -Wall -Wextra -Weffc++ -fno-default-inline -pipe
+AM_CXXFLAGS = $(WARNING_CXXFLAGS) $(PICKY_CXXFLAGS) -fno-default-inline -pipe
 
 noinst_LIBRARIES = libmoshutil.a