Small fixes for the 2702 implementation

Improve the INSTALL documentation for static builds, remove a few
unnecessary lines from configure.in and tweak the changelog message
slightly.

INSTALL

@@ -23,12 +23,20 @@ If it doesn't build for you:
   Lastly, check out
   https://www.torproject.org/docs/faq#DoesntWork
 
-An example of how to build a mostly static Tor:
+How to do static builds of tor:
 
-Libevent should be built with:
+Tor supports linking each of the libraries it needs statically. Use the
-% ./configure --disable-shared --enable-static --with-pic
+--enable-static-X ./configure option in conjunction with the --with-X-dir
+option for libevent, zlib, and openssl. For this to work sanely, libevent
+should be built with --disable-shared --enable-static --with-pic, and
+OpenSSL should be built with no-shared no-dso.
 
-An example of how to build a mostly static Tor:
+If you need to build tor so that system libraries are also statically linked,
+use the --enable-static-tor ./configure option. This won't work on OS X
+unless you build the required crt0.o yourself. It is also incompatible with
+the --enable-gcc-hardening option.
+
+An example of how to build a mostly static tor:
 ./configure --enable-static-libevent \
             --enable-static-openssl  \
             --enable-static-zlib     \
@@ -36,29 +44,9 @@ An example of how to build a mostly static Tor:
             --with-openssl-dir=/tmp/static-tor/openssl-0.9.8r/ \
             --with-zlib-dir=/tmp/static-tor/zlib-1.2.5
 
-An example of how to build an entirely static Tor (no Mac OS X support, sorry):
+An example of how to build an entirely static tor:
 ./configure --enable-static-tor \
-            --enable-static-libevent \
-            --enable-static-openssl  \
-            --enable-static-zlib     \
             --with-libevent-dir=/tmp/static-tor/libevent-1.4.14b-stable \
             --with-openssl-dir=/tmp/static-tor/openssl-0.9.8r/ \
             --with-zlib-dir=/tmp/static-tor/zlib-1.2.5
 
-This currently does not work with --enable-gcc-hardening because of libevent issues:
-
-configure:6176: gcc -o conftest  -D_FORTIFY_SOURCE=2 -fstack-protector-all -fwrapv -fPIE -Wstack-protector
---param ssp-buffer-size=1 -I/tmp/static-tor/libevent-1.4.14b-stable  -I${top_srcdir}/src/common -
-L/tmp/static-tor/libevent-1.4.14b-stable  -pie conftest.c -lpthread -ldl  -levent -lrt  >&5
-/usr/bin/ld: /tmp/static-tor/libevent-1.4.14b-stable/libevent.a(event.o): relocation R_X86_64_32 against `.rodata.str1.1' can not be used when making a shared object; recompile with -fPIC
-/tmp/static-tor/libevent-1.4.14b-stable/libevent.a: could not read symbols: Bad value
-    collect2: ld returned 1 exit status
-    configure:6176: $? = 1
-
-This produces the following Tor binaries on Gnu/Linux x86-64:
-
-% file src/or/tor
-src/or/tor: ELF 64-bit LSB executable, x86-64, version 1 (GNU/Linux), statically linked, for GNU/Linux 2.6.15, not stripped
-
-% ldd src/or/tor
-    not a dynamic executable

changes/bug2702

@@ -1,5 +1,5 @@
-  o Minor enhancement
+  o Minor features:
-    - Implements --enable-static-tor for configure time. Closes bug 2702.
+    - Implements --enable-static-tor for configure time. Implements ticket
-      Idea, general hackery and thoughts from Alexei Czeskis, John Gilmore,
+      2702. Idea, general hackery and thoughts from Alexei Czeskis, John
-      Jacob Appelbaum.
+      Gilmore, Jacob Appelbaum.
 

configure.in

@@ -33,14 +33,12 @@ AC_ARG_ENABLE(static-libevent,
 AC_ARG_ENABLE(static-zlib,
    AS_HELP_STRING(--enable-static-zlib, Link against a static zlib library. Requires --with-zlib-dir))
 AC_ARG_ENABLE(static-tor,
-   AS_HELP_STRING(--enable-static-tor, Create an entirely static Tor binary. Requires --static-openssl
+   AS_HELP_STRING(--enable-static-tor, Create an entirely static Tor binary. Requires --with-openssl-dir and --with-libevent-dir and --with-zlib-dir))
-                                       --static-libevent and --static-zlib))
 
 if test "$enable_static_tor" = "yes"; then
   enable_static_libevent="yes";
   enable_static_openssl="yes";
   enable_static_zlib="yes";
-  AC_MSG_NOTICE("We're attempting to build a static Tor.")
   CFLAGS="$CFLAGS -static"
 fi
 
@@ -527,20 +525,6 @@ else
 fi
 AC_SUBST(TOR_ZLIB_LIBS)
 
-if test "$enable_static_tor" = "yes"; then
-  if test "$enable_static_libevent" = "no"; then
-     AC_MSG_ERROR("You must configure with --enable-static-libevent")
-  fi
-  if test "$enable_static_openssl" = "no"; then
-     AC_MSG_ERROR("You must configure with --enable-static-openssl")
-  fi
-  if test "$enable_static_zlib" = "no"; then
-     AC_MSG_ERROR("You must configure with --enable-static-zlib")
-  fi
-  AC_MSG_NOTICE("We're attempting to build a static Tor.")
-  CFLAGS="$CFLAGS -static"
-fi
-
 dnl Make sure to enable support for large off_t if available.