Re-enable NaCl toolchains when requested

With some minor fixes, the build is able to run and produce an irt_core
binary when configured with the Saigo toolchain.
Added documentation how to do this to the README.

Still keeping the 'if nacltools' guards I added so that sel_ldr can be
built without acquiring any NaCl toolchains.

Author: slipher

README.md

@@ -7,9 +7,28 @@ Dependencies:
 - LLVM (must be installed in /usr/bin)
 - SCons
 
-Build with:
+### Build the NaCl loader and boostrap loader
 ```
-scons platform=x86-64 MODE=opt-host naclsdk_validate=0 sysinfo=0 sel_ldr
+scons --mode=opt-host platform=x86-64 sel_ldr
+```
+
+### Build the IRT
+This requires the Saigo NaCl toolchain. You can provide it by either
+(a) passing `saigo_newlib_dir=<path>` on the command line (the directory
+you want to target is normally called `saigo_newlib`), or
+(b) dropping the toolchain in `toolchain/linux_x86/` and renaming its
+top-level directory from `saigo_newlib` to `saigo_newlib_raw`.
+
+The following command builds one `irt_core_raw.nexe`. You need to strip it
+yourself; ordinary Linux `strip` seems to work.
+```
+scons --mode=nacl saigo=1 platform=x86-64 irt_core_raw [optional saigo_newlib_dir=...]
+```
+
+### Try some tests
+This builds both components and runs some tests.
+```
+scons --mode=opt-host,nacl saigo=1 platform=x86-64 --keep-going small_tests medium_tests
 ```
 ---
 

SConstruct

@@ -34,8 +34,6 @@ import pynacl.platform
 import gc
 gc.disable()
 
-nacltool = False # Daemon: not yet implemented
-
 # REPORT
 CMD_COUNTER = {}
 ENV_COUNTER = {}
@@ -2798,7 +2796,7 @@ pre_base_env.Append(
 nacl_env = MakeArchSpecificEnv()
 # See comment below about libc++ and libpthread in NONIRT_LIBS.
 using_nacl_libcxx = nacl_env.Bit('bitcode') or nacl_env.Bit('nacl_clang')
-if nacltool: nacl_env = nacl_env.Clone(
+if UsingNaclMode(): nacl_env = nacl_env.Clone(
     tools = ['naclsdk'],
     NACL_BUILD_FAMILY = 'UNTRUSTED',
     BUILD_TYPE = 'nacl',
@@ -3138,7 +3136,7 @@ if nacl_env.Bit('running_on_valgrind'):
     nacl_env.Append(LINKFLAGS = ['-Wl,-u,have_nacl_valgrind_interceptors'],
                     LIBS = ['valgrind'])
 
-if nacltool: environment_list.append(nacl_env)
+if UsingNaclMode(): environment_list.append(nacl_env)
 
 if not nacl_env.Bit('nacl_glibc'):
   # These are all specific to nacl-newlib so we do not include them
@@ -3392,11 +3390,11 @@ nacl_irt_env.ClearBits('bitcode')
 # used to build user/test code. nacl-clang is used everywhere for the IRT.
 nacl_irt_env.SetBits('nacl_clang')
 
-if nacltool: nacl_irt_env.Tool('naclsdk')
+if UsingNaclMode(): nacl_irt_env.Tool('naclsdk')
 # These are unfortunately clobbered by running Tool, which
 # we needed to do to get the destination directory reset.
 # We want all the same values from nacl_env.
-if nacltool: nacl_irt_env.Replace(EXTRA_CFLAGS=nacl_env['EXTRA_CFLAGS'],
+if UsingNaclMode(): nacl_irt_env.Replace(EXTRA_CFLAGS=nacl_env['EXTRA_CFLAGS'],
                      EXTRA_CXXFLAGS=nacl_env['EXTRA_CXXFLAGS'],
                      CCFLAGS=nacl_env['CCFLAGS'],
                      CFLAGS=nacl_env['CFLAGS'],
@@ -3417,7 +3415,7 @@ if nacl_irt_env.Bit('build_x86_32'):
 # The IRT is C only, don't link with the C++ linker so that it doesn't
 # start depending on the C++ standard library and (in the case of
 # libc++) pthread.
-if nacltool: nacl_irt_env.Replace(LINK=(nacl_irt_env['LINK'].
+if UsingNaclMode(): nacl_irt_env.Replace(LINK=(nacl_irt_env['LINK'].
                            replace('nacl-clang++', 'nacl-clang')))
 
 # TODO(mcgrathr): Clean up uses of these methods.
@@ -3533,8 +3531,8 @@ def AddImplicitLibs(env):
     # The -B<dir>/ flag is necessary to tell gcc to look for crt[1in].o there.
     env.Prepend(LINKFLAGS=['-B${LIB_DIR}/'])
 
-if nacltool: AddImplicitLibs(nacl_env)
-if nacltool: AddImplicitLibs(nacl_irt_env)
+if UsingNaclMode(): AddImplicitLibs(nacl_env)
+if UsingNaclMode(): AddImplicitLibs(nacl_irt_env)
 
 nacl_irt_env.Append(
     BUILD_SCONSCRIPTS = [
@@ -3549,7 +3547,7 @@ nacl_irt_env.Append(
     ])
 nacl_irt_env.AddChromeFilesFromGroup('untrusted_irt_scons_files')
 
-if nacltool: environment_list.append(nacl_irt_env)
+if UsingNaclMode(): environment_list.append(nacl_irt_env)
 
 # Since browser_tests already use the IRT normally, those are fully covered
 # in nacl_env.  But the non_browser_tests don't use the IRT in nacl_env.
@@ -3614,7 +3612,7 @@ def IrtTestAddNodeToTestSuite(env, node, suite_name, node_name=None,
                             is_broken, is_flaky)
 nacl_irt_test_env.AddMethod(IrtTestAddNodeToTestSuite, 'AddNodeToTestSuite')
 
-if nacltool: environment_list.append(nacl_irt_test_env)
+if UsingNaclMode(): environment_list.append(nacl_irt_test_env)
 
 
 windows_coverage_env = windows_debug_env.Clone(

site_scons/site_init.py

@@ -131,6 +131,11 @@ def BuildEnvironmentSConscripts(env):
           'Bad location for a SConscript. "%s" is not under '
           '\$TARGET_ROOT or \$MAIN_DIR' % c_script)
 
+def UsingNaclMode():
+  build_modes = SCons.Script.ARGUMENTS.get('MODE') or SCons.Script.GetOption('build_mode')
+  build_modes = build_modes.split(',')
+  return any('nacl' in mode for mode in build_modes)
+
 def FilterEnvironments(environments):
   """Filters out the environments to be actually build from the specified list
 

src/trusted/validator_ragel/build.scons

@@ -164,10 +164,13 @@ ragel_targets = set([
     'dfachecktries'])
 ragel_involved = ragel_targets.intersection(COMMAND_LINE_TARGETS)
 
-#gas = env.MakeUntrustedNativeEnv()['AS']
-#objdump = env.MakeUntrustedNativeEnv()['OBJDUMP']
-gas = "AAAAAAAAAAAAA"
-objdump = "BBBBBBB"
+if UsingNaclMode():
+  gas = env.MakeUntrustedNativeEnv()['AS']
+  objdump = env.MakeUntrustedNativeEnv()['OBJDUMP']
+else:
+  gas = 'AS_UNAVAILABLE_WITHOUT_MODE_NACL'
+  objdump = 'OBJDUMP_UNAVAILABLE_WITHOUT_MODE_NACL'
+
 
 if ragel_involved:
   if not env.Bit('host_linux'):