Support specifying which architecture to target
This patch adds the `target_arch` configuration variable to scons. It
allows the user to build vixl for either AArch32, AArch64 or both.
The default configuration are changed slightly with this patch:
- On architectures other than AArch32 (x86_64), we build VIXL for both
AArch32 and AArch64. If the architecture is not AArch64, this will
include the simulator.
- On AArch32, including cross-compiling, we build VIXL for AArch32
only. The reason for this is VIXL's AArch64 target does not build on a
32 bit platform yet.
Of course, the user can override this by setting `target_arch`.
Finally, we have dropped the use of `platform.machine()` from
`SConstruct` as it doesn't cope with cross-compilation. Instead, we
directly query the compiler using the `-dumpmachine` option which print
the target triplet. This will set the `host_arch` variable which will
then influence `target_arch`.
Change-Id: I5f9fbc1343e0957475a2a8309bca00c4d35a7724
diff --git a/SConstruct b/SConstruct
index 360a4e6..bca8766 100644
--- a/SConstruct
+++ b/SConstruct
@@ -30,6 +30,7 @@
import platform
import subprocess
import sys
+from collections import OrderedDict
root_dir = os.path.dirname(File('SConstruct').rfile().abspath)
sys.path.insert(0, join(root_dir, 'tools'))
@@ -92,7 +93,7 @@
'mode:release' : {
'CCFLAGS' : ['-O3'],
},
- 'simulator:on' : {
+ 'simulator:aarch64' : {
'CCFLAGS' : ['-DVIXL_INCLUDE_SIMULATOR_AARCH64'],
},
'symbols:on' : {
@@ -115,29 +116,68 @@
env['symbols'] = 'on' if 'mode' in env and env['mode'] == 'debug' else 'off'
-vars_default_handlers = {
+# The architecture targeted by default will depend on the compiler being
+# used. 'host_arch' is extracted from the compiler while 'target_arch' can be
+# set by the user.
+# By default, we target both AArch32 and AArch64 unless the compiler
+# targets AArch32. At the moment, we cannot build VIXL's AArch64 support on a 32
+# bit platform.
+# TODO: Port VIXL to build on a 32 bit platform.
+def target_arch_handler(env):
+ if env['host_arch'] == 'aarch32':
+ env['target_arch'] = 'aarch32'
+ else:
+ env['target_arch'] = 'both'
+
+
+# By default, include the simulator only if AArch64 is targeted and we are not
+# building VIXL natively for AArch64.
+def simulator_handler(env):
+ if env['host_arch'] != 'aarch64' and \
+ env['target_arch'] in ['aarch64', 'both']:
+ env['simulator'] = 'aarch64'
+ else:
+ env['simulator'] = 'none'
+
+
+# Default variables may depend on each other, therefore we need this dictionnary
+# to be ordered.
+vars_default_handlers = OrderedDict({
# variable_name : [ 'default val', 'handler' ]
'symbols' : [ 'mode==debug', symbols_handler ],
- 'modifiable_flags' : [ 'mode==debug', modifiable_flags_handler ]
- }
+ 'modifiable_flags' : [ 'mode==debug', modifiable_flags_handler ],
+ 'target_arch' : [ 'same as host architecture if running on AArch32 - '
+ 'otherwise both',
+ target_arch_handler ],
+ 'simulator' : ['on if the target architectures include AArch64 but '
+ 'the host is not AArch64, else off',
+ simulator_handler ]
+ })
-def DefaultVariable(name, help, allowed):
+def DefaultVariable(name, help, allowed_values):
+ help = '%s (%s)' % (help, '|'.join(allowed_values))
default_value = vars_default_handlers[name][0]
- allowed.append(default_value)
- return EnumVariable(name, help, default_value, allowed)
+ def validator(name, value, env):
+ if value != default_value and value not in allowed_values:
+ raise SCons.Errors.UserError(
+ 'Invalid value for option {name}: {value}. '
+ 'Valid values are: {allowed_values}'.format(name,
+ value,
+ allowed_values))
+ return (name, help, default_value, validator)
vars = Variables()
# Define command line build options.
-sim_default = 'off' if platform.machine() == 'aarch64' else 'on'
vars.AddVariables(
EnumVariable('mode', 'Build mode',
'release', allowed_values=config.build_options_modes),
DefaultVariable('symbols', 'Include debugging symbols in the binaries',
['on', 'off']),
- EnumVariable('simulator', 'Build for the simulator',
- sim_default, allowed_values=['on', 'off']),
+ DefaultVariable('target_arch', 'Target architecture',
+ ['aarch32', 'aarch64', 'both']),
+ DefaultVariable('simulator', 'Simulators to include', ['aarch64', 'none']),
('std', 'C++ standard. The standards tested are: %s.' % \
', '.join(config.tested_cpp_standards))
)
@@ -152,7 +192,9 @@
# options are changed, different build paths are used depending on the options
# set. These are the options that should be reflected in the build directory
# path.
-options_influencing_build_path = ['mode', 'symbols', 'CXX', 'std', 'simulator']
+options_influencing_build_path = [
+ 'target_arch', 'mode', 'symbols', 'CXX', 'std', 'simulator'
+]
@@ -180,13 +222,18 @@
env[var] += options['all'][var]
else:
env[var] = options['all'][var]
+
# Other build options must match 'option:value'
env_dict = env.Dictionary()
+
+ # First apply the default variables handlers in order.
+ for key, value in vars_default_handlers.items():
+ default = value[0]
+ handler = value[1]
+ if env_dict.get(key) == default:
+ handler(env_dict)
+
for key in env_dict.keys():
- # First apply the default variables handlers.
- if key in vars_default_handlers and \
- env_dict[key] == vars_default_handlers[key][0]:
- vars_default_handlers[key][1](env_dict)
# Then update the environment according to the value of the variable.
key_val_couple = key + ':%s' % env_dict[key]
if key_val_couple in options:
@@ -235,6 +282,7 @@
def ConfigureEnvironment(env):
RetrieveEnvironmentVariables(env)
+ env['host_arch'] = util.GetHostArch(env['CXX'])
ProcessBuildOptions(env)
if 'std' in env:
env.Append(CPPFLAGS = ['-std=' + env['std']])
@@ -267,11 +315,13 @@
subprocess.check_call(["ln", "-s", build_dir, config.dir_build_latest])
# Source files are in `src` and in `src/aarch64/`.
variant_dir_vixl = PrepareVariantDir(join('src'), build_dir)
- variant_dir_aarch32 = PrepareVariantDir(join('src', 'aarch32'), build_dir)
- variant_dir_aarch64 = PrepareVariantDir(join('src', 'aarch64'), build_dir)
- sources = [Glob(join(variant_dir_vixl, '*.cc')),
- Glob(join(variant_dir_aarch32, '*.cc')),
- Glob(join(variant_dir_aarch64, '*.cc'))]
+ sources = [Glob(join(variant_dir_vixl, '*.cc'))]
+ if env['target_arch'] in ['aarch32', 'both']:
+ variant_dir_aarch32 = PrepareVariantDir(join('src', 'aarch32'), build_dir)
+ sources.append(Glob(join(variant_dir_aarch32, '*.cc')))
+ if env['target_arch'] in ['aarch64', 'both']:
+ variant_dir_aarch64 = PrepareVariantDir(join('src', 'aarch64'), build_dir)
+ sources.append(Glob(join(variant_dir_aarch64, '*.cc')))
return env.Library(join(build_dir, 'vixl'), sources)
@@ -288,66 +338,72 @@
top_level_targets.Add('', 'Build the VIXL library.')
-# The benchmarks.
-aarch64_benchmark_names = util.ListCCFilesWithoutExt(config.dir_aarch64_benchmarks)
-aarch64_benchmarks_build_dir = PrepareVariantDir('benchmarks/aarch64', TargetBuildDir(env))
-aarch64_benchmark_targets = []
-for bench in aarch64_benchmark_names:
- prog = env.Program(join(aarch64_benchmarks_build_dir, bench),
- join(aarch64_benchmarks_build_dir, bench + '.cc'),
- LIBS=[libvixl])
- aarch64_benchmark_targets.append(prog)
-env.Alias('aarch64_benchmarks', aarch64_benchmark_targets)
-top_level_targets.Add('aarch64_benchmarks', 'Build the benchmarks for AArch64.')
-
-
-# The examples.
-aarch64_example_names = util.ListCCFilesWithoutExt(config.dir_aarch64_examples)
-aarch64_examples_build_dir = PrepareVariantDir('examples/aarch64', TargetBuildDir(env))
-aarch64_example_targets = []
-for example in aarch64_example_names:
- prog = env.Program(join(aarch64_examples_build_dir, example),
- join(aarch64_examples_build_dir, example + '.cc'),
- LIBS=[libvixl])
- aarch64_example_targets.append(prog)
-env.Alias('aarch64_examples', aarch64_example_targets)
-top_level_targets.Add('aarch64_examples', 'Build the examples for AArch64.')
-aarch32_example_names = util.ListCCFilesWithoutExt(config.dir_aarch32_examples)
-aarch32_examples_build_dir = PrepareVariantDir('examples/aarch32', TargetBuildDir(env))
-aarch32_example_targets = []
-for example in aarch32_example_names:
- prog = env.Program(join(aarch32_examples_build_dir, example),
- join(aarch32_examples_build_dir, example + '.cc'),
- LIBS=[libvixl])
- aarch32_example_targets.append(prog)
-env.Alias('aarch32_examples', aarch32_example_targets)
-top_level_targets.Add('aarch32_examples', 'Build the examples for AArch32.')
-
-
-# The tests.
+# Common test code.
test_build_dir = PrepareVariantDir('test', TargetBuildDir(env))
test_objects = [env.Object(Glob(join(test_build_dir, '*.cc')))]
-test_aarch32_build_dir = PrepareVariantDir(join('test', 'aarch32'), TargetBuildDir(env))
-test_objects.append(env.Object(
- Glob(join(test_aarch32_build_dir, '*.cc')),
- CPPPATH = env['CPPPATH'] + [config.dir_tests]))
+# AArch32 support
+if env['target_arch'] in ['aarch32', 'both']:
+ # The examples.
+ aarch32_example_names = util.ListCCFilesWithoutExt(config.dir_aarch32_examples)
+ aarch32_examples_build_dir = PrepareVariantDir('examples/aarch32', TargetBuildDir(env))
+ aarch32_example_targets = []
+ for example in aarch32_example_names:
+ prog = env.Program(join(aarch32_examples_build_dir, example),
+ join(aarch32_examples_build_dir, example + '.cc'),
+ LIBS=[libvixl])
+ aarch32_example_targets.append(prog)
+ env.Alias('aarch32_examples', aarch32_example_targets)
+ top_level_targets.Add('aarch32_examples', 'Build the examples for AArch32.')
-test_aarch64_build_dir = PrepareVariantDir(join('test', 'aarch64'), TargetBuildDir(env))
-test_objects.append(env.Object(
- Glob(join(test_aarch64_build_dir, '*.cc')),
- CPPPATH = env['CPPPATH'] + [config.dir_tests]))
+ # The tests.
+ test_aarch32_build_dir = PrepareVariantDir(join('test', 'aarch32'), TargetBuildDir(env))
+ test_objects.append(env.Object(
+ Glob(join(test_aarch32_build_dir, '*.cc')),
+ CPPPATH = env['CPPPATH'] + [config.dir_tests]))
-# The test requires building the example files with specific options, so we
-# create a separate variant dir for the example objects built this way.
-test_aarch64_examples_vdir = join(TargetBuildDir(env), 'test', 'aarch64', 'test_examples')
-VariantDir(test_aarch64_examples_vdir, '.')
-test_aarch64_examples_obj = env.Object(
- [Glob(join(test_aarch64_examples_vdir, join('test', 'aarch64', 'examples/aarch64', '*.cc'))),
- Glob(join(test_aarch64_examples_vdir, join('examples/aarch64', '*.cc')))],
- CCFLAGS = env['CCFLAGS'] + ['-DTEST_EXAMPLES'],
- CPPPATH = env['CPPPATH'] + [config.dir_aarch64_examples] + [config.dir_tests])
-test_objects.append(test_aarch64_examples_obj)
+# AArch64 support
+if env['target_arch'] in ['aarch64', 'both']:
+ # The benchmarks.
+ aarch64_benchmark_names = util.ListCCFilesWithoutExt(config.dir_aarch64_benchmarks)
+ aarch64_benchmarks_build_dir = PrepareVariantDir('benchmarks/aarch64', TargetBuildDir(env))
+ aarch64_benchmark_targets = []
+ for bench in aarch64_benchmark_names:
+ prog = env.Program(join(aarch64_benchmarks_build_dir, bench),
+ join(aarch64_benchmarks_build_dir, bench + '.cc'),
+ LIBS=[libvixl])
+ aarch64_benchmark_targets.append(prog)
+ env.Alias('aarch64_benchmarks', aarch64_benchmark_targets)
+ top_level_targets.Add('aarch64_benchmarks', 'Build the benchmarks for AArch64.')
+
+ # The examples.
+ aarch64_example_names = util.ListCCFilesWithoutExt(config.dir_aarch64_examples)
+ aarch64_examples_build_dir = PrepareVariantDir('examples/aarch64', TargetBuildDir(env))
+ aarch64_example_targets = []
+ for example in aarch64_example_names:
+ prog = env.Program(join(aarch64_examples_build_dir, example),
+ join(aarch64_examples_build_dir, example + '.cc'),
+ LIBS=[libvixl])
+ aarch64_example_targets.append(prog)
+ env.Alias('aarch64_examples', aarch64_example_targets)
+ top_level_targets.Add('aarch64_examples', 'Build the examples for AArch64.')
+
+ # The tests.
+ test_aarch64_build_dir = PrepareVariantDir(join('test', 'aarch64'), TargetBuildDir(env))
+ test_objects.append(env.Object(
+ Glob(join(test_aarch64_build_dir, '*.cc')),
+ CPPPATH = env['CPPPATH'] + [config.dir_tests]))
+
+ # The test requires building the example files with specific options, so we
+ # create a separate variant dir for the example objects built this way.
+ test_aarch64_examples_vdir = join(TargetBuildDir(env), 'test', 'aarch64', 'test_examples')
+ VariantDir(test_aarch64_examples_vdir, '.')
+ test_aarch64_examples_obj = env.Object(
+ [Glob(join(test_aarch64_examples_vdir, join('test', 'aarch64', 'examples/aarch64', '*.cc'))),
+ Glob(join(test_aarch64_examples_vdir, join('examples/aarch64', '*.cc')))],
+ CCFLAGS = env['CCFLAGS'] + ['-DTEST_EXAMPLES'],
+ CPPPATH = env['CPPPATH'] + [config.dir_aarch64_examples] + [config.dir_tests])
+ test_objects.append(test_aarch64_examples_obj)
test = env.Program(join(test_build_dir, 'test-runner'), test_objects,
LIBS=[libvixl])