Add support for macOS

* Add 'macos' as an additional OS build option
* Guard unsupported paths like thread scheduling control and hwcaps
checking with the __APPLE__ macro
* Map linker options to respective Mach-O linker options

Change-Id: I67bd9fa3c20831427b218ca7d3b4b9d454ab4fec
Signed-off-by: Georgios Pinitas <georgios.pinitas@arm.com>
Reviewed-on: https://review.mlplatform.org/c/ml/ComputeLibrary/+/4788
Reviewed-by: Sang-Hoon Park <sang-hoon.park@arm.com>
Reviewed-by: Giorgio Arena <giorgio.arena@arm.com>
Comments-Addressed: Arm Jenkins <bsgcomp@arm.com>
Tested-by: Arm Jenkins <bsgcomp@arm.com>
diff --git a/examples/SConscript b/examples/SConscript
index ff457fa..c7bc7df 100644
--- a/examples/SConscript
+++ b/examples/SConscript
@@ -32,7 +32,7 @@
 # Build examples
 utils = examples_env.Object("../utils/Utils.cpp")
 
-if env['os'] in ['android', 'bare_metal'] or env['standalone']:
+if env['os'] in ['android', 'macos', 'bare_metal'] or env['standalone']:
     Import('arm_compute_graph_a')
     Import('arm_compute_a')
     Import('arm_compute_core_a')
@@ -52,6 +52,12 @@
 if env['os'] != 'bare_metal':
     extra_link_flags += ['-fstack-protector-strong']
 
+load_whole_archive = '-Wl,--whole-archive'
+noload_whole_archive = '-Wl,--no-whole-archive'
+if 'macos' in examples_env['os']:
+    load_whole_archive = '-Wl,-force_load'
+    noload_whole_archive = '-Wl,-noall_load'
+
 # Build graph examples
 graph_utils = examples_env.Object("../utils/GraphUtils.cpp")
 graph_utils += examples_env.Object("../utils/CommonGraphOptions.cpp")
@@ -60,8 +66,8 @@
     example = os.path.basename(os.path.splitext(str(file))[0])
     prog = None
 
-    if env['os'] in ['android', 'bare_metal'] or env['standalone']:
-        prog = examples_env.Program(example, ["{}.cpp".format(example), utils, graph_utils], LIBS = examples_libs + arm_compute_graph_libs, LINKFLAGS=examples_env["LINKFLAGS"]+['-Wl,--whole-archive',graph_dependency,'-Wl,--no-whole-archive'] + extra_link_flags)
+    if env['os'] in ['android', 'macos', 'bare_metal'] or env['standalone']:
+        prog = examples_env.Program(example, ["{}.cpp".format(example), utils, graph_utils], LIBS = examples_libs + arm_compute_graph_libs, LINKFLAGS=examples_env["LINKFLAGS"]+[load_whole_archive, graph_dependency, noload_whole_archive] + extra_link_flags)
         Depends(prog, graph_dependency)
         prog = install_bin(prog)
     else:
@@ -95,8 +101,8 @@
     for file in Glob("./gemm_tuner/cl_*.cpp"):
         example = os.path.basename(os.path.splitext(str(file))[0])
         example = os.path.join("gemm_tuner", example)
-        if env['os'] in ['android', 'bare_metal'] or env['standalone']:
-            prog = examples_env.Program(example, ["{}.cpp".format(example), utils, gemm_tuner_common_options], CPPDEFINES=['ARM_COMPUTE_CL'], LIBS = examples_libs + arm_compute_graph_libs, LINKFLAGS=examples_env["LINKFLAGS"]+['-Wl,--whole-archive',graph_dependency,'-Wl,--no-whole-archive', '-fstack-protector-strong'] )
+        if env['os'] in ['android', 'macos', 'bare_metal'] or env['standalone']:
+            prog = examples_env.Program(example, ["{}.cpp".format(example), utils, gemm_tuner_common_options], CPPDEFINES=['ARM_COMPUTE_CL'], LIBS = examples_libs + arm_compute_graph_libs, LINKFLAGS=examples_env["LINKFLAGS"]+[load_whole_archive, graph_dependency, noload_whole_archive, '-fstack-protector-strong'] )
             Depends(prog, graph_dependency)
             prog = install_bin(prog)
         else:
@@ -136,8 +142,8 @@
         example = os.path.basename(os.path.splitext(str(file))[0])
         prog = None
 
-        if env['os'] in ['android', 'bare_metal'] or env['standalone']:
-            prog = examples_env.Program(example, [examples_env.Object(source=file, target=example), utils, graph_utils], LIBS = examples_libs + arm_compute_graph_libs, LINKFLAGS=examples_env["LINKFLAGS"]+['-Wl,--whole-archive',graph_dependency,'-Wl,--no-whole-archive'] + extra_link_flags)
+        if env['os'] in ['android', 'macos', 'bare_metal'] or env['standalone']:
+            prog = examples_env.Program(example, [examples_env.Object(source=file, target=example), utils, graph_utils], LIBS = examples_libs + arm_compute_graph_libs, LINKFLAGS=examples_env["LINKFLAGS"]+[load_whole_archive, graph_dependency, noload_whole_archive] + extra_link_flags)
             Depends(prog, graph_dependency)
             prog = install_bin(prog)
         else: