Add CPU feature helper function (#50402)

Author: wsmoses

src/jl_exported_funcs.inc

@@ -212,6 +212,7 @@
     XX(jl_get_binding_or_error) \
     XX(jl_get_binding_wr) \
     XX(jl_get_cpu_name) \
+    XX(jl_get_cpu_features) \
     XX(jl_get_current_task) \
     XX(jl_get_default_sysimg_path) \
     XX(jl_get_excstack) \

src/processor.h

@@ -221,6 +221,8 @@ jl_image_t jl_init_processor_pkgimg(void *hdl);
 
 // Return the name of the host CPU as a julia string.
 JL_DLLEXPORT jl_value_t *jl_get_cpu_name(void);
+// Return the features of the host CPU as a julia string.
+JL_DLLEXPORT jl_value_t *jl_get_cpu_features(void);
 // Dump the name and feature set of the host CPU
 // For debugging only
 JL_DLLEXPORT void jl_dump_host_cpu(void);

src/processor_arm.cpp

@@ -1802,6 +1802,11 @@ JL_DLLEXPORT jl_value_t *jl_get_cpu_name(void)
     return jl_cstr_to_string(host_cpu_name().c_str());
 }
 
+JL_DLLEXPORT jl_value_t *jl_get_cpu_features(void)
+{
+    return jl_cstr_to_string(jl_get_cpu_features_llvm().c_str());
+}
+
 jl_image_t jl_init_processor_sysimg(void *hdl)
 {
     if (!jit_targets.empty())

src/processor_fallback.cpp

@@ -164,6 +164,11 @@ JL_DLLEXPORT jl_value_t *jl_get_cpu_name(void)
     return jl_cstr_to_string(host_cpu_name().c_str());
 }
 
+JL_DLLEXPORT jl_value_t *jl_get_cpu_features(void)
+{
+    return jl_cstr_to_string(jl_get_cpu_features_llvm().c_str());
+}
+
 JL_DLLEXPORT void jl_dump_host_cpu(void)
 {
     jl_safe_printf("CPU: %s\n", host_cpu_name().c_str());

src/processor_x86.cpp

@@ -1042,6 +1042,11 @@ JL_DLLEXPORT jl_value_t *jl_get_cpu_name(void)
     return jl_cstr_to_string(host_cpu_name().c_str());
 }
 
+JL_DLLEXPORT jl_value_t *jl_get_cpu_features(void)
+{
+    return jl_cstr_to_string(jl_get_cpu_features_llvm().c_str());
+}
+
 jl_image_t jl_init_processor_sysimg(void *hdl)
 {
     if (!jit_targets.empty())

test/sysinfo.jl

@@ -10,6 +10,9 @@ Base.Sys.loadavg()
 @test Base.libllvm_path() isa Symbol
 @test contains(String(Base.libllvm_path()), "LLVM")
 
+@test length(ccall(:jl_get_cpu_name, String, ())) != 0
+@test length(ccall(:jl_get_cpu_features, String, ())) >= 0
+
 if Sys.isunix()
     mktempdir() do tempdir
         firstdir = joinpath(tempdir, "first")