Implement System for Win32

src/crystal/system/win32/cpucount.cr

@@ -0,0 +1,8 @@
+require "c/sysinfoapi"
+
+module Crystal::System
+  def self.cpu_count
+    LibC.GetNativeSystemInfo(out system_info)
+    system_info.dwNumberOfProcessors
+  end
+end

src/crystal/system/win32/hostname.cr

@@ -0,0 +1,12 @@
+require "c/sysinfoapi"
+
+module Crystal::System
+  def self.hostname
+    name_size = LibC::MAX_COMPUTER_NAME_SIZE.to_u32
+    unless LibC.GetComputerNameExW(LibC::COMPUTER_NAME_FORMAT::ComputerNameDnsHostname, out machine_name, pointerof(name_size))
+      raise WinError.new("Failed to get machine hostname")
+    end
+    actual_name = Slice.new(machine_name.to_unsafe, name_size)
+    String.from_utf16(actual_name)
+  end
+end

src/lib_c/x86_64-windows-msvc/c/int_safe.cr

@@ -1,3 +1,4 @@
 lib LibC
   alias DWORD = UInt32
+  alias DWORD_PTR = UInt32*
 end

src/lib_c/x86_64-windows-msvc/c/sysinfoapi.cr

@@ -0,0 +1,54 @@
+require "c/winnt"
+require "c/win_def"
+require "c/int_safe"
+
+lib LibC
+  fun GetNativeSystemInfo = GetNativeSystemInfo(system_info : SYSTEM_INFO*)
+
+  PROCESSOR_ARCHITECTURE_AMD64   =      9
+  PROCESSOR_ARCHITECTURE_ARM     =      5
+  PROCESSOR_ARCHITECTURE_ARM64   =     12
+  PROCESSOR_ARCHITECTURE_IA64    =      6
+  PROCESSOR_ARCHITECTURE_INTEL   =      0
+  PROCESSOR_ARCHITECTURE_UNKNOWN = 0xffff
+
+  struct PROCESSOR_INFO
+    wProcessorArchitecture : WORD
+    wReserved : WORD
+  end
+
+  union OEM_PROCESSOR_INFO
+    dwOemId : DWORD
+    processorInfo : PROCESSOR_INFO
+  end
+
+  struct SYSTEM_INFO
+    oemProcessorInfo : OEM_PROCESSOR_INFO
+    dwPageSize : DWORD
+    lpMinimumApplicationAddress : LPVOID
+    lpMaximumApplicationAddress : LPVOID
+    dwActiveProcessorMask : DWORD_PTR
+    dwNumberOfProcessors : DWORD
+    dwProcessorType : DWORD
+    dwAllocationGranularity : DWORD
+    wProcessorLevel : WORD
+    wProcessorRevision : WORD
+  end
+
+  fun GetComputerNameExW = GetComputerNameExW(computer_name_format : COMPUTER_NAME_FORMAT,
+                                              machine_name : WCHAR[MAX_COMPUTER_NAME_SIZE]*,
+                                              machine_name_size_ptr : DWORD_PTR) : BOOLEAN
+
+  MAX_COMPUTER_NAME_SIZE = 255
+
+  enum COMPUTER_NAME_FORMAT
+    ComputerNameNetBIOS
+    ComputerNameDnsHostname
+    ComputerNameDnsDomain
+    ComputerNameDnsFullyQualified
+    ComputerNamePhysicalNetBIOS
+    ComputerNamePhysicalDnsHostname
+    ComputerNamePhysicalDomain
+    ComputerNamePhysicalDnsFullyQualified
+  end
+end

src/lib_c/x86_64-windows-msvc/c/winnt.cr

@@ -8,6 +8,7 @@ lib LibC
   alias LPWSTR = WCHAR*
   alias LPWCH = WCHAR*
 
+  alias LPVOID = Void*
   alias HANDLE = Void*
 
   INVALID_FILE_ATTRIBUTES      = DWORD.new(-1)