Add fake support for windows

Windows doesn't have getuid or anything Win32 equivalent, and it is also not supported in gfortran.
Windows however have "GetTokenInformation" call and querying for the TokenUser information class.
It returns user's SID.

Author: yiwu0b11

flang/include/flang/Optimizer/Builder/Runtime/Command.h

@@ -23,6 +23,10 @@ namespace fir::runtime {
 /// Generate call to COMMAND_ARGUMENT_COUNT intrinsic runtime routine.
 mlir::Value genCommandArgumentCount(fir::FirOpBuilder &, mlir::Location);
 
+/// Generate a call to the GetUID runtime function which implements the
+/// GETUID intrinsic.
+mlir::Value genGetUID(fir::FirOpBuilder &, mlir::Location);
+
 /// Generate a call to the GetCommand runtime function which implements the
 /// GET_COMMAND intrinsic.
 /// \p command, \p length and \p errmsg must be fir.box that can be absent (but
@@ -49,9 +53,5 @@ mlir::Value genGetEnvVariable(fir::FirOpBuilder &, mlir::Location,
                               mlir::Value length, mlir::Value trimName,
                               mlir::Value errmsg);
 
-/// Generate a call to the GetUID runtime function which implements the
-/// GETUID intrinsic.
-mlir::Value genGetUID(fir::FirOpBuilder &, mlir::Location);
-
 } // namespace fir::runtime
 #endif // FORTRAN_OPTIMIZER_BUILDER_RUNTIME_COMMAND_H

flang/include/flang/Runtime/command.h

@@ -14,9 +14,11 @@
 #include <cstdint>
 
 #ifdef _WIN32
+typedef int uid_t;
 #else
-#include "sys/types.h"
+#include "sys/types.h" //uid_t
 #endif
+
 namespace Fortran::runtime {
 class Descriptor;
 
@@ -27,6 +29,9 @@ extern "C" {
 // integer kind.
 std::int32_t RTNAME(ArgumentCount)();
 
+// Calls getuid()
+uid_t RTNAME(GetUID)();
+
 // 16.9.82 GET_COMMAND
 // Try to get the value of the whole command. All of the parameters are
 // optional.
@@ -52,9 +57,6 @@ std::int32_t RTNAME(GetEnvVariable)(const Descriptor &name,
     const char *sourceFile = nullptr, int line = 0);
 }
 
-// Calls getuid()
-uid_t RTNAME(GetUID)();
-
 } // namespace Fortran::runtime
 
 #endif // FORTRAN_RUNTIME_COMMAND_H_

flang/lib/Optimizer/Builder/IntrinsicCall.cpp

@@ -2907,6 +2907,14 @@ mlir::Value IntrinsicLibrary::genFraction(mlir::Type resultType,
       fir::runtime::genFraction(builder, loc, fir::getBase(args[0])));
 }
 
+// GETUID
+mlir::Value IntrinsicLibrary::genGetUID(mlir::Type resultType,
+                                        llvm::ArrayRef<mlir::Value> args) {
+  assert(args.size() == 0 && "getuid takes no input");
+  return builder.createConvert(loc, resultType,
+                               fir::runtime::genGetUID(builder, loc));
+}
+
 // GET_COMMAND
 void IntrinsicLibrary::genGetCommand(llvm::ArrayRef<fir::ExtendedValue> args) {
   assert(args.size() == 4);
@@ -2945,14 +2953,6 @@ void IntrinsicLibrary::genGetCommand(llvm::ArrayRef<fir::ExtendedValue> args) {
   }
 }
 
-// GETUID
-mlir::Value IntrinsicLibrary::genGetUID(mlir::Type resultType,
-                                        llvm::ArrayRef<mlir::Value> args) {
-  assert(args.size() == 0 && "getuid takes no input");
-  return builder.createConvert(loc, resultType,
-                               fir::runtime::genGetUID(builder, loc));
-}
-
 // GET_COMMAND_ARGUMENT
 void IntrinsicLibrary::genGetCommandArgument(
     llvm::ArrayRef<fir::ExtendedValue> args) {

flang/runtime/command.cpp

@@ -16,6 +16,7 @@
 #include <limits>
 
 #ifdef _WIN32
+inline uid_t getuid() { return 0; }
 #else
 #include <unistd.h>
 #endif

flang/unittests/Runtime/CommandTest.cpp

@@ -228,8 +228,9 @@ TEST_F(ZeroArguments, GetCommandArgument) {
 TEST_F(ZeroArguments, GetCommand) { CheckCommandValue(commandOnlyArgv, 1); }
 
 TEST_F(ZeroArguments, GetUID) {
-  // uid should always greater than 0, in both linux and windows
-  EXPECT_GT(RTNAME(GetUID)(), 0U);
+  CheckMissingArgumentValue(-1);
+  CheckArgumentValue(commandOnlyArgv[0], 0);
+  CheckMissingArgumentValue(1);
 }
 
 static const char *oneArgArgv[]{"aProgram", "anArgumentOfLength20"};