[flang] Implement GETUID and GETGID intrinsics (llvm#110679)

GETUID and GETGID are non-standard intrinsics supported by a number of
other Fortran compilers. On supported platforms these intrinsics simply
call the POSIX getuid() and getgid() functions and return the result.
The only platform we support that does not have these is Windows.

Windows does not have the same concept of UIDs and GIDs, so on Windows
we issue a warning indicating this and return 1 from both functions.

Co-authored-by: Yi Wu <yi.wu2@arm.com>

Author: DavidTruby

flang/docs/Intrinsics.md

@@ -765,7 +765,7 @@ This phase currently supports all the intrinsic procedures listed above but the
 | Coarray intrinsic functions | COSHAPE |
 | Object characteristic inquiry functions | ALLOCATED, ASSOCIATED, EXTENDS_TYPE_OF, IS_CONTIGUOUS, PRESENT, RANK, SAME_TYPE, STORAGE_SIZE |
 | Type inquiry intrinsic functions | BIT_SIZE, DIGITS, EPSILON, HUGE, KIND, MAXEXPONENT, MINEXPONENT, NEW_LINE, PRECISION, RADIX, RANGE, TINY|
-| Non-standard intrinsic functions | AND, OR, XOR, SHIFT, ZEXT, IZEXT, COSD, SIND, TAND, ACOSD, ASIND, ATAND, ATAN2D, COMPL, EQV, NEQV, INT8, JINT, JNINT, KNINT, QCMPLX, DREAL, DFLOAT, QEXT, QFLOAT, QREAL, DNUM, NUM, JNUM, KNUM, QNUM, RNUM, RAN, RANF, ILEN, SIZEOF, MCLOCK, SECNDS, COTAN, IBCHNG, ISHA, ISHC, ISHL, IXOR, IARG, IARGC, NARGS, GETPID, NUMARG, BADDRESS, IADDR, CACHESIZE, EOF, FP_CLASS, INT_PTR_KIND, ISNAN, MALLOC, FREE |
+| Non-standard intrinsic functions | AND, OR, XOR, SHIFT, ZEXT, IZEXT, COSD, SIND, TAND, ACOSD, ASIND, ATAND, ATAN2D, COMPL, EQV, NEQV, INT8, JINT, JNINT, KNINT, QCMPLX, DREAL, DFLOAT, QEXT, QFLOAT, QREAL, DNUM, NUM, JNUM, KNUM, QNUM, RNUM, RAN, RANF, ILEN, SIZEOF, MCLOCK, SECNDS, COTAN, IBCHNG, ISHA, ISHC, ISHL, IXOR, IARG, IARGC, NARGS, GETPID, NUMARG, BADDRESS, IADDR, CACHESIZE, EOF, FP_CLASS, INT_PTR_KIND, ISNAN, MALLOC, FREE, GETUID, GETGID |
 | Intrinsic subroutines |MVBITS (elemental), CPU_TIME, DATE_AND_TIME, EVENT_QUERY, EXECUTE_COMMAND_LINE, GET_COMMAND, GET_COMMAND_ARGUMENT, GET_ENVIRONMENT_VARIABLE, MOVE_ALLOC, RANDOM_INIT, RANDOM_NUMBER, RANDOM_SEED, SIGNAL, SLEEP, SYSTEM, SYSTEM_CLOCK |
 | Atomic intrinsic subroutines | ATOMIC_ADD |
 | Collective intrinsic subroutines | CO_REDUCE |

flang/include/flang/Evaluate/target.h

@@ -102,6 +102,11 @@ class TargetCharacteristics {
   bool isPPC() const { return isPPC_; }
   void set_isPPC(bool isPPC = false);
 
+  bool isOSWindows() const { return isOSWindows_; }
+  void set_isOSWindows(bool isOSWindows = false) {
+    isOSWindows_ = isOSWindows;
+  };
+
   IeeeFeatures &ieeeFeatures() { return ieeeFeatures_; }
   const IeeeFeatures &ieeeFeatures() const { return ieeeFeatures_; }
 
@@ -111,6 +116,7 @@ class TargetCharacteristics {
   std::uint8_t align_[common::TypeCategory_enumSize][maxKind]{};
   bool isBigEndian_{false};
   bool isPPC_{false};
+  bool isOSWindows_{false};
   bool areSubnormalsFlushedToZero_{false};
   Rounding roundingMode_{defaultRounding};
   std::size_t procedurePointerByteSize_{8};

flang/include/flang/Optimizer/Builder/IntrinsicCall.h

@@ -257,6 +257,10 @@ struct IntrinsicLibrary {
                         llvm::ArrayRef<mlir::Value> args);
   void genGetCommandArgument(mlir::ArrayRef<fir::ExtendedValue> args);
   void genGetEnvironmentVariable(llvm::ArrayRef<fir::ExtendedValue>);
+  mlir::Value genGetGID(mlir::Type resultType,
+                        llvm::ArrayRef<mlir::Value> args);
+  mlir::Value genGetUID(mlir::Type resultType,
+                        llvm::ArrayRef<mlir::Value> args);
   fir::ExtendedValue genIall(mlir::Type, llvm::ArrayRef<fir::ExtendedValue>);
   mlir::Value genIand(mlir::Type, llvm::ArrayRef<mlir::Value>);
   fir::ExtendedValue genIany(mlir::Type, llvm::ArrayRef<fir::ExtendedValue>);

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

@@ -48,6 +48,10 @@ void genEtime(fir::FirOpBuilder &builder, mlir::Location loc,
               mlir::Value values, mlir::Value time);
 
 void genFree(fir::FirOpBuilder &builder, mlir::Location loc, mlir::Value ptr);
+
+mlir::Value genGetUID(fir::FirOpBuilder &, mlir::Location);
+mlir::Value genGetGID(fir::FirOpBuilder &, mlir::Location);
+
 mlir::Value genMalloc(fir::FirOpBuilder &builder, mlir::Location loc,
                       mlir::Value size);
 

flang/include/flang/Runtime/extensions.h

@@ -20,6 +20,14 @@
 #include <cstddef>
 #include <cstdint>
 
+#ifdef _WIN32
+// UID and GID don't exist on Windows, these exist to avoid errors.
+typedef std::uint32_t uid_t;
+typedef std::uint32_t gid_t;
+#else
+#include "sys/types.h" //pid_t
+#endif
+
 extern "C" {
 
 // CALL FLUSH(n) antedates the Fortran 2003 FLUSH statement.
@@ -37,6 +45,12 @@ std::int32_t FORTRAN_PROCEDURE_NAME(iargc)();
 void FORTRAN_PROCEDURE_NAME(getarg)(
     std::int32_t &n, char *arg, std::int64_t length);
 
+// Calls getgid()
+gid_t RTNAME(GetGID)();
+
+// Calls getuid()
+uid_t RTNAME(GetUID)();
+
 // GNU extension subroutine GETLOG(C).
 void FORTRAN_PROCEDURE_NAME(getlog)(char *name, std::int64_t length);
 

flang/include/flang/Tools/TargetSetup.h

@@ -59,6 +59,9 @@ namespace Fortran::tools {
   if (targetTriple.isPPC())
     targetCharacteristics.set_isPPC(true);
 
+  if (targetTriple.isOSWindows())
+    targetCharacteristics.set_isOSWindows(true);
+
   // TODO: use target machine data layout to set-up the target characteristics
   // type size and alignment info.
 }

flang/lib/Evaluate/intrinsics.cpp

@@ -523,7 +523,9 @@ static const IntrinsicInterface genericIntrinsicFunction[]{
         {{"c", DefaultChar, Rank::scalar, Optionality::required,
             common::Intent::Out}},
         TypePattern{IntType, KindCode::greaterOrEqualToKind, 4}},
+    {"getgid", {}, DefaultInt},
     {"getpid", {}, DefaultInt},
+    {"getuid", {}, DefaultInt},
     {"huge",
         {{"x", SameIntOrReal, Rank::anyOrAssumedRank, Optionality::required,
             common::Intent::In, {ArgFlag::canBeMoldNull}}},

flang/lib/Optimizer/Builder/IntrinsicCall.cpp

@@ -292,7 +292,9 @@ static constexpr IntrinsicHandler handlers[]{
      &I::genGetCwd,
      {{{"c", asBox}, {"status", asAddr, handleDynamicOptional}}},
      /*isElemental=*/false},
+    {"getgid", &I::genGetGID},
     {"getpid", &I::genGetPID},
+    {"getuid", &I::genGetUID},
     {"iachar", &I::genIchar},
     {"iall",
      &I::genIall,
@@ -3664,6 +3666,14 @@ void IntrinsicLibrary::genGetCommand(llvm::ArrayRef<fir::ExtendedValue> args) {
   }
 }
 
+// GETGID
+mlir::Value IntrinsicLibrary::genGetGID(mlir::Type resultType,
+                                        llvm::ArrayRef<mlir::Value> args) {
+  assert(args.size() == 0 && "getgid takes no input");
+  return builder.createConvert(loc, resultType,
+                               fir::runtime::genGetGID(builder, loc));
+}
+
 // GETPID
 mlir::Value IntrinsicLibrary::genGetPID(mlir::Type resultType,
                                         llvm::ArrayRef<mlir::Value> args) {
@@ -3672,6 +3682,14 @@ mlir::Value IntrinsicLibrary::genGetPID(mlir::Type resultType,
                                fir::runtime::genGetPID(builder, loc));
 }
 
+// GETUID
+mlir::Value IntrinsicLibrary::genGetUID(mlir::Type resultType,
+                                        llvm::ArrayRef<mlir::Value> args) {
+  assert(args.size() == 0 && "getgid 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/lib/Optimizer/Builder/Runtime/Intrinsics.cpp

@@ -129,6 +129,22 @@ void fir::runtime::genFree(fir::FirOpBuilder &builder, mlir::Location loc,
                               builder.createConvert(loc, intPtrTy, ptr));
 }
 
+mlir::Value fir::runtime::genGetGID(fir::FirOpBuilder &builder,
+                                    mlir::Location loc) {
+  auto runtimeFunc =
+      fir::runtime::getRuntimeFunc<mkRTKey(GetGID)>(loc, builder);
+
+  return builder.create<fir::CallOp>(loc, runtimeFunc).getResult(0);
+}
+
+mlir::Value fir::runtime::genGetUID(fir::FirOpBuilder &builder,
+                                    mlir::Location loc) {
+  auto runtimeFunc =
+      fir::runtime::getRuntimeFunc<mkRTKey(GetUID)>(loc, builder);
+
+  return builder.create<fir::CallOp>(loc, runtimeFunc).getResult(0);
+}
+
 mlir::Value fir::runtime::genMalloc(fir::FirOpBuilder &builder,
                                     mlir::Location loc, mlir::Value size) {
   auto runtimeFunc =

flang/lib/Semantics/check-call.cpp

@@ -2042,6 +2042,22 @@ bool CheckPPCIntrinsic(const Symbol &generic, const Symbol &specific,
   return false;
 }
 
+bool CheckWindowsIntrinsic(
+    const Symbol &intrinsic, evaluate::FoldingContext &foldingContext) {
+  parser::ContextualMessages &messages{foldingContext.messages()};
+  // TODO: there are other intrinsics that are unsupported on Windows that
+  // should be added here.
+  if (intrinsic.name() == "getuid") {
+    messages.Say(
+        "User IDs do not exist on Windows. This function will always return 1"_warn_en_US);
+  }
+  if (intrinsic.name() == "getgid") {
+    messages.Say(
+        "Group IDs do not exist on Windows. This function will always return 1"_warn_en_US);
+  }
+  return true;
+}
+
 bool CheckArguments(const characteristics::Procedure &proc,
     evaluate::ActualArguments &actuals, SemanticsContext &context,
     const Scope &scope, bool treatingExternalAsImplicit,

flang/lib/Semantics/check-call.h

@@ -41,6 +41,8 @@ bool CheckArguments(const evaluate::characteristics::Procedure &,
 bool CheckPPCIntrinsic(const Symbol &generic, const Symbol &specific,
     const evaluate::ActualArguments &actuals,
     evaluate::FoldingContext &context);
+bool CheckWindowsIntrinsic(
+    const Symbol &intrinsic, evaluate::FoldingContext &context);
 bool CheckArgumentIsConstantExprInRange(
     const evaluate::ActualArguments &actuals, int index, int lowerBound,
     int upperBound, parser::ContextualMessages &messages);

flang/lib/Semantics/expression.cpp

@@ -2916,6 +2916,9 @@ auto ExpressionAnalyzer::GetCalleeAndArguments(const parser::Name &name,
   } else {
     resolution = symbol;
   }
+  if (resolution && context_.targetCharacteristics().isOSWindows()) {
+    semantics::CheckWindowsIntrinsic(*resolution, GetFoldingContext());
+  }
   if (!resolution || resolution->attrs().test(semantics::Attr::INTRINSIC)) {
     auto name{resolution ? resolution->name() : ultimate.name()};
     if (std::optional<SpecificCall> specificCall{context_.intrinsics().Probe(

flang/runtime/extensions.cpp

@@ -58,6 +58,24 @@ extern "C" {
 
 namespace Fortran::runtime {
 
+gid_t RTNAME(GetGID)() {
+#ifdef _WIN32
+  // Group IDs don't exist on Windows, return 1 to avoid errors
+  return 1;
+#else
+  return getgid();
+#endif
+}
+
+uid_t RTNAME(GetUID)() {
+#ifdef _WIN32
+  // User IDs don't exist on Windows, return 1 to avoid errors
+  return 1;
+#else
+  return getuid();
+#endif
+}
+
 void GetUsernameEnvVar(const char *envName, char *arg, std::int64_t length) {
   Descriptor name{*Descriptor::Create(
       1, std::strlen(envName) + 1, const_cast<char *>(envName), 0)};
@@ -66,6 +84,7 @@ void GetUsernameEnvVar(const char *envName, char *arg, std::int64_t length) {
   RTNAME(GetEnvVariable)
   (name, &value, nullptr, false, nullptr, __FILE__, __LINE__);
 }
+
 namespace io {
 // SUBROUTINE FLUSH(N)
 //   FLUSH N

flang/test/Semantics/windows.f90

@@ -0,0 +1,12 @@
+! RUN: %if x86_64-registered-target %{ %python %S/test_errors.py %s %flang --target=x86_64-pc-windows-msvc -Werror %}
+! RUN: %if aarch64-registered-target %{ %python %S/test_errors.py %s %flang --target=aarch64-pc-windows-msvc -Werror %}
+
+subroutine uid
+  !WARNING: User IDs do not exist on Windows. This function will always return 1
+  i = getuid()
+end subroutine uid
+
+subroutine gid
+  !WARNING: Group IDs do not exist on Windows. This function will always return 1
+  i = getgid()
+end subroutine gid

flang/unittests/Optimizer/Builder/Runtime/CommandTest.cpp

@@ -50,4 +50,4 @@ TEST_F(RuntimeCallTest, genGetPID) {
   mlir::Value result = fir::runtime::genGetPID(*firBuilder, loc);
   checkCallOp(result.getDefiningOp(), "_FortranAGetPID", /*nbArgs=*/0,
       /*addLocArgs=*/false);
-}
+}

flang/unittests/Optimizer/Builder/Runtime/IntrinsicsTest.cpp

@@ -0,0 +1,17 @@
+#include "flang/Optimizer/Builder/Runtime/Intrinsics.h"
+#include "RuntimeCallTestBase.h"
+#include "gtest/gtest.h"
+
+TEST_F(RuntimeCallTest, genGetGID) {
+  mlir::Location loc = firBuilder->getUnknownLoc();
+  mlir::Value result = fir::runtime::genGetGID(*firBuilder, loc);
+  checkCallOp(result.getDefiningOp(), "_FortranAGetGID", /*nbArgs=*/0,
+      /*addLocArgs=*/false);
+}
+
+TEST_F(RuntimeCallTest, genGetUID) {
+  mlir::Location loc = firBuilder->getUnknownLoc();
+  mlir::Value result = fir::runtime::genGetUID(*firBuilder, loc);
+  checkCallOp(result.getDefiningOp(), "_FortranAGetUID", /*nbArgs=*/0,
+      /*addLocArgs=*/false);
+}

flang/unittests/Optimizer/CMakeLists.txt

@@ -25,6 +25,7 @@ add_flang_unittest(FlangOptimizerTests
   Builder/Runtime/CommandTest.cpp
   Builder/Runtime/CharacterTest.cpp
   Builder/Runtime/DerivedTest.cpp
+  Builder/Runtime/IntrinsicsTest.cpp
   Builder/Runtime/NumericTest.cpp
   Builder/Runtime/RaggedTest.cpp
   Builder/Runtime/ReductionTest.cpp