[flang-commits] [flang] flang: allow EXIT to accept integer arguments of any kind (PR #174610)

[via flang-commits]

https://github.com/blazie2004 created https://github.com/llvm/llvm-project/pull/174610

### Overview 

This change removes a strict semantic check for the EXIT intrinsic in Flang and allows the STATUS argument to be an INTEGER of any kind, similar to gfortran and Cray Fortran.

### Problem

Flang currently rejects calls such as:

  integer(8) :: status
  call exit(status)

with a semantic error indicating an invalid integer kind. Other major Fortran
compilers accept this code and implicitly convert the argument to the default
integer kind.

Although Flang already performs the required conversion during lowering, the
call is rejected earlier during intrinsic interface matching.

### Solution

This PR:
- Relaxes intrinsic argument matching for `EXIT` to accept any INTEGER kind
- Preserves explicit conversion to default integer kind during lowering

### Files Modified

- flang/lib/Evaluate/intrinsics.cpp
- flang/lib/Optimizer/Builder/IntrinsicCall.cpp




>From 083a655a22da3558d34f149266246e944031f0bb Mon Sep 17 00:00:00 2001
From: Jay Satish Kumar Patel <kumarpat at pe31.hpc.amslabs.hpecorp.net>
Date: Tue, 6 Jan 2026 09:28:25 -0600
Subject: [PATCH] flang: allow EXIT to accept integer arguments of any kind

---
 flang/lib/Evaluate/intrinsics.cpp             | 15 ++++++++++++---
 flang/lib/Optimizer/Builder/IntrinsicCall.cpp |  9 +++++++--
 2 files changed, 19 insertions(+), 5 deletions(-)

diff --git a/flang/lib/Evaluate/intrinsics.cpp b/flang/lib/Evaluate/intrinsics.cpp
index da39f199cab43..2e22819ce4e30 100644
--- a/flang/lib/Evaluate/intrinsics.cpp
+++ b/flang/lib/Evaluate/intrinsics.cpp
@@ -1604,7 +1604,7 @@ static const IntrinsicInterface intrinsicSubroutine[]{
             {"cmdmsg", DefaultChar, Rank::scalar, Optionality::optional,
                 common::Intent::InOut}},
         {}, Rank::elemental, IntrinsicClass::impureSubroutine},
-    {"exit", {{"status", DefaultInt, Rank::scalar, Optionality::optional}}, {},
+    {"exit", {{"status", AnyInt, Rank::scalar, Optionality::optional}}, {},
         Rank::elemental, IntrinsicClass::impureSubroutine},
     {"free", {{"ptr", Addressable}}, {}},
     {"flush",
@@ -2157,8 +2157,16 @@ std::optional<SpecificCall> IntrinsicInterface::Match(
           semantics::IsTeamType(&type->GetDerivedTypeSpec());
       break;
     case KindCode::defaultIntegerKind:
-      argOk = type->kind() == defaults.GetDefaultKind(TypeCategory::Integer);
-      break;
+  if (name == "exit" && d.keyword == "status" &&
+      type->category() == TypeCategory::Integer) {
+    // GNU / CCE compatibility: allow any integer kind
+    argOk = true;
+  } else {
+    argOk = type->kind() ==
+        defaults.GetDefaultKind(TypeCategory::Integer);
+  }
+  break;
+
     case KindCode::defaultRealKind:
       argOk = type->kind() == defaults.GetDefaultKind(TypeCategory::Real);
       break;
@@ -2286,6 +2294,7 @@ std::optional<SpecificCall> IntrinsicInterface::Match(
           d.keyword, type->AsFortran());
       return std::nullopt;
     }
+    
   }
 
   // Check the ranks of the arguments against the intrinsic's interface.
diff --git a/flang/lib/Optimizer/Builder/IntrinsicCall.cpp b/flang/lib/Optimizer/Builder/IntrinsicCall.cpp
index 75a74eeb18417..ccf500f852fbf 100644
--- a/flang/lib/Optimizer/Builder/IntrinsicCall.cpp
+++ b/flang/lib/Optimizer/Builder/IntrinsicCall.cpp
@@ -3852,12 +3852,17 @@ void IntrinsicLibrary::genExit(llvm::ArrayRef<fir::ExtendedValue> args) {
                                           EXIT_SUCCESS)
           : fir::getBase(args[0]);
 
-  assert(status.getType() == builder.getDefaultIntegerType() &&
-         "STATUS parameter must be an INTEGER of default kind");
+  mlir::Type defaultIntTy = builder.getDefaultIntegerType();
+
+  // Convert INTEGER(any kind) → default INTEGER
+  if (status.getType() != defaultIntTy) {
+    status = builder.createConvert(loc, defaultIntTy, status);
+  }
 
   fir::runtime::genExit(builder, loc, status);
 }
 
+
 // EXPONENT
 mlir::Value IntrinsicLibrary::genExponent(mlir::Type resultType,
                                           llvm::ArrayRef<mlir::Value> args) {