[flang] Ensure that the integer for Cray pointer is sized correctly

[eugeneepshteyn]

The integer used for Cray pointers should have the size equivalent to platform's pointer size.

[llvmbot]

@llvm/pr-subscribers-flang-semantics

Author: Eugene Epshteyn (eugeneepshteyn)

Changes

The integer used for Cray pointers should have the size equivalent to platform's pointer size.

---

Full diff: https://github.com/llvm/llvm-project/pull/140822.diff

3 Files Affected:

• (modified) flang/include/flang/Evaluate/target.h (+6)
• (modified) flang/include/flang/Tools/TargetSetup.h (+3)
• (modified) flang/lib/Semantics/resolve-names.cpp (+1-1)

diff --git a/flang/include/flang/Evaluate/target.h b/flang/include/flang/Evaluate/target.h
index cc6172b492b3c..281e42d5285fb 100644
--- a/flang/include/flang/Evaluate/target.h
+++ b/flang/include/flang/Evaluate/target.h
@@ -131,6 +131,11 @@ class TargetCharacteristics {
   IeeeFeatures &ieeeFeatures() { return ieeeFeatures_; }
   const IeeeFeatures &ieeeFeatures() const { return ieeeFeatures_; }
 
+  std::size_t pointerSize() { return pointerSize_; }
+  void set_pointerSize(std::size_t pointerSize) {
+    pointerSize_ = pointerSize;
+  }
+
 private:
   static constexpr int maxKind{common::maxKind};
   std::uint8_t byteSize_[common::TypeCategory_enumSize][maxKind + 1]{};
@@ -156,6 +161,7 @@ class TargetCharacteristics {
       IeeeFeature::Io, IeeeFeature::NaN, IeeeFeature::Rounding,
       IeeeFeature::Sqrt, IeeeFeature::Standard, IeeeFeature::Subnormal,
       IeeeFeature::UnderflowControl};
+  std::size_t pointerSize_{8 /* bytes */};
 };
 
 } // namespace Fortran::evaluate
diff --git a/flang/include/flang/Tools/TargetSetup.h b/flang/include/flang/Tools/TargetSetup.h
index de3fb0519cf6b..a30c725e21fb4 100644
--- a/flang/include/flang/Tools/TargetSetup.h
+++ b/flang/include/flang/Tools/TargetSetup.h
@@ -94,6 +94,9 @@ namespace Fortran::tools {
   if (targetTriple.isOSWindows())
     targetCharacteristics.set_isOSWindows(true);
 
+  targetCharacteristics.set_pointerSize(
+    targetTriple.getArchPointerBitWidth() / 8);
+
   // TODO: use target machine data layout to set-up the target characteristics
   // type size and alignment info.
 }
diff --git a/flang/lib/Semantics/resolve-names.cpp b/flang/lib/Semantics/resolve-names.cpp
index 92a3277191ae0..2f6fe4fea4da2 100644
--- a/flang/lib/Semantics/resolve-names.cpp
+++ b/flang/lib/Semantics/resolve-names.cpp
@@ -6690,7 +6690,7 @@ void DeclarationVisitor::Post(const parser::BasedPointer &bp) {
   }
   pointer->set(Symbol::Flag::CrayPointer);
   const DeclTypeSpec &pointerType{MakeNumericType(
-      TypeCategory::Integer, context().defaultKinds().subscriptIntegerKind())};
+      TypeCategory::Integer, context().targetCharacteristics().pointerSize())};
   const auto *type{pointer->GetType()};
   if (!type) {
     pointer->SetType(pointerType);

[github-actions]

✅ With the latest revision this PR passed the C/C++ code formatter.

[klausler]

The names in this code assumes that integer kinds equal their byte sizes. Steve has been wanting me to make the kind/size relationship configurable, or to at least not always have that assumption by having mapping functions.

integerKindForPointer or something along those lines would avoid that assumption. We don't really need a byte size here, since it's just a selection of an integer kind.

[kkwli]

Looks good. Thanks.