[Flang] Move non-common headers to FortranSupport (#124416)

Move non-common files from FortranCommon to FortranSupport (analogous to
LLVMSupport) such that

* declarations and definitions that are only used by the Flang compiler,
but not by the runtime, are moved to FortranSupport

* declarations and definitions that are used by both ("common"), the
compiler and the runtime, remain in FortranCommon

* generic STL-like/ADT/utility classes and algorithms remain in
FortranCommon

This allows a for cleaner separation between compiler and runtime
components, which are compiled differently. For instance, runtime
sources must not use STL's `<optional>` which causes problems with CUDA
support. Instead, the surrogate header `flang/Common/optional.h` must be
used. This PR fixes this for `fast-int-sel.h`.

Declarations in include/Runtime are also used by both, but are
header-only. `ISO_Fortran_binding_wrapper.h`, a header used by compiler
and runtime, is also moved into FortranCommon.

Author: Meinersbur

flang/include/flang/ISO_Fortran_binding_wrapper.h renamed to flang/include/flang/Common/ISO_Fortran_binding_wrapper.h

@@ -1,14 +1,13 @@
-/*===-- include/flang/ISO_Fortran_binding_wrapper.h ---------------*- C++ -*-===
+/*===-- include/flang/Common/ISO_Fortran_binding_wrapper.h --------*- C++ -*-===
  *
  * Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
  * See https://llvm.org/LICENSE.txt for license information.
  * SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
  *
- * ===-----------------------------------------------------------------------===
- */
+ *===----------------------------------------------------------------------===*/
 
-#ifndef FORTRAN_ISO_FORTRAN_BINDING_WRAPPER_H_
-#define FORTRAN_ISO_FORTRAN_BINDING_WRAPPER_H_
+#ifndef FORTRAN_COMMON_ISO_FORTRAN_BINDING_WRAPPER_H_
+#define FORTRAN_COMMON_ISO_FORTRAN_BINDING_WRAPPER_H_
 
 /* A thin wrapper around flang/include/ISO_Fortran_binding.h
  * This header file must be included when ISO_Fortran_binding.h
@@ -23,17 +22,17 @@
 
 /* clang-format off */
 #include <stddef.h>
-#include "Common/api-attrs.h"
+#include "api-attrs.h"
 #ifdef __cplusplus
 namespace Fortran {
 namespace ISO {
 #define FORTRAN_ISO_NAMESPACE_ ::Fortran::ISO
 #endif /* __cplusplus */
-#include "ISO_Fortran_binding.h"
+#include "flang/ISO_Fortran_binding.h"
 #ifdef __cplusplus
 } // namespace ISO
 } // namespace Fortran
 #endif /* __cplusplus */
 /* clang-format on */
 
-#endif /* FORTRAN_ISO_FORTRAN_BINDING_WRAPPER_H_ */
+#endif /* FORTRAN_COMMON_ISO_FORTRAN_BINDING_WRAPPER_H_ */

flang/include/flang/Common/erfc-scaled.h

@@ -9,6 +9,9 @@
 #ifndef FORTRAN_COMMON_ERFC_SCALED_H_
 #define FORTRAN_COMMON_ERFC_SCALED_H_
 
+#include <cmath>
+#include <limits>
+
 namespace Fortran::common {
 template <typename T> inline T ErfcScaled(T arg) {
   // Coefficients for approximation to erfc in the first interval.

flang/include/flang/Common/fast-int-set.h

@@ -24,7 +24,7 @@
 #ifndef FORTRAN_COMMON_FAST_INT_SET_H_
 #define FORTRAN_COMMON_FAST_INT_SET_H_
 
-#include <optional>
+#include "optional.h"
 
 namespace Fortran::common {
 
@@ -83,9 +83,9 @@ template <int N> class FastIntSet {
     }
   }
 
-  std::optional<int> PopValue() {
+  optional<int> PopValue() {
     if (IsEmpty()) {
-      return std::nullopt;
+      return nullopt;
     } else {
       return value_[--size_];
     }

flang/include/flang/Common/format.h

@@ -9,8 +9,8 @@
 #ifndef FORTRAN_COMMON_FORMAT_H_
 #define FORTRAN_COMMON_FORMAT_H_
 
+#include "Fortran-consts.h"
 #include "enum-set.h"
-#include "flang/Common/Fortran-consts.h"
 #include <cstring>
 
 // Define a FormatValidator class template to validate a format expression

flang/include/flang/Common/optional.h

@@ -26,7 +26,7 @@
 #ifndef FORTRAN_COMMON_OPTIONAL_H
 #define FORTRAN_COMMON_OPTIONAL_H
 
-#include "flang/Common/api-attrs.h"
+#include "api-attrs.h"
 #include <optional>
 #include <type_traits>
 

flang/include/flang/Common/real.h

@@ -13,7 +13,7 @@
 // The various representations are distinguished by their binary precisions
 // (number of explicit significand bits and any implicit MSB in the fraction).
 
-#include "flang/Common/api-attrs.h"
+#include "api-attrs.h"
 #include <cinttypes>
 
 namespace Fortran::common {

flang/include/flang/Common/reference-wrapper.h

@@ -25,7 +25,7 @@
 #ifndef FORTRAN_COMMON_REFERENCE_WRAPPER_H
 #define FORTRAN_COMMON_REFERENCE_WRAPPER_H
 
-#include "flang/Common/api-attrs.h"
+#include "api-attrs.h"
 #include <functional>
 #include <type_traits>
 

flang/include/flang/Common/restorer.h

@@ -18,8 +18,8 @@
 
 #ifndef FORTRAN_COMMON_RESTORER_H_
 #define FORTRAN_COMMON_RESTORER_H_
+#include "api-attrs.h"
 #include "idioms.h"
-#include "flang/Common/api-attrs.h"
 namespace Fortran::common {
 template <typename A> class Restorer {
 public:

flang/include/flang/Common/target-rounding.h

@@ -9,8 +9,8 @@
 #ifndef FORTRAN_COMMON_TARGET_ROUNDING_H_
 #define FORTRAN_COMMON_TARGET_ROUNDING_H_
 
-#include "flang/Common/Fortran-consts.h"
-#include "flang/Common/enum-set.h"
+#include "Fortran-consts.h"
+#include "enum-set.h"
 
 namespace Fortran::common {
 

flang/include/flang/Common/template.h

@@ -9,8 +9,8 @@
 #ifndef FORTRAN_COMMON_TEMPLATE_H_
 #define FORTRAN_COMMON_TEMPLATE_H_
 
+#include "idioms.h"
 #include "variant.h"
-#include "flang/Common/idioms.h"
 #include <functional>
 #include <optional>
 #include <tuple>

flang/include/flang/Common/uint128.h

@@ -19,8 +19,8 @@
 #define AVOID_NATIVE_UINT128_T 0
 #endif
 
+#include "api-attrs.h"
 #include "leading-zero-bit-count.h"
-#include "flang/Common/api-attrs.h"
 #include <cstdint>
 #include <type_traits>
 

flang/include/flang/Common/visit.h

@@ -21,8 +21,8 @@
 #ifndef FORTRAN_COMMON_VISIT_H_
 #define FORTRAN_COMMON_VISIT_H_
 
+#include "api-attrs.h"
 #include "variant.h"
-#include "flang/Common/api-attrs.h"
 #include <type_traits>
 
 namespace Fortran::common {

flang/include/flang/Evaluate/call.h

@@ -13,11 +13,11 @@
 #include "constant.h"
 #include "formatting.h"
 #include "type.h"
-#include "flang/Common/Fortran.h"
 #include "flang/Common/indirection.h"
 #include "flang/Common/reference.h"
 #include "flang/Parser/char-block.h"
 #include "flang/Semantics/attr.h"
+#include "flang/Support/Fortran.h"
 #include <optional>
 #include <vector>
 

flang/include/flang/Evaluate/characteristics.h

@@ -18,13 +18,13 @@
 #include "shape.h"
 #include "tools.h"
 #include "type.h"
-#include "flang/Common/Fortran-features.h"
-#include "flang/Common/Fortran.h"
 #include "flang/Common/enum-set.h"
 #include "flang/Common/idioms.h"
 #include "flang/Common/indirection.h"
 #include "flang/Parser/char-block.h"
 #include "flang/Semantics/symbol.h"
+#include "flang/Support/Fortran-features.h"
+#include "flang/Support/Fortran.h"
 #include <optional>
 #include <string>
 #include <variant>

flang/include/flang/Evaluate/common.h

@@ -9,16 +9,16 @@
 #ifndef FORTRAN_EVALUATE_COMMON_H_
 #define FORTRAN_EVALUATE_COMMON_H_
 
-#include "flang/Common/Fortran-features.h"
-#include "flang/Common/Fortran.h"
-#include "flang/Common/default-kinds.h"
 #include "flang/Common/enum-set.h"
 #include "flang/Common/idioms.h"
 #include "flang/Common/indirection.h"
 #include "flang/Common/restorer.h"
 #include "flang/Common/target-rounding.h"
 #include "flang/Parser/char-block.h"
 #include "flang/Parser/message.h"
+#include "flang/Support/Fortran-features.h"
+#include "flang/Support/Fortran.h"
+#include "flang/Support/default-kinds.h"
 #include <cinttypes>
 #include <map>
 #include <set>

flang/include/flang/Evaluate/constant.h

@@ -11,8 +11,8 @@
 
 #include "formatting.h"
 #include "type.h"
-#include "flang/Common/default-kinds.h"
 #include "flang/Common/reference.h"
+#include "flang/Support/default-kinds.h"
 #include <map>
 #include <vector>
 

flang/include/flang/Evaluate/expression.h

@@ -21,11 +21,11 @@
 #include "formatting.h"
 #include "type.h"
 #include "variable.h"
-#include "flang/Common/Fortran.h"
 #include "flang/Common/idioms.h"
 #include "flang/Common/indirection.h"
 #include "flang/Common/template.h"
 #include "flang/Parser/char-block.h"
+#include "flang/Support/Fortran.h"
 #include <algorithm>
 #include <list>
 #include <tuple>

flang/include/flang/Evaluate/intrinsics.h

@@ -12,9 +12,9 @@
 #include "call.h"
 #include "characteristics.h"
 #include "type.h"
-#include "flang/Common/default-kinds.h"
 #include "flang/Parser/char-block.h"
 #include "flang/Parser/message.h"
+#include "flang/Support/default-kinds.h"
 #include <memory>
 #include <optional>
 #include <string>

flang/include/flang/Evaluate/target.h

@@ -12,11 +12,11 @@
 #ifndef FORTRAN_EVALUATE_TARGET_H_
 #define FORTRAN_EVALUATE_TARGET_H_
 
-#include "flang/Common/Fortran.h"
 #include "flang/Common/enum-class.h"
 #include "flang/Common/enum-set.h"
 #include "flang/Common/target-rounding.h"
 #include "flang/Evaluate/common.h"
+#include "flang/Support/Fortran.h"
 #include <cstdint>
 
 namespace Fortran::evaluate {

flang/include/flang/Evaluate/type.h

@@ -22,11 +22,11 @@
 #include "integer.h"
 #include "logical.h"
 #include "real.h"
-#include "flang/Common/Fortran-features.h"
-#include "flang/Common/Fortran.h"
 #include "flang/Common/idioms.h"
 #include "flang/Common/real.h"
 #include "flang/Common/template.h"
+#include "flang/Support/Fortran-features.h"
+#include "flang/Support/Fortran.h"
 #include <cinttypes>
 #include <optional>
 #include <string>

flang/include/flang/Frontend/CompilerInvocation.h

@@ -13,14 +13,14 @@
 #ifndef FORTRAN_FRONTEND_COMPILERINVOCATION_H
 #define FORTRAN_FRONTEND_COMPILERINVOCATION_H
 
-#include "flang/Common/LangOptions.h"
 #include "flang/Frontend/CodeGenOptions.h"
 #include "flang/Frontend/FrontendOptions.h"
 #include "flang/Frontend/PreprocessorOptions.h"
 #include "flang/Frontend/TargetOptions.h"
 #include "flang/Lower/LoweringOptions.h"
 #include "flang/Parser/parsing.h"
 #include "flang/Semantics/semantics.h"
+#include "flang/Support/LangOptions.h"
 #include "mlir/Support/Timing.h"
 #include "clang/Basic/Diagnostic.h"
 #include "clang/Basic/DiagnosticOptions.h"

flang/include/flang/Frontend/FrontendOptions.h

@@ -13,10 +13,10 @@
 #ifndef FORTRAN_FRONTEND_FRONTENDOPTIONS_H
 #define FORTRAN_FRONTEND_FRONTENDOPTIONS_H
 
-#include "flang/Common/Fortran-features.h"
 #include "flang/Lower/EnvironmentDefault.h"
 #include "flang/Parser/characters.h"
 #include "flang/Parser/unparse.h"
+#include "flang/Support/Fortran-features.h"
 #include "llvm/ADT/StringRef.h"
 #include "llvm/Support/MemoryBuffer.h"
 #include <cstdint>

flang/include/flang/ISO_Fortran_binding.h

@@ -14,7 +14,7 @@
  * it does so by means of a wrapper header that establishes namespaces and
  * a macro for extra function attributes (RT_API_ATTRS).
  */
-#ifndef FORTRAN_ISO_FORTRAN_BINDING_WRAPPER_H_
+#ifndef FORTRAN_COMMON_ISO_FORTRAN_BINDING_WRAPPER_H_
 #include <stddef.h>
 #define FORTRAN_ISO_NAMESPACE_
 #endif

flang/include/flang/Lower/AbstractConverter.h

@@ -13,12 +13,12 @@
 #ifndef FORTRAN_LOWER_ABSTRACTCONVERTER_H
 #define FORTRAN_LOWER_ABSTRACTCONVERTER_H
 
-#include "flang/Common/Fortran.h"
 #include "flang/Lower/LoweringOptions.h"
 #include "flang/Lower/PFTDefs.h"
 #include "flang/Optimizer/Builder/BoxValue.h"
 #include "flang/Optimizer/Dialect/FIRAttr.h"
 #include "flang/Semantics/symbol.h"
+#include "flang/Support/Fortran.h"
 #include "mlir/IR/Builders.h"
 #include "mlir/IR/BuiltinOps.h"
 #include "mlir/IR/Operation.h"

flang/include/flang/Lower/Bridge.h

@@ -13,7 +13,6 @@
 #ifndef FORTRAN_LOWER_BRIDGE_H
 #define FORTRAN_LOWER_BRIDGE_H
 
-#include "flang/Common/Fortran.h"
 #include "flang/Frontend/CodeGenOptions.h"
 #include "flang/Frontend/TargetOptions.h"
 #include "flang/Lower/AbstractConverter.h"
@@ -22,6 +21,7 @@
 #include "flang/Lower/StatementContext.h"
 #include "flang/Optimizer/Builder/FIRBuilder.h"
 #include "flang/Optimizer/Dialect/Support/KindMapping.h"
+#include "flang/Support/Fortran.h"
 #include "mlir/IR/BuiltinOps.h"
 #include "mlir/IR/OwningOpRef.h"
 #include <set>

flang/include/flang/Lower/ConvertType.h

@@ -21,8 +21,8 @@
 #ifndef FORTRAN_LOWER_CONVERT_TYPE_H
 #define FORTRAN_LOWER_CONVERT_TYPE_H
 
-#include "flang/Common/Fortran.h"
 #include "flang/Evaluate/type.h"
+#include "flang/Support/Fortran.h"
 #include "mlir/IR/BuiltinTypes.h"
 
 namespace mlir {

flang/include/flang/Lower/LoweringOptions.h

@@ -15,7 +15,7 @@
 #ifndef FLANG_LOWER_LOWERINGOPTIONS_H
 #define FLANG_LOWER_LOWERINGOPTIONS_H
 
-#include "flang/Common/MathOptionsBase.h"
+#include "flang/Support/MathOptionsBase.h"
 
 namespace Fortran::lower {
 

flang/include/flang/Optimizer/Builder/FIRBuilder.h

@@ -16,12 +16,12 @@
 #ifndef FORTRAN_OPTIMIZER_BUILDER_FIRBUILDER_H
 #define FORTRAN_OPTIMIZER_BUILDER_FIRBUILDER_H
 
-#include "flang/Common/MathOptionsBase.h"
 #include "flang/Optimizer/Dialect/FIROps.h"
 #include "flang/Optimizer/Dialect/FIROpsSupport.h"
 #include "flang/Optimizer/Dialect/FIRType.h"
 #include "flang/Optimizer/Dialect/Support/FIRContext.h"
 #include "flang/Optimizer/Dialect/Support/KindMapping.h"
+#include "flang/Support/MathOptionsBase.h"
 #include "mlir/IR/Builders.h"
 #include "mlir/IR/BuiltinOps.h"
 #include "llvm/ADT/DenseMap.h"

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

@@ -17,12 +17,12 @@
 #ifndef FORTRAN_OPTIMIZER_BUILDER_RUNTIME_RTBUILDER_H
 #define FORTRAN_OPTIMIZER_BUILDER_RUNTIME_RTBUILDER_H
 
-#include "flang/Common/Fortran.h"
 #include "flang/Common/uint128.h"
 #include "flang/Optimizer/Builder/FIRBuilder.h"
 #include "flang/Optimizer/Dialect/FIRDialect.h"
 #include "flang/Optimizer/Dialect/FIRType.h"
 #include "flang/Runtime/reduce.h"
+#include "flang/Support/Fortran.h"
 #include "mlir/IR/BuiltinTypes.h"
 #include "mlir/IR/MLIRContext.h"
 #include "llvm/ADT/SmallVector.h"

flang/include/flang/Optimizer/CodeGen/DescriptorModel.h

@@ -22,7 +22,7 @@
 #ifndef OPTIMIZER_DESCRIPTOR_MODEL_H
 #define OPTIMIZER_DESCRIPTOR_MODEL_H
 
-#include "flang/ISO_Fortran_binding_wrapper.h"
+#include "flang/Common/ISO_Fortran_binding_wrapper.h"
 #include "flang/Runtime/descriptor-consts.h"
 #include "mlir/Dialect/LLVMIR/LLVMTypes.h"
 #include "mlir/IR/BuiltinTypes.h"