[Flang][NFC] Split common headers to reduce dependencies. (#110244)

Fortran.h and target.h are defining symbols where some are used by both, the Fortran runtime (Flang-RT) and Fortran compiler (Flang), and others are used by Flang only. With the upcoming refactoring of the Fortran runtime into its own subproject (#110217), move the declarations that are used by both into new headers to minimize the amount of code that will need to be shared by Flang-RT and Flang.

Details:

 * `Fortran.h`: Flang-RT  only uses some enum definitions out of this file, but not `AsFortran` which is defined in `Fortran.cpp`. Moving the enums into `Fortran-consts.h` allows keeping `Fortran.cpp` within Flang.

 * `target.h`: Contains some floating-point definitions that is used by the non-GTest unittests in `fp-testing.h`. Flang-RT also uses some non-GTest as well. Moving those definitions avoids the dependence on the entire FortranEvaluate library.

Author: Meinersbur

flang/include/flang/Common/Fortran-consts.h

@@ -0,0 +1,44 @@
+//===-- include/flang/Common/Fortran-consts.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_COMMON_FORTRAN_CONSTS_H_
+#define FORTRAN_COMMON_FORTRAN_CONSTS_H_
+
+#include "flang/Common/enum-class.h"
+#include <cstdint>
+
+namespace Fortran::common {
+
+// Fortran has five kinds of intrinsic data types, plus the derived types.
+ENUM_CLASS(TypeCategory, Integer, Real, Complex, Character, Logical, Derived)
+ENUM_CLASS(VectorElementCategory, Integer, Unsigned, Real)
+
+ENUM_CLASS(IoStmtKind, None, Backspace, Close, Endfile, Flush, Inquire, Open,
+    Print, Read, Rewind, Wait, Write)
+
+// Defined I/O variants
+ENUM_CLASS(
+    DefinedIo, ReadFormatted, ReadUnformatted, WriteFormatted, WriteUnformatted)
+
+// Fortran arrays may have up to 15 dimensions (See Fortran 2018 section 5.4.6).
+static constexpr int maxRank{15};
+
+// Floating-point rounding modes; these are packed into a byte to save
+// room in the runtime's format processing context structure.  These
+// enumerators are defined with the corresponding values returned from
+// llvm.get.rounding.
+enum class RoundingMode : std::uint8_t {
+  ToZero, // ROUND=ZERO, RZ - truncation
+  TiesToEven, // ROUND=NEAREST, RN - default IEEE rounding
+  Up, // ROUND=UP, RU
+  Down, // ROUND=DOWN, RD
+  TiesAwayFromZero, // ROUND=COMPATIBLE, RC - ties round away from zero
+};
+
+} // namespace Fortran::common
+#endif /* FORTRAN_COMMON_FORTRAN_CONSTS_H_ */

flang/include/flang/Common/Fortran.h

@@ -14,17 +14,14 @@
 
 #include "enum-set.h"
 #include "idioms.h"
+#include "flang/Common/Fortran-consts.h"
 #include <cinttypes>
 #include <optional>
 #include <string>
 
 namespace Fortran::common {
 class LanguageFeatureControl;
 
-// Fortran has five kinds of intrinsic data types, plus the derived types.
-ENUM_CLASS(TypeCategory, Integer, Real, Complex, Character, Logical, Derived)
-ENUM_CLASS(VectorElementCategory, Integer, Unsigned, Real)
-
 constexpr bool IsNumericTypeCategory(TypeCategory category) {
   return category == TypeCategory::Integer || category == TypeCategory::Real ||
       category == TypeCategory::Complex;
@@ -47,9 +44,6 @@ const char *AsFortran(RelationalOperator);
 
 ENUM_CLASS(Intent, Default, In, Out, InOut)
 
-ENUM_CLASS(IoStmtKind, None, Backspace, Close, Endfile, Flush, Inquire, Open,
-    Print, Read, Rewind, Wait, Write)
-
 // Union of specifiers for all I/O statements.
 ENUM_CLASS(IoSpecKind, Access, Action, Advance, Asynchronous, Blank, Decimal,
     Delim, Direct, Encoding, End, Eor, Err, Exist, File, Fmt, Form, Formatted,
@@ -61,29 +55,11 @@ ENUM_CLASS(IoSpecKind, Access, Action, Advance, Asynchronous, Blank, Decimal,
     Dispose, // nonstandard
 )
 
-// Defined I/O variants
-ENUM_CLASS(
-    DefinedIo, ReadFormatted, ReadUnformatted, WriteFormatted, WriteUnformatted)
 const char *AsFortran(DefinedIo);
 
-// Floating-point rounding modes; these are packed into a byte to save
-// room in the runtime's format processing context structure.  These
-// enumerators are defined with the corresponding values returned from
-// llvm.get.rounding.
-enum class RoundingMode : std::uint8_t {
-  ToZero, // ROUND=ZERO, RZ - truncation
-  TiesToEven, // ROUND=NEAREST, RN - default IEEE rounding
-  Up, // ROUND=UP, RU
-  Down, // ROUND=DOWN, RD
-  TiesAwayFromZero, // ROUND=COMPATIBLE, RC - ties round away from zero
-};
-
 // Fortran label. Must be in [1..99999].
 using Label = std::uint64_t;
 
-// Fortran arrays may have up to 15 dimensions (See Fortran 2018 section 5.4.6).
-static constexpr int maxRank{15};
-
 // CUDA subprogram attribute combinations
 ENUM_CLASS(CUDASubprogramAttrs, Host, Device, HostDevice, Global, Grid_Global)
 

flang/include/flang/Common/format.h

@@ -10,7 +10,7 @@
 #define FORTRAN_COMMON_FORMAT_H_
 
 #include "enum-set.h"
-#include "flang/Common/Fortran.h"
+#include "flang/Common/Fortran-consts.h"
 #include <cstring>
 
 // Define a FormatValidator class template to validate a format expression

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

@@ -0,0 +1,37 @@
+//===-- include/flang/Common/target-rounding.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_COMMON_TARGET_ROUNDING_H_
+#define FORTRAN_COMMON_TARGET_ROUNDING_H_
+
+#include "flang/Common/Fortran-consts.h"
+#include "flang/Common/enum-set.h"
+
+namespace Fortran::common {
+
+// Floating-point rounding control
+struct Rounding {
+  common::RoundingMode mode{common::RoundingMode::TiesToEven};
+  // When set, emulate status flag behavior peculiar to x86
+  // (viz., fail to set the Underflow flag when an inexact product of a
+  // multiplication is rounded up to a normal number from a subnormal
+  // in some rounding modes)
+#if __x86_64__ || __riscv || __loongarch__
+  bool x86CompatibleBehavior{true};
+#else
+  bool x86CompatibleBehavior{false};
+#endif
+};
+
+// These are ordered like the bits in a common fenv.h header file.
+ENUM_CLASS(RealFlag, InvalidArgument, Denorm, DivideByZero, Overflow, Underflow,
+    Inexact)
+using RealFlags = common::EnumSet<RealFlag, RealFlag_enumSize>;
+
+} // namespace Fortran::common
+#endif /* FORTRAN_COMMON_TARGET_ROUNDING_H_ */

flang/include/flang/Evaluate/common.h

@@ -16,6 +16,7 @@
 #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 <cinttypes>
@@ -32,6 +33,8 @@ class IntrinsicProcTable;
 class TargetCharacteristics;
 
 using common::ConstantSubscript;
+using common::RealFlag;
+using common::RealFlags;
 using common::RelationalOperator;
 
 // Integers are always ordered; reals may not be.
@@ -128,11 +131,6 @@ static constexpr bool Satisfies(RelationalOperator op, Relation relation) {
   return false; // silence g++ warning
 }
 
-// These are ordered like the bits in a common fenv.h header file.
-ENUM_CLASS(RealFlag, InvalidArgument, Denorm, DivideByZero, Overflow, Underflow,
-    Inexact)
-using RealFlags = common::EnumSet<RealFlag, RealFlag_enumSize>;
-
 template <typename A> struct ValueWithRealFlags {
   A AccumulateFlags(RealFlags &f) {
     f |= flags;

flang/include/flang/Evaluate/target.h

@@ -15,24 +15,13 @@
 #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 <cstdint>
 
 namespace Fortran::evaluate {
 
-// Floating-point rounding control
-struct Rounding {
-  common::RoundingMode mode{common::RoundingMode::TiesToEven};
-  // When set, emulate status flag behavior peculiar to x86
-  // (viz., fail to set the Underflow flag when an inexact product of a
-  // multiplication is rounded up to a normal number from a subnormal
-  // in some rounding modes)
-#if __x86_64__ || __riscv || __loongarch__
-  bool x86CompatibleBehavior{true};
-#else
-  bool x86CompatibleBehavior{false};
-#endif
-};
+using common::Rounding;
 
 ENUM_CLASS(IeeeFeature, Denormal, Divide, Flags, Halting, Inf, Io, NaN,
     Rounding, Sqrt, Standard, Subnormal, UnderflowControl)

flang/include/flang/Runtime/cpp-type.h

@@ -11,7 +11,7 @@
 #ifndef FORTRAN_RUNTIME_CPP_TYPE_H_
 #define FORTRAN_RUNTIME_CPP_TYPE_H_
 
-#include "flang/Common/Fortran.h"
+#include "flang/Common/Fortran-consts.h"
 #include "flang/Common/float128.h"
 #include "flang/Common/float80.h"
 #include "flang/Common/uint128.h"

flang/include/flang/Runtime/type-code.h

@@ -9,7 +9,7 @@
 #ifndef FORTRAN_RUNTIME_TYPE_CODE_H_
 #define FORTRAN_RUNTIME_TYPE_CODE_H_
 
-#include "flang/Common/Fortran.h"
+#include "flang/Common/Fortran-consts.h"
 #include "flang/Common/optional.h"
 #include "flang/ISO_Fortran_binding_wrapper.h"
 #include <utility>

flang/runtime/format.h

@@ -13,7 +13,7 @@
 
 #include "environment.h"
 #include "io-error.h"
-#include "flang/Common/Fortran.h"
+#include "flang/Common/Fortran-consts.h"
 #include "flang/Common/optional.h"
 #include "flang/Decimal/decimal.h"
 #include "flang/Runtime/freestanding-tools.h"

flang/runtime/non-tbp-dio.h

@@ -22,7 +22,8 @@
 #ifndef FORTRAN_RUNTIME_NON_TBP_DIO_H_
 #define FORTRAN_RUNTIME_NON_TBP_DIO_H_
 
-#include "flang/Common/Fortran.h"
+#include "flang/Common/Fortran-consts.h"
+#include "flang/Common/api-attrs.h"
 #include <cstddef>
 
 namespace Fortran::runtime::typeInfo {

flang/runtime/type-info.h

@@ -13,7 +13,7 @@
 // flang/module/__fortran_type_info.f90.
 
 #include "terminator.h"
-#include "flang/Common/Fortran.h"
+#include "flang/Common/Fortran-consts.h"
 #include "flang/Common/bit-population-count.h"
 #include "flang/Common/optional.h"
 #include "flang/Runtime/descriptor.h"

flang/unittests/Evaluate/fp-testing.cpp

@@ -7,8 +7,8 @@
 #include <xmmintrin.h>
 #endif
 
+using Fortran::common::RealFlag;
 using Fortran::common::RoundingMode;
-using Fortran::evaluate::RealFlag;
 
 ScopedHostFloatingPointEnvironment::ScopedHostFloatingPointEnvironment(
 #if __x86_64__

flang/unittests/Evaluate/fp-testing.h

@@ -1,12 +1,12 @@
 #ifndef FORTRAN_TEST_EVALUATE_FP_TESTING_H_
 #define FORTRAN_TEST_EVALUATE_FP_TESTING_H_
 
-#include "flang/Evaluate/target.h"
+#include "flang/Common/target-rounding.h"
 #include <fenv.h>
 
+using Fortran::common::RealFlags;
+using Fortran::common::Rounding;
 using Fortran::common::RoundingMode;
-using Fortran::evaluate::RealFlags;
-using Fortran::evaluate::Rounding;
 
 class ScopedHostFloatingPointEnvironment {
 public:

flang/unittests/Runtime/Complex.cpp

@@ -13,7 +13,7 @@
 #pragma clang diagnostic ignored "-Wc99-extensions"
 #endif
 
-#include "flang/Common/Fortran.h"
+#include "flang/Common/Fortran-consts.h"
 #include "flang/Runtime/cpp-type.h"
 #include "flang/Runtime/entry-names.h"