From 8bdd67ccc3c5db2a9bd0519dd014fe93acb88f4a Mon Sep 17 00:00:00 2001
From: Fabian Schiebel <52407375+fabianbs96@users.noreply.github.com>
Date: Sun, 7 Apr 2024 14:05:36 +0200
Subject: [PATCH] Fix C++20 build (#705)

* Fix C++20 build + minor

* Update readme
---
 CMakeLists.txt                                |  8 +---
 README.md                                     |  6 +--
 cmake/phasar_macros.cmake                     |  2 +
 include/phasar/ControlFlow/CFGBase.h          |  2 +-
 include/phasar/ControlFlow/ICFGBase.h         |  2 +-
 .../phasar/DataFlow/IfdsIde/EdgeFunction.h    |  2 +-
 .../phasar/DataFlow/IfdsIde/FlowFunctions.h   |  2 +-
 include/phasar/Pointer/AliasInfoBase.h        |  4 +-
 include/phasar/Pointer/PointsToInfoBase.h     |  4 +-
 include/phasar/Utils/AdjacencyList.h          |  4 +-
 include/phasar/Utils/ByRef.h                  |  4 +-
 include/phasar/Utils/GraphTraits.h            |  2 +-
 include/phasar/Utils/IotaIterator.h           |  3 +-
 include/phasar/Utils/JoinLattice.h            |  5 ++-
 include/phasar/Utils/Printer.h                |  2 +-
 include/phasar/Utils/TypeTraits.h             | 44 +++++++++----------
 16 files changed, 47 insertions(+), 49 deletions(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index eaf415b14..b9b6bf810 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -31,13 +31,7 @@ endif()
 
 option(PHASAR_EXPERIMENTAL_CXX20 "Build phasar in C++20 mode. This is an experimental feature" OFF)
 
-set(CMAKE_EXPORT_COMPILE_COMMANDS YES)
-if(PHASAR_EXPERIMENTAL_CXX20)
-  message(STATUS "Selected experimental C++20 build")
-  set(CMAKE_CXX_STANDARD 20)
-else()
-  set(CMAKE_CXX_STANDARD 17)
-endif()
+set(CMAKE_EXPORT_COMPILE_COMMANDS ON)
 set(CMAKE_CXX_STANDARD_REQUIRED ON)
 set(CMAKE_CXX_EXTENSIONS OFF)
 
diff --git a/README.md b/README.md
index 2d213e6c5..d7ceb3cd9 100644
--- a/README.md
+++ b/README.md
@@ -17,8 +17,8 @@ Lead developers of PhASAR are:  Fabian Schiebel (@fabianbs96)(<fabian.schiebel@i
 
 PhASAR requires C++-17.
 
-However, building in C++20 mode is supported as an experimental feature. You may enable this by turning the cmake option `PHASAR_EXPERIMENTAL_CXX20` on.
-Although phasar currently does not make use of C++20 features (except for some `concept`s behind an #ifdef border), your client application that just *uses* phasar as a library may want to use C++20 ealier.
+However, building in C++20 mode is supported as an experimental feature. You may enable this setting the cmake variable `CMAKE_CXX_STANDARD` to `20`.
+Although phasar currently does not make use of C++-20 features (except for some `concept`s behind an #ifdef border), your client application that just *uses* phasar as a library may want to use C++20 ealier.
 
 ## Currently Supported Version of LLVM
 
@@ -124,7 +124,7 @@ When using CMake to compile PhASAR the following optional parameters can be used
 | **PHASAR_ENABLE_PAMM** : STRING | Enable the performance measurement mechanism ('Off', 'Core' or 'Full', default is Off) |
 | **PHASAR_ENABLE_PIC** : BOOL | Build Position-Independed Code (default is ON) |
 | **PHASAR_ENABLE_WARNINGS** : BOOL | Enable compiler warnings (default is ON) |
-| **PHASAR_EXPERIMENTAL_CXX20** : BOOL|Build phasar in C++20 mode. This is an experimental feature  (default is OFF)|
+| **CMAKE_CXX_STANDARD** : INT|Build phasar in C++17 or C++20 mode (default is 17)|
 
 You can use these parameters either directly or modify the installer-script `bootstrap.sh`
 
diff --git a/cmake/phasar_macros.cmake b/cmake/phasar_macros.cmake
index 8499a4905..3a6d28dbb 100644
--- a/cmake/phasar_macros.cmake
+++ b/cmake/phasar_macros.cmake
@@ -188,6 +188,8 @@ function(add_phasar_library name)
     EXPORT_NAME ${component_name}
   )
 
+  target_compile_features(${name} PUBLIC cxx_std_17)
+
   if(LLVM_COMMON_DEPENDS)
     add_dependencies(${name} ${LLVM_COMMON_DEPENDS})
   endif(LLVM_COMMON_DEPENDS)
diff --git a/include/phasar/ControlFlow/CFGBase.h b/include/phasar/ControlFlow/CFGBase.h
index 57e358225..4067f05c1 100644
--- a/include/phasar/ControlFlow/CFGBase.h
+++ b/include/phasar/ControlFlow/CFGBase.h
@@ -144,7 +144,7 @@ template <typename Derived> class CFGBase {
 
 template <typename ICF, typename Domain>
 // NOLINTNEXTLINE(readability-identifier-naming)
-constexpr bool is_cfg_v = is_crtp_base_of_v<CFGBase, ICF>
+PSR_CONCEPT is_cfg_v = is_crtp_base_of_v<CFGBase, ICF>
     &&std::is_same_v<typename ICF::n_t, typename Domain::n_t>
         &&std::is_same_v<typename ICF::f_t, typename Domain::f_t>;
 
diff --git a/include/phasar/ControlFlow/ICFGBase.h b/include/phasar/ControlFlow/ICFGBase.h
index fea37796c..4291faf20 100644
--- a/include/phasar/ControlFlow/ICFGBase.h
+++ b/include/phasar/ControlFlow/ICFGBase.h
@@ -121,7 +121,7 @@ template <typename Derived> class ICFGBase {
 /// from the given analysis-Domain
 template <typename ICF, typename Domain>
 // NOLINTNEXTLINE(readability-identifier-naming)
-constexpr bool is_icfg_v = is_crtp_base_of_v<ICFGBase, ICF>
+PSR_CONCEPT is_icfg_v = is_crtp_base_of_v<ICFGBase, ICF>
     &&std::is_same_v<typename ICF::n_t, typename Domain::n_t>
         &&std::is_same_v<typename ICF::f_t, typename Domain::f_t>;
 
diff --git a/include/phasar/DataFlow/IfdsIde/EdgeFunction.h b/include/phasar/DataFlow/IfdsIde/EdgeFunction.h
index 7f8e98df8..ee7ee4b92 100644
--- a/include/phasar/DataFlow/IfdsIde/EdgeFunction.h
+++ b/include/phasar/DataFlow/IfdsIde/EdgeFunction.h
@@ -53,7 +53,7 @@ struct IsEdgeFunction<
 
 } // namespace detail
 template <typename T>
-static inline constexpr bool IsEdgeFunction = detail::IsEdgeFunction<T>::value;
+static constexpr bool IsEdgeFunction = detail::IsEdgeFunction<T>::value;
 
 #else
 // clang-format off
diff --git a/include/phasar/DataFlow/IfdsIde/FlowFunctions.h b/include/phasar/DataFlow/IfdsIde/FlowFunctions.h
index b4246db4f..ad41e1e10 100644
--- a/include/phasar/DataFlow/IfdsIde/FlowFunctions.h
+++ b/include/phasar/DataFlow/IfdsIde/FlowFunctions.h
@@ -83,7 +83,7 @@ template <typename FF> struct IsFlowFunction {
 /// Helper template to check at compile-time whether a type implements the
 /// FlowFunction interface, no matter which data-flow fact type it uses.
 template <typename FF>
-static constexpr bool is_flowfunction_v = IsFlowFunction<FF>::value; // NOLINT
+PSR_CONCEPT is_flowfunction_v = IsFlowFunction<FF>::value; // NOLINT
 
 /// Given a flow-function type FF, returns a (smart) pointer type pointing to FF
 template <typename FF, typename = std::enable_if_t<is_flowfunction_v<FF>>>
diff --git a/include/phasar/Pointer/AliasInfoBase.h b/include/phasar/Pointer/AliasInfoBase.h
index b3bb828c1..039a212ed 100644
--- a/include/phasar/Pointer/AliasInfoBase.h
+++ b/include/phasar/Pointer/AliasInfoBase.h
@@ -11,6 +11,7 @@
 #define PHASAR_POINTER_ALIASINFOBASE_H
 
 #include "phasar/Pointer/AliasInfoTraits.h"
+#include "phasar/Utils/TypeTraits.h"
 
 #include "llvm/ADT/DenseSet.h"
 #include "llvm/Support/raw_ostream.h"
@@ -74,8 +75,7 @@ struct IsAliasInfo<
 };
 } // namespace detail
 
-template <typename T>
-static constexpr bool IsAliasInfo = detail::IsAliasInfo<T>::value;
+template <typename T> PSR_CONCEPT IsAliasInfo = detail::IsAliasInfo<T>::value;
 
 } // namespace psr
 
diff --git a/include/phasar/Pointer/PointsToInfoBase.h b/include/phasar/Pointer/PointsToInfoBase.h
index 696065646..9eef7cf3a 100644
--- a/include/phasar/Pointer/PointsToInfoBase.h
+++ b/include/phasar/Pointer/PointsToInfoBase.h
@@ -36,12 +36,12 @@ struct is_PointsToTraits<
     : std::true_type {};
 
 template <typename T>
-static constexpr bool is_PointsToTraits_v = // NOLINT
+PSR_CONCEPT is_PointsToTraits_v = // NOLINT
     is_PointsToTraits<T>::value;
 
 // clang-format off
 template <typename T1, typename T2>
-static constexpr bool is_equivalent_PointsToTraits_v = // NOLINT
+PSR_CONCEPT is_equivalent_PointsToTraits_v = // NOLINT
     is_PointsToTraits_v<T1> && is_PointsToTraits_v<T2> &&
     std::is_same_v<typename T1::n_t, typename T2::n_t> &&
     std::is_same_v<typename T1::v_t, typename T2::v_t> &&
diff --git a/include/phasar/Utils/AdjacencyList.h b/include/phasar/Utils/AdjacencyList.h
index e09bb99fa..b69abe74c 100644
--- a/include/phasar/Utils/AdjacencyList.h
+++ b/include/phasar/Utils/AdjacencyList.h
@@ -163,7 +163,7 @@ struct GraphTraits<AdjacencyList<T, EdgeTy>> {
     if constexpr (!std::is_same_v<value_type, llvm::NoneType>) {
       assert(G.Adj.size() == G.Nodes.size());
     }
-    return psr::iota(size_t(0), G.Adj.size());
+    return psr::iota(vertex_t(0), G.Adj.size());
   }
 
   /// Gets the node-tag for node Vtx in graph G. Vtx must be part of G
@@ -292,8 +292,8 @@ struct GraphTraits<AdjacencyList<T, EdgeTy>> {
 
 #if __cplusplus >= 202002L
   static_assert(is_graph<AdjacencyList<T>>);
-  static_assert(is_reservable_graph_trait<GraphTraits<AdjacencyList<T>>>);
 #endif
+  static_assert(is_reservable_graph_trait_v<GraphTraits<AdjacencyList<T>>>);
 };
 
 } // namespace psr
diff --git a/include/phasar/Utils/ByRef.h b/include/phasar/Utils/ByRef.h
index 4e0f21bed..f98bd9eaa 100644
--- a/include/phasar/Utils/ByRef.h
+++ b/include/phasar/Utils/ByRef.h
@@ -10,12 +10,14 @@
 #ifndef PHASAR_UTILS_BYREF_H
 #define PHASAR_UTILS_BYREF_H
 
+#include "phasar/Utils/TypeTraits.h"
+
 #include <type_traits>
 
 namespace psr {
 
 template <typename T>
-static constexpr bool CanEfficientlyPassByValue =
+PSR_CONCEPT CanEfficientlyPassByValue =
     sizeof(T) <= 2 * sizeof(void *) && std::is_trivially_copyable_v<T>;
 
 template <typename T>
diff --git a/include/phasar/Utils/GraphTraits.h b/include/phasar/Utils/GraphTraits.h
index be00b4b84..76915be0f 100644
--- a/include/phasar/Utils/GraphTraits.h
+++ b/include/phasar/Utils/GraphTraits.h
@@ -69,7 +69,7 @@ concept is_graph_trait = requires(typename GraphTrait::graph_type &graph,
     } -> psr::is_iterable_over_v<typename GraphTrait::value_type>;
   {
     GraphTrait::vertices(cgraph)
-    } -> psr::is_iterable_over_v<typename GraphTrait::value_type>;
+    } -> psr::is_iterable_over_v<typename GraphTrait::vertex_t>;
   {
     GraphTrait::node(cgraph, vtx)
     } -> std::convertible_to<typename GraphTrait::value_type>;
diff --git a/include/phasar/Utils/IotaIterator.h b/include/phasar/Utils/IotaIterator.h
index 9eab786b6..c45a8efd0 100644
--- a/include/phasar/Utils/IotaIterator.h
+++ b/include/phasar/Utils/IotaIterator.h
@@ -59,7 +59,8 @@ template <typename T> class IotaIterator {
 
 template <typename T>
 using IotaRangeType = llvm::iterator_range<IotaIterator<T>>;
-template <typename T> constexpr auto iota(T From, T To) noexcept {
+template <typename T>
+constexpr auto iota(T From, type_identity_t<T> To) noexcept {
   static_assert(std::is_integral_v<T>, "Iota only works on integers");
   using iterator_type = IotaIterator<std::decay_t<T>>;
   auto Ret = llvm::make_range(iterator_type(From), iterator_type(To));
diff --git a/include/phasar/Utils/JoinLattice.h b/include/phasar/Utils/JoinLattice.h
index 8e748cf78..203027cf2 100644
--- a/include/phasar/Utils/JoinLattice.h
+++ b/include/phasar/Utils/JoinLattice.h
@@ -17,6 +17,8 @@
 #ifndef PHASAR_UTILS_JOINLATTICE_H
 #define PHASAR_UTILS_JOINLATTICE_H
 
+#include "phasar/Utils/TypeTraits.h"
+
 #include <type_traits>
 #include <utility>
 
@@ -41,8 +43,7 @@ struct HasJoinLatticeTraitsHelper<
                                  L>>> : std::true_type {};
 } // namespace detail
 template <typename L>
-static constexpr bool HasJoinLatticeTraits =
-    detail::HasJoinLatticeTraitsHelper<L>::value;
+PSR_CONCEPT HasJoinLatticeTraits = detail::HasJoinLatticeTraitsHelper<L>::value;
 
 template <typename AnalysisDomainTy, typename = void> class JoinLattice {
 public:
diff --git a/include/phasar/Utils/Printer.h b/include/phasar/Utils/Printer.h
index 31a08cdb4..76cb2e5e5 100644
--- a/include/phasar/Utils/Printer.h
+++ b/include/phasar/Utils/Printer.h
@@ -27,7 +27,7 @@ class Function;
 namespace psr {
 namespace detail {
 template <typename T>
-static constexpr bool IsSomehowPrintable =
+PSR_CONCEPT IsSomehowPrintable =
     has_str_v<T> || is_llvm_printable_v<T> || has_adl_to_string_v<T>;
 
 template <typename T> decltype(auto) printSomehow(const T &Val) {
diff --git a/include/phasar/Utils/TypeTraits.h b/include/phasar/Utils/TypeTraits.h
index f4c6736f2..2c6d771c7 100644
--- a/include/phasar/Utils/TypeTraits.h
+++ b/include/phasar/Utils/TypeTraits.h
@@ -23,8 +23,10 @@
 namespace psr {
 
 #if __cplusplus < 202002L
+#define PSR_CONCEPT static constexpr bool
 template <typename T> struct type_identity { using type = T; };
 #else
+#define PSR_CONCEPT concept
 template <typename T> using type_identity = std::type_identity<T>;
 #endif
 
@@ -173,44 +175,44 @@ struct variant_idx<std::variant<Ts...>, T>
 } // namespace detail
 
 template <typename T>
-constexpr bool is_iterable_v = detail::is_iterable<T>::value; // NOLINT
+PSR_CONCEPT is_iterable_v = detail::is_iterable<T>::value; // NOLINT
 
 template <typename T, typename Over>
-constexpr bool is_iterable_over_v = // NOLINT
+PSR_CONCEPT is_iterable_over_v = // NOLINT
     detail::is_iterable_over<T, Over>::value;
 
 template <typename T>
-constexpr bool is_pair_v = detail::is_pair<T>::value; // NOLINT
+PSR_CONCEPT is_pair_v = detail::is_pair<T>::value; // NOLINT
 
 template <typename T>
-constexpr bool is_tuple_v = detail::is_tuple<T>::value; // NOLINT
+PSR_CONCEPT is_tuple_v = detail::is_tuple<T>::value; // NOLINT
 
 template <typename T>
-constexpr bool is_llvm_printable_v = // NOLINT
+PSR_CONCEPT is_llvm_printable_v = // NOLINT
     detail::is_llvm_printable<T>::value;
 
 template <typename T>
-constexpr bool is_std_printable_v = // NOLINT
+PSR_CONCEPT is_std_printable_v = // NOLINT
     detail::is_std_printable<T>::value;
 
 template <typename T, typename OS>
-constexpr bool is_printable_v = detail::is_printable<T, OS>::value; // NOLINT
+PSR_CONCEPT is_printable_v = detail::is_printable<T, OS>::value; // NOLINT
 
 template <typename T>
-constexpr bool has_str_v = detail::has_str<T>::value; // NOLINT
+PSR_CONCEPT has_str_v = detail::has_str<T>::value; // NOLINT
 
 template <typename T>
-constexpr bool has_adl_to_string_v = detail::has_adl_to_string<T>::value;
+PSR_CONCEPT has_adl_to_string_v = detail::has_adl_to_string<T>::value;
 
 template <typename T>
-constexpr bool has_erase_iterator_v = // NOLINT
+PSR_CONCEPT has_erase_iterator_v = // NOLINT
     detail::has_erase_iterator<T>::value;
 
 template <typename T>
-constexpr bool is_std_hashable_v = detail::is_std_hashable<T>::value; // NOLINT
+PSR_CONCEPT is_std_hashable_v = detail::is_std_hashable<T>::value; // NOLINT
 
 template <typename T>
-constexpr bool is_llvm_hashable_v = // NOLINT
+PSR_CONCEPT is_llvm_hashable_v = // NOLINT
     detail::is_llvm_hashable<T>::value;
 
 template <typename T> struct is_variant : std::false_type {}; // NOLINT
@@ -218,30 +220,26 @@ template <typename T> struct is_variant : std::false_type {}; // NOLINT
 template <typename... Args>
 struct is_variant<std::variant<Args...>> : std::true_type {}; // NOLINT
 
-template <typename T>
-inline constexpr bool is_variant_v = is_variant<T>::value; // NOLINT
+template <typename T> PSR_CONCEPT is_variant_v = is_variant<T>::value; // NOLINT
 
 template <typename T>
 // NOLINTNEXTLINE
-constexpr bool is_string_like_v = std::is_convertible_v<T, std::string_view>;
+PSR_CONCEPT is_string_like_v = std::is_convertible_v<T, std::string_view>;
 
 template <template <typename> typename Base, typename Derived>
-constexpr bool is_crtp_base_of_v = // NOLINT
+PSR_CONCEPT is_crtp_base_of_v = // NOLINT
     detail::is_crtp_base_of<Base, Derived>::value;
 
 template <typename T>
-static inline constexpr bool HasIsConstant = detail::HasIsConstant<T>::value;
+PSR_CONCEPT HasIsConstant = detail::HasIsConstant<T>::value;
 
-template <typename T>
-static inline constexpr bool HasDepth = detail::HasDepth<T>::value;
+template <typename T> PSR_CONCEPT HasDepth = detail::HasDepth<T>::value;
 
 template <typename T>
-static inline constexpr bool IsEqualityComparable =
-    detail::IsEqualityComparable<T>::value;
+PSR_CONCEPT IsEqualityComparable = detail::IsEqualityComparable<T>::value;
 
 template <typename T, typename U>
-static inline constexpr bool AreEqualityComparable =
-    detail::AreEqualityComparable<T, U>::value;
+PSR_CONCEPT AreEqualityComparable = detail::AreEqualityComparable<T, U>::value;
 
 template <typename T> using type_identity_t = typename type_identity<T>::type;