From f8ad69b3204d5932fe7dd6948219921a8ca20675 Mon Sep 17 00:00:00 2001
From: Gabe Black <gabeblack@google.com>
Date: Mon, 11 Jun 2018 18:47:49 -0700
Subject: [PATCH] systemc: Fill out some of the sc_vector.hh classes.

The iterator class needs to have some operators, etc., defined so that
tests written against it can compile correctly. The implementations
were heavily influenced by the Accellera implementation.

Also it should be noted that the systemc spec is incorrect where it
defines these classes. When implemented like they are in the
Accellera version, the versions of bind in sc_vector_assembly which
take sc_vector<T>::iterator and iterator parameters are different, and
so they can overload each other. If implemented as described by the
spec however, those types are the same and the code won't compile.

Change-Id: I62852adf7e6c0a2f3df076ba4e93d2501859c32d
Reviewed-on: https://gem5-review.googlesource.com/11177
Reviewed-by: Gabe Black <gabeblack@google.com>
Maintainer: Gabe Black <gabeblack@google.com>
---
 src/systemc/ext/utils/sc_vector.hh | 434 +++++++++++++++++++++++++----
 1 file changed, 373 insertions(+), 61 deletions(-)

diff --git a/src/systemc/ext/utils/sc_vector.hh b/src/systemc/ext/utils/sc_vector.hh
index 073b17c88..fea49c296 100644
--- a/src/systemc/ext/utils/sc_vector.hh
+++ b/src/systemc/ext/utils/sc_vector.hh
@@ -33,11 +33,102 @@
 #include <stdint.h>
 
 #include <exception>
+#include <iterator>
 #include <vector>
 
 #include "../core/sc_object.hh"
 #include "warn_unimpl.hh"
 
+namespace sc_gem5
+{
+
+// Goop for supporting sc_vector_iter, simplified from the Accellera version.
+
+#if __cplusplus >= 201103L
+
+using std::enable_if;
+using std::remove_const;
+using std::is_same;
+using std::is_const;
+
+#else
+
+template<bool Cond, typename T=void>
+struct enable_if
+{};
+
+template<typename T>
+struct enable_if<true, T>
+{
+    typedef T type;
+};
+
+template <typename T>
+struct remove_const
+{
+    typedef T type;
+};
+template <typename T>
+struct remove_const<const T>
+{
+    typedef T type;
+};
+
+template <typename T, typename U>
+struct is_same
+{
+    static const bool value = false;
+};
+template <typename T>
+struct is_same<T, T>
+{
+    static const bool value = true;
+};
+
+template <typename T>
+struct is_const
+{
+    static const bool value = false;
+};
+template <typename T>
+struct is_const<const T>
+{
+    static const bool value = true;
+};
+
+#endif
+
+template <typename CT, typename T>
+struct is_more_const
+{
+    static const bool value =
+        is_same<typename remove_const<CT>::type,
+                typename remove_const<T>::type>::value &&
+        is_const<CT>::value >= is_const<T>::value;
+};
+
+struct special_result
+{};
+
+template <typename T>
+struct remove_special_fptr
+{};
+
+template <typename T>
+struct remove_special_fptr<special_result & (*)(T)>
+{
+    typedef T type;
+};
+
+#define SC_RPTYPE_(Type) \
+    ::sc_gem5::remove_special_fptr< \
+        ::sc_gem5::special_result & (*) Type>::type::value
+
+#define SC_ENABLE_IF_(Cond) \
+    typename ::sc_gem5::enable_if<SC_RPTYPE_(Cond)>::type * = NULL
+
+} // namespace sc_gem5
+
 namespace sc_core
 {
 
@@ -61,14 +152,247 @@ class sc_vector_base : public sc_object
     const std::vector<sc_object *> &get_elements() const;
 };
 
-template <typename T>
+
+/*
+ * Non-standard iterator access adapters. Without using these, the classes as
+ * defined in the standard won't compile because of redundant bind() overloads.
+ */
+
+template <typename Element>
+class sc_direct_access
+{
+  public:
+    typedef Element ElementType;
+    typedef ElementType Type;
+    typedef typename sc_gem5::remove_const<ElementType>::type PlainType;
+
+    typedef sc_direct_access<ElementType> Policy;
+    typedef sc_direct_access<PlainType> NonConstPolicy;
+    typedef sc_direct_access<const PlainType> ConstPolicy;
+
+    sc_direct_access() {}
+    sc_direct_access(const NonConstPolicy &) {}
+
+    template <typename U>
+    sc_direct_access(const U &,
+        SC_ENABLE_IF_((
+            sc_gem5::is_more_const<
+                    ElementType, typename U::Policy::ElementType>
+        ))
+    )
+    {}
+
+    ElementType *
+    get(ElementType *this_) const
+    {
+        return this_;
+    }
+};
+
+template <typename Element, typename Access>
+class sc_member_access
+{
+  public:
+    template <typename, typename>
+    friend class sc_member_access;
+
+    typedef Element ElementType;
+    typedef Access AccessType;
+    typedef AccessType (ElementType::*MemberType);
+    typedef AccessType Type;
+    typedef typename sc_gem5::remove_const<AccessType>::type PlainType;
+    typedef typename sc_gem5::remove_const<ElementType>::type PlainElemType;
+
+    typedef sc_member_access<ElementType, AccessType> Policy;
+    typedef sc_member_access<PlainElemType, PlainType> NonConstPolicy;
+    typedef sc_member_access<const PlainElemType, const PlainType> ConstPolicy;
+
+    sc_member_access(MemberType ptr) : ptr_(ptr) {}
+    sc_member_access(const NonConstPolicy &other) : ptr_(other.ptr_) {}
+
+    AccessType *get(ElementType *this_) const { return &(this_->*ptr_); }
+
+  private:
+    MemberType ptr_;
+};
+
+template <typename Element,
+          typename AccessPolicy=sc_direct_access<Element> >
 class sc_vector_iter :
-        public std::iterator<std::random_access_iterator_tag, T>
+        public std::iterator<std::random_access_iterator_tag,
+                             typename AccessPolicy::Type>,
+        private AccessPolicy
 {
+  private:
+    typedef Element ElementType;
+    typedef typename AccessPolicy::Policy Policy;
+    typedef typename AccessPolicy::NonConstPolicy NonConstPolicy;
+    typedef typename AccessPolicy::ConstPolicy ConstPolicy;
+    typedef typename Policy::Type AccessType;
+
+    typedef typename sc_gem5::remove_const<ElementType>::type PlainType;
+    typedef const PlainType ConstPlainType;
+    typedef typename sc_direct_access<PlainType>::ConstPolicy
+        ConstDirectPolicy;
+
+    friend class sc_vector<PlainType>;
+    template <typename, typename>
+    friend class sc_vector_assembly;
+    template <typename, typename>
+    friend class sc_vector_iter;
+
+    typedef std::iterator<std::random_access_iterator_tag, AccessType>
+        BaseType;
+    typedef sc_vector_iter ThisType;
+    typedef sc_vector<PlainType> VectorType;
+    typedef std::vector<void *> StorageType;
+
+    template <typename U>
+    struct SelectIter
+    {
+        typedef typename std::vector<void *>::iterator type;
+    };
+    template <typename U>
+    struct SelectIter<const U>
+    {
+        typedef typename std::vector<void *>::const_iterator type;
+    };
+    typedef typename SelectIter<ElementType>::type RawIterator;
+    typedef sc_vector_iter<ConstPlainType, ConstPolicy> ConstIterator;
+    typedef sc_vector_iter<ConstPlainType, ConstDirectPolicy>
+        ConstDirectIterator;
+
+    RawIterator it_;
+
+    sc_vector_iter(RawIterator it, Policy acc=Policy()) :
+        Policy(acc), it_(it)
+    {}
+
+    Policy const &get_policy() const { return *this; }
+
+  public:
     // Conforms to Random Access Iterator category.
     // See ISO/IEC 14882:2003(E), 24.1 [lib.iterator.requirements]
 
-    // Implementation-defined
+    typedef typename BaseType::difference_type difference_type;
+    typedef typename BaseType::reference reference;
+    typedef typename BaseType::pointer pointer;
+
+    sc_vector_iter() : Policy(), it_() {}
+
+    template <typename It>
+    sc_vector_iter(const It &it,
+        SC_ENABLE_IF_((
+            sc_gem5::is_more_const<
+                ElementType, typename It::Policy::ElementType>
+        ))
+    ) : Policy(it.get_policy()), it_(it.it_)
+    {}
+
+    ThisType &
+    operator ++ ()
+    {
+        ++it_;
+        return *this;
+    }
+    ThisType &
+    operator -- ()
+    {
+        --it_;
+        return *this;
+    }
+    ThisType
+    operator ++ (int)
+    {
+        ThisType old(*this);
+        ++it_;
+        return old;
+    }
+    ThisType
+    operator -- (int)
+    {
+        ThisType old(*this);
+        --it_;
+        return old;
+    }
+
+    ThisType
+    operator + (difference_type n) const
+    {
+        return ThisType(it_ + n, get_policy());
+    }
+    ThisType
+    operator - (difference_type n) const
+    {
+        return ThisType(it_ - n, get_policy());
+    }
+
+    ThisType &
+    operator += (difference_type n)
+    {
+        it_ += n;
+        return *this;
+    }
+
+    ThisType &
+    operator -= (difference_type n)
+    {
+        it_ -= n;
+        return *this;
+    }
+
+    bool
+    operator == (const ConstDirectIterator &other) const
+    {
+        return it_ == other.it_;
+    }
+    bool
+    operator != (const ConstDirectIterator &other) const
+    {
+        return it_ != other.it_;
+    }
+    bool
+    operator <= (const ConstDirectIterator &other) const
+    {
+        return it_ <= other.it_;
+    }
+    bool
+    operator >= (const ConstDirectIterator &other) const
+    {
+        return it_ >= other.it_;
+    }
+    bool
+    operator < (const ConstDirectIterator &other) const
+    {
+        return it_ < other.it_;
+    }
+    bool
+    operator > (const ConstDirectIterator &other) const
+    {
+        return it_ > other.it_;
+    }
+
+    reference
+    operator * () const
+    {
+        return *Policy::get(static_cast<ElementType *>((void *)*it_));
+    }
+    pointer
+    operator -> () const
+    {
+        return Policy::get(static_cast<ElementType *>((void *)*it_));
+    }
+    reference
+    operator [] (difference_type n) const
+    {
+        return *Policy::get(static_cast<ElementType *>((void *)it_[n]));
+    }
+
+    difference_type
+    operator - (ConstDirectIterator const &other) const
+    {
+        return it_ - other.it_;
+    }
 };
 
 template <typename T>
@@ -257,53 +581,46 @@ class sc_vector_assembly
 {
   public:
     friend sc_vector_assembly<T, MT> sc_assemble_vector<>(
-            sc_vector<T> &, MT(T::* member_ptr));
+            sc_vector<T> &, MT (T::*));
 
     typedef size_t size_type;
-    // These next two types are supposed to be implementation defined. We'll
-    // just stick in a substitute for now, but these should probably not just
-    // be STL vector iterators.
-    typedef typename std::vector<T>::iterator iterator;
-    typedef typename std::vector<T>::const_iterator const_iterator;
-    typedef MT (T::* member_type);
+    typedef sc_vector_iter<T, sc_member_access<T, MT> > iterator;
+    typedef sc_vector_iter<
+        const T, sc_member_access<const T, const MT> > const_iterator;
+    typedef MT (T::*MemberType);
 
     sc_vector_assembly(const sc_vector_assembly &)
     {
         sc_utils_warn_unimpl(__PRETTY_FUNCTION__);
     }
 
-    iterator
-    begin()
-    {
-        sc_utils_warn_unimpl(__PRETTY_FUNCTION__);
-        return iterator();
-    }
-    iterator
-    end()
-    {
-        sc_utils_warn_unimpl(__PRETTY_FUNCTION__);
-        return iterator();
-    }
+    iterator begin() { return iterator(vec_->begin().it_, ptr_); }
+    iterator end() { return iterator(vec_->end().it_, ptr_); }
 
     const_iterator
     cbegin() const
     {
-        sc_utils_warn_unimpl(__PRETTY_FUNCTION__);
-        return const_iterator();
+        return const_iterator(vec_->begin().it_, ptr_);
     }
     const_iterator
     cend() const
     {
-        sc_utils_warn_unimpl(__PRETTY_FUNCTION__);
-        return const_iterator();
+        return const_iterator(vec_->end().it_, ptr_);
     }
 
-    size_type
-    size() const
+    const_iterator
+    begin() const
     {
-        sc_utils_warn_unimpl(__PRETTY_FUNCTION__);
-        return 0;
+        return const_iterator(vec_->begin().it_, ptr_);
+    }
+    const_iterator
+    end() const
+    {
+        return const_iterator(vec_->end().it_, ptr_);
     }
+
+    size_type size() const { return vec_->size(); }
+
     std::vector<sc_object *>
     get_elements() const
     {
@@ -312,29 +629,25 @@ class sc_vector_assembly
     }
 
     typename iterator::reference
-    operator [] (size_type)
+    operator [] (size_type i)
     {
-        sc_utils_warn_unimpl(__PRETTY_FUNCTION__);
-        return typename iterator::reference();
+        return (*vec_)[i].*ptr_;
     }
     typename const_iterator::reference
-    operator [] (size_type) const
+    operator [] (size_type i) const
     {
-        sc_utils_warn_unimpl(__PRETTY_FUNCTION__);
-        return typename iterator::reference();
+        return (*vec_)[i].*ptr_;
     }
 
     typename iterator::reference
-    at(size_type)
+    at(size_type i)
     {
-        sc_utils_warn_unimpl(__PRETTY_FUNCTION__);
-        return typename iterator::reference();
+        return vec_->at(i).*ptr_;
     }
     typename const_iterator::reference
-    at(size_type) const
+    at(size_type i) const
     {
-        sc_utils_warn_unimpl(__PRETTY_FUNCTION__);
-        return typename iterator::reference();
+        return vec_->at(i).*ptr_;
     }
 
     template <typename ContainerType, typename ArgumentType>
@@ -342,7 +655,7 @@ class sc_vector_assembly
     bind(sc_vector_assembly<ContainerType, ArgumentType>)
     {
         sc_utils_warn_unimpl(__PRETTY_FUNCTION__);
-        return iterator();
+        return begin();
     }
 
     template <typename BindableContainer>
@@ -350,7 +663,7 @@ class sc_vector_assembly
     bind(BindableContainer &)
     {
         sc_utils_warn_unimpl(__PRETTY_FUNCTION__);
-        return iterator();
+        return begin();
     }
 
     template <typename BindableIterator>
@@ -358,7 +671,7 @@ class sc_vector_assembly
     bind(BindableIterator, BindableIterator)
     {
         sc_utils_warn_unimpl(__PRETTY_FUNCTION__);
-        return iterator();
+        return begin();
     }
 
     template <typename BindableIterator>
@@ -366,7 +679,7 @@ class sc_vector_assembly
     bind(BindableIterator, BindableIterator, iterator)
     {
         sc_utils_warn_unimpl(__PRETTY_FUNCTION__);
-        return iterator();
+        return begin();
     }
 
     template <typename BindableIterator>
@@ -374,7 +687,7 @@ class sc_vector_assembly
     bind(BindableIterator, BindableIterator, typename sc_vector<T>::iterator)
     {
         sc_utils_warn_unimpl(__PRETTY_FUNCTION__);
-        return iterator();
+        return begin();
     }
 
     template <typename ContainerType, typename ArgumentType>
@@ -382,7 +695,7 @@ class sc_vector_assembly
     operator () (sc_vector_assembly<ContainerType, ArgumentType>)
     {
         sc_utils_warn_unimpl(__PRETTY_FUNCTION__);
-        return iterator();
+        return begin();
     }
 
     template <typename ArgumentContainer>
@@ -390,7 +703,7 @@ class sc_vector_assembly
     operator () (ArgumentContainer &)
     {
         sc_utils_warn_unimpl(__PRETTY_FUNCTION__);
-        return iterator();
+        return begin();
     }
 
     template <typename ArgumentIterator>
@@ -398,7 +711,7 @@ class sc_vector_assembly
     operator () (ArgumentIterator, ArgumentIterator)
     {
         sc_utils_warn_unimpl(__PRETTY_FUNCTION__);
-        return iterator();
+        return begin();
     }
 
     template <typename ArgumentIterator>
@@ -406,7 +719,7 @@ class sc_vector_assembly
     operator () (ArgumentIterator, ArgumentIterator, iterator)
     {
         sc_utils_warn_unimpl(__PRETTY_FUNCTION__);
-        return iterator();
+        return begin();
     }
 
     template <typename ArgumentIterator>
@@ -415,24 +728,23 @@ class sc_vector_assembly
                  typename sc_vector<T>::iterator)
     {
         sc_utils_warn_unimpl(__PRETTY_FUNCTION__);
-        return iterator();
+        return begin();
     }
 
   private:
-    // Temporary constructor which will (eventually) actually bind an
-    // sc_vector_assembly instance to an sc_vector.
-    sc_vector_assembly<T, MT>()
-    {
-        sc_utils_warn_unimpl(__PRETTY_FUNCTION__);
-    }
+    sc_vector_assembly(sc_vector<T> &v, MemberType ptr) :
+        vec_(&v), ptr_(ptr)
+    {}
+
+    sc_vector<T> *vec_;
+    MemberType ptr_;
 };
 
 template <typename T, typename MT>
 sc_vector_assembly<T, MT>
-sc_assemble_vector(sc_vector<T> &, MT(T::* member_ptr))
+sc_assemble_vector(sc_vector<T> &v, MT (T::*ptr))
 {
-    sc_utils_warn_unimpl(__PRETTY_FUNCTION__);
-    return sc_vector_assembly<T, MT>();
+    return sc_vector_assembly<T, MT>(v, ptr);
 }
 
 } // namespace sc_core
-- 
2.30.2