[devel] [PATCH for apt 2/2 v2] Fix pointer arithmetics

[Aleksei Nikiforov <darktemplar@altlinux.org>]

This change should fix pointer arithmetic issues for e2k.
---
 apt/apt-pkg/Makefile.am           |  1 +
 apt/apt-pkg/cacheiterators.h      | 26 ++++++++++++++------------
 apt/apt-pkg/contrib/mmap.cc       |  8 +++++---
 apt/apt-pkg/pkgcachegen.cc        | 29 +++++++++++++++--------------
 apt/apt-pkg/pkgcachegen.h         |  6 +++---
 apt/apt-pkg/rebase_pointer.h      | 16 ++++++++++++++++
 apt/apt-pkg/rpm/rpmlistparser.cc  |  5 +++--
 apt/apt-pkg/rpm/rpmpackagedata.cc |  2 +-
 8 files changed, 58 insertions(+), 35 deletions(-)
 create mode 100644 apt/apt-pkg/rebase_pointer.h

diff --git a/apt/apt-pkg/Makefile.am b/apt/apt-pkg/Makefile.am
index 4c0d234..d038d01 100644
--- a/apt/apt-pkg/Makefile.am
+++ b/apt/apt-pkg/Makefile.am
@@ -94,6 +94,7 @@ libapt_pkg_la_SOURCES = \
 	pkgsystem.h \
 	policy.cc \
 	policy.h \
+	rebase_pointer.h \
 	repository.cc \
 	repository.h \
 	scopeexit.h \
diff --git a/apt/apt-pkg/cacheiterators.h b/apt/apt-pkg/cacheiterators.h
index a4bf670..118838e 100644
--- a/apt/apt-pkg/cacheiterators.h
+++ b/apt/apt-pkg/cacheiterators.h
@@ -34,6 +34,8 @@
 #pragma interface "apt-pkg/cacheiterators.h"
 #endif 
 
+#include <apt-pkg/rebase_pointer.h>
+
 #include <set>
 
 // Package Iterator
@@ -85,11 +87,11 @@ class pkgCache::PkgIterator
    inline unsigned long long Index() const {return Pkg - Owner->PkgP;};
    OkState State() const;
 
-   void ReMap(void const * const oldMap, void const * const newMap)
+   void ReMap(void *oldMap, void *newMap)
    {
       if (Owner == 0 || Pkg == 0)
          return;
-      Pkg += static_cast<Package const *>(newMap) - static_cast<Package const *>(oldMap);
+      Pkg = RebasePointer(Pkg, oldMap, newMap);
    }
 
    // Constructors
@@ -147,11 +149,11 @@ class pkgCache::VerIterator
    bool Automatic() const;
    VerFileIterator NewestFile() const;
 
-   void ReMap(void const * const oldMap, void const * const newMap)
+   void ReMap(void *oldMap, void *newMap)
    {
       if (Owner == 0 || Ver == 0)
          return;
-      Ver += static_cast<Version const *>(newMap) - static_cast<Version const *>(oldMap);
+      Ver = RebasePointer(Ver, oldMap, newMap);
    }
 
    inline VerIterator() : Ver(0), Owner(0) {};   
@@ -220,11 +222,11 @@ class pkgCache::DepIterator
    inline const char *CompType() {return Owner->CompType(Dep->CompareOp);};
    inline const char *DepType() {return Owner->DepType(Dep->Type);};
 
-   void ReMap(void const * const oldMap, void const * const newMap)
+   void ReMap(void *oldMap, void *newMap)
    {
       if (Owner == 0 || Dep == 0)
          return;
-      Dep += static_cast<Dependency const *>(newMap) - static_cast<Dependency const *>(oldMap);
+      Dep = RebasePointer(Dep, oldMap, newMap);
    }
 
    inline DepIterator(pkgCache &Owner,Dependency *Trg,Version * = 0) :
@@ -279,11 +281,11 @@ class pkgCache::PrvIterator
    inline PkgIterator OwnerPkg() const {return PkgIterator(*Owner,Owner->PkgP + Owner->VerP[Prv->Version].ParentPkg);};
    inline unsigned long long Index() const {return Prv - Owner->ProvideP;};
 
-   void ReMap(void const * const oldMap, void const * const newMap)
+   void ReMap(void *oldMap, void *newMap)
    {
       if (Owner == 0 || Prv == 0)
          return;
-      Prv += static_cast<Provides const *>(newMap) - static_cast<Provides const *>(oldMap);
+      Prv = RebasePointer(Prv, oldMap, newMap);
    }
 
    inline PrvIterator() : Prv(0), Type(PrvVer), Owner(0)  {};
@@ -342,11 +344,11 @@ class pkgCache::PkgFileIterator
    bool IsOk();
    string RelStr();
 
-   void ReMap(void const * const oldMap, void const * const newMap)
+   void ReMap(void *oldMap, void *newMap)
    {
       if (Owner == 0 || File == 0)
          return;
-      File += static_cast<PackageFile const *>(newMap) - static_cast<PackageFile const *>(oldMap);
+      File = RebasePointer(File, oldMap, newMap);
    }
 
    // Constructors
@@ -383,11 +385,11 @@ class pkgCache::VerFileIterator
    inline PkgFileIterator File() const {return PkgFileIterator(*Owner,FileP->File + Owner->PkgFileP);};
    inline unsigned long long Index() const {return FileP - Owner->VerFileP;};
 
-   void ReMap(void const * const oldMap, void const * const newMap)
+   void ReMap(void *oldMap, void *newMap)
    {
       if (Owner == 0 || FileP == 0)
          return;
-      FileP += static_cast<VerFile const *>(newMap) - static_cast<VerFile const *>(oldMap);
+      FileP = RebasePointer(FileP, oldMap, newMap);
    }
 
    inline VerFileIterator() : Owner(0), FileP(0) {};
diff --git a/apt/apt-pkg/contrib/mmap.cc b/apt/apt-pkg/contrib/mmap.cc
index cf01be9..35f1a25 100644
--- a/apt/apt-pkg/contrib/mmap.cc
+++ b/apt/apt-pkg/contrib/mmap.cc
@@ -30,6 +30,7 @@
 #include <apt-pkg/configuration.h>
 #include <apt-pkg/mmap.h>
 #include <apt-pkg/error.h>
+#include <apt-pkg/rebase_pointer.h>
 
 #include <apti18n.h>
 
@@ -301,7 +302,7 @@ std::experimental::optional<map_ptrloc> DynamicMMap::Allocate(unsigned long Item
       Pool* oldPools = Pools;
       auto idxResult = RawAllocate(I->Count*ItemSize,ItemSize);
       if (Pools != oldPools)
-         I += Pools - oldPools;
+         I = RebasePointer(I, oldPools, Pools);
 
       // Does the allocation failed ?
       if (!idxResult)
@@ -371,7 +372,7 @@ bool DynamicMMap::Grow(unsigned long long size)
       Fd->Write(&C,sizeof(C));
    }
 
-   unsigned long const poolOffset = Pools - ((Pool*) Base);
+   void *old_base = Base;
 
    if (Fd != 0)
    {
@@ -408,7 +409,8 @@ bool DynamicMMap::Grow(unsigned long long size)
       memset((char*)Base + WorkSpace, 0, newSize - WorkSpace);
    }
 
-   Pools = (Pool*) Base + poolOffset;
+   if (Base != old_base)
+      Pools = RebasePointer(Pools, old_base, Base);
    WorkSpace = newSize;
 
    return true;
diff --git a/apt/apt-pkg/pkgcachegen.cc b/apt/apt-pkg/pkgcachegen.cc
index 654c81c..37364e9 100644
--- a/apt/apt-pkg/pkgcachegen.cc
+++ b/apt/apt-pkg/pkgcachegen.cc
@@ -26,6 +26,7 @@
 #include <apt-pkg/strutl.h>
 #include <apt-pkg/sptr.h>
 #include <apt-pkg/pkgsystem.h>
+#include <apt-pkg/rebase_pointer.h>
 
 #include <apti18n.h>
 
@@ -109,18 +110,18 @@ pkgCacheGenerator::~pkgCacheGenerator()
    Map.Sync(0,sizeof(pkgCache::Header));
 }
 									/*}}}*/
-void pkgCacheGenerator::ReMap(void const * const oldMap, void const * const newMap)
+void pkgCacheGenerator::ReMap(void *oldMap, void *newMap)
 {
    if (oldMap == newMap)
       return;
 
    Cache.ReMap(false);
 
-   CurrentFile += (pkgCache::PackageFile*) newMap - (pkgCache::PackageFile*) oldMap;
+   CurrentFile = RebasePointer(CurrentFile, oldMap, newMap);
 
    for (size_t i = 0; i < _count(UniqHash); ++i)
       if (UniqHash[i] != 0)
-         UniqHash[i] += (pkgCache::StringItem*) newMap - (pkgCache::StringItem*) oldMap;
+         UniqHash[i] = RebasePointer(UniqHash[i], oldMap, newMap);
 
    for (auto i = Dynamic<pkgCache::PkgIterator>::toReMap.begin();
         i != Dynamic<pkgCache::PkgIterator>::toReMap.end(); ++i)
@@ -147,7 +148,7 @@ void pkgCacheGenerator::ReMap(void const * const oldMap, void const * const newM
 // CacheGenerator::WriteStringInMap					/*{{{*/
 std::experimental::optional<map_ptrloc> pkgCacheGenerator::WriteStringInMap(const char *String,
 					unsigned long Len) {
-   void const * const oldMap = Map.Data();
+   void *oldMap = Map.Data();
    const auto index = Map.WriteString(String, Len);
    if (index)
       ReMap(oldMap, Map.Data());
@@ -156,7 +157,7 @@ std::experimental::optional<map_ptrloc> pkgCacheGenerator::WriteStringInMap(cons
 									/*}}}*/
 // CacheGenerator::WriteStringInMap					/*{{{*/
 std::experimental::optional<map_ptrloc> pkgCacheGenerator::WriteStringInMap(const char *String) {
-   void const * const oldMap = Map.Data();
+   void *oldMap = Map.Data();
    const auto index = Map.WriteString(String);
    if (index)
       ReMap(oldMap, Map.Data());
@@ -164,7 +165,7 @@ std::experimental::optional<map_ptrloc> pkgCacheGenerator::WriteStringInMap(cons
 }
 									/*}}}*/
 std::experimental::optional<map_ptrloc> pkgCacheGenerator::AllocateInMap(unsigned long size) {/*{{{*/
-   void const * const oldMap = Map.Data();
+   void *oldMap = Map.Data();
    const auto index = Map.Allocate(size);
    if (index)
       ReMap(oldMap, Map.Data());
@@ -229,7 +230,7 @@ bool pkgCacheGenerator::MergeList(ListParser &List,
       pkgCache::VerIterator Ver = Pkg.VersionList();
       Dynamic<pkgCache::VerIterator> DynVer(Ver);
       map_ptrloc *Last = &Pkg->VersionList;
-      const void * oldMap = Map.Data();
+      void *oldMap = Map.Data();
       int Res = 1;
       for (; Ver.end() == false; Last = &Ver->NextVer, Ver++)
       {
@@ -271,7 +272,7 @@ bool pkgCacheGenerator::MergeList(ListParser &List,
 
       if (oldMap != Map.Data())
       {
-         Last += (map_ptrloc*) Map.Data() - (map_ptrloc*) oldMap;
+         Last = RebasePointer(Last, oldMap, Map.Data());
          oldMap = Map.Data();
       }
 
@@ -297,7 +298,7 @@ bool pkgCacheGenerator::MergeList(ListParser &List,
                               PackageName.c_str(), 1);
 
       if (oldMap != Map.Data())
-         Last += (map_ptrloc*) Map.Data() - (map_ptrloc*) oldMap;
+         Last = RebasePointer(Last, oldMap, Map.Data());
       *Last = *verindex;
 
       Ver->ParentPkg = Pkg.Index();
@@ -553,7 +554,7 @@ bool pkgCacheGenerator::ListParser::NewDepends(pkgCache::VerIterator &Ver,
 					       unsigned int Op,
 					       unsigned int Type)
 {
-   void const * const oldMap = Owner->Map.Data();
+   void *oldMap = Owner->Map.Data();
    pkgCache &Cache = Owner->Cache;
    
    // Get a structure
@@ -605,7 +606,7 @@ bool pkgCacheGenerator::ListParser::NewDepends(pkgCache::VerIterator &Ver,
 	 OldDepLast = &D->NextDepends;
       OldDepVer = Ver;
    } else if (oldMap != Owner->Map.Data())
-      OldDepLast += (map_ptrloc*) Owner->Map.Data() - (map_ptrloc*) oldMap;
+      OldDepLast = RebasePointer(OldDepLast, oldMap, Owner->Map.Data());
 
    // Is it a file dependency?
    if (PackageName[0] == '/')
@@ -739,7 +740,7 @@ std::experimental::optional<map_ptrloc> pkgCacheGenerator::WriteUniqString(const
    }
    
    // Get a structure
-   void const * const oldMap = Map.Data();
+   void *oldMap = Map.Data();
    const auto Item = AllocateInMap(sizeof(pkgCache::StringItem));
    const auto idxString = WriteStringInMap(S, Size);
    if ((!Item) || (!idxString))
@@ -747,8 +748,8 @@ std::experimental::optional<map_ptrloc> pkgCacheGenerator::WriteUniqString(const
 
    if (oldMap != Map.Data())
    {
-      Last += (map_ptrloc*) Map.Data() - (map_ptrloc*) oldMap;
-      I += (pkgCache::StringItem*) Map.Data() - (pkgCache::StringItem*) oldMap;
+      Last = RebasePointer(Last, oldMap, Map.Data());
+      I = RebasePointer(I, oldMap, Map.Data());
    }
 
    *Last = *Item;
diff --git a/apt/apt-pkg/pkgcachegen.h b/apt/apt-pkg/pkgcachegen.h
index 77075a6..0faf6e1 100644
--- a/apt/apt-pkg/pkgcachegen.h
+++ b/apt/apt-pkg/pkgcachegen.h
@@ -72,7 +72,7 @@ class pkgCacheGenerator
    class DynamicFunction
    {
    public:
-      typedef std::function<void(const void *, const void *)> function;
+      typedef std::function<void(void *, void *)> function;
 
       static std::set<DynamicFunction*> toReMap;
 
@@ -93,7 +93,7 @@ class pkgCacheGenerator
          toReMap.erase(this);
       }
 
-      void call(const void *oldMap, const void *newMap)
+      void call(void *oldMap, void *newMap)
       {
          if (m_function)
             m_function(oldMap, newMap);
@@ -140,7 +140,7 @@ class pkgCacheGenerator
    // CNC:2003-03-18
    inline void ResetFileDeps() {FoundFileDeps = false;};
 
-   void ReMap(void const * const oldMap, void const * const newMap);
+   void ReMap(void *oldMap, void *newMap);
 
    pkgCacheGenerator(DynamicMMap *Map,OpProgress *Progress);
    ~pkgCacheGenerator();
diff --git a/apt/apt-pkg/rebase_pointer.h b/apt/apt-pkg/rebase_pointer.h
new file mode 100644
index 0000000..f6b3c15
--- /dev/null
+++ b/apt/apt-pkg/rebase_pointer.h
@@ -0,0 +1,16 @@
+#ifndef PKGLIB_REBASE_POINTER_H
+#define PKGLIB_REBASE_POINTER_H
+
+template <typename T>
+static inline T* RebasePointer(T *ptr, void *old_base, void *new_base)
+{
+   return reinterpret_cast<T*>(reinterpret_cast<char*>(new_base) + (reinterpret_cast<char*>(ptr) - reinterpret_cast<char*>(old_base)));
+}
+
+template <typename T>
+static inline const T* RebasePointer(const T *ptr, void *old_base, void *new_base)
+{
+   return reinterpret_cast<const T*>(reinterpret_cast<char*>(new_base) + (reinterpret_cast<const char*>(ptr) - reinterpret_cast<char*>(old_base)));
+}
+
+#endif
diff --git a/apt/apt-pkg/rpm/rpmlistparser.cc b/apt/apt-pkg/rpm/rpmlistparser.cc
index 9b2e9ad..bd13b99 100644
--- a/apt/apt-pkg/rpm/rpmlistparser.cc
+++ b/apt/apt-pkg/rpm/rpmlistparser.cc
@@ -25,6 +25,7 @@
 #include <apt-pkg/strutl.h>
 #include <apt-pkg/crc-16.h>
 #include <apt-pkg/tagfile.h>
+#include <apt-pkg/rebase_pointer.h>
 
 #include <apti18n.h>
 
@@ -50,13 +51,13 @@ rpmListParser::rpmListParser(RPMHandler *Handler)
    {
       SeenPackages.reset(new SeenPackagesType);
       m_SeenPackagesRealloc.reset(new pkgCacheGenerator::DynamicFunction(
-         [this] (void const *oldMap, void const *newMap)
+         [this] (void *oldMap, void *newMap)
       {
          SeenPackagesType tmp;
 
          for (auto iter: *SeenPackages)
          {
-            tmp.insert(iter + (static_cast<const char *>(newMap) - static_cast<const char *>(oldMap)));
+            tmp.insert(RebasePointer(iter, oldMap, newMap));
          }
 
          SeenPackages->swap(tmp);
diff --git a/apt/apt-pkg/rpm/rpmpackagedata.cc b/apt/apt-pkg/rpm/rpmpackagedata.cc
index 61c15d5..d6c677b 100644
--- a/apt/apt-pkg/rpm/rpmpackagedata.cc
+++ b/apt/apt-pkg/rpm/rpmpackagedata.cc
@@ -23,7 +23,7 @@ RPMPackageData::RPMPackageData()
 #endif
 {
    m_VerMapRealloc.reset(new pkgCacheGenerator::DynamicFunction(
-      [this] (void const *oldMap, void const *newMap)
+      [this] (void *oldMap, void *newMap)
    {
       for (auto iter1 = VerMap.begin(); iter1 != VerMap.end(); ++iter1)
       {
-- 
2.24.0