Fix padding in vectors

clasp-developers · Sep 25, 2024 · 530df3f · 530df3f
1 parent 78446ca
commit 530df3f
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Showing 3 changed files with 8 additions and 7 deletions.
diff --git a/include/clasp/core/array.h b/include/clasp/core/array.h
@@ -226,7 +226,7 @@ class Array_O : public General_O {
   /*! length() doesn't dispatch - it reaches into the subclass
       through the _Length[0] array to read the first size_t element
       which is the Length/FillPointer for vectors and a Dummy value for arrays */
-  virtual size_t length() const { return this->_Length[0]; };
+  size_t length() const { return this->_Length[0]; };
   virtual bool equal(T_sp other) const override = 0;
   virtual bool equalp(T_sp other) const override = 0;
   virtual size_t arrayTotalSize() const = 0;

diff --git a/include/clasp/core/array_long_float.h b/include/clasp/core/array_long_float.h
@@ -30,8 +30,6 @@ class SimpleVector_long_float_O : public specialized_SimpleVector_long_float {
 public:
   typedef specialized_SimpleVector_long_float TemplatedBase;
 
-  size_t length() const override { return this->_Data.length(); };
-
   static value_type default_initial_element(void) { return long_float_t{0.0}; }
   static value_type from_object(T_sp obj) { return core::Number_O::as_long_float(obj.as<Number_O>()); };
   static T_sp to_object(const value_type& v) { return core::LongFloat_O::create(v); };

diff --git a/include/clasp/gctools/gcarray.h b/include/clasp/gctools/gcarray.h
@@ -30,9 +30,12 @@ THE SOFTWARE.
 
 namespace gctools {
 
-template <class T> class GCArray_moveable : public GCContainer {
+// The following class is packed to ensure that no padding is inserted
+// before _MaybeSignedLength. Padding will break our non-virtual
+// length method.
+template <class T> class __attribute__((__packed__)) GCArray_moveable : public GCContainer {
 public:
-  GCArray_moveable(){};
+  GCArray_moveable() {};
 
 public:
   typedef T value_type;
@@ -92,7 +95,7 @@ template <class T> class GCArray_moveable : public GCContainer {
 // how C++ reference semantics work.
 template <class T> class GCArray_atomic : public GCContainer {
 public:
-  GCArray_atomic(){};
+  GCArray_atomic() {};
 
 public:
   int64_t _Length; // Index one beyond the total number of elements allocated
@@ -130,7 +133,7 @@ template <typename Array> void Array0_dump(const Array& v, const char* head = ""
 
 template <class T> class GCArraySignedLength_moveable : public GCArray_moveable<T> {
 public:
-  GCArraySignedLength_moveable(){};
+  GCArraySignedLength_moveable() {};
 
 public:
   GCArraySignedLength_moveable(int64_t length, const T& initialElement, bool initialElementSupplied, size_t initialContentsSize = 0,