Implemented a helper class to retrieve a string value from the stack as a string or generate a formatted string if necessary.

source/Base/Shared.cpp

@@ -24,6 +24,9 @@
 #include <cstring>
 #include <algorithm>
 
+// ------------------------------------------------------------------------------------------------
+#include <sqstdstring.h>
+
 // ------------------------------------------------------------------------------------------------
 namespace SqMod {
 
@@ -37,7 +40,7 @@ PluginCallbacks*    _Clbk = NULL;
 PluginInfo*         _Info = NULL;
 
 /* ------------------------------------------------------------------------------------------------
- * Common buffer to reduce memory allocations. To be immediately copied uppon return!
+ * Common buffer to reduce memory allocations. To be immediately copied upon return!
 */
 static SQChar g_Buffer[4096];
 
@@ -93,6 +96,96 @@ Object BufferToStrObj(const Buffer & b, Uint32 size)
 }
 
 // --------------------------------------------------------------------------------------------
+StackStrF::StackStrF(HSQUIRRELVM vm, SQInteger idx, bool fmt)
+    : mPtr(nullptr)
+    , mLen(-1)
+    , mRes(SQ_OK)
+    , mObj()
+    , mVM(vm)
+{
+    const Int32 top = sq_gettop(vm);
+    // Reset the converted value object
+    sq_resetobject(&mObj);
+    // Was the string or value specified?
+    if (top <= (idx - 1))
+    {
+        mRes = sq_throwerror(vm, "Missing string or value");
+    }
+    // Do we have enough values to call the format function and are we allowed to?
+    else if (top > idx && fmt)
+    {
+        // Pointer to the generated string
+        SStr str = nullptr;
+        // Attempt to generate the specified string format
+        mRes = sqstd_format(vm, idx, &mLen, &str);
+        // Did the format succeeded but ended up with a null string pointer?
+        if (SQ_SUCCEEDED(mRes) && !str)
+        {
+            mRes = sq_throwerror(vm, "Unable to generate the string");
+        }
+        else
+        {
+            mPtr = const_cast< CSStr >(str);
+        }
+    }
+    // Is the value on the stack an actual string?
+    else if (sq_gettype(vm, idx) == OT_STRING)
+    {
+        // Obtain a reference to the string object
+        mRes = sq_getstackobj(vm, idx, &mObj);
+        // Could we retrieve the object from the stack?
+        if (SQ_SUCCEEDED(mRes))
+        {
+            // Keep a strong reference to the object
+            sq_addref(vm, &mObj);
+            // Attempt to retrieve the string value from the stack
+            mRes = sq_getstring(vm, idx, &mPtr);
+        }
+        // Did the retrieval succeeded but ended up with a null string pointer?
+        if (SQ_SUCCEEDED(mRes) && !mPtr)
+        {
+            mRes = sq_throwerror(vm, "Unable to retrieve the string");
+        }
+    }
+    // We have to try and convert it to string
+    else
+    {
+        // Attempt to convert the value from the stack to a string
+        mRes = sq_tostring(vm, idx);
+        // Could we convert the specified value to string?
+        if (SQ_SUCCEEDED(mRes))
+        {
+            // Obtain a reference to the resulted object
+            mRes = sq_getstackobj(vm, -1, &mObj);
+            // Could we retrieve the object from the stack?
+            if (SQ_SUCCEEDED(mRes))
+            {
+                // Keep a strong reference to the object
+                sq_addref(vm, &mObj);
+                // Attempt to obtain the string pointer
+                mRes = sq_getstring(vm, -1, &mPtr);
+            }
+        }
+        // Pop a value from the stack regardless of the result
+        sq_pop(vm, 1);
+        // Did the retrieval succeeded but ended up with a null string pointer?
+        if (SQ_SUCCEEDED(mRes) && !mPtr)
+        {
+            mRes = sq_throwerror(vm, "Unable to retrieve the value");
+        }
+    }
+}
+
+// ------------------------------------------------------------------------------------------------
+StackStrF::~StackStrF()
+{
+    if (mVM && !sq_isnull(mObj))
+    {
+        sq_release(mVM, &mObj);
+    }
+}
+
+// ------------------------------------------------------------------------------------------------
 bool SToB(CSStr str)
 {
     return (strcmp(str, "true") == 0 || strcmp(str, "yes") == 0 ||

source/Base/Shared.hpp

@@ -82,6 +82,49 @@ private:
     HSQUIRRELVM m_VM; /* The VM where the stack should be restored. */
 };
 
+/* ------------------------------------------------------------------------------------------------
+ * Helper structure for retrieving a value from the stack as a string or a formatted string.
+*/
+struct StackStrF
+{
+    // --------------------------------------------------------------------------------------------
+    CSStr       mPtr; // Pointer to the C string that was retrieved.
+    SQInteger   mLen; // The string length if it could be retrieved.
+    SQRESULT    mRes; // The result of the retrieval attempts.
+    HSQOBJECT   mObj; // Strong reference to the string object.
+    HSQUIRRELVM mVM; // The associated virtual machine.
+
+    /* --------------------------------------------------------------------------------------------
+     * Base constructor.
+    */
+    StackStrF(HSQUIRRELVM vm, SQInteger idx, bool fmt = true);
+
+    /* --------------------------------------------------------------------------------------------
+     * Copy constructor. (disabled)
+    */
+    StackStrF(const StackStrF & o) = delete;
+
+    /* --------------------------------------------------------------------------------------------
+     * Copy constructor. (disabled)
+    */
+    StackStrF(StackStrF && o) = delete;
+
+    /* --------------------------------------------------------------------------------------------
+     * Destructor.
+    */
+    ~StackStrF();
+
+    /* --------------------------------------------------------------------------------------------
+     * Copy constructor. (disabled)
+    */
+    StackStrF & operator = (const StackStrF & o) = delete;
+
+    /* --------------------------------------------------------------------------------------------
+     * Copy constructor. (disabled)
+    */
+    StackStrF & operator = (StackStrF && o) = delete;
+};
+
 /* ------------------------------------------------------------------------------------------------
  * Perform an equality comparison between two values taking into account floating point issues.
 */
@@ -241,14 +284,12 @@ Object BufferToStrObj(const Buffer & b, Uint32 size);
 */
 template < typename T > Object MakeObject(const T & v)
 {
+    // Remember the current stack size
+    const StackGuard sg;
     // Transform the specified value into a script object
     PushVar< T >(DefaultVM::Get(), v);
-    // Get the object from the stack to obtain a strong reference to it
+    // Get the object from the stack and return it
-    Var< Object > var(DefaultVM::Get(), -1);
+    return Var< Object >(DefaultVM::Get(), -1).value;
-    // Now it's safe to pop the object from the stack
-    sq_pop(DefaultVM::Get(), 1);
-    // Return the resulted script object
-    return var.value;
 }
 
 /* ------------------------------------------------------------------------------------------------
@@ -256,14 +297,12 @@ template < typename T > Object MakeObject(const T & v)
 */
 template < typename T > Object MakeObject(HSQUIRRELVM vm, const T & v)
 {
+    // Remember the current stack size
+    const StackGuard sg;
     // Transform the specified value into a script object
     PushVar< T >(vm, v);
-    // Get the object from the stack to obtain a strong reference to it
+    // Get the object from the stack and return it
-    Var< Object > var(vm, -1);
+    return Var< Object >(vm, -1).value;
-    // Now it's safe to pop the object from the stack
-    sq_pop(vm, 1);
-    // Return the resulted script object
-    return var.value;
 }
 
 /* ------------------------------------------------------------------------------------------------