replaced alloca() (a.k.a. cvStackAlloc) with AutoBuffer or vector()...

replaced alloca() (a.k.a. cvStackAlloc) with AutoBuffer or vector() everywhere. cvStackAlloc() is still defined, but we do not need alloca() anymore to compile and run OpenCV (fixes #889 and may be some others)

modules/calib3d/src/stereogc.cpp

@@ -483,7 +483,7 @@ icvComputeK( CvStereoGCState* state )
     int x, y, x1, d, i, j, rows = state->left->rows, cols = state->left->cols, n = 0;
     int mind = state->minDisparity, nd = state->numberOfDisparities, maxd = mind + nd;
     int k = MIN(MAX((nd + 2)/4, 3), nd), delta, t, sum = 0;
-    vector<int> _arr(k);
+    std::vector<int> _arr(k+1);
     int *arr = &_arr[0];
 
     for( y = 0; y < rows; y++ )
@@ -902,7 +902,7 @@ CV_IMPL void cvFindStereoCorrespondenceGC( const CvArr* _left, const CvArr* _rig
     icvInitStereoConstTabs();
     icvInitGraySubpix( left, right, state->left, state->right );
     
-    vector<int> disp(state->numberOfDisparities);
+    std::vector<int> disp(state->numberOfDisparities);
     CvMat _disp = cvMat( 1, (int)disp.size(), CV_32S, &disp[0] );
     cvRange( &_disp, state->minDisparity, state->minDisparity + state->numberOfDisparities );
     cvRandShuffle( &_disp, &rng );

modules/core/src/persistence.cpp

@@ -3619,7 +3619,6 @@ icvReadSparseMat( CvFileStorage* fs, CvFileNode* node )
     CvFileNode* sizes_node;
     CvSeqReader reader;
     CvSeq* elements;
-    int* idx;
     int sizes[CV_MAX_DIM_HEAP], dims, elem_type, cn;
     int i;
 
@@ -3645,7 +3644,7 @@ icvReadSparseMat( CvFileStorage* fs, CvFileNode* node )
     mat = cvCreateSparseMat( dims, sizes, elem_type );
 
     cn = CV_MAT_CN(elem_type);
-    idx = (int*)alloca( dims*sizeof(idx[0]) );
+    int idx[CV_MAX_DIM_HEAP];
     elements = data->data.seq;
     cvStartReadRawData( fs, data, &reader );
 

modules/ml/src/rtrees.cpp

@@ -646,7 +646,8 @@ float CvRTrees::predict( const CvMat* sample, const CvMat* missing ) const
     if( nclasses > 0 ) //classification
     {
         int max_nvotes = 0;
-        int* votes = (int*)alloca( sizeof(int)*nclasses );
+        cv::AutoBuffer<int> _votes(nclasses);
+        int* votes = _votes;
         memset( votes, 0, sizeof(*votes)*nclasses );
         for( k = 0; k < ntrees; k++ )
         {
@@ -682,7 +683,8 @@ float CvRTrees::predict_prob( const CvMat* sample, const CvMat* missing) const
 	if( nclasses == 2 ) //classification
     {
         int max_nvotes = 0;
-        int* votes = (int*)alloca( sizeof(int)*nclasses );
+        cv::AutoBuffer<int> _votes(nclasses);
+        int* votes = _votes;
         memset( votes, 0, sizeof(*votes)*nclasses );
         for( k = 0; k < ntrees; k++ )
         {