2008-04-20 Thomas Koenig <tkoenig@gcc.gnu.org>

	PR libfortran/35960
	* intrinsics/reshape_generic.c (reshape_internal): If the size
	of the resized array is zero, as determined by the SHAPE
	argument, return early.
	* m4/reshape.m4:  Likewise.
	* generated/reshape_i4.c:  Regererated.
	* generated/reshape_i8.c:  Regenerated.
	* generated/reshape_i16.c:  Regenerated.
	* generated/reshape_r4.c:  Regenerated.
	* generated/reshape_r8.c:  Regenerated.
	* generated/reshape_r10.c:  Regenerated.
	* generated/reshape_r16.c:  Regenerated.
	* generated/reshape_c4.c:  Regenerated.
	* generated/reshape_c8.c:  Regenerated.
	* generated/reshape_c10.c:  Regenerated.
	* generated/reshape_c16.c:  Regenerated.

2008-04-20  Thomas Koenig  <tkoenig@gcc.gnu.org>

	PR libfortran/35960
	* gfortran.dg/reshape_zerosize_1.f90:  New file.



git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@134490 138bc75d-0d04-0410-961f-82ee72b054a4

11 files changed, 275 insertions, 88 deletions

diff --git a/libgfortran/generated/reshape_c10.c b/libgfortran/generated/reshape_c10.c
index b9eb754481a..28cad4a0b6e 100644
--- a/libgfortran/generated/reshape_c10.c
+++ b/libgfortran/generated/reshape_c10.c
@@ -81,16 +81,32 @@ reshape_c10 (gfc_array_c10 * const restrict ret,
   const GFC_COMPLEX_10 *src;
   int n;
   int dim;
-  int sempty, pempty;
+  int sempty, pempty, shape_empty;
+  index_type shape_data[GFC_MAX_DIMENSIONS];
+
+  rdim = shape->dim[0].ubound - shape->dim[0].lbound + 1;
+  if (rdim != GFC_DESCRIPTOR_RANK(ret))
+    runtime_error("rank of return array incorrect in RESHAPE intrinsic");
+
+  shape_empty = 0;
+
+  for (n = 0; n < rdim; n++)
+    {
+      shape_data[n] = shape->data[n * shape->dim[0].stride];
+      if (shape_data[n] <= 0)
+      {
+        shape_data[n] = 0;
+	shape_empty = 1;
+      }
+    }
 
   if (ret->data == NULL)
     {
-      rdim = shape->dim[0].ubound - shape->dim[0].lbound + 1;
       rs = 1;
       for (n = 0; n < rdim; n++)
 	{
 	  ret->dim[n].lbound = 0;
-	  rex = shape->data[n * shape->dim[0].stride];
+	  rex = shape_data[n];
 	  ret->dim[n].ubound =  rex - 1;
 	  ret->dim[n].stride = rs;
 	  rs *= rex;
@@ -99,10 +115,9 @@ reshape_c10 (gfc_array_c10 * const restrict ret,
       ret->data = internal_malloc_size ( rs * sizeof (GFC_COMPLEX_10));
       ret->dtype = (source->dtype & ~GFC_DTYPE_RANK_MASK) | rdim;
     }
-  else
-    {
-      rdim = GFC_DESCRIPTOR_RANK (ret);
-    }
+
+  if (shape_empty)
+    return;
 
   rsize = 1;
   for (n = 0; n < rdim; n++)
@@ -115,8 +130,10 @@ reshape_c10 (gfc_array_c10 * const restrict ret,
       rcount[n] = 0;
       rstride[n] = ret->dim[dim].stride;
       rextent[n] = ret->dim[dim].ubound + 1 - ret->dim[dim].lbound;
+      if (rextent[n] < 0)
+        rextent[n] == 0;
 
-      if (rextent[n] != shape->data[dim * shape->dim[0].stride])
+      if (rextent[n] != shape_data[dim])
         runtime_error ("shape and target do not conform");
 
       if (rsize == rstride[n])
diff --git a/libgfortran/generated/reshape_c16.c b/libgfortran/generated/reshape_c16.c
index c9cdaa931a9..ce658dae668 100644
--- a/libgfortran/generated/reshape_c16.c
+++ b/libgfortran/generated/reshape_c16.c
@@ -81,16 +81,32 @@ reshape_c16 (gfc_array_c16 * const restrict ret,
   const GFC_COMPLEX_16 *src;
   int n;
   int dim;
-  int sempty, pempty;
+  int sempty, pempty, shape_empty;
+  index_type shape_data[GFC_MAX_DIMENSIONS];
+
+  rdim = shape->dim[0].ubound - shape->dim[0].lbound + 1;
+  if (rdim != GFC_DESCRIPTOR_RANK(ret))
+    runtime_error("rank of return array incorrect in RESHAPE intrinsic");
+
+  shape_empty = 0;
+
+  for (n = 0; n < rdim; n++)
+    {
+      shape_data[n] = shape->data[n * shape->dim[0].stride];
+      if (shape_data[n] <= 0)
+      {
+        shape_data[n] = 0;
+	shape_empty = 1;
+      }
+    }
 
   if (ret->data == NULL)
     {
-      rdim = shape->dim[0].ubound - shape->dim[0].lbound + 1;
       rs = 1;
       for (n = 0; n < rdim; n++)
 	{
 	  ret->dim[n].lbound = 0;
-	  rex = shape->data[n * shape->dim[0].stride];
+	  rex = shape_data[n];
 	  ret->dim[n].ubound =  rex - 1;
 	  ret->dim[n].stride = rs;
 	  rs *= rex;
@@ -99,10 +115,9 @@ reshape_c16 (gfc_array_c16 * const restrict ret,
       ret->data = internal_malloc_size ( rs * sizeof (GFC_COMPLEX_16));
       ret->dtype = (source->dtype & ~GFC_DTYPE_RANK_MASK) | rdim;
     }
-  else
-    {
-      rdim = GFC_DESCRIPTOR_RANK (ret);
-    }
+
+  if (shape_empty)
+    return;
 
   rsize = 1;
   for (n = 0; n < rdim; n++)
@@ -115,8 +130,10 @@ reshape_c16 (gfc_array_c16 * const restrict ret,
       rcount[n] = 0;
       rstride[n] = ret->dim[dim].stride;
       rextent[n] = ret->dim[dim].ubound + 1 - ret->dim[dim].lbound;
+      if (rextent[n] < 0)
+        rextent[n] == 0;
 
-      if (rextent[n] != shape->data[dim * shape->dim[0].stride])
+      if (rextent[n] != shape_data[dim])
         runtime_error ("shape and target do not conform");
 
       if (rsize == rstride[n])
diff --git a/libgfortran/generated/reshape_c4.c b/libgfortran/generated/reshape_c4.c
index 3d1eac24824..fd33a954a06 100644
--- a/libgfortran/generated/reshape_c4.c
+++ b/libgfortran/generated/reshape_c4.c
@@ -81,16 +81,32 @@ reshape_c4 (gfc_array_c4 * const restrict ret,
   const GFC_COMPLEX_4 *src;
   int n;
   int dim;
-  int sempty, pempty;
+  int sempty, pempty, shape_empty;
+  index_type shape_data[GFC_MAX_DIMENSIONS];
+
+  rdim = shape->dim[0].ubound - shape->dim[0].lbound + 1;
+  if (rdim != GFC_DESCRIPTOR_RANK(ret))
+    runtime_error("rank of return array incorrect in RESHAPE intrinsic");
+
+  shape_empty = 0;
+
+  for (n = 0; n < rdim; n++)
+    {
+      shape_data[n] = shape->data[n * shape->dim[0].stride];
+      if (shape_data[n] <= 0)
+      {
+        shape_data[n] = 0;
+	shape_empty = 1;
+      }
+    }
 
   if (ret->data == NULL)
     {
-      rdim = shape->dim[0].ubound - shape->dim[0].lbound + 1;
       rs = 1;
       for (n = 0; n < rdim; n++)
 	{
 	  ret->dim[n].lbound = 0;
-	  rex = shape->data[n * shape->dim[0].stride];
+	  rex = shape_data[n];
 	  ret->dim[n].ubound =  rex - 1;
 	  ret->dim[n].stride = rs;
 	  rs *= rex;
@@ -99,10 +115,9 @@ reshape_c4 (gfc_array_c4 * const restrict ret,
       ret->data = internal_malloc_size ( rs * sizeof (GFC_COMPLEX_4));
       ret->dtype = (source->dtype & ~GFC_DTYPE_RANK_MASK) | rdim;
     }
-  else
-    {
-      rdim = GFC_DESCRIPTOR_RANK (ret);
-    }
+
+  if (shape_empty)
+    return;
 
   rsize = 1;
   for (n = 0; n < rdim; n++)
@@ -115,8 +130,10 @@ reshape_c4 (gfc_array_c4 * const restrict ret,
       rcount[n] = 0;
       rstride[n] = ret->dim[dim].stride;
       rextent[n] = ret->dim[dim].ubound + 1 - ret->dim[dim].lbound;
+      if (rextent[n] < 0)
+        rextent[n] == 0;
 
-      if (rextent[n] != shape->data[dim * shape->dim[0].stride])
+      if (rextent[n] != shape_data[dim])
         runtime_error ("shape and target do not conform");
 
       if (rsize == rstride[n])
diff --git a/libgfortran/generated/reshape_c8.c b/libgfortran/generated/reshape_c8.c
index 4a4a3e68161..d23cf88c0a3 100644
--- a/libgfortran/generated/reshape_c8.c
+++ b/libgfortran/generated/reshape_c8.c
@@ -81,16 +81,32 @@ reshape_c8 (gfc_array_c8 * const restrict ret,
   const GFC_COMPLEX_8 *src;
   int n;
   int dim;
-  int sempty, pempty;
+  int sempty, pempty, shape_empty;
+  index_type shape_data[GFC_MAX_DIMENSIONS];
+
+  rdim = shape->dim[0].ubound - shape->dim[0].lbound + 1;
+  if (rdim != GFC_DESCRIPTOR_RANK(ret))
+    runtime_error("rank of return array incorrect in RESHAPE intrinsic");
+
+  shape_empty = 0;
+
+  for (n = 0; n < rdim; n++)
+    {
+      shape_data[n] = shape->data[n * shape->dim[0].stride];
+      if (shape_data[n] <= 0)
+      {
+        shape_data[n] = 0;
+	shape_empty = 1;
+      }
+    }
 
   if (ret->data == NULL)
     {
-      rdim = shape->dim[0].ubound - shape->dim[0].lbound + 1;
       rs = 1;
       for (n = 0; n < rdim; n++)
 	{
 	  ret->dim[n].lbound = 0;
-	  rex = shape->data[n * shape->dim[0].stride];
+	  rex = shape_data[n];
 	  ret->dim[n].ubound =  rex - 1;
 	  ret->dim[n].stride = rs;
 	  rs *= rex;
@@ -99,10 +115,9 @@ reshape_c8 (gfc_array_c8 * const restrict ret,
       ret->data = internal_malloc_size ( rs * sizeof (GFC_COMPLEX_8));
       ret->dtype = (source->dtype & ~GFC_DTYPE_RANK_MASK) | rdim;
     }
-  else
-    {
-      rdim = GFC_DESCRIPTOR_RANK (ret);
-    }
+
+  if (shape_empty)
+    return;
 
   rsize = 1;
   for (n = 0; n < rdim; n++)
@@ -115,8 +130,10 @@ reshape_c8 (gfc_array_c8 * const restrict ret,
       rcount[n] = 0;
       rstride[n] = ret->dim[dim].stride;
       rextent[n] = ret->dim[dim].ubound + 1 - ret->dim[dim].lbound;
+      if (rextent[n] < 0)
+        rextent[n] == 0;
 
-      if (rextent[n] != shape->data[dim * shape->dim[0].stride])
+      if (rextent[n] != shape_data[dim])
         runtime_error ("shape and target do not conform");
 
       if (rsize == rstride[n])
diff --git a/libgfortran/generated/reshape_i16.c b/libgfortran/generated/reshape_i16.c
index 9e58dcc3d5a..c9b3694c5de 100644
--- a/libgfortran/generated/reshape_i16.c
+++ b/libgfortran/generated/reshape_i16.c
@@ -81,16 +81,32 @@ reshape_16 (gfc_array_i16 * const restrict ret,
   const GFC_INTEGER_16 *src;
   int n;
   int dim;
-  int sempty, pempty;
+  int sempty, pempty, shape_empty;
+  index_type shape_data[GFC_MAX_DIMENSIONS];
+
+  rdim = shape->dim[0].ubound - shape->dim[0].lbound + 1;
+  if (rdim != GFC_DESCRIPTOR_RANK(ret))
+    runtime_error("rank of return array incorrect in RESHAPE intrinsic");
+
+  shape_empty = 0;
+
+  for (n = 0; n < rdim; n++)
+    {
+      shape_data[n] = shape->data[n * shape->dim[0].stride];
+      if (shape_data[n] <= 0)
+      {
+        shape_data[n] = 0;
+	shape_empty = 1;
+      }
+    }
 
   if (ret->data == NULL)
     {
-      rdim = shape->dim[0].ubound - shape->dim[0].lbound + 1;
       rs = 1;
       for (n = 0; n < rdim; n++)
 	{
 	  ret->dim[n].lbound = 0;
-	  rex = shape->data[n * shape->dim[0].stride];
+	  rex = shape_data[n];
 	  ret->dim[n].ubound =  rex - 1;
 	  ret->dim[n].stride = rs;
 	  rs *= rex;
@@ -99,10 +115,9 @@ reshape_16 (gfc_array_i16 * const restrict ret,
       ret->data = internal_malloc_size ( rs * sizeof (GFC_INTEGER_16));
       ret->dtype = (source->dtype & ~GFC_DTYPE_RANK_MASK) | rdim;
     }
-  else
-    {
-      rdim = GFC_DESCRIPTOR_RANK (ret);
-    }
+
+  if (shape_empty)
+    return;
 
   rsize = 1;
   for (n = 0; n < rdim; n++)
@@ -115,8 +130,10 @@ reshape_16 (gfc_array_i16 * const restrict ret,
       rcount[n] = 0;
       rstride[n] = ret->dim[dim].stride;
       rextent[n] = ret->dim[dim].ubound + 1 - ret->dim[dim].lbound;
+      if (rextent[n] < 0)
+        rextent[n] == 0;
 
-      if (rextent[n] != shape->data[dim * shape->dim[0].stride])
+      if (rextent[n] != shape_data[dim])
         runtime_error ("shape and target do not conform");
 
       if (rsize == rstride[n])
diff --git a/libgfortran/generated/reshape_i4.c b/libgfortran/generated/reshape_i4.c
index b8114123a8a..4a55b68fed6 100644
--- a/libgfortran/generated/reshape_i4.c
+++ b/libgfortran/generated/reshape_i4.c
@@ -81,16 +81,32 @@ reshape_4 (gfc_array_i4 * const restrict ret,
   const GFC_INTEGER_4 *src;
   int n;
   int dim;
-  int sempty, pempty;
+  int sempty, pempty, shape_empty;
+  index_type shape_data[GFC_MAX_DIMENSIONS];
+
+  rdim = shape->dim[0].ubound - shape->dim[0].lbound + 1;
+  if (rdim != GFC_DESCRIPTOR_RANK(ret))
+    runtime_error("rank of return array incorrect in RESHAPE intrinsic");
+
+  shape_empty = 0;
+
+  for (n = 0; n < rdim; n++)
+    {
+      shape_data[n] = shape->data[n * shape->dim[0].stride];
+      if (shape_data[n] <= 0)
+	{
+          shape_data[n] = 0;
+	  shape_empty = 1;
+        }
+    }
 
   if (ret->data == NULL)
     {
-      rdim = shape->dim[0].ubound - shape->dim[0].lbound + 1;
       rs = 1;
       for (n = 0; n < rdim; n++)
 	{
 	  ret->dim[n].lbound = 0;
-	  rex = shape->data[n * shape->dim[0].stride];
+	  rex = shape_data[n];
 	  ret->dim[n].ubound =  rex - 1;
 	  ret->dim[n].stride = rs;
 	  rs *= rex;
@@ -99,10 +115,9 @@ reshape_4 (gfc_array_i4 * const restrict ret,
       ret->data = internal_malloc_size ( rs * sizeof (GFC_INTEGER_4));
       ret->dtype = (source->dtype & ~GFC_DTYPE_RANK_MASK) | rdim;
     }
-  else
-    {
-      rdim = GFC_DESCRIPTOR_RANK (ret);
-    }
+
+  if (shape_empty)
+    return;
 
   rsize = 1;
   for (n = 0; n < rdim; n++)
@@ -115,8 +130,10 @@ reshape_4 (gfc_array_i4 * const restrict ret,
       rcount[n] = 0;
       rstride[n] = ret->dim[dim].stride;
       rextent[n] = ret->dim[dim].ubound + 1 - ret->dim[dim].lbound;
+      if (rextent[n] < 0)
+        rextent[n] == 0;
 
-      if (rextent[n] != shape->data[dim * shape->dim[0].stride])
+      if (rextent[n] != shape_data[dim])
         runtime_error ("shape and target do not conform");
 
       if (rsize == rstride[n])
diff --git a/libgfortran/generated/reshape_i8.c b/libgfortran/generated/reshape_i8.c
index ffec9bb8d6e..d496ca9d7ef 100644
--- a/libgfortran/generated/reshape_i8.c
+++ b/libgfortran/generated/reshape_i8.c
@@ -81,16 +81,32 @@ reshape_8 (gfc_array_i8 * const restrict ret,
   const GFC_INTEGER_8 *src;
   int n;
   int dim;
-  int sempty, pempty;
+  int sempty, pempty, shape_empty;
+  index_type shape_data[GFC_MAX_DIMENSIONS];
+
+  rdim = shape->dim[0].ubound - shape->dim[0].lbound + 1;
+  if (rdim != GFC_DESCRIPTOR_RANK(ret))
+    runtime_error("rank of return array incorrect in RESHAPE intrinsic");
+
+  shape_empty = 0;
+
+  for (n = 0; n < rdim; n++)
+    {
+      shape_data[n] = shape->data[n * shape->dim[0].stride];
+      if (shape_data[n] <= 0)
+      {
+        shape_data[n] = 0;
+	shape_empty = 1;
+      }
+    }
 
   if (ret->data == NULL)
     {
-      rdim = shape->dim[0].ubound - shape->dim[0].lbound + 1;
       rs = 1;
       for (n = 0; n < rdim; n++)
 	{
 	  ret->dim[n].lbound = 0;
-	  rex = shape->data[n * shape->dim[0].stride];
+	  rex = shape_data[n];
 	  ret->dim[n].ubound =  rex - 1;
 	  ret->dim[n].stride = rs;
 	  rs *= rex;
@@ -99,10 +115,9 @@ reshape_8 (gfc_array_i8 * const restrict ret,
       ret->data = internal_malloc_size ( rs * sizeof (GFC_INTEGER_8));
       ret->dtype = (source->dtype & ~GFC_DTYPE_RANK_MASK) | rdim;
     }
-  else
-    {
-      rdim = GFC_DESCRIPTOR_RANK (ret);
-    }
+
+  if (shape_empty)
+    return;
 
   rsize = 1;
   for (n = 0; n < rdim; n++)
@@ -115,8 +130,10 @@ reshape_8 (gfc_array_i8 * const restrict ret,
       rcount[n] = 0;
       rstride[n] = ret->dim[dim].stride;
       rextent[n] = ret->dim[dim].ubound + 1 - ret->dim[dim].lbound;
+      if (rextent[n] < 0)
+        rextent[n] == 0;
 
-      if (rextent[n] != shape->data[dim * shape->dim[0].stride])
+      if (rextent[n] != shape_data[dim])
         runtime_error ("shape and target do not conform");
 
       if (rsize == rstride[n])
diff --git a/libgfortran/generated/reshape_r10.c b/libgfortran/generated/reshape_r10.c
index 8bca529b7c9..61e367c96ce 100644
--- a/libgfortran/generated/reshape_r10.c
+++ b/libgfortran/generated/reshape_r10.c
@@ -81,16 +81,32 @@ reshape_r10 (gfc_array_r10 * const restrict ret,
   const GFC_REAL_10 *src;
   int n;
   int dim;
-  int sempty, pempty;
+  int sempty, pempty, shape_empty;
+  index_type shape_data[GFC_MAX_DIMENSIONS];
+
+  rdim = shape->dim[0].ubound - shape->dim[0].lbound + 1;
+  if (rdim != GFC_DESCRIPTOR_RANK(ret))
+    runtime_error("rank of return array incorrect in RESHAPE intrinsic");
+
+  shape_empty = 0;
+
+  for (n = 0; n < rdim; n++)
+    {
+      shape_data[n] = shape->data[n * shape->dim[0].stride];
+      if (shape_data[n] <= 0)
+      {
+        shape_data[n] = 0;
+	shape_empty = 1;
+      }
+    }
 
   if (ret->data == NULL)
     {
-      rdim = shape->dim[0].ubound - shape->dim[0].lbound + 1;
       rs = 1;
       for (n = 0; n < rdim; n++)
 	{
 	  ret->dim[n].lbound = 0;
-	  rex = shape->data[n * shape->dim[0].stride];
+	  rex = shape_data[n];
 	  ret->dim[n].ubound =  rex - 1;
 	  ret->dim[n].stride = rs;
 	  rs *= rex;
@@ -99,10 +115,9 @@ reshape_r10 (gfc_array_r10 * const restrict ret,
       ret->data = internal_malloc_size ( rs * sizeof (GFC_REAL_10));
       ret->dtype = (source->dtype & ~GFC_DTYPE_RANK_MASK) | rdim;
     }
-  else
-    {
-      rdim = GFC_DESCRIPTOR_RANK (ret);
-    }
+
+  if (shape_empty)
+    return;
 
   rsize = 1;
   for (n = 0; n < rdim; n++)
@@ -115,8 +130,10 @@ reshape_r10 (gfc_array_r10 * const restrict ret,
       rcount[n] = 0;
       rstride[n] = ret->dim[dim].stride;
       rextent[n] = ret->dim[dim].ubound + 1 - ret->dim[dim].lbound;
+      if (rextent[n] < 0)
+        rextent[n] == 0;
 
-      if (rextent[n] != shape->data[dim * shape->dim[0].stride])
+      if (rextent[n] != shape_data[dim])
         runtime_error ("shape and target do not conform");
 
       if (rsize == rstride[n])
diff --git a/libgfortran/generated/reshape_r16.c b/libgfortran/generated/reshape_r16.c
index cd5527297f8..f04fe32c6a8 100644
--- a/libgfortran/generated/reshape_r16.c
+++ b/libgfortran/generated/reshape_r16.c
@@ -81,16 +81,32 @@ reshape_r16 (gfc_array_r16 * const restrict ret,
   const GFC_REAL_16 *src;
   int n;
   int dim;
-  int sempty, pempty;
+  int sempty, pempty, shape_empty;
+  index_type shape_data[GFC_MAX_DIMENSIONS];
+
+  rdim = shape->dim[0].ubound - shape->dim[0].lbound + 1;
+  if (rdim != GFC_DESCRIPTOR_RANK(ret))
+    runtime_error("rank of return array incorrect in RESHAPE intrinsic");
+
+  shape_empty = 0;
+
+  for (n = 0; n < rdim; n++)
+    {
+      shape_data[n] = shape->data[n * shape->dim[0].stride];
+      if (shape_data[n] <= 0)
+      {
+        shape_data[n] = 0;
+	shape_empty = 1;
+      }
+    }
 
   if (ret->data == NULL)
     {
-      rdim = shape->dim[0].ubound - shape->dim[0].lbound + 1;
       rs = 1;
       for (n = 0; n < rdim; n++)
 	{
 	  ret->dim[n].lbound = 0;
-	  rex = shape->data[n * shape->dim[0].stride];
+	  rex = shape_data[n];
 	  ret->dim[n].ubound =  rex - 1;
 	  ret->dim[n].stride = rs;
 	  rs *= rex;
@@ -99,10 +115,9 @@ reshape_r16 (gfc_array_r16 * const restrict ret,
       ret->data = internal_malloc_size ( rs * sizeof (GFC_REAL_16));
       ret->dtype = (source->dtype & ~GFC_DTYPE_RANK_MASK) | rdim;
     }
-  else
-    {
-      rdim = GFC_DESCRIPTOR_RANK (ret);
-    }
+
+  if (shape_empty)
+    return;
 
   rsize = 1;
   for (n = 0; n < rdim; n++)
@@ -115,8 +130,10 @@ reshape_r16 (gfc_array_r16 * const restrict ret,
       rcount[n] = 0;
       rstride[n] = ret->dim[dim].stride;
       rextent[n] = ret->dim[dim].ubound + 1 - ret->dim[dim].lbound;
+      if (rextent[n] < 0)
+        rextent[n] == 0;
 
-      if (rextent[n] != shape->data[dim * shape->dim[0].stride])
+      if (rextent[n] != shape_data[dim])
         runtime_error ("shape and target do not conform");
 
       if (rsize == rstride[n])
diff --git a/libgfortran/generated/reshape_r4.c b/libgfortran/generated/reshape_r4.c
index ace0f4e7728..0323a724624 100644
--- a/libgfortran/generated/reshape_r4.c
+++ b/libgfortran/generated/reshape_r4.c
@@ -81,16 +81,32 @@ reshape_r4 (gfc_array_r4 * const restrict ret,
   const GFC_REAL_4 *src;
   int n;
   int dim;
-  int sempty, pempty;
+  int sempty, pempty, shape_empty;
+  index_type shape_data[GFC_MAX_DIMENSIONS];
+
+  rdim = shape->dim[0].ubound - shape->dim[0].lbound + 1;
+  if (rdim != GFC_DESCRIPTOR_RANK(ret))
+    runtime_error("rank of return array incorrect in RESHAPE intrinsic");
+
+  shape_empty = 0;
+
+  for (n = 0; n < rdim; n++)
+    {
+      shape_data[n] = shape->data[n * shape->dim[0].stride];
+      if (shape_data[n] <= 0)
+      {
+        shape_data[n] = 0;
+	shape_empty = 1;
+      }
+    }
 
   if (ret->data == NULL)
     {
-      rdim = shape->dim[0].ubound - shape->dim[0].lbound + 1;
       rs = 1;
       for (n = 0; n < rdim; n++)
 	{
 	  ret->dim[n].lbound = 0;
-	  rex = shape->data[n * shape->dim[0].stride];
+	  rex = shape_data[n];
 	  ret->dim[n].ubound =  rex - 1;
 	  ret->dim[n].stride = rs;
 	  rs *= rex;
@@ -99,10 +115,9 @@ reshape_r4 (gfc_array_r4 * const restrict ret,
       ret->data = internal_malloc_size ( rs * sizeof (GFC_REAL_4));
       ret->dtype = (source->dtype & ~GFC_DTYPE_RANK_MASK) | rdim;
     }
-  else
-    {
-      rdim = GFC_DESCRIPTOR_RANK (ret);
-    }
+
+  if (shape_empty)
+    return;
 
   rsize = 1;
   for (n = 0; n < rdim; n++)
@@ -115,8 +130,10 @@ reshape_r4 (gfc_array_r4 * const restrict ret,
       rcount[n] = 0;
       rstride[n] = ret->dim[dim].stride;
       rextent[n] = ret->dim[dim].ubound + 1 - ret->dim[dim].lbound;
+      if (rextent[n] < 0)
+        rextent[n] == 0;
 
-      if (rextent[n] != shape->data[dim * shape->dim[0].stride])
+      if (rextent[n] != shape_data[dim])
         runtime_error ("shape and target do not conform");
 
       if (rsize == rstride[n])
diff --git a/libgfortran/generated/reshape_r8.c b/libgfortran/generated/reshape_r8.c
index 8d0fd6619c5..e6be1ef03be 100644
--- a/libgfortran/generated/reshape_r8.c
+++ b/libgfortran/generated/reshape_r8.c
@@ -81,16 +81,32 @@ reshape_r8 (gfc_array_r8 * const restrict ret,
   const GFC_REAL_8 *src;
   int n;
   int dim;
-  int sempty, pempty;
+  int sempty, pempty, shape_empty;
+  index_type shape_data[GFC_MAX_DIMENSIONS];
+
+  rdim = shape->dim[0].ubound - shape->dim[0].lbound + 1;
+  if (rdim != GFC_DESCRIPTOR_RANK(ret))
+    runtime_error("rank of return array incorrect in RESHAPE intrinsic");
+
+  shape_empty = 0;
+
+  for (n = 0; n < rdim; n++)
+    {
+      shape_data[n] = shape->data[n * shape->dim[0].stride];
+      if (shape_data[n] <= 0)
+      {
+        shape_data[n] = 0;
+	shape_empty = 1;
+      }
+    }
 
   if (ret->data == NULL)
     {
-      rdim = shape->dim[0].ubound - shape->dim[0].lbound + 1;
       rs = 1;
       for (n = 0; n < rdim; n++)
 	{
 	  ret->dim[n].lbound = 0;
-	  rex = shape->data[n * shape->dim[0].stride];
+	  rex = shape_data[n];
 	  ret->dim[n].ubound =  rex - 1;
 	  ret->dim[n].stride = rs;
 	  rs *= rex;
@@ -99,10 +115,9 @@ reshape_r8 (gfc_array_r8 * const restrict ret,
       ret->data = internal_malloc_size ( rs * sizeof (GFC_REAL_8));
       ret->dtype = (source->dtype & ~GFC_DTYPE_RANK_MASK) | rdim;
     }
-  else
-    {
-      rdim = GFC_DESCRIPTOR_RANK (ret);
-    }
+
+  if (shape_empty)
+    return;
 
   rsize = 1;
   for (n = 0; n < rdim; n++)
@@ -115,8 +130,10 @@ reshape_r8 (gfc_array_r8 * const restrict ret,
       rcount[n] = 0;
       rstride[n] = ret->dim[dim].stride;
       rextent[n] = ret->dim[dim].ubound + 1 - ret->dim[dim].lbound;
+      if (rextent[n] < 0)
+        rextent[n] == 0;
 
-      if (rextent[n] != shape->data[dim * shape->dim[0].stride])
+      if (rextent[n] != shape_data[dim])
         runtime_error ("shape and target do not conform");
 
       if (rsize == rstride[n])