Embed scm_t_port in scm_t_port_internal

* libguile/ports-internal.h (scm_t_port_internal)
* libguile/ports.h (scm_t_port): Embed scm_t_port in scm_t_port_internal
  so that we have just one allocation.
* libguile/ports-internal.h (SCM_PORT_GET_INTERNAL): Adapt.
* libguile/ports.c (scm_i_port_property, scm_i_set_port_property_x)
  (scm_c_make_port_with_encoding): Adapt.

3 files changed, 7 insertions, 16 deletions

diff --git a/libguile/ports-internal.h b/libguile/ports-internal.h
index 689e61c17..a7d61d405 100644
--- a/libguile/ports-internal.h
+++ b/libguile/ports-internal.h
@@ -226,6 +226,7 @@ typedef struct scm_iconv_descriptors scm_t_iconv_descriptors;
 
 struct scm_port_internal
 {
+  scm_t_port pt;
   unsigned at_stream_start_for_bom_read  : 1;
   unsigned at_stream_start_for_bom_write : 1;
   scm_t_iconv_descriptors *iconv_descriptors;
@@ -236,7 +237,7 @@ typedef struct scm_port_internal scm_t_port_internal;
 
 #define SCM_UNICODE_BOM  0xFEFFUL  /* Unicode byte-order mark */
 
-#define SCM_PORT_GET_INTERNAL(x)  (SCM_PTAB_ENTRY(x)->internal)
+#define SCM_PORT_GET_INTERNAL(x)  ((scm_t_port_internal*) SCM_PTAB_ENTRY(x))
 
 typedef enum scm_t_port_rw_active {
   SCM_PORT_NEITHER = 0,
diff --git a/libguile/ports.c b/libguile/ports.c
index 6003129e2..c3d5f5ee1 100644
--- a/libguile/ports.c
+++ b/libguile/ports.c
@@ -366,15 +366,9 @@ SCM_DEFINE (scm_i_port_property, "%port-property", 2, 0, 0,
             "Return the property of @var{port} associated with @var{key}.")
 #define FUNC_NAME s_scm_i_port_property
 {
-  SCM result;
-  scm_t_port *pt;
-
   SCM_VALIDATE_OPPORT (1, port);
 
-  pt = SCM_PTAB_ENTRY (port);
-  result = scm_assq_ref (pt->internal->alist, key);
-
-  return result;
+  return scm_assq_ref (SCM_PORT_GET_INTERNAL (port)->alist, key);
 }
 #undef FUNC_NAME
 
@@ -383,12 +377,12 @@ SCM_DEFINE (scm_i_set_port_property_x, "%set-port-property!", 3, 0, 0,
             "Set the property of @var{port} associated with @var{key} to @var{value}.")
 #define FUNC_NAME s_scm_i_set_port_property_x
 {
-  scm_t_port *pt;
+  scm_t_port_internal *pti;
 
   SCM_VALIDATE_OPPORT (1, port);
 
-  pt = SCM_PTAB_ENTRY (port);
-  pt->internal->alist = scm_assq_set_x (pt->internal->alist, key, value);
+  pti = SCM_PORT_GET_INTERNAL (port);
+  pti->alist = scm_assq_set_x (pti->alist, key, value);
 
   return SCM_UNSPECIFIED;
 }
@@ -725,15 +719,14 @@ scm_c_make_port_with_encoding (scm_t_bits tag, unsigned long mode_bits,
   scm_t_port_internal *pti;
   scm_t_ptob_descriptor *ptob;
 
-  entry = scm_gc_typed_calloc (scm_t_port);
   pti = scm_gc_typed_calloc (scm_t_port_internal);
+  entry = &pti->pt;
   ptob = scm_c_port_type_ref (SCM_TC2PTOBNUM (tag));
 
   ret = scm_words (tag | mode_bits, 3);
   SCM_SET_CELL_WORD_1 (ret, (scm_t_bits) entry);
   SCM_SET_CELL_WORD_2 (ret, (scm_t_bits) ptob);
 
-  entry->internal = pti;
   entry->file_name = SCM_BOOL_F;
   entry->stream = stream;
   entry->encoding = encoding;
diff --git a/libguile/ports.h b/libguile/ports.h
index 84f4e0183..793523b71 100644
--- a/libguile/ports.h
+++ b/libguile/ports.h
@@ -81,9 +81,6 @@ enum scm_port_buffer_field {
 
 typedef struct 
 {
-  /* Pointer to internal-only port structure. */
-  struct scm_port_internal *internal;
-
   /* Data for the underlying port implementation as a raw C value.  */
   scm_t_bits stream;