Major rip-up of internal function insertion interface. The old

_glapi_add_entrypoint has been replaced by a new routine called
_glapi_add_dispatch.  This new routine dynamically assignes dispatch offsets
to functions added.  This allows IHVs to add support for extension functions
that do not have assigned dispatch offsets.

It also means that a driver has no idea what offset will be assigned to a
function.  The vast majority of the changes in this commit account for that.
An additional table, driDispatchRemapTable, is added.  Functions not in the
Linux OpenGL ABI (i.e., anything not in GL 1.2 + ARB_multitexture) has a
fixed offset in this new table.  The entry in this table specifies the
offset in of the function in the real dispatch table.

The internal interface was also bumped from version 20050725 to 20050727.

This has been tested with various programs in progs/demos on:

radeon (Radeon Mobility M6)
r128 (Rage 128 Pro)
mga (G400)

1 files changed, 222 insertions, 90 deletions

diff --git a/src/mesa/glapi/glapi.c b/src/mesa/glapi/glapi.c
index 5132bebaef..47a1f16458 100644
--- a/src/mesa/glapi/glapi.c
+++ b/src/mesa/glapi/glapi.c
@@ -671,14 +671,52 @@ get_static_proc_name( GLuint offset )
 #define DISPATCH_TABLE_SIZE (sizeof(struct _glapi_table) / sizeof(void *) + MAX_EXTENSION_FUNCS)
 
 
-struct name_address_offset {
-   const char *Name;
-   _glapi_proc Address;
-   GLuint Offset;
+/**
+ * Track information about a function added to the GL API.
+ */
+struct _glapi_function {
+   /**
+    * Name of the function.
+    */
+   const char * name;
+
+
+   /**
+    * Text string that describes the types of the parameters passed to the
+    * named function.   Parameter types are converted to characters using the
+    * following rules:
+    *   - 'i' for \c GLint, \c GLuint, and \c GLenum
+    *   - 'p' for any pointer type
+    *   - 'f' for \c GLfloat and \c GLclampf
+    *   - 'd' for \c GLdouble and \c GLclampd
+    */
+   const char * parameter_signature;
+
+
+   /**
+    * Offset in the dispatch table where the pointer to the real function is
+    * located.  If the driver has not requested that the named function be
+    * added to the dispatch table, this will have the value ~0.
+    */
+   unsigned dispatch_offset;
+
+
+   /**
+    * Pointer to the dispatch stub for the named function.
+    * 
+    * \todo
+    * The semantic of this field should be changed slightly.  Currently, it
+    * is always expected to be non-\c NULL.  However, it would be better to
+    * only allocate the entry-point stub when the application requests the
+    * function via \c glXGetProcAddress.  This would save memory for all the
+    * functions that the driver exports but that the application never wants
+    * to call.
+    */
+   _glapi_proc dispatch_stub;
 };
 
 
-static struct name_address_offset ExtEntryTable[MAX_EXTENSION_FUNCS];
+static struct _glapi_function ExtEntryTable[MAX_EXTENSION_FUNCS];
 static GLuint NumExtEntryPoints = 0;
 
 #ifdef USE_SPARC_ASM
@@ -814,76 +852,189 @@ fill_in_entrypoint_offset(_glapi_proc entrypoint, GLuint offset)
 
 
 /**
- * Add a new extension function entrypoint.
- * Return: GL_TRUE = success or GL_FALSE = failure
+ * Generate new entrypoint
+ *
+ * Use a temporary dispatch offset of ~0 (i.e. -1).  Later, when the driver
+ * calls \c _glapi_add_dispatch we'll put in the proper offset.  If that
+ * never happens, and the user calls this function, he'll segfault.  That's
+ * what you get when you try calling a GL function that doesn't really exist.
+ * 
+ * \param funcName  Name of the function to create an entry-point for.
+ * 
+ * \sa _glapi_add_entrypoint
  */
-PUBLIC GLboolean
-_glapi_add_entrypoint(const char *funcName, GLuint offset)
+
+static struct _glapi_function *
+add_function_name( const char * funcName )
 {
-   /* trivial rejection test */
+   struct _glapi_function * entry = NULL;
+   
+   if (NumExtEntryPoints < MAX_EXTENSION_FUNCS) {
+      _glapi_proc entrypoint = generate_entrypoint(~0);
+      if (entrypoint != NULL) {
+	 entry = & ExtEntryTable[NumExtEntryPoints];
+
+	 ExtEntryTable[NumExtEntryPoints].name = str_dup(funcName);
+	 ExtEntryTable[NumExtEntryPoints].parameter_signature = NULL;
+	 ExtEntryTable[NumExtEntryPoints].dispatch_offset = ~0;
+	 ExtEntryTable[NumExtEntryPoints].dispatch_stub = entrypoint;
+	 NumExtEntryPoints++;
+      }
+   }
+
+   return entry;
+}
+
+
+/**
+ * Fill-in the dispatch stub for the named function.
+ * 
+ * This function is intended to be called by a hardware driver.  When called,
+ * a dispatch stub may be created created for the function.  A pointer to this
+ * dispatch function will be returned by glXGetProcAddress.
+ *
+ * \param function_names       Array of pointers to function names that should
+ *                             share a common dispatch offset.
+ * \param parameter_signature  String representing the types of the parameters
+ *                             passed to the named function.  Parameter types
+ *                             are converted to characters using the following
+ *                             rules:
+ *                               - 'i' for \c GLint, \c GLuint, and \c GLenum
+ *                               - 'p' for any pointer type
+ *                               - 'f' for \c GLfloat and \c GLclampf
+ *                               - 'd' for \c GLdouble and \c GLclampd
+ *
+ * \returns
+ * The offset in the dispatch table of the named function.  A pointer to the
+ * driver's implementation of the named function should be stored at
+ * \c dispatch_table[\c offset].
+ *
+ * \sa glXGetProcAddress
+ *
+ * \warning
+ * This function can only handle up to 8 names at a time.  As far as I know,
+ * the maximum number of names ever associated with an existing GL function is
+ * 4 (\c glPointParameterfSGIS, \c glPointParameterfEXT,
+ * \c glPointParameterfARB, and \c glPointParameterf), so this should not be
+ * too painful of a limitation.
+ *
+ * \todo
+ * Determine whether or not \c parameter_signature should be allowed to be
+ * \c NULL.  It doesn't seem like much of a hardship for drivers to have to
+ * pass in an empty string.
+ *
+ * \todo
+ * Determine if code should be added to reject function names that start with
+ * 'glX'.
+ * 
+ * \bug
+ * Add code to compare \c parameter_signature with the parameter signature of
+ * a static function.  In order to do that, we need to find a way to \b get
+ * the parameter signature of a static function.
+ */
+
+PUBLIC int
+_glapi_add_dispatch( const char * const * function_names,
+		     const char * parameter_signature )
+{
+   static int next_dynamic_offset = _gloffset_FIRST_DYNAMIC;
+   const char * const real_sig = (parameter_signature != NULL)
+     ? parameter_signature : "";
+   struct _glapi_function * entry[8];
+   GLboolean is_static[8];
+   unsigned i;
+   unsigned j;
+   int offset = ~0;
+   int new_offset;
+
+
+   (void) memset( is_static, 0, sizeof( is_static ) );
+   (void) memset( entry, 0, sizeof( entry ) );
+
+   for ( i = 0 ; function_names[i] != NULL ; i++ ) {
+      /* Do some trivial validation on the name of the function.
+       */
+
 #ifdef MANGLE
-   if (!funcName || funcName[0] != 'm' || funcName[1] != 'g' || funcName[2] != 'l')
-      return GL_FALSE;
+      if (!function_names[i] || function_names[i][0] != 'm' || function_names[i][1] != 'g' || function_names[i][2] != 'l')
+	return GL_FALSE;
 #else
-   if (!funcName || funcName[0] != 'g' || funcName[1] != 'l')
-      return GL_FALSE;
+      if (!function_names[i] || function_names[i][0] != 'g' || function_names[i][1] != 'l')
+	return GL_FALSE;
 #endif
-
-   /* first check if the named function is already statically present */
-   {
-      GLint index = get_static_proc_offset(funcName);
-      if (index >= 0) {
-         return (GLboolean) ((GLuint) index == offset);  /* bad offset! */
+   
+   
+      /* Determine if the named function already exists.  If the function does
+       * exist, it must have the same parameter signature as the function
+       * being added.
+       */
+
+      new_offset = get_static_proc_offset(function_names[i]);
+      if (new_offset >= 0) {
+	 /* FIXME: Make sure the parameter signatures match!  How do we get
+	  * FIXME: the parameter signature for static functions?
+	  */
+
+	 if ( (offset != ~0) && (new_offset != offset) ) {
+	    return -1;
+	 }
+
+	 is_static[i] = GL_TRUE;
+	 offset = new_offset;
       }
-   }
-
-   /* See if this function has already been dynamically added */
-   {
-      GLuint i;
-      for (i = 0; i < NumExtEntryPoints; i++) {
-         if (strcmp(ExtEntryTable[i].Name, funcName) == 0) {
-            /* function already registered */
-            if (ExtEntryTable[i].Offset == offset) {
-               return GL_TRUE;  /* offsets match */
-            }
-            else if (ExtEntryTable[i].Offset == (GLuint) ~0
-                     && offset < DISPATCH_TABLE_SIZE) {
-               /* need to patch-up the dispatch code */
-               if (offset != (GLuint) ~0) {
-                  fill_in_entrypoint_offset(ExtEntryTable[i].Address, offset);
-                  ExtEntryTable[i].Offset = offset;
-               }
-               return GL_TRUE;
-            }
-            else {
-               return GL_FALSE;  /* bad offset! */
-            }
-         }
+   
+   
+      for ( j = 0 ; j < NumExtEntryPoints ; j++ ) {
+	 if (strcmp(ExtEntryTable[j].name, function_names[i]) == 0) {
+	    /* The offset may be ~0 if the function name was added by
+	     * glXGetProcAddress but never filled in by the driver.
+	     */
+
+	    if (ExtEntryTable[j].dispatch_offset != ~0) {
+	       if (strcmp(real_sig, ExtEntryTable[j].parameter_signature) 
+		   != 0) {
+		  return -1;
+	       }
+
+	       if ( (offset != ~0) && (ExtEntryTable[j].dispatch_offset != offset) ) {
+		  return -1;
+	       }
+
+	       offset = ExtEntryTable[j].dispatch_offset;
+	    }
+	    
+	    entry[i] = & ExtEntryTable[j];
+	    break;
+	 }
       }
    }
 
-   /* This is a new function, try to add it.  */
-   if (NumExtEntryPoints >= MAX_EXTENSION_FUNCS ||
-       offset >= DISPATCH_TABLE_SIZE) {
-      /* No space left */
-      return GL_FALSE;
+
+   if (offset == ~0) {
+      offset = next_dynamic_offset;
+      next_dynamic_offset++;
    }
-   else {
-      _glapi_proc entrypoint = generate_entrypoint(offset);
-      if (!entrypoint)
-         return GL_FALSE; /* couldn't generate assembly */
 
-      /* OK! */
-      ExtEntryTable[NumExtEntryPoints].Name = str_dup(funcName);
-      ExtEntryTable[NumExtEntryPoints].Offset = offset;
-      ExtEntryTable[NumExtEntryPoints].Address = entrypoint;
-      NumExtEntryPoints++;
 
-      return GL_TRUE;  /* success */
-   }
+   for ( i = 0 ; function_names[i] != NULL ; i++ ) {
+      if (! is_static[i] ) {
+	 if (entry[i] == NULL) {
+	    entry[i] = add_function_name( function_names[i] );
+	    if (entry[i] == NULL) {
+	       /* FIXME: Possible memory leak here.
+		*/
+	       return -1;
+	    }
+	 }
+
 
-   /* should never get here, silence compiler warnings */
-   return GL_FALSE;
+	 entry[i]->parameter_signature = str_dup(real_sig);
+	 fill_in_entrypoint_offset(entry[i]->dispatch_stub, offset);
+	 entry[i]->dispatch_offset = offset;
+      }
+   }
+   
+   return offset;
 }
 
 
@@ -896,8 +1047,8 @@ _glapi_get_proc_offset(const char *funcName)
    /* search extension functions first */
    GLuint i;
    for (i = 0; i < NumExtEntryPoints; i++) {
-      if (strcmp(ExtEntryTable[i].Name, funcName) == 0) {
-         return ExtEntryTable[i].Offset;
+      if (strcmp(ExtEntryTable[i].name, funcName) == 0) {
+         return ExtEntryTable[i].dispatch_offset;
       }
    }
 
@@ -915,6 +1066,7 @@ _glapi_get_proc_offset(const char *funcName)
 PUBLIC _glapi_proc
 _glapi_get_proc_address(const char *funcName)
 {
+   struct _glapi_function * entry;
    GLuint i;
 
 #ifdef MANGLE
@@ -927,8 +1079,8 @@ _glapi_get_proc_address(const char *funcName)
 
    /* search extension functions first */
    for (i = 0; i < NumExtEntryPoints; i++) {
-      if (strcmp(ExtEntryTable[i].Name, funcName) == 0) {
-         return ExtEntryTable[i].Address;
+      if (strcmp(ExtEntryTable[i].name, funcName) == 0) {
+         return ExtEntryTable[i].dispatch_stub;
       }
    }
 
@@ -939,28 +1091,8 @@ _glapi_get_proc_address(const char *funcName)
          return func;
    }
 
-   /* generate new entrypoint - use a temporary dispatch offset of
-    * ~0 (i.e. -1).  Later, when the driver calls _glapi_add_entrypoint()
-    * we'll put in the proper offset.  If that never happens, and the
-    * user calls this function, he'll segfault.  That's what you get
-    * when you try calling a GL function that doesn't really exist.
-    */
-   if (NumExtEntryPoints < MAX_EXTENSION_FUNCS) {
-      _glapi_proc entrypoint = generate_entrypoint(~0);
-      if (!entrypoint)
-         return GL_FALSE;
-
-      ExtEntryTable[NumExtEntryPoints].Name = str_dup(funcName);
-      ExtEntryTable[NumExtEntryPoints].Offset = ~0;
-      ExtEntryTable[NumExtEntryPoints].Address = entrypoint;
-      NumExtEntryPoints++;
-
-      return entrypoint;
-   }
-   else {
-      /* no space for new functions! */
-      return NULL;
-   }
+   entry = add_function_name(funcName);
+   return (entry == NULL) ? NULL : entry->dispatch_stub;
 }
 
 
@@ -983,8 +1115,8 @@ _glapi_get_proc_name(GLuint offset)
 
    /* search added extension functions */
    for (i = 0; i < NumExtEntryPoints; i++) {
-      if (ExtEntryTable[i].Offset == offset) {
-         return ExtEntryTable[i].Name;
+      if (ExtEntryTable[i].dispatch_offset == offset) {
+         return ExtEntryTable[i].name;
       }
    }
    return NULL;