mesa: refactor: move GetProcAddress code from glapi.c into new glapi_getproc.c file

1 files changed, 615 insertions, 0 deletions

diff --git a/src/mesa/glapi/glapi_getproc.c b/src/mesa/glapi/glapi_getproc.c
new file mode 100644
index 00000000000..92a6fdc3220
--- /dev/null
+++ b/src/mesa/glapi/glapi_getproc.c
@@ -0,0 +1,615 @@
+/*
+ * Mesa 3-D graphics library
+ * Version:  7.1
+ *
+ * Copyright (C) 1999-2008  Brian Paul   All Rights Reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included
+ * in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+ * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
+ * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+/**
+ * \file glapi_getproc.
+ *
+ * Code for implementing glXGetProcAddress(), etc.
+ * This was originally in glapi.c but refactored out.
+ */
+
+
+#include <stdlib.h>
+#include <string.h>
+#include "glheader.h"
+#include "glapi.h"
+#include "glapioffsets.h"
+#include "glapitable.h"
+
+
+/**
+ * strdup() is actually not a standard ANSI C or POSIX routine.
+ * Irix will not define it if ANSI mode is in effect.
+ */
+static char *
+str_dup(const char *str)
+{
+   char *copy;
+   copy = (char*) malloc(strlen(str) + 1);
+   if (!copy)
+      return NULL;
+   strcpy(copy, str);
+   return copy;
+}
+
+
+
+#if defined(USE_X64_64_ASM) && defined(GLX_USE_TLS)
+# define DISPATCH_FUNCTION_SIZE  16
+#elif defined(USE_X86_ASM)
+# if defined(THREADS) && !defined(GLX_USE_TLS)
+#  define DISPATCH_FUNCTION_SIZE  32
+# else
+#  define DISPATCH_FUNCTION_SIZE  16
+# endif
+#endif
+
+#if !defined(DISPATCH_FUNCTION_SIZE) && !defined(XFree86Server) && !defined(XGLServer)
+# define NEED_FUNCTION_POINTER
+#endif
+
+/* The code in this file is auto-generated with Python */
+#include "glprocs.h"
+
+
+/**
+ * Search the table of static entrypoint functions for the named function
+ * and return the corresponding glprocs_table_t entry.
+ */
+static const glprocs_table_t *
+find_entry( const char * n )
+{
+   GLuint i;
+   for (i = 0; static_functions[i].Name_offset >= 0; i++) {
+      const char *testName = gl_string_table + static_functions[i].Name_offset;
+      if (strcmp(testName, n) == 0) {
+	 return &static_functions[i];
+      }
+   }
+   return NULL;
+}
+
+
+/**
+ * Return dispatch table offset of the named static (built-in) function.
+ * Return -1 if function not found.
+ */
+static GLint
+get_static_proc_offset(const char *funcName)
+{
+   const glprocs_table_t * const f = find_entry( funcName );
+   if (f) {
+      return f->Offset;
+   }
+   return -1;
+}
+
+
+#if !defined(XFree86Server) && !defined(XGLServer)
+#ifdef USE_X86_ASM
+
+#if defined( GLX_USE_TLS )
+extern       GLubyte gl_dispatch_functions_start[];
+extern       GLubyte gl_dispatch_functions_end[];
+#else
+extern const GLubyte gl_dispatch_functions_start[];
+#endif
+
+#endif /* USE_X86_ASM */
+
+
+/**
+ * Return dispatch function address for the named static (built-in) function.
+ * Return NULL if function not found.
+ */
+static _glapi_proc
+get_static_proc_address(const char *funcName)
+{
+   const glprocs_table_t * const f = find_entry( funcName );
+   if (f) {
+#if defined(DISPATCH_FUNCTION_SIZE) && defined(GLX_INDIRECT_RENDERING)
+      return (f->Address == NULL)
+	 ? (_glapi_proc) (gl_dispatch_functions_start
+			  + (DISPATCH_FUNCTION_SIZE * f->Offset))
+         : f->Address;
+#elif defined(DISPATCH_FUNCTION_SIZE)
+      return (_glapi_proc) (gl_dispatch_functions_start 
+                            + (DISPATCH_FUNCTION_SIZE * f->Offset));
+#else
+      return f->Address;
+#endif
+   }
+   else {
+      return NULL;
+   }
+}
+
+#endif /* !defined(XFree86Server) && !defined(XGLServer) */
+
+
+
+/**
+ * Return the name of the function at the given offset in the dispatch
+ * table.  For debugging only.
+ */
+static const char *
+get_static_proc_name( GLuint offset )
+{
+   GLuint i;
+   for (i = 0; static_functions[i].Name_offset >= 0; i++) {
+      if (static_functions[i].Offset == offset) {
+	 return gl_string_table + static_functions[i].Name_offset;
+      }
+   }
+   return NULL;
+}
+
+
+
+/**********************************************************************
+ * Extension function management.
+ */
+
+
+/**
+ * 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 _glapi_function ExtEntryTable[MAX_EXTENSION_FUNCS];
+static GLuint NumExtEntryPoints = 0;
+
+#ifdef USE_SPARC_ASM
+extern void __glapi_sparc_icache_flush(unsigned int *);
+#endif
+
+/**
+ * Generate a dispatch function (entrypoint) which jumps through
+ * the given slot number (offset) in the current dispatch table.
+ * We need assembly language in order to accomplish this.
+ */
+static _glapi_proc
+generate_entrypoint(GLuint functionOffset)
+{
+#if defined(USE_X86_ASM)
+   /* 32 is chosen as something of a magic offset.  For x86, the dispatch
+    * at offset 32 is the first one where the offset in the
+    * "jmp OFFSET*4(%eax)" can't be encoded in a single byte.
+    */
+   const GLubyte * const template_func = gl_dispatch_functions_start 
+     + (DISPATCH_FUNCTION_SIZE * 32);
+   GLubyte * const code = (GLubyte *) malloc(DISPATCH_FUNCTION_SIZE);
+
+
+   if ( code != NULL ) {
+      (void) memcpy(code, template_func, DISPATCH_FUNCTION_SIZE);
+      fill_in_entrypoint_offset( (_glapi_proc) code, functionOffset );
+   }
+
+   return (_glapi_proc) code;
+#elif defined(USE_SPARC_ASM)
+
+#ifdef __arch64__
+   static const unsigned int insn_template[] = {
+	   0x05000000,	/* sethi	%uhi(_glapi_Dispatch), %g2	*/
+	   0x03000000,	/* sethi	%hi(_glapi_Dispatch), %g1	*/
+	   0x8410a000,	/* or		%g2, %ulo(_glapi_Dispatch), %g2	*/
+	   0x82106000,	/* or		%g1, %lo(_glapi_Dispatch), %g1	*/
+	   0x8528b020,	/* sllx		%g2, 32, %g2			*/
+	   0xc2584002,	/* ldx		[%g1 + %g2], %g1		*/
+	   0x05000000,	/* sethi	%hi(8 * glapioffset), %g2	*/
+	   0x8410a000,	/* or		%g2, %lo(8 * glapioffset), %g2	*/
+	   0xc6584002,	/* ldx		[%g1 + %g2], %g3		*/
+	   0x81c0c000,	/* jmpl		%g3, %g0			*/
+	   0x01000000	/*  nop						*/
+   };
+#else
+   static const unsigned int insn_template[] = {
+	   0x03000000,	/* sethi	%hi(_glapi_Dispatch), %g1	  */
+	   0xc2006000,	/* ld		[%g1 + %lo(_glapi_Dispatch)], %g1 */
+	   0xc6006000,	/* ld		[%g1 + %lo(4*glapioffset)], %g3	  */
+	   0x81c0c000,	/* jmpl		%g3, %g0			  */
+	   0x01000000	/*  nop						  */
+   };
+#endif /* __arch64__ */
+   unsigned int *code = (unsigned int *) malloc(sizeof(insn_template));
+   unsigned long glapi_addr = (unsigned long) &_glapi_Dispatch;
+   if (code) {
+      memcpy(code, insn_template, sizeof(insn_template));
+
+#ifdef __arch64__
+      code[0] |= (glapi_addr >> (32 + 10));
+      code[1] |= ((glapi_addr & 0xffffffff) >> 10);
+      __glapi_sparc_icache_flush(&code[0]);
+      code[2] |= ((glapi_addr >> 32) & ((1 << 10) - 1));
+      code[3] |= (glapi_addr & ((1 << 10) - 1));
+      __glapi_sparc_icache_flush(&code[2]);
+      code[6] |= ((functionOffset * 8) >> 10);
+      code[7] |= ((functionOffset * 8) & ((1 << 10) - 1));
+      __glapi_sparc_icache_flush(&code[6]);
+#else
+      code[0] |= (glapi_addr >> 10);
+      code[1] |= (glapi_addr & ((1 << 10) - 1));
+      __glapi_sparc_icache_flush(&code[0]);
+      code[2] |= (functionOffset * 4);
+      __glapi_sparc_icache_flush(&code[2]);
+#endif /* __arch64__ */
+   }
+   return (_glapi_proc) code;
+#else
+   (void) functionOffset;
+   return NULL;
+#endif /* USE_*_ASM */
+}
+
+
+/**
+ * This function inserts a new dispatch offset into the assembly language
+ * stub that was generated with the preceeding function.
+ */
+static void
+fill_in_entrypoint_offset(_glapi_proc entrypoint, GLuint offset)
+{
+#if defined(USE_X86_ASM)
+   GLubyte * const code = (GLubyte *) entrypoint;
+
+#if DISPATCH_FUNCTION_SIZE == 32
+   *((unsigned int *)(code + 11)) = 4 * offset;
+   *((unsigned int *)(code + 22)) = 4 * offset;
+#elif DISPATCH_FUNCTION_SIZE == 16 && defined( GLX_USE_TLS )
+   *((unsigned int *)(code +  8)) = 4 * offset;
+#elif DISPATCH_FUNCTION_SIZE == 16
+   *((unsigned int *)(code +  7)) = 4 * offset;
+#else
+# error Invalid DISPATCH_FUNCTION_SIZE!
+#endif
+
+#elif defined(USE_SPARC_ASM)
+
+   /* XXX this hasn't been tested! */
+   unsigned int *code = (unsigned int *) entrypoint;
+#ifdef __arch64__
+   code[6] = 0x05000000;  /* sethi	%hi(8 * glapioffset), %g2	*/
+   code[7] = 0x8410a000;  /* or		%g2, %lo(8 * glapioffset), %g2	*/
+   code[6] |= ((offset * 8) >> 10);
+   code[7] |= ((offset * 8) & ((1 << 10) - 1));
+   __glapi_sparc_icache_flush(&code[6]);
+#else /* __arch64__ */
+   code[2] = 0xc6006000;  /* ld		[%g1 + %lo(4*glapioffset)], %g3	  */
+   code[2] |= (offset * 4);
+   __glapi_sparc_icache_flush(&code[2]);
+#endif /* __arch64__ */
+
+#else
+
+   /* an unimplemented architecture */
+   (void) entrypoint;
+   (void) offset;
+
+#endif /* USE_*_ASM */
+}
+
+
+/**
+ * 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
+ */
+
+static struct _glapi_function *
+add_function_name( const char * funcName )
+{
+   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].  Return -1 if error/problem.
+ *
+ * \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.
+       */
+
+      if (!function_names[i] || function_names[i][0] != 'g' || function_names[i][1] != 'l')
+         return -1;
+   
+      /* 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;
+      }
+   
+   
+      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;
+	 }
+      }
+   }
+
+   if (offset == ~0) {
+      offset = next_dynamic_offset;
+      next_dynamic_offset++;
+   }
+
+   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;
+	    }
+	 }
+
+	 entry[i]->parameter_signature = str_dup(real_sig);
+	 fill_in_entrypoint_offset(entry[i]->dispatch_stub, offset);
+	 entry[i]->dispatch_offset = offset;
+      }
+   }
+   
+   return offset;
+}
+
+
+/**
+ * Return offset of entrypoint for named function within dispatch table.
+ */
+PUBLIC GLint
+_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].dispatch_offset;
+      }
+   }
+   /* search static functions */
+   return get_static_proc_offset(funcName);
+}
+
+
+
+/**
+ * Return pointer to the named function.  If the function name isn't found
+ * in the name of static functions, try generating a new API entrypoint on
+ * the fly with assembly language.
+ */
+_glapi_proc
+_glapi_get_proc_address(const char *funcName)
+{
+   struct _glapi_function * entry;
+   GLuint i;
+
+#ifdef MANGLE
+   if (funcName[0] != 'm' || funcName[1] != 'g' || funcName[2] != 'l')
+      return NULL;
+#else
+   if (funcName[0] != 'g' || funcName[1] != 'l')
+      return NULL;
+#endif
+
+   /* search extension functions first */
+   for (i = 0; i < NumExtEntryPoints; i++) {
+      if (strcmp(ExtEntryTable[i].name, funcName) == 0) {
+         return ExtEntryTable[i].dispatch_stub;
+      }
+   }
+
+#if !defined( XFree86Server ) && !defined( XGLServer )
+   /* search static functions */
+   {
+      const _glapi_proc func = get_static_proc_address(funcName);
+      if (func)
+         return func;
+   }
+#endif /* !defined( XFree86Server ) */
+
+   entry = add_function_name(funcName);
+   return (entry == NULL) ? NULL : entry->dispatch_stub;
+}
+
+
+
+/**
+ * Return the name of the function at the given dispatch offset.
+ * This is only intended for debugging.
+ */
+const char *
+_glapi_get_proc_name(GLuint offset)
+{
+   GLuint i;
+   const char * n;
+
+   /* search built-in functions */
+   n = get_static_proc_name(offset);
+   if ( n != NULL ) {
+      return n;
+   }
+
+   /* search added extension functions */
+   for (i = 0; i < NumExtEntryPoints; i++) {
+      if (ExtEntryTable[i].dispatch_offset == offset) {
+         return ExtEntryTable[i].name;
+      }
+   }
+   return NULL;
+}