slang_compile.c

Mesa is an open-source implementation of the OpenGL specification - a system for rendering interacti

/*
 * Mesa 3-D graphics library
 * Version:  6.5.2
 *
 * Copyright (C) 2005-2006  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 slang_compile.c
 * slang front-end compiler
 * \author Michal Krol
 */

#include "main/imports.h"
#include "main/context.h"
#include "shader/program.h"
#include "shader/programopt.h"
#include "shader/prog_print.h"
#include "shader/prog_parameter.h"
#include "shader/grammar/grammar_mesa.h"
#include "slang_codegen.h"
#include "slang_compile.h"
#include "slang_preprocess.h"
#include "slang_storage.h"
#include "slang_emit.h"
#include "slang_log.h"
#include "slang_mem.h"
#include "slang_vartable.h"
#include "slang_simplify.h"

#include "slang_print.h"

/*
 * This is a straightforward implementation of the slang front-end
 * compiler.  Lots of error-checking functionality is missing but
 * every well-formed shader source should compile successfully and
 * execute as expected. However, some semantically ill-formed shaders
 * may be accepted resulting in undefined behaviour.
 */


/** re-defined below, should be the same though */
#define TYPE_SPECIFIER_COUNT 32


/**
 * Check if the given identifier is legal.
 */
static GLboolean
legal_identifier(slang_atom name)
{
   /* "gl_" is a reserved prefix */
   if (_mesa_strncmp((char *) name, "gl_", 3) == 0) {
      return GL_FALSE;
   }
   return GL_TRUE;
}


/**
 * Allocate storage for a variable of 'size' bytes from given pool.
 * Return the allocated address for the variable.
 */
static GLuint
slang_var_pool_alloc(slang_var_pool * pool, unsigned int size)
{
   const GLuint addr = pool->next_addr;
   pool->next_addr += size;
   return addr;
}

/*
 * slang_code_unit
 */

GLvoid
_slang_code_unit_ctr(slang_code_unit * self,
                     struct slang_code_object_ * object)
{
   _slang_variable_scope_ctr(&self->vars);
   _slang_function_scope_ctr(&self->funs);
   _slang_struct_scope_ctr(&self->structs);
   self->object = object;
}

GLvoid
_slang_code_unit_dtr(slang_code_unit * self)
{
   slang_variable_scope_destruct(&self->vars);
   slang_function_scope_destruct(&self->funs);
   slang_struct_scope_destruct(&self->structs);
}

/*
 * slang_code_object
 */

GLvoid
_slang_code_object_ctr(slang_code_object * self)
{
   GLuint i;

   for (i = 0; i < SLANG_BUILTIN_TOTAL; i++)
      _slang_code_unit_ctr(&self->builtin[i], self);
   _slang_code_unit_ctr(&self->unit, self);
   self->varpool.next_addr = 0;
   slang_atom_pool_construct(&self->atompool);
}

GLvoid
_slang_code_object_dtr(slang_code_object * self)
{
   GLuint i;

   for (i = 0; i < SLANG_BUILTIN_TOTAL; i++)
      _slang_code_unit_dtr(&self->builtin[i]);
   _slang_code_unit_dtr(&self->unit);
   slang_atom_pool_destruct(&self->atompool);
}


/* slang_parse_ctx */

typedef struct slang_parse_ctx_
{
   const byte *I;
   slang_info_log *L;
   int parsing_builtin;
   GLboolean global_scope;   /**< Is object being declared a global? */
   slang_atom_pool *atoms;
   slang_unit_type type;     /**< Vertex vs. Fragment */
   GLuint version;           /**< user-specified (or default) #version */
} slang_parse_ctx;

/* slang_output_ctx */

typedef struct slang_output_ctx_
{
   slang_variable_scope *vars;
   slang_function_scope *funs;
   slang_struct_scope *structs;
   slang_var_pool *global_pool;
   struct gl_program *program;
   slang_var_table *vartable;
   GLuint default_precision[TYPE_SPECIFIER_COUNT];
} slang_output_ctx;

/* _slang_compile() */

static void
parse_identifier_str(slang_parse_ctx * C, char **id)
{
   *id = (char *) C->I;
   C->I += _mesa_strlen(*id) + 1;
}

static slang_atom
parse_identifier(slang_parse_ctx * C)
{
   const char *id;

   id = (const char *) C->I;
   C->I += _mesa_strlen(id) + 1;
   return slang_atom_pool_atom(C->atoms, id);
}

static int
parse_number(slang_parse_ctx * C, int *number)
{
   const int radix = (int) (*C->I++);
   *number = 0;
   while (*C->I != '\0') {
      int digit;
      if (*C->I >= '0' && *C->I <= '9')
         digit = (int) (*C->I - '0');
      else if (*C->I >= 'A' && *C->I <= 'Z')
         digit = (int) (*C->I - 'A') + 10;
      else
         digit = (int) (*C->I - 'a') + 10;
      *number = *number * radix + digit;
      C->I++;
   }
   C->I++;
   if (*number > 65535)
      slang_info_log_warning(C->L, "%d: literal integer overflow.", *number);
   return 1;
}

static int
parse_float(slang_parse_ctx * C, float *number)
{
   char *integral = NULL;
   char *fractional = NULL;
   char *exponent = NULL;
   char *whole = NULL;

   parse_identifier_str(C, &integral);
   parse_identifier_str(C, &fractional);
   parse_identifier_str(C, &exponent);

   whole = (char *) _slang_alloc((_mesa_strlen(integral) +
                                  _mesa_strlen(fractional) +
                                  _mesa_strlen(exponent) + 3) * sizeof(char));
   if (whole == NULL) {
      slang_info_log_memory(C->L);
      return 0;
   }

   slang_string_copy(whole, integral);
   slang_string_concat(whole, ".");
   slang_string_concat(whole, fractional);
   slang_string_concat(whole, "E");
   slang_string_concat(whole, exponent);

   *number = (float) (_mesa_strtod(whole, (char **) NULL));

   _slang_free(whole);

   return 1;
}

/* revision number - increment after each change affecting emitted output */
#define REVISION 4

static int
check_revision(slang_parse_ctx * C)
{
   if (*C->I != REVISION) {
      slang_info_log_error(C->L, "Internal compiler error.");
      return 0;
   }
   C->I++;
   return 1;
}

static int parse_statement(slang_parse_ctx *, slang_output_ctx *,
                           slang_operation *);
static int parse_expression(slang_parse_ctx *, slang_output_ctx *,
                            slang_operation *);
static int parse_type_specifier(slang_parse_ctx *, slang_output_ctx *,
                                slang_type_specifier *);

static GLboolean
parse_array_len(slang_parse_ctx * C, slang_output_ctx * O, GLuint * len)
{
   slang_operation array_size;
   slang_name_space space;
   GLboolean result;

   if (!slang_operation_construct(&array_size))
      return GL_FALSE;
   if (!parse_expression(C, O, &array_size)) {
      slang_operation_destruct(&array_size);
      return GL_FALSE;
   }

   space.funcs = O->funs;
   space.structs = O->structs;
   space.vars = O->vars;

   /* evaluate compile-time expression which is array size */
   _slang_simplify(&array_size, &space, C->atoms);

   if (array_size.type == SLANG_OPER_LITERAL_INT) {
      result = GL_TRUE;
      *len = (GLint) array_size.literal[0];
   } else if (array_size.type == SLANG_OPER_IDENTIFIER) {
      slang_variable *var = _slang_locate_variable(array_size.locals, array_size.a_id, GL_TRUE);
      if (!var) {
         slang_info_log_error(C->L, "undefined variable '%s'",
                              (char *) array_size.a_id);
         result = GL_FALSE;
      } else if (var->type.qualifier == SLANG_QUAL_CONST &&
                 var->type.specifier.type == SLANG_SPEC_INT) {
         if (var->initializer &&
             var->initializer->type == SLANG_OPER_LITERAL_INT) {
            *len = (GLint) var->initializer->literal[0];
            result = GL_TRUE;
         } else {
            slang_info_log_error(C->L, "unable to parse array size declaration");
            result = GL_FALSE;
         }
      } else {
         slang_info_log_error(C->L, "unable to parse array size declaration");
         result = GL_FALSE;
      }
   } else {
      result = GL_FALSE;
   }

   slang_operation_destruct(&array_size);
   return result;
}

static GLboolean
calculate_var_size(slang_parse_ctx * C, slang_output_ctx * O,
                   slang_variable * var)
{
   slang_storage_aggregate agg;

   if (!slang_storage_aggregate_construct(&agg))
      return GL_FALSE;
   if (!_slang_aggregate_variable(&agg, &var->type.specifier, var->array_len,
                                  O->funs, O->structs, O->vars, C->atoms)) {
      slang_storage_aggregate_destruct(&agg);
      return GL_FALSE;
   }
   var->size = _slang_sizeof_aggregate(&agg);
   slang_storage_aggregate_destruct(&agg);
   return GL_TRUE;
}

static GLboolean
convert_to_array(slang_parse_ctx * C, slang_variable * var,
                 const slang_type_specifier * sp)
{
   /* sized array - mark it as array, copy the specifier to the array element and
    * parse the expression */
   var->type.specifier.type = SLANG_SPEC_ARRAY;
   var->type.specifier._array = (slang_type_specifier *)
      _slang_alloc(sizeof(slang_type_specifier));
   if (var->type.specifier._array == NULL) {
      slang_info_log_memory(C->L);
      return GL_FALSE;
   }
   slang_type_specifier_ctr(var->type.specifier._array);
   return slang_type_specifier_copy(var->type.specifier._array, sp);
}

/* structure field */
#define FIELD_NONE 0
#define FIELD_NEXT 1
#define FIELD_ARRAY 2

static GLboolean
parse_struct_field_var(slang_parse_ctx * C, slang_output_ctx * O,
                       slang_variable * var, slang_atom a_name,
                       const slang_type_specifier * sp)
{
   var->a_name = a_name;
   if (var->a_name == SLANG_ATOM_NULL)
      return GL_FALSE;

   switch (*C->I++) {
   case FIELD_NONE:
      if (!slang_type_specifier_copy(&var->type.specifier, sp))
         return GL_FALSE;
      break;
   case FIELD_ARRAY:
      if (!convert_to_array(C, var, sp))
         return GL_FALSE;
      if (!parse_array_len(C, O, &var->array_len))
         return GL_FALSE;
      break;
   default:
      return GL_FALSE;
   }

   return calculate_var_size(C, O, var);
}

static int
parse_struct_field(slang_parse_ctx * C, slang_output_ctx * O,
                   slang_struct * st, slang_type_specifier * sp)
{
   slang_output_ctx o = *O;

   o.structs = st->structs;
   if (!parse_type_specifier(C, &o, sp))
      return 0;

   do {
      slang_atom a_name;
      slang_variable *var = slang_variable_scope_grow(st->fields);
      if (!var) {
         slang_info_log_memory(C->L);
         return 0;
      }
      a_name = parse_identifier(C);
      if (_slang_locate_variable(st->fields, a_name, GL_FALSE)) {
         slang_info_log_error(C->L, "duplicate field '%s'", (char *) a_name);
         return 0;
      }

      if (!parse_struct_field_var(C, &o, var, a_name, sp))
         return 0;
   }
   while (*C->I++ != FIELD_NONE);

   return 1;
}

static int
parse_struct(slang_parse_ctx * C, slang_output_ctx * O, slang_struct ** st)
{
   slang_atom a_name;
   const char *name;

   /* parse struct name (if any) and make sure it is unique in current scope */
   a_name = parse_identifier(C);
   if (a_name == SLANG_ATOM_NULL)
      return 0;

   name = slang_atom_pool_id(C->atoms, a_name);
   if (name[0] != '\0'
       && slang_struct_scope_find(O->structs, a_name, 0) != NULL) {
      slang_info_log_error(C->L, "%s: duplicate type name.", name);
      return 0;
   }

   /* set-up a new struct */
   *st = (slang_struct *) _slang_alloc(sizeof(slang_struct));
   if (*st == NULL) {
      slang_info_log_memory(C->L);
      return 0;
   }
   if (!slang_struct_construct(*st)) {
      _slang_free(*st);
      *st = NULL;
      slang_info_log_memory(C->L);
      return 0;
   }
   (**st).a_name = a_name;
   (**st).structs->outer_scope = O->structs;

   /* parse individual struct fields */
   do {
      slang_type_specifier sp;

      slang_type_specifier_ctr(&sp);
      if (!parse_struct_field(C, O, *st, &sp)) {
         slang_type_specifier_dtr(&sp);
         return 0;
      }
      slang_type_specifier_dtr(&sp);
   }
   while (*C->I++ != FIELD_NONE);

   /* if named struct, copy it to current scope */
   if (name[0] != '\0') {