slang_compile.c

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

#define PARAMETER_NONE 0
#define PARAMETER_NEXT 1

/* operator type */
#define OPERATOR_ADDASSIGN 1
#define OPERATOR_SUBASSIGN 2
#define OPERATOR_MULASSIGN 3
#define OPERATOR_DIVASSIGN 4
/*#define OPERATOR_MODASSIGN 5*/
/*#define OPERATOR_LSHASSIGN 6*/
/*#define OPERATOR_RSHASSIGN 7*/
/*#define OPERATOR_ANDASSIGN 8*/
/*#define OPERATOR_XORASSIGN 9*/
/*#define OPERATOR_ORASSIGN 10*/
#define OPERATOR_LOGICALXOR 11
/*#define OPERATOR_BITOR 12*/
/*#define OPERATOR_BITXOR 13*/
/*#define OPERATOR_BITAND 14*/
#define OPERATOR_LESS 15
#define OPERATOR_GREATER 16
#define OPERATOR_LESSEQUAL 17
#define OPERATOR_GREATEREQUAL 18
/*#define OPERATOR_LSHIFT 19*/
/*#define OPERATOR_RSHIFT 20*/
#define OPERATOR_MULTIPLY 21
#define OPERATOR_DIVIDE 22
/*#define OPERATOR_MODULUS 23*/
#define OPERATOR_INCREMENT 24
#define OPERATOR_DECREMENT 25
#define OPERATOR_PLUS 26
#define OPERATOR_MINUS 27
/*#define OPERATOR_COMPLEMENT 28*/
#define OPERATOR_NOT 29

static const struct
{
   unsigned int o_code;
   const char *o_name;
} operator_names[] = {
   {OPERATOR_INCREMENT, "++"},
   {OPERATOR_ADDASSIGN, "+="},
   {OPERATOR_PLUS, "+"},
   {OPERATOR_DECREMENT, "--"},
   {OPERATOR_SUBASSIGN, "-="},
   {OPERATOR_MINUS, "-"},
   {OPERATOR_NOT, "!"},
   {OPERATOR_MULASSIGN, "*="},
   {OPERATOR_MULTIPLY, "*"},
   {OPERATOR_DIVASSIGN, "/="},
   {OPERATOR_DIVIDE, "/"},
   {OPERATOR_LESSEQUAL, "<="},
   /*{ OPERATOR_LSHASSIGN, "<<=" }, */
   /*{ OPERATOR_LSHIFT, "<<" }, */
   {OPERATOR_LESS, "<"},
   {OPERATOR_GREATEREQUAL, ">="},
   /*{ OPERATOR_RSHASSIGN, ">>=" }, */
   /*{ OPERATOR_RSHIFT, ">>" }, */
   {OPERATOR_GREATER, ">"},
   /*{ OPERATOR_MODASSIGN, "%=" }, */
   /*{ OPERATOR_MODULUS, "%" }, */
   /*{ OPERATOR_ANDASSIGN, "&=" }, */
   /*{ OPERATOR_BITAND, "&" }, */
   /*{ OPERATOR_ORASSIGN, "|=" }, */
   /*{ OPERATOR_BITOR, "|" }, */
   /*{ OPERATOR_COMPLEMENT, "~" }, */
   /*{ OPERATOR_XORASSIGN, "^=" }, */
   {OPERATOR_LOGICALXOR, "^^"},
   /*{ OPERATOR_BITXOR, "^" } */
};

static slang_atom
parse_operator_name(slang_parse_ctx * C)
{
   unsigned int i;

   for (i = 0; i < sizeof(operator_names) / sizeof(*operator_names); i++) {
      if (operator_names[i].o_code == (unsigned int) (*C->I)) {
         slang_atom atom =
            slang_atom_pool_atom(C->atoms, operator_names[i].o_name);
         if (atom == SLANG_ATOM_NULL) {
            slang_info_log_memory(C->L);
            return 0;
         }
         C->I++;
         return atom;
      }
   }
   return 0;
}


static int
parse_function_prototype(slang_parse_ctx * C, slang_output_ctx * O,
                         slang_function * func)
{
   /* parse function type and name */
   if (!parse_fully_specified_type(C, O, &func->header.type))
      return 0;
   switch (*C->I++) {
   case FUNCTION_ORDINARY:
      func->kind = SLANG_FUNC_ORDINARY;
      func->header.a_name = parse_identifier(C);
      if (func->header.a_name == SLANG_ATOM_NULL)
         return 0;
      break;
   case FUNCTION_CONSTRUCTOR:
      func->kind = SLANG_FUNC_CONSTRUCTOR;
      if (func->header.type.specifier.type == SLANG_SPEC_STRUCT)
         return 0;
      func->header.a_name =
         slang_atom_pool_atom(C->atoms,
                              slang_type_specifier_type_to_string
                              (func->header.type.specifier.type));
      if (func->header.a_name == SLANG_ATOM_NULL) {
         slang_info_log_memory(C->L);
         return 0;
      }
      break;
   case FUNCTION_OPERATOR:
      func->kind = SLANG_FUNC_OPERATOR;
      func->header.a_name = parse_operator_name(C);
      if (func->header.a_name == SLANG_ATOM_NULL)
         return 0;
      break;
   default:
      return 0;
   }

   if (!legal_identifier(func->header.a_name)) {
      slang_info_log_error(C->L, "illegal function name '%s'",
                           (char *) func->header.a_name);
      return 0;
   }

   /* parse function parameters */
   while (*C->I++ == PARAMETER_NEXT) {
      slang_variable *p = slang_variable_scope_grow(func->parameters);
      if (!p) {
         slang_info_log_memory(C->L);
         return 0;
      }
      if (!parse_parameter_declaration(C, O, p))
         return 0;
   }

   /* if the function returns a value, append a hidden __retVal 'out'
    * parameter that corresponds to the return value.
    */
   if (_slang_function_has_return_value(func)) {
      slang_variable *p = slang_variable_scope_grow(func->parameters);
      slang_atom a_retVal = slang_atom_pool_atom(C->atoms, "__retVal");
      assert(a_retVal);
      p->a_name = a_retVal;
      p->type = func->header.type;
      p->type.qualifier = SLANG_QUAL_OUT;
   }

   /* function formal parameters and local variables share the same
    * scope, so save the information about param count in a seperate
    * place also link the scope to the global variable scope so when a
    * given identifier is not found here, the search process continues
    * in the global space
    */
   func->param_count = func->parameters->num_variables;
   func->parameters->outer_scope = O->vars;

   return 1;
}

static int
parse_function_definition(slang_parse_ctx * C, slang_output_ctx * O,
                          slang_function * func)
{
   slang_output_ctx o = *O;

   if (!parse_function_prototype(C, O, func))
      return 0;

   /* create function's body operation */
   func->body = (slang_operation *) _slang_alloc(sizeof(slang_operation));
   if (func->body == NULL) {
      slang_info_log_memory(C->L);
      return 0;
   }
   if (!slang_operation_construct(func->body)) {
      _slang_free(func->body);
      func->body = NULL;
      slang_info_log_memory(C->L);
      return 0;
   }

   /* to parse the body the parse context is modified in order to
    * capture parsed variables into function's local variable scope
    */
   C->global_scope = GL_FALSE;
   o.vars = func->parameters;
   if (!parse_statement(C, &o, func->body))
      return 0;

   C->global_scope = GL_TRUE;
   return 1;
}

static GLboolean
initialize_global(slang_assemble_ctx * A, slang_variable * var)
{
   slang_operation op_id, op_assign;
   GLboolean result;

   /* construct the left side of assignment */
   if (!slang_operation_construct(&op_id))
      return GL_FALSE;
   op_id.type = SLANG_OPER_IDENTIFIER;
   op_id.a_id = var->a_name;

   /* put the variable into operation's scope */
   op_id.locals->variables =
      (slang_variable **) _slang_alloc(sizeof(slang_variable *));
   if (op_id.locals->variables == NULL) {
      slang_operation_destruct(&op_id);
      return GL_FALSE;
   }
   op_id.locals->num_variables = 1;
   op_id.locals->variables[0] = var;

   /* construct the assignment expression */
   if (!slang_operation_construct(&op_assign)) {
      op_id.locals->num_variables = 0;
      slang_operation_destruct(&op_id);
      return GL_FALSE;
   }
   op_assign.type = SLANG_OPER_ASSIGN;
   op_assign.children =
      (slang_operation *) _slang_alloc(2 * sizeof(slang_operation));
   if (op_assign.children == NULL) {
      slang_operation_destruct(&op_assign);
      op_id.locals->num_variables = 0;
      slang_operation_destruct(&op_id);
      return GL_FALSE;
   }
   op_assign.num_children = 2;
   op_assign.children[0] = op_id;
   op_assign.children[1] = *var->initializer;

   result = 1;

   /* carefully destroy the operations */
   op_assign.num_children = 0;
   _slang_free(op_assign.children);
   op_assign.children = NULL;
   slang_operation_destruct(&op_assign);
   op_id.locals->num_variables = 0;
   slang_operation_destruct(&op_id);

   if (!result)
      return GL_FALSE;

   return GL_TRUE;
}

/* init declarator list */
#define DECLARATOR_NONE 0
#define DECLARATOR_NEXT 1

/* variable declaration */
#define VARIABLE_NONE 0
#define VARIABLE_IDENTIFIER 1
#define VARIABLE_INITIALIZER 2
#define VARIABLE_ARRAY_EXPLICIT 3
#define VARIABLE_ARRAY_UNKNOWN 4


/**
 * Parse the initializer for a variable declaration.
 */
static int
parse_init_declarator(slang_parse_ctx * C, slang_output_ctx * O,
                      const slang_fully_specified_type * type)
{
   slang_variable *var;
   slang_atom a_name;

   /* empty init declatator (without name, e.g. "float ;") */
   if (*C->I++ == VARIABLE_NONE)
      return 1;

   a_name = parse_identifier(C);

   /* check if name is already in this scope */
   if (_slang_locate_variable(O->vars, a_name, GL_FALSE)) {
      slang_info_log_error(C->L,
                   "declaration of '%s' conflicts with previous declaration",
                   (char *) a_name);
      return 0;
   }

   /* make room for the new variable and initialize it */
   var = slang_variable_scope_grow(O->vars);
   if (!var) {
      slang_info_log_memory(C->L);
      return 0;
   }

   /* copy the declarator qualifier type, parse the identifier */
   var->type.qualifier = type->qualifier;
   var->a_name = a_name;
   if (var->a_name == SLANG_ATOM_NULL)
      return 0;

   switch (*C->I++) {
   case VARIABLE_NONE:
      /* simple variable declarator - just copy the specifier */
      if (!slang_type_specifier_copy(&var->type.specifier, &type->specifier))
         return 0;
      break;
   case VARIABLE_INITIALIZER:
      /* initialized variable - copy the specifier and parse the expression */
      if (!slang_type_specifier_copy(&var->type.specifier, &type->specifier))
         return 0;
      var->initializer =
         (slang_operation *) _slang_alloc(sizeof(slang_operation));
      if (var->initializer == NULL) {
         slang_info_log_memory(C->L);
         return 0;
      }
      if (!slang_operation_construct(var->initializer)) {
         _slang_free(var->initializer);
         var->initializer = NULL;
         slang_info_log_memory(C->L);
         return 0;
      }
      if (!parse_expression(C, O, var->initializer))
         return 0;
      break;
   case VARIABLE_ARRAY_UNKNOWN:
      /* unsized array - mark it as array and copy the specifier to
         the array element
      */
      if (!convert_to_array(C, var, &type->specifier))
         return GL_FALSE;
      break;
   case VARIABLE_ARRAY_EXPLICIT:
      if (!convert_to_array(C, var, &type->specifier))
         return GL_FALSE;
      if (!parse_array_len(C, O, &var->array_len))
         return GL_FALSE;
      break;
   default:
      return 0;
   }

   /* allocate global address space for a variable with a known size */
   if (C->global_scope
       && !(var->type.specifier.type == SLANG_SPEC_ARRAY
            && var->array_len == 0)) {
      if (!calculate_var_size(C, O, var))
         return GL_FALSE;
      var->address = slang_var_pool_alloc(O->global_pool, var->size);
   }

   /* emit code for global var decl */
   if (C->global_scope) {
      slang_assemble_ctx A;
      A.atoms = C->atoms;
      A.space.funcs = O->funs;
      A.space.structs = O->structs;
      A.space.vars = O->vars;
      A.program = O->program;
      A.vartable = O->vartable;
      A.log = C->L;
      A.curFuncEndLabel = NULL;
      if (!_slang_codegen_global_variable(&A, var, C->type))
         return 0;
   }

   /* initialize global variable */
   if (C->global_scope) {
      if (var->initializer != NULL) {
         slang_assemble_ctx A;

         A.atoms = C->atoms;
         A.space.funcs = O->funs;
         A.space.structs = O->structs;
         A.space.vars = O->vars;
         if (!initialize_global(&A, var))
            return 0;
      }
   }
   return 1;
}

/**
 * Parse a list of variable declarations.  Each variable may have an
 * initializer.
 */
static int
parse_init_declarator_list(slang_parse_ctx * C, slang_output_ctx * O)
{
   slang_fully_specified_type type;

   /* parse the fully specified type, common to all declarators */
   if (!slang_fully_specified_type_construct(&type))
      return 0;
   if (!parse_fully_specified_type(C, O, &type)) {
      slang_fully_specified_type_destruct(&type);
      return 0;
   }

   /* parse declarators, pass-in the parsed type */
   do {
      if (!parse_init_declarator(C, O, &type)) {
         slang_fully_specified_type_destruct(&type);
         return 0;
      }
   }
   while (*C->I++ == DECLARATOR_NEXT);

   slang_fully_specified_type_destruct(&type);
   return 1;
}


/**
 * Parse a function definition or declaration.
 * \param C  parsing context
 * \param O  output context
 * \param definition if non-zero expect a definition, else a declaration
 * \param parsed_func_ret  returns the parsed function
 * \return GL_TRUE if success, GL_FALSE if failure
 */
static GLboolean
parse_function(slang_parse_ctx * C, slang_output_ctx * O, int definition,
               slang_function ** parsed_func_ret)
{
   slang_function parsed_func, *found_func;

   /* parse function definition/declaration */
   if (!slang_function_construct(&parsed_func))
      return GL_FALSE;
   if (definition) {
      if (!parse_function_definition(C, O, &parsed_func)) {
         slang_function_destruct(&parsed_func);
         return GL_FALSE;
      }
   }
   else {
      if (!parse_function_prototype(C, O, &parsed_func)) {
         slang_function_destruct(&parsed_func);
         return GL_FALSE;
      }
   }

   /* find a function with a prototype matching the parsed one - only
    * the current scope is being searched to allow built-in function
    * overriding
    */
   found_func = slang_function_scope_find(O->funs, &parsed_func, 0);