src/glsl/ast.h

   1 /* -*- c++ -*- */
   2 /*
   3  * Copyright © 2009 Intel Corporation
   4  *
   5  * Permission is hereby granted, free of charge, to any person obtaining a
   6  * copy of this software and associated documentation files (the "Software"),
   7  * to deal in the Software without restriction, including without limitation
   8  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
   9  * and/or sell copies of the Software, and to permit persons to whom the
  10  * Software is furnished to do so, subject to the following conditions:
  11  *
  12  * The above copyright notice and this permission notice (including the next
  13  * paragraph) shall be included in all copies or substantial portions of the
  14  * Software.
  15  *
  16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  19  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  20  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  21  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
  22  * DEALINGS IN THE SOFTWARE.
  23  */
  24
  25 #pragma once
  26 #ifndef AST_H
  27 #define AST_H
  28
  29 #include "list.h"
  30 #include "glsl_parser_extras.h"
  31
  32 struct _mesa_glsl_parse_state;
  33
  34 struct YYLTYPE;
  35
  36 /**
  37  * \defgroup AST Abstract syntax tree node definitions
  38  *
  39  * An abstract syntax tree is generated by the parser.  This is a fairly
  40  * direct representation of the gramma derivation for the source program.
  41  * No symantic checking is done during the generation of the AST.  Only
  42  * syntactic checking is done.  Symantic checking is performed by a later
  43  * stage that converts the AST to a more generic intermediate representation.
  44  *
  45  *@{
  46  */
  47 /**
  48  * Base class of all abstract syntax tree nodes
  49  */
  50 class ast_node {
  51 public:
  52    /* Callers of this ralloc-based new need not call delete. It's
  53     * easier to just ralloc_free 'ctx' (or any of its ancestors). */
  54    static void* operator new(size_t size, void *ctx)
  55    {
  56       void *node;
  57
  58       node = rzalloc_size(ctx, size);
  59       assert(node != NULL);
  60
  61       return node;
  62    }
  63
  64    /* If the user *does* call delete, that's OK, we will just
  65     * ralloc_free in that case. */
  66    static void operator delete(void *table)
  67    {
  68       ralloc_free(table);
  69    }
  70
  71    /**
  72     * Print an AST node in something approximating the original GLSL code
  73     */
  74    virtual void print(void) const;
  75
  76    /**
  77     * Convert the AST node to the high-level intermediate representation
  78     */
  79    virtual ir_rvalue *hir(exec_list *instructions,
  80                           struct _mesa_glsl_parse_state *state);
  81
  82    /**
  83     * Retrieve the source location of an AST node
  84     *
  85     * This function is primarily used to get the source position of an AST node
  86     * into a form that can be passed to \c _mesa_glsl_error.
  87     *
  88     * \sa _mesa_glsl_error, ast_node::set_location
  89     */
  90    struct YYLTYPE get_location(void) const
  91    {
  92       struct YYLTYPE locp;
  93
  94       locp.source = this->location.source;
  95       locp.first_line = this->location.line;
  96       locp.first_column = this->location.column;
  97       locp.last_line = locp.first_line;
  98       locp.last_column = locp.first_column;
  99
 100       return locp;
 101    }
 102
 103    /**
 104     * Set the source location of an AST node from a parser location
 105     *
 106     * \sa ast_node::get_location
 107     */
 108    void set_location(const struct YYLTYPE &locp)
 109    {
 110       this->location.source = locp.source;
 111       this->location.line = locp.first_line;
 112       this->location.column = locp.first_column;
 113    }
 114
 115    /**
 116     * Source location of the AST node.
 117     */
 118    struct {
 119       unsigned source;    /**< GLSL source number. */
 120       unsigned line;      /**< Line number within the source string. */
 121       unsigned column;    /**< Column in the line. */
 122    } location;
 123
 124    exec_node link;
 125
 126 protected:
 127    /**
 128     * The only constructor is protected so that only derived class objects can
 129     * be created.
 130     */
 131    ast_node(void);
 132 };
 133
 134
 135 /**
 136  * Operators for AST expression nodes.
 137  */
 138 enum ast_operators {
 139    ast_assign,
 140    ast_plus,        /**< Unary + operator. */
 141    ast_neg,
 142    ast_add,
 143    ast_sub,
 144    ast_mul,
 145    ast_div,
 146    ast_mod,
 147    ast_lshift,
 148    ast_rshift,
 149    ast_less,
 150    ast_greater,
 151    ast_lequal,
 152    ast_gequal,
 153    ast_equal,
 154    ast_nequal,
 155    ast_bit_and,
 156    ast_bit_xor,
 157    ast_bit_or,
 158    ast_bit_not,
 159    ast_logic_and,
 160    ast_logic_xor,
 161    ast_logic_or,
 162    ast_logic_not,
 163
 164    ast_mul_assign,
 165    ast_div_assign,
 166    ast_mod_assign,
 167    ast_add_assign,
 168    ast_sub_assign,
 169    ast_ls_assign,
 170    ast_rs_assign,
 171    ast_and_assign,
 172    ast_xor_assign,
 173    ast_or_assign,
 174
 175    ast_conditional,
 176
 177    ast_pre_inc,
 178    ast_pre_dec,
 179    ast_post_inc,
 180    ast_post_dec,
 181    ast_field_selection,
 182    ast_array_index,
 183
 184    ast_function_call,
 185
 186    ast_identifier,
 187    ast_int_constant,
 188    ast_uint_constant,
 189    ast_float_constant,
 190    ast_bool_constant,
 191
 192    ast_sequence
 193 };
 194
 195 /**
 196  * Representation of any sort of expression.
 197  */
 198 class ast_expression : public ast_node {
 199 public:
 200    ast_expression(int oper, ast_expression *,
 201                   ast_expression *, ast_expression *);
 202
 203    ast_expression(const char *identifier) :
 204       oper(ast_identifier)
 205    {
 206       subexpressions[0] = NULL;
 207       subexpressions[1] = NULL;
 208       subexpressions[2] = NULL;
 209       primary_expression.identifier = identifier;
 210       this->non_lvalue_description = NULL;
 211    }
 212
 213    static const char *operator_string(enum ast_operators op);
 214
 215    virtual ir_rvalue *hir(exec_list *instructions,
 216                           struct _mesa_glsl_parse_state *state);
 217
 218    virtual void print(void) const;
 219
 220    enum ast_operators oper;
 221
 222    ast_expression *subexpressions[3];
 223
 224    union {
 225       const char *identifier;
 226       int int_constant;
 227       float float_constant;
 228       unsigned uint_constant;
 229       int bool_constant;
 230    } primary_expression;
 231
 232
 233    /**
 234     * List of expressions for an \c ast_sequence or parameters for an
 235     * \c ast_function_call
 236     */
 237    exec_list expressions;
 238
 239    /**
 240     * For things that can't be l-values, this describes what it is.
 241     *
 242     * This text is used by the code that generates IR for assignments to
 243     * detect and emit useful messages for assignments to some things that
 244     * can't be l-values.  For example, pre- or post-incerement expressions.
 245     *
 246     * \note
 247     * This pointer may be \c NULL.
 248     */
 249    const char *non_lvalue_description;
 250 };
 251
 252 class ast_expression_bin : public ast_expression {
 253 public:
 254    ast_expression_bin(int oper, ast_expression *, ast_expression *);
 255
 256    virtual void print(void) const;
 257 };
 258
 259 /**
 260  * Subclass of expressions for function calls
 261  */
 262 class ast_function_expression : public ast_expression {
 263 public:
 264    ast_function_expression(ast_expression *callee)
 265       : ast_expression(ast_function_call, callee,
 266                        NULL, NULL),
 267         cons(false)
 268    {
 269       /* empty */
 270    }
 271
 272    ast_function_expression(class ast_type_specifier *type)
 273       : ast_expression(ast_function_call, (ast_expression *) type,
 274                        NULL, NULL),
 275         cons(true)
 276    {
 277       /* empty */
 278    }
 279
 280    bool is_constructor() const
 281    {
 282       return cons;
 283    }
 284
 285    virtual ir_rvalue *hir(exec_list *instructions,
 286                           struct _mesa_glsl_parse_state *state);
 287
 288 private:
 289    /**
 290     * Is this function call actually a constructor?
 291     */
 292    bool cons;
 293 };
 294
 295
 296 /**
 297  * Number of possible operators for an ast_expression
 298  *
 299  * This is done as a define instead of as an additional value in the enum so
 300  * that the compiler won't generate spurious messages like "warning:
 301  * enumeration value ‘ast_num_operators’ not handled in switch"
 302  */
 303 #define AST_NUM_OPERATORS (ast_sequence + 1)
 304
 305
 306 class ast_compound_statement : public ast_node {
 307 public:
 308    ast_compound_statement(int new_scope, ast_node *statements);
 309    virtual void print(void) const;
 310
 311    virtual ir_rvalue *hir(exec_list *instructions,
 312                           struct _mesa_glsl_parse_state *state);
 313
 314    int new_scope;
 315    exec_list statements;
 316 };
 317
 318 class ast_declaration : public ast_node {
 319 public:
 320    ast_declaration(const char *identifier, bool is_array, ast_expression *array_size,
 321                    ast_expression *initializer);
 322    virtual void print(void) const;
 323
 324    const char *identifier;
 325
 326    bool is_array;
 327    ast_expression *array_size;
 328
 329    ast_expression *initializer;
 330 };
 331
 332
 333 enum {
 334    ast_precision_none = 0, /**< Absence of precision qualifier. */
 335    ast_precision_high,
 336    ast_precision_medium,
 337    ast_precision_low
 338 };
 339
 340 struct ast_type_qualifier {
 341    /* Callers of this ralloc-based new need not call delete. It's
 342     * easier to just ralloc_free 'ctx' (or any of its ancestors). */
 343    static void* operator new(size_t size, void *ctx)
 344    {
 345       void *node;
 346
 347       node = rzalloc_size(ctx, size);
 348       assert(node != NULL);
 349
 350       return node;
 351    }
 352
 353    /* If the user *does* call delete, that's OK, we will just
 354     * ralloc_free in that case. */
 355    static void operator delete(void *table)
 356    {
 357       ralloc_free(table);
 358    }
 359
 360    union {
 361       struct {
 362          unsigned invariant:1;
 363          unsigned constant:1;
 364          unsigned attribute:1;
 365          unsigned varying:1;
 366          unsigned in:1;
 367          unsigned out:1;
 368          unsigned centroid:1;
 369          unsigned uniform:1;
 370          unsigned smooth:1;
 371          unsigned flat:1;
 372          unsigned noperspective:1;
 373
 374          /** \name Layout qualifiers for GL_ARB_fragment_coord_conventions */
 375          /*@{*/
 376          unsigned origin_upper_left:1;
 377          unsigned pixel_center_integer:1;
 378          /*@}*/
 379
 380          /**
 381           * Flag set if GL_ARB_explicit_attrib_location "location" layout
 382           * qualifier is used.
 383           */
 384          unsigned explicit_location:1;
 385          /**
 386           * Flag set if GL_ARB_explicit_attrib_location "index" layout
 387           * qualifier is used.
 388           */
 389          unsigned explicit_index:1;
 390
 391          /** \name Layout qualifiers for GL_AMD_conservative_depth */
 392          /** \{ */
 393          unsigned depth_any:1;
 394          unsigned depth_greater:1;
 395          unsigned depth_less:1;
 396          unsigned depth_unchanged:1;
 397          /** \} */
 398
 399          /** \name Layout qualifiers for GL_ARB_uniform_buffer_object */
 400          /** \{ */
 401          unsigned std140:1;
 402          unsigned shared:1;
 403          unsigned packed:1;
 404          unsigned column_major:1;
 405          unsigned row_major:1;
 406          /** \} */
 407       }
 408       /** \brief Set of flags, accessed by name. */
 409       q;
 410
 411       /** \brief Set of flags, accessed as a bitmask. */
 412       unsigned i;
 413    } flags;
 414
 415    /**
 416     * Location specified via GL_ARB_explicit_attrib_location layout
 417     *
 418     * \note
 419     * This field is only valid if \c explicit_location is set.
 420     */
 421    int location;
 422    /**
 423     * Index specified via GL_ARB_explicit_attrib_location layout
 424     *
 425     * \note
 426     * This field is only valid if \c explicit_index is set.
 427     */
 428    int index;
 429
 430    /**
 431     * Return true if and only if an interpolation qualifier is present.
 432     */
 433    bool has_interpolation() const;
 434
 435    /**
 436     * \brief Return string representation of interpolation qualifier.
 437     *
 438     * If an interpolation qualifier is present, then return that qualifier's
 439     * string representation. Otherwise, return null. For example, if the
 440     * noperspective bit is set, then this returns "noperspective".
 441     *
 442     * If multiple interpolation qualifiers are somehow present, then the
 443     * returned string is undefined but not null.
 444     */
 445    const char *interpolation_string() const;
 446
 447    bool merge_qualifier(YYLTYPE *loc,
 448                         _mesa_glsl_parse_state *state,
 449                         ast_type_qualifier q);
 450 };
 451
 452 class ast_declarator_list;
 453
 454 class ast_struct_specifier : public ast_node {
 455 public:
 456    /**
 457     * \brief Make a shallow copy of an ast_struct_specifier.
 458     *
 459     * Use only if the objects are allocated from the same context and will not
 460     * be modified. Zeros the inherited ast_node's fields.
 461     */
 462    ast_struct_specifier(const ast_struct_specifier& that):
 463       ast_node(), name(that.name), declarations(that.declarations)
 464    {
 465       /* empty */
 466    }
 467
 468    ast_struct_specifier(const char *identifier,
 469                         ast_declarator_list *declarator_list);
 470    virtual void print(void) const;
 471
 472    virtual ir_rvalue *hir(exec_list *instructions,
 473                           struct _mesa_glsl_parse_state *state);
 474
 475    const char *name;
 476    /* List of ast_declarator_list * */
 477    exec_list declarations;
 478 };
 479
 480
 481
 482 class ast_type_specifier : public ast_node {
 483 public:
 484    /**
 485     * \brief Make a shallow copy of an ast_type_specifier, specifying array
 486     *        fields.
 487     *
 488     * Use only if the objects are allocated from the same context and will not
 489     * be modified. Zeros the inherited ast_node's fields.
 490     */
 491    ast_type_specifier(const ast_type_specifier *that, bool is_array,
 492                       ast_expression *array_size)
 493       : ast_node(), type_name(that->type_name), structure(that->structure),
 494         is_array(is_array), array_size(array_size), precision(that->precision),
 495         is_precision_statement(that->is_precision_statement)
 496    {
 497       /* empty */
 498    }
 499
 500    /** Construct a type specifier from a type name */
 501    ast_type_specifier(const char *name)
 502       : type_name(name), structure(NULL),
 503         is_array(false), array_size(NULL), precision(ast_precision_none),
 504         is_precision_statement(false)
 505    {
 506       /* empty */
 507    }
 508
 509    /** Construct a type specifier from a structure definition */
 510    ast_type_specifier(ast_struct_specifier *s)
 511       : type_name(s->name), structure(s),
 512         is_array(false), array_size(NULL), precision(ast_precision_none),
 513         is_precision_statement(false)
 514    {
 515       /* empty */
 516    }
 517
 518    const struct glsl_type *glsl_type(const char **name,
 519                                      struct _mesa_glsl_parse_state *state)
 520       const;
 521
 522    virtual void print(void) const;
 523
 524    ir_rvalue *hir(exec_list *, struct _mesa_glsl_parse_state *);
 525
 526    const char *type_name;
 527    ast_struct_specifier *structure;
 528
 529    bool is_array;
 530    ast_expression *array_size;
 531
 532    unsigned precision:2;
 533
 534    bool is_precision_statement;
 535 };
 536
 537
 538 class ast_fully_specified_type : public ast_node {
 539 public:
 540    virtual void print(void) const;
 541    bool has_qualifiers() const;
 542
 543    ast_type_qualifier qualifier;
 544    ast_type_specifier *specifier;
 545 };
 546
 547
 548 class ast_declarator_list : public ast_node {
 549 public:
 550    ast_declarator_list(ast_fully_specified_type *);
 551    virtual void print(void) const;
 552
 553    virtual ir_rvalue *hir(exec_list *instructions,
 554                           struct _mesa_glsl_parse_state *state);
 555
 556    ast_fully_specified_type *type;
 557    /** List of 'ast_declaration *' */
 558    exec_list declarations;
 559
 560    /**
 561     * Special flag for vertex shader "invariant" declarations.
 562     *
 563     * Vertex shaders can contain "invariant" variable redeclarations that do
 564     * not include a type.  For example, "invariant gl_Position;".  This flag
 565     * is used to note these cases when no type is specified.
 566     */
 567    int invariant;
 568
 569    /**
 570     * Flag indicating that these declarators are in a uniform block,
 571     * allowing UBO type qualifiers.
 572     */
 573    bool ubo_qualifiers_valid;
 574 };
 575
 576
 577 class ast_parameter_declarator : public ast_node {
 578 public:
 579    ast_parameter_declarator() :
 580       type(NULL),
 581       identifier(NULL),
 582       is_array(false),
 583       array_size(NULL),
 584       formal_parameter(false),
 585       is_void(false)
 586    {
 587       /* empty */
 588    }
 589
 590    virtual void print(void) const;
 591
 592    virtual ir_rvalue *hir(exec_list *instructions,
 593                           struct _mesa_glsl_parse_state *state);
 594
 595    ast_fully_specified_type *type;
 596    const char *identifier;
 597    bool is_array;
 598    ast_expression *array_size;
 599
 600    static void parameters_to_hir(exec_list *ast_parameters,
 601                                  bool formal, exec_list *ir_parameters,
 602                                  struct _mesa_glsl_parse_state *state);
 603
 604 private:
 605    /** Is this parameter declaration part of a formal parameter list? */
 606    bool formal_parameter;
 607
 608    /**
 609     * Is this parameter 'void' type?
 610     *
 611     * This field is set by \c ::hir.
 612     */
 613    bool is_void;
 614 };
 615
 616
 617 class ast_function : public ast_node {
 618 public:
 619    ast_function(void);
 620
 621    virtual void print(void) const;
 622
 623    virtual ir_rvalue *hir(exec_list *instructions,
 624                           struct _mesa_glsl_parse_state *state);
 625
 626    ast_fully_specified_type *return_type;
 627    const char *identifier;
 628
 629    exec_list parameters;
 630
 631 private:
 632    /**
 633     * Is this prototype part of the function definition?
 634     *
 635     * Used by ast_function_definition::hir to process the parameters, etc.
 636     * of the function.
 637     *
 638     * \sa ::hir
 639     */
 640    bool is_definition;
 641
 642    /**
 643     * Function signature corresponding to this function prototype instance
 644     *
 645     * Used by ast_function_definition::hir to process the parameters, etc.
 646     * of the function.
 647     *
 648     * \sa ::hir
 649     */
 650    class ir_function_signature *signature;
 651
 652    friend class ast_function_definition;
 653 };
 654
 655
 656 class ast_expression_statement : public ast_node {
 657 public:
 658    ast_expression_statement(ast_expression *);
 659    virtual void print(void) const;
 660
 661    virtual ir_rvalue *hir(exec_list *instructions,
 662                           struct _mesa_glsl_parse_state *state);
 663
 664    ast_expression *expression;
 665 };
 666
 667
 668 class ast_case_label : public ast_node {
 669 public:
 670    ast_case_label(ast_expression *test_value);
 671    virtual void print(void) const;
 672
 673    virtual ir_rvalue *hir(exec_list *instructions,
 674                           struct _mesa_glsl_parse_state *state);
 675
 676    /**
 677     * An test value of NULL means 'default'.
 678     */
 679    ast_expression *test_value;
 680 };
 681
 682
 683 class ast_case_label_list : public ast_node {
 684 public:
 685    ast_case_label_list(void);
 686    virtual void print(void) const;
 687
 688    virtual ir_rvalue *hir(exec_list *instructions,
 689                           struct _mesa_glsl_parse_state *state);
 690
 691    /**
 692     * A list of case labels.
 693     */
 694    exec_list labels;
 695 };
 696
 697
 698 class ast_case_statement : public ast_node {
 699 public:
 700    ast_case_statement(ast_case_label_list *labels);
 701    virtual void print(void) const;
 702
 703    virtual ir_rvalue *hir(exec_list *instructions,
 704                           struct _mesa_glsl_parse_state *state);
 705
 706    ast_case_label_list *labels;
 707
 708    /**
 709     * A list of statements.
 710     */
 711    exec_list stmts;
 712 };
 713
 714
 715 class ast_case_statement_list : public ast_node {
 716 public:
 717    ast_case_statement_list(void);
 718    virtual void print(void) const;
 719
 720    virtual ir_rvalue *hir(exec_list *instructions,
 721                           struct _mesa_glsl_parse_state *state);
 722
 723    /**
 724     * A list of cases.
 725     */
 726    exec_list cases;
 727 };
 728
 729
 730 class ast_switch_body : public ast_node {
 731 public:
 732    ast_switch_body(ast_case_statement_list *stmts);
 733    virtual void print(void) const;
 734
 735    virtual ir_rvalue *hir(exec_list *instructions,
 736                           struct _mesa_glsl_parse_state *state);
 737
 738    ast_case_statement_list *stmts;
 739 };
 740
 741
 742 class ast_selection_statement : public ast_node {
 743 public:
 744    ast_selection_statement(ast_expression *condition,
 745                            ast_node *then_statement,
 746                            ast_node *else_statement);
 747    virtual void print(void) const;
 748
 749    virtual ir_rvalue *hir(exec_list *instructions,
 750                           struct _mesa_glsl_parse_state *state);
 751
 752    ast_expression *condition;
 753    ast_node *then_statement;
 754    ast_node *else_statement;
 755 };
 756
 757
 758 class ast_switch_statement : public ast_node {
 759 public:
 760    ast_switch_statement(ast_expression *test_expression,
 761                         ast_node *body);
 762    virtual void print(void) const;
 763
 764    virtual ir_rvalue *hir(exec_list *instructions,
 765                           struct _mesa_glsl_parse_state *state);
 766
 767    ast_expression *test_expression;
 768    ast_node *body;
 769
 770 protected:
 771    void test_to_hir(exec_list *, struct _mesa_glsl_parse_state *);
 772 };
 773
 774 class ast_iteration_statement : public ast_node {
 775 public:
 776    ast_iteration_statement(int mode, ast_node *init, ast_node *condition,
 777                            ast_expression *rest_expression, ast_node *body);
 778
 779    virtual void print(void) const;
 780
 781    virtual ir_rvalue *hir(exec_list *, struct _mesa_glsl_parse_state *);
 782
 783    enum ast_iteration_modes {
 784       ast_for,
 785       ast_while,
 786       ast_do_while
 787    } mode;
 788
 789
 790    ast_node *init_statement;
 791    ast_node *condition;
 792    ast_expression *rest_expression;
 793
 794    ast_node *body;
 795
 796 private:
 797    /**
 798     * Generate IR from the condition of a loop
 799     *
 800     * This is factored out of ::hir because some loops have the condition
 801     * test at the top (for and while), and others have it at the end (do-while).
 802     */
 803    void condition_to_hir(class ir_loop *, struct _mesa_glsl_parse_state *);
 804 };
 805
 806
 807 class ast_jump_statement : public ast_node {
 808 public:
 809    ast_jump_statement(int mode, ast_expression *return_value);
 810    virtual void print(void) const;
 811
 812    virtual ir_rvalue *hir(exec_list *instructions,
 813                           struct _mesa_glsl_parse_state *state);
 814
 815    enum ast_jump_modes {
 816       ast_continue,
 817       ast_break,
 818       ast_return,
 819       ast_discard
 820    } mode;
 821
 822    ast_expression *opt_return_value;
 823 };
 824
 825
 826 class ast_function_definition : public ast_node {
 827 public:
 828    virtual void print(void) const;
 829
 830    virtual ir_rvalue *hir(exec_list *instructions,
 831                           struct _mesa_glsl_parse_state *state);
 832
 833    ast_function *prototype;
 834    ast_compound_statement *body;
 835 };
 836
 837 class ast_interface_block : public ast_node {
 838 public:
 839    ast_interface_block(ast_type_qualifier layout,
 840                      const char *instance_name,
 841                      ast_expression *array_size)
 842    : layout(layout), block_name(NULL), instance_name(instance_name),
 843      array_size(array_size)
 844    {
 845       /* empty */
 846    }
 847
 848    virtual ir_rvalue *hir(exec_list *instructions,
 849                           struct _mesa_glsl_parse_state *state);
 850
 851    ast_type_qualifier layout;
 852    const char *block_name;
 853
 854    /**
 855     * Declared name of the block instance, if specified.
 856     *
 857     * If the block does not have an instance name, this field will be
 858     * \c NULL.
 859     */
 860    const char *instance_name;
 861
 862    /** List of ast_declarator_list * */
 863    exec_list declarations;
 864
 865    /**
 866     * Declared array size of the block instance
 867     *
 868     * If the block is not declared as an array, this field will be \c NULL.
 869     *
 870     * \note
 871     * A block can only be an array if it also has an instance name.  If this
 872     * field is not \c NULL, ::instance_name must also not be \c NULL.
 873     */
 874    ast_expression *array_size;
 875 };
 876 /*@}*/
 877
 878 extern void
 879 _mesa_ast_to_hir(exec_list *instructions, struct _mesa_glsl_parse_state *state);
 880
 881 extern ir_rvalue *
 882 _mesa_ast_field_selection_to_hir(const ast_expression *expr,
 883                                  exec_list *instructions,
 884                                  struct _mesa_glsl_parse_state *state);
 885
 886 extern ir_rvalue *
 887 _mesa_ast_array_index_to_hir(void *mem_ctx,
 888                              struct _mesa_glsl_parse_state *state,
 889                              ir_rvalue *array, ir_rvalue *idx,
 890                              YYLTYPE &loc, YYLTYPE &idx_loc);
 891
 892 void
 893 emit_function(_mesa_glsl_parse_state *state, ir_function *f);
 894
 895 extern void
 896 check_builtin_array_max_size(const char *name, unsigned size,
 897                              YYLTYPE loc, struct _mesa_glsl_parse_state *state);
 898
 899 #endif /* AST_H */