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, int is_array, ast_expression *array_size,
 321                    ast_expression *initializer);
 322    virtual void print(void) const;
 323
 324    const char *identifier;
 325
 326    int 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    union {
 342       struct {
 343          unsigned invariant:1;
 344          unsigned constant:1;
 345          unsigned attribute:1;
 346          unsigned varying:1;
 347          unsigned in:1;
 348          unsigned out:1;
 349          unsigned centroid:1;
 350          unsigned uniform:1;
 351          unsigned smooth:1;
 352          unsigned flat:1;
 353          unsigned noperspective:1;
 354
 355          /** \name Layout qualifiers for GL_ARB_fragment_coord_conventions */
 356          /*@{*/
 357          unsigned origin_upper_left:1;
 358          unsigned pixel_center_integer:1;
 359          /*@}*/
 360
 361          /**
 362           * Flag set if GL_ARB_explicit_attrib_location "location" layout
 363           * qualifier is used.
 364           */
 365          unsigned explicit_location:1;
 366          /**
 367           * Flag set if GL_ARB_explicit_attrib_location "index" layout
 368           * qualifier is used.
 369           */
 370          unsigned explicit_index:1;
 371
 372          /** \name Layout qualifiers for GL_AMD_conservative_depth */
 373          /** \{ */
 374          unsigned depth_any:1;
 375          unsigned depth_greater:1;
 376          unsigned depth_less:1;
 377          unsigned depth_unchanged:1;
 378          /** \} */
 379       }
 380       /** \brief Set of flags, accessed by name. */
 381       q;
 382
 383       /** \brief Set of flags, accessed as a bitmask. */
 384       unsigned i;
 385    } flags;
 386
 387    /**
 388     * Location specified via GL_ARB_explicit_attrib_location layout
 389     *
 390     * \note
 391     * This field is only valid if \c explicit_location is set.
 392     */
 393    int location;
 394    /**
 395     * Index specified via GL_ARB_explicit_attrib_location layout
 396     *
 397     * \note
 398     * This field is only valid if \c explicit_index is set.
 399     */
 400    int index;
 401
 402    /**
 403     * Return true if and only if an interpolation qualifier is present.
 404     */
 405    bool has_interpolation() const;
 406
 407    /**
 408     * \brief Return string representation of interpolation qualifier.
 409     *
 410     * If an interpolation qualifier is present, then return that qualifier's
 411     * string representation. Otherwise, return null. For example, if the
 412     * noperspective bit is set, then this returns "noperspective".
 413     *
 414     * If multiple interpolation qualifiers are somehow present, then the
 415     * returned string is undefined but not null.
 416     */
 417    const char *interpolation_string() const;
 418 };
 419
 420 class ast_declarator_list;
 421
 422 class ast_struct_specifier : public ast_node {
 423 public:
 424    ast_struct_specifier(const char *identifier,
 425                         ast_declarator_list *declarator_list);
 426    virtual void print(void) const;
 427
 428    virtual ir_rvalue *hir(exec_list *instructions,
 429                           struct _mesa_glsl_parse_state *state);
 430
 431    const char *name;
 432    /* List of ast_declarator_list * */
 433    exec_list declarations;
 434 };
 435
 436
 437
 438 class ast_type_specifier : public ast_node {
 439 public:
 440    /** Construct a type specifier from a type name */
 441    ast_type_specifier(const char *name)
 442       : type_name(name), structure(NULL),
 443         is_array(false), array_size(NULL), precision(ast_precision_none),
 444         is_precision_statement(false)
 445    {
 446       /* empty */
 447    }
 448
 449    /** Construct a type specifier from a structure definition */
 450    ast_type_specifier(ast_struct_specifier *s)
 451       : type_name(s->name), structure(s),
 452         is_array(false), array_size(NULL), precision(ast_precision_none),
 453         is_precision_statement(false)
 454    {
 455       /* empty */
 456    }
 457
 458    const struct glsl_type *glsl_type(const char **name,
 459                                      struct _mesa_glsl_parse_state *state)
 460       const;
 461
 462    virtual void print(void) const;
 463
 464    ir_rvalue *hir(exec_list *, struct _mesa_glsl_parse_state *);
 465
 466    const char *type_name;
 467    ast_struct_specifier *structure;
 468
 469    int is_array;
 470    ast_expression *array_size;
 471
 472    unsigned precision:2;
 473
 474    bool is_precision_statement;
 475 };
 476
 477
 478 class ast_fully_specified_type : public ast_node {
 479 public:
 480    virtual void print(void) const;
 481    bool has_qualifiers() const;
 482
 483    ast_type_qualifier qualifier;
 484    ast_type_specifier *specifier;
 485 };
 486
 487
 488 class ast_declarator_list : public ast_node {
 489 public:
 490    ast_declarator_list(ast_fully_specified_type *);
 491    virtual void print(void) const;
 492
 493    virtual ir_rvalue *hir(exec_list *instructions,
 494                           struct _mesa_glsl_parse_state *state);
 495
 496    ast_fully_specified_type *type;
 497    exec_list declarations;
 498
 499    /**
 500     * Special flag for vertex shader "invariant" declarations.
 501     *
 502     * Vertex shaders can contain "invariant" variable redeclarations that do
 503     * not include a type.  For example, "invariant gl_Position;".  This flag
 504     * is used to note these cases when no type is specified.
 505     */
 506    int invariant;
 507 };
 508
 509
 510 class ast_parameter_declarator : public ast_node {
 511 public:
 512    ast_parameter_declarator()
 513    {
 514       this->identifier = NULL;
 515       this->is_array = false;
 516       this->array_size = 0;
 517    }
 518
 519    virtual void print(void) const;
 520
 521    virtual ir_rvalue *hir(exec_list *instructions,
 522                           struct _mesa_glsl_parse_state *state);
 523
 524    ast_fully_specified_type *type;
 525    const char *identifier;
 526    int is_array;
 527    ast_expression *array_size;
 528
 529    static void parameters_to_hir(exec_list *ast_parameters,
 530                                  bool formal, exec_list *ir_parameters,
 531                                  struct _mesa_glsl_parse_state *state);
 532
 533 private:
 534    /** Is this parameter declaration part of a formal parameter list? */
 535    bool formal_parameter;
 536
 537    /**
 538     * Is this parameter 'void' type?
 539     *
 540     * This field is set by \c ::hir.
 541     */
 542    bool is_void;
 543 };
 544
 545
 546 class ast_function : public ast_node {
 547 public:
 548    ast_function(void);
 549
 550    virtual void print(void) const;
 551
 552    virtual ir_rvalue *hir(exec_list *instructions,
 553                           struct _mesa_glsl_parse_state *state);
 554
 555    ast_fully_specified_type *return_type;
 556    const char *identifier;
 557
 558    exec_list parameters;
 559
 560 private:
 561    /**
 562     * Is this prototype part of the function definition?
 563     *
 564     * Used by ast_function_definition::hir to process the parameters, etc.
 565     * of the function.
 566     *
 567     * \sa ::hir
 568     */
 569    bool is_definition;
 570
 571    /**
 572     * Function signature corresponding to this function prototype instance
 573     *
 574     * Used by ast_function_definition::hir to process the parameters, etc.
 575     * of the function.
 576     *
 577     * \sa ::hir
 578     */
 579    class ir_function_signature *signature;
 580
 581    friend class ast_function_definition;
 582 };
 583
 584
 585 class ast_expression_statement : public ast_node {
 586 public:
 587    ast_expression_statement(ast_expression *);
 588    virtual void print(void) const;
 589
 590    virtual ir_rvalue *hir(exec_list *instructions,
 591                           struct _mesa_glsl_parse_state *state);
 592
 593    ast_expression *expression;
 594 };
 595
 596
 597 class ast_case_label : public ast_node {
 598 public:
 599    ast_case_label(ast_expression *test_value);
 600    virtual void print(void) const;
 601
 602    virtual ir_rvalue *hir(exec_list *instructions,
 603                           struct _mesa_glsl_parse_state *state);
 604
 605    /**
 606     * An test value of NULL means 'default'.
 607     */
 608    ast_expression *test_value;
 609 };
 610
 611
 612 class ast_case_label_list : public ast_node {
 613 public:
 614    ast_case_label_list(void);
 615    virtual void print(void) const;
 616
 617    virtual ir_rvalue *hir(exec_list *instructions,
 618                           struct _mesa_glsl_parse_state *state);
 619
 620    /**
 621     * A list of case labels.
 622     */
 623    exec_list labels;
 624 };
 625
 626
 627 class ast_case_statement : public ast_node {
 628 public:
 629    ast_case_statement(ast_case_label_list *labels);
 630    virtual void print(void) const;
 631
 632    virtual ir_rvalue *hir(exec_list *instructions,
 633                           struct _mesa_glsl_parse_state *state);
 634
 635    ast_case_label_list *labels;
 636
 637    /**
 638     * A list of statements.
 639     */
 640    exec_list stmts;
 641 };
 642
 643
 644 class ast_case_statement_list : public ast_node {
 645 public:
 646    ast_case_statement_list(void);
 647    virtual void print(void) const;
 648
 649    virtual ir_rvalue *hir(exec_list *instructions,
 650                           struct _mesa_glsl_parse_state *state);
 651
 652    /**
 653     * A list of cases.
 654     */
 655    exec_list cases;
 656 };
 657
 658
 659 class ast_switch_body : public ast_node {
 660 public:
 661    ast_switch_body(ast_case_statement_list *stmts);
 662    virtual void print(void) const;
 663
 664    virtual ir_rvalue *hir(exec_list *instructions,
 665                           struct _mesa_glsl_parse_state *state);
 666
 667    ast_case_statement_list *stmts;
 668 };
 669
 670
 671 class ast_selection_statement : public ast_node {
 672 public:
 673    ast_selection_statement(ast_expression *condition,
 674                            ast_node *then_statement,
 675                            ast_node *else_statement);
 676    virtual void print(void) const;
 677
 678    virtual ir_rvalue *hir(exec_list *instructions,
 679                           struct _mesa_glsl_parse_state *state);
 680
 681    ast_expression *condition;
 682    ast_node *then_statement;
 683    ast_node *else_statement;
 684 };
 685
 686
 687 class ast_switch_statement : public ast_node {
 688 public:
 689    ast_switch_statement(ast_expression *test_expression,
 690                         ast_node *body);
 691    virtual void print(void) const;
 692
 693    virtual ir_rvalue *hir(exec_list *instructions,
 694                           struct _mesa_glsl_parse_state *state);
 695
 696    ast_expression *test_expression;
 697    ast_node *body;
 698
 699 protected:
 700    void test_to_hir(exec_list *, struct _mesa_glsl_parse_state *);
 701 };
 702
 703 class ast_iteration_statement : public ast_node {
 704 public:
 705    ast_iteration_statement(int mode, ast_node *init, ast_node *condition,
 706                            ast_expression *rest_expression, ast_node *body);
 707
 708    virtual void print(void) const;
 709
 710    virtual ir_rvalue *hir(exec_list *, struct _mesa_glsl_parse_state *);
 711
 712    enum ast_iteration_modes {
 713       ast_for,
 714       ast_while,
 715       ast_do_while
 716    } mode;
 717
 718
 719    ast_node *init_statement;
 720    ast_node *condition;
 721    ast_expression *rest_expression;
 722
 723    ast_node *body;
 724
 725 private:
 726    /**
 727     * Generate IR from the condition of a loop
 728     *
 729     * This is factored out of ::hir because some loops have the condition
 730     * test at the top (for and while), and others have it at the end (do-while).
 731     */
 732    void condition_to_hir(class ir_loop *, struct _mesa_glsl_parse_state *);
 733 };
 734
 735
 736 class ast_jump_statement : public ast_node {
 737 public:
 738    ast_jump_statement(int mode, ast_expression *return_value);
 739    virtual void print(void) const;
 740
 741    virtual ir_rvalue *hir(exec_list *instructions,
 742                           struct _mesa_glsl_parse_state *state);
 743
 744    enum ast_jump_modes {
 745       ast_continue,
 746       ast_break,
 747       ast_return,
 748       ast_discard
 749    } mode;
 750
 751    ast_expression *opt_return_value;
 752 };
 753
 754
 755 class ast_function_definition : public ast_node {
 756 public:
 757    virtual void print(void) const;
 758
 759    virtual ir_rvalue *hir(exec_list *instructions,
 760                           struct _mesa_glsl_parse_state *state);
 761
 762    ast_function *prototype;
 763    ast_compound_statement *body;
 764 };
 765 /*@}*/
 766
 767 extern void
 768 _mesa_ast_to_hir(exec_list *instructions, struct _mesa_glsl_parse_state *state);
 769
 770 extern ir_rvalue *
 771 _mesa_ast_field_selection_to_hir(const ast_expression *expr,
 772                                  exec_list *instructions,
 773                                  struct _mesa_glsl_parse_state *state);
 774
 775 void
 776 emit_function(_mesa_glsl_parse_state *state, ir_function *f);
 777
 778 #endif /* AST_H */