bc-emit.h

gcc库的原代码,对编程有很大帮助.

/* bc-emit.h - declare entry points for producing object files of bytecodes. */

/* Internal format of symbol table for the object file. */
struct bc_sym
{
  /* Private copy separately malloc'd. */
  char *name;

  /* Symbol has a defined value. */
  unsigned int defined:1;

  /* Symbol has been globalized. */
  unsigned int global:1;

  /* Symbol is common. */
  unsigned int common:1;

  /* Value if defined. */
  unsigned long int val;

  /* Used in internal symbol table structure. */
  struct bc_sym *next;
};


/* List of symbols defined in a particular segment. */
struct bc_segsym
{
  struct bc_sym *sym;
  struct bc_segsym *next;
};


/* List of relocations needed in a particular segment. */
struct bc_segreloc
{
  /* Offset of datum to be relocated. */
  unsigned int offset;

  /* Symbol to be relocated by. */
  struct bc_sym *sym;

  struct bc_segreloc *next;
};


/* Segment of an object file. */
struct bc_seg
{
  /* Size allocated to contents. */
  unsigned int alloc;

  /* Pointer to base of contents. */
  char *data;

  /* Actual size of contents. */
  unsigned int size;

  /* List of symbols defined in this segment. */
  struct bc_segsym *syms;

  /* List of relocations for this segment. */
  struct bc_segreloc *relocs;
};


/* Anonymous bytecode label within a single function. */
struct bc_label
{
  /* Offset of label from start of segment. */
  unsigned int offset;

  /* True when offset is valid. */
  unsigned int defined:1;

  /* Unique bytecode ID, used to determine innermost
     block containment */
  int uid;

  /* Next node in list */
  struct bc_label *next;
};


/* Reference to a bc_label; a list of all such references is kept for
   the function, then when it is finished they are backpatched to
   contain the correct values. */

struct bc_labelref
{
  /* Label referenced. */
  struct bc_label *label;

  /* Code offset of reference. */
  unsigned int offset;

  /* Next labelref in list */
  struct bc_labelref *next;
};



extern void bc_initialize();
extern int bc_begin_function();
extern char *bc_emit_trampoline();
extern void bc_emit_bytecode();
extern void bc_emit_bytecode_const();
extern struct bc_label *bc_get_bytecode_label();
extern int bc_emit_bytecode_labeldef();
extern void bc_emit_bytecode_labelref();
extern void bc_emit_code_labelref();
extern char *bc_end_function();
extern void bc_align_const();
extern void bc_emit_const();
extern void bc_emit_const_skip();
extern int bc_emit_const_labeldef();
extern void bc_emit_const_labelref();
extern void bc_align_data();
extern void bc_emit_data();
extern void bc_emit_data_skip();
extern int bc_emit_data_labeldef();
extern void bc_emit_data_labelref();
extern int bc_define_pointer ();
extern int bc_emit_common();
extern void bc_globalize_label();
extern void bc_text();
extern void bc_data();
extern void bc_align();
extern void bc_emit();
extern void bc_emit_skip();
extern int bc_emit_labeldef();
extern void bc_emit_labelref();
extern void bc_write_file();