tcc.c

小而快的c编译器

/*
 *  TCC - Tiny C Compiler
 * 
 *  Copyright (c) 2001, 2002, 2003 Fabrice Bellard
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */
#define _GNU_SOURCE
#include "config.h"

#include <stdlib.h>
#include <stdio.h>
#include <stdarg.h>
#include <string.h>
#include <errno.h>
#include <math.h>
#include <unistd.h>
#include <signal.h>
#include <unistd.h>
#include <fcntl.h>
#include <setjmp.h>
#include <time.h>
#ifdef WIN32
#include <sys/timeb.h>
#endif
#ifndef WIN32
#include <sys/time.h>
#include <sys/ucontext.h>
#endif
#include "elf.h"
#include "stab.h"
#ifndef CONFIG_TCC_STATIC
#include <dlfcn.h>
#endif

#include "libtcc.h"

/* parser debug */
//#define PARSE_DEBUG
/* preprocessor debug */
//#define PP_DEBUG
/* include file debug */
//#define INC_DEBUG

//#define MEM_DEBUG

/* assembler debug */
//#define ASM_DEBUG

/* target selection */
//#define TCC_TARGET_I386   /* i386 code generator */

/* default target is I386 */
#if !defined(TCC_TARGET_I386)
#define TCC_TARGET_I386
#endif

#if !defined(WIN32) && !defined(TCC_UCLIBC)
#define CONFIG_TCC_BCHECK /* enable bound checking code */
#endif

/* define it to include assembler support */
#define CONFIG_TCC_ASM

/* path to find crt1.o, crti.o and crtn.o. Only needed when generating
   executables or dlls */
#define CONFIG_TCC_CRT_PREFIX "/usr/lib"

#define INCLUDE_STACK_SIZE  32
#define IFDEF_STACK_SIZE    64
#define VSTACK_SIZE         64
#define STRING_MAX_SIZE     1024

#define TOK_HASH_SIZE       2048 /* must be a power of two */
#define TOK_ALLOC_INCR      512  /* must be a power of two */
#define TOK_STR_ALLOC_INCR_BITS 6
#define TOK_STR_ALLOC_INCR (1 << TOK_STR_ALLOC_INCR_BITS)
#define TOK_MAX_SIZE        4 /* token max size in int unit when stored in string */

/* token symbol management */
typedef struct TokenSym {
    struct TokenSym *hash_next;
    struct Sym *sym_define; /* direct pointer to define */
    struct Sym *sym_label; /* direct pointer to label */
    struct Sym *sym_struct; /* direct pointer to structure */
    struct Sym *sym_identifier; /* direct pointer to identifier */
    int tok; /* token number */
    int len;
    char str[1];
} TokenSym;

typedef struct CString {
    int size; /* size in bytes */
    void *data; /* either 'char *' or 'int *' */
    int size_allocated;
    void *data_allocated; /* if non NULL, data has been malloced */
} CString;

/* type definition */
typedef struct CType {
    int t;
    struct Sym *ref;
} CType;

/* constant value */
typedef union CValue {
    long double ld;
    double d;
    float f;
    int i;
    unsigned int ui;
    unsigned int ul; /* address (should be unsigned long on 64 bit cpu) */
    long long ll;
    unsigned long long ull;
    struct CString *cstr;
    void *ptr;
    int tab[1];
} CValue;

/* value on stack */
typedef struct SValue {
    CType type;      /* type */
    unsigned short r;      /* register + flags */
    unsigned short r2;     /* second register, used for 'long long'
                              type. If not used, set to VT_CONST */
    CValue c;              /* constant, if VT_CONST */
    struct Sym *sym;       /* symbol, if (VT_SYM | VT_CONST) */
} SValue;

/* symbol management */
typedef struct Sym {
    int v;    /* symbol token */
    int r;    /* associated register */
    int c;    /* associated number */
    CType type;    /* associated type */
    struct Sym *next; /* next related symbol */
    struct Sym *prev; /* prev symbol in stack */
    struct Sym *prev_tok; /* previous symbol for this token */
} Sym;

/* section definition */
/* XXX: use directly ELF structure for parameters ? */
/* special flag to indicate that the section should not be linked to
   the other ones */
#define SHF_PRIVATE 0x80000000

typedef struct Section {
    unsigned long data_offset; /* current data offset */
    unsigned char *data;       /* section data */
    unsigned long data_allocated; /* used for realloc() handling */
    int sh_name;             /* elf section name (only used during output) */
    int sh_num;              /* elf section number */
    int sh_type;             /* elf section type */
    int sh_flags;            /* elf section flags */
    int sh_info;             /* elf section info */
    int sh_addralign;        /* elf section alignment */
    int sh_entsize;          /* elf entry size */
    unsigned long sh_size;   /* section size (only used during output) */
    unsigned long sh_addr;      /* address at which the section is relocated */
    unsigned long sh_offset;      /* address at which the section is relocated */
    int nb_hashed_syms;      /* used to resize the hash table */
    struct Section *link;    /* link to another section */
    struct Section *reloc;   /* corresponding section for relocation, if any */
    struct Section *hash;     /* hash table for symbols */
    struct Section *next;
    char name[1];           /* section name */
} Section;

typedef struct DLLReference {
    int level;
    char name[1];
} DLLReference;

/* GNUC attribute definition */
typedef struct AttributeDef {
    int aligned;
    Section *section;
    unsigned char func_call; /* FUNC_CDECL or FUNC_STDCALL */
} AttributeDef;

#define SYM_STRUCT     0x40000000 /* struct/union/enum symbol space */
#define SYM_FIELD      0x20000000 /* struct/union field symbol space */
#define SYM_FIRST_ANOM (1 << (31 - VT_STRUCT_SHIFT)) /* first anonymous sym */

/* stored in 'Sym.c' field */
#define FUNC_NEW       1 /* ansi function prototype */
#define FUNC_OLD       2 /* old function prototype */
#define FUNC_ELLIPSIS  3 /* ansi function prototype with ... */

/* stored in 'Sym.r' field */
#define FUNC_CDECL     0 /* standard c call */
#define FUNC_STDCALL   1 /* pascal c call */

/* field 'Sym.t' for macros */
#define MACRO_OBJ      0 /* object like macro */
#define MACRO_FUNC     1 /* function like macro */

/* field 'Sym.r' for C labels */
#define LABEL_DEFINED  0 /* label is defined */
#define LABEL_FORWARD  1 /* label is forward defined */
#define LABEL_DECLARED 2 /* label is declared but never used */

/* type_decl() types */
#define TYPE_ABSTRACT  1 /* type without variable */
#define TYPE_DIRECT    2 /* type with variable */

#define IO_BUF_SIZE 8192

typedef struct BufferedFile {
    uint8_t *buf_ptr;
    uint8_t *buf_end;
    int fd;
    int line_num;    /* current line number - here to simplify code */
    int ifndef_macro;  /* #ifndef macro / #endif search */
    int ifndef_macro_saved; /* saved ifndef_macro */
    int *ifdef_stack_ptr; /* ifdef_stack value at the start of the file */
    char inc_type;          /* type of include */
    char inc_filename[512]; /* filename specified by the user */
    char filename[1024];    /* current filename - here to simplify code */
    unsigned char buffer[IO_BUF_SIZE + 1]; /* extra size for CH_EOB char */
} BufferedFile;

#define CH_EOB   '\\'       /* end of buffer or '\0' char in file */
#define CH_EOF   (-1)   /* end of file */

/* parsing state (used to save parser state to reparse part of the
   source several times) */
typedef struct ParseState {
    int *macro_ptr;
    int line_num;
    int tok;
    CValue tokc;
} ParseState;

/* used to record tokens */
typedef struct TokenString {
    int *str;
    int len;
    int allocated_len;
    int last_line_num;
} TokenString;

/* include file cache, used to find files faster and also to eliminate
   inclusion if the include file is protected by #ifndef ... #endif */
typedef struct CachedInclude {
    int ifndef_macro;
    char type; /* '"' or '>' to give include type */
    char filename[1]; /* path specified in #include */
} CachedInclude;

/* parser */
static struct BufferedFile *file;
static int ch, tok;
static CValue tokc;
static CString tokcstr; /* current parsed string, if any */
/* additional informations about token */
static int tok_flags;
#define TOK_FLAG_BOL   0x0001 /* beginning of line before */
#define TOK_FLAG_BOF   0x0002 /* beginning of file before */
#define TOK_FLAG_ENDIF 0x0004 /* a endif was found matching starting #ifdef */

static int *macro_ptr, *macro_ptr_allocated;
static int *unget_saved_macro_ptr;
static int unget_saved_buffer[TOK_MAX_SIZE + 1];
static int unget_buffer_enabled;
static int parse_flags;
#define PARSE_FLAG_PREPROCESS 0x0001 /* activate preprocessing */
#define PARSE_FLAG_TOK_NUM    0x0002 /* return numbers instead of TOK_PPNUM */
#define PARSE_FLAG_LINEFEED   0x0004 /* line feed is returned as a
                                        token. line feed is also
                                        returned at eof */
 
static Section *text_section, *data_section, *bss_section; /* predefined sections */
static Section *cur_text_section; /* current section where function code is
                              generated */
/* bound check related sections */
static Section *bounds_section; /* contains global data bound description */
static Section *lbounds_section; /* contains local data bound description */
/* symbol sections */
static Section *symtab_section, *strtab_section;

/* debug sections */
static Section *stab_section, *stabstr_section;

/* loc : local variable index
   ind : output code index
   rsym: return symbol
   anon_sym: anonymous symbol index
*/
static int rsym, anon_sym, ind, loc;
/* expression generation modifiers */
static int const_wanted; /* true if constant wanted */
static int nocode_wanted; /* true if no code generation wanted for an expression */
static int global_expr;  /* true if compound literals must be allocated
                            globally (used during initializers parsing */
static CType func_vt; /* current function return type (used by return
                         instruction) */
static int func_vc;
static int last_line_num, last_ind, func_ind; /* debug last line number and pc */
static int tok_ident;
static TokenSym **table_ident;
static TokenSym *hash_ident[TOK_HASH_SIZE];
static char token_buf[STRING_MAX_SIZE + 1];
static char *funcname;
static Sym *global_stack, *local_stack;
static Sym *define_stack;
static Sym *global_label_stack, *local_label_stack;

static SValue vstack[VSTACK_SIZE], *vtop;
/* some predefined types */
static CType char_pointer_type, func_old_type, int_type;
/* true if isid(c) || isnum(c) */
static unsigned char isidnum_table[256];

/* compile with debug symbol (and use them if error during execution) */
static int do_debug = 0;

/* compile with built-in memory and bounds checker */
static int do_bounds_check = 0;

/* display benchmark infos */
#if !defined(LIBTCC)
static int do_bench = 0;
#endif
static int total_lines;
static int total_bytes;

/* use GNU C extensions */
static int gnu_ext = 1;

/* use Tiny C extensions */
static int tcc_ext = 1;

/* max number of callers shown if error */
static int num_callers = 6;
static const char **rt_bound_error_msg;

/* XXX: get rid of this ASAP */
static struct TCCState *tcc_state;

/* give the path of the tcc libraries */
static const char *tcc_lib_path = CONFIG_TCC_LIBDIR "/tcc";

struct TCCState {
    int output_type;
 
    BufferedFile **include_stack_ptr;
    int *ifdef_stack_ptr;

    /* include file handling */
    char **include_paths;
    int nb_include_paths;
    char **sysinclude_paths;
    int nb_sysinclude_paths;
    CachedInclude **cached_includes;
    int nb_cached_includes;

    char **library_paths;
    int nb_library_paths;

    /* array of all loaded dlls (including those referenced by loaded
       dlls) */
    DLLReference **loaded_dlls;
    int nb_loaded_dlls;

    /* sections */
    Section **sections;
    int nb_sections; /* number of sections, including first dummy section */

    /* got handling */
    Section *got;
    Section *plt;
    unsigned long *got_offsets;
    int nb_got_offsets;
    /* give the correspondance from symtab indexes to dynsym indexes */
    int *symtab_to_dynsym;

    /* temporary dynamic symbol sections (for dll loading) */
    Section *dynsymtab_section;
    /* exported dynamic symbol section */
    Section *dynsym;

    int nostdinc; /* if true, no standard headers are added */
    int nostdlib; /* if true, no standard libraries are added */

    /* if true, static linking is performed */
    int static_link;

    /* if true, all symbols are exported */
    int rdynamic;

    /* if true, only link in referenced objects from archive */
    int alacarte_link;

    /* warning switches */
    int warn_write_strings;
    int warn_unsupported;
    int warn_error;
    int warn_none;

    /* error handling */
    void *error_opaque;
    void (*error_func)(void *opaque, const char *msg);
    int error_set_jmp_enabled;
    jmp_buf error_jmp_buf;
    int nb_errors;

    /* tiny assembler state */
    Sym *asm_labels;

    /* see include_stack_ptr */
    BufferedFile *include_stack[INCLUDE_STACK_SIZE];

    /* see ifdef_stack_ptr */
    int ifdef_stack[IFDEF_STACK_SIZE];
};

/* The current value can be: */
#define VT_VALMASK   0x00ff
#define VT_CONST     0x00f0  /* constant in vc 
                              (must be first non register value) */
#define VT_LLOCAL    0x00f1  /* lvalue, offset on stack */
#define VT_LOCAL     0x00f2  /* offset on stack */
#define VT_CMP       0x00f3  /* the value is stored in processor flags (in vc) */
#define VT_JMP       0x00f4  /* value is the consequence of jmp true (even) */
#define VT_JMPI      0x00f5  /* value is the consequence of jmp false (odd) */
#define VT_LVAL      0x0100  /* var is an lvalue */
#define VT_SYM       0x0200  /* a symbol value is added */
#define VT_MUSTCAST  0x0400  /* value must be casted to be correct (used for
                                char/short stored in integer registers) */
#define VT_MUSTBOUND 0x0800  /* bound checking must be done before
                                dereferencing value */
#define VT_BOUNDED   0x8000  /* value is bounded. The address of the
                                bounding function call point is in vc */
#define VT_LVAL_BYTE     0x1000  /* lvalue is a byte */
#define VT_LVAL_SHORT    0x2000  /* lvalue is a short */
#define VT_LVAL_UNSIGNED 0x4000  /* lvalue is unsigned */
#define VT_LVAL_TYPE     (VT_LVAL_BYTE | VT_LVAL_SHORT | VT_LVAL_UNSIGNED)

/* types */
#define VT_INT        0  /* integer type */
#define VT_BYTE       1  /* signed byte type */
#define VT_SHORT      2  /* short type */
#define VT_VOID       3  /* void type */
#define VT_PTR        4  /* pointer */
#define VT_ENUM       5  /* enum definition */
#define VT_FUNC       6  /* function type */
#define VT_STRUCT     7  /* struct/union definition */
#define VT_FLOAT      8  /* IEEE float */
#define VT_DOUBLE     9  /* IEEE double */
#define VT_LDOUBLE   10  /* IEEE long double */
#define VT_BOOL      11  /* ISOC99 boolean type */
#define VT_LLONG     12  /* 64 bit integer */
#define VT_LONG      13  /* long integer (NEVER USED as type, only
                            during parsing) */
#define VT_BTYPE      0x000f /* mask for basic type */
#define VT_UNSIGNED   0x0010  /* unsigned type */
#define VT_ARRAY      0x0020  /* array type (also has VT_PTR) */
#define VT_BITFIELD   0x0040  /* bitfield modifier */
#define VT_CONSTANT   0x0800  /* const modifier */
#define VT_VOLATILE   0x1000  /* volatile modifier */

/* storage */
#define VT_EXTERN  0x00000080  /* extern definition */
#define VT_STATIC  0x00000100  /* static variable */
#define VT_TYPEDEF 0x00000200  /* typedef definition */
#define VT_INLINE  0x00000400  /* inline definition */

#define VT_STRUCT_SHIFT 16   /* shift for bitfield shift values */

/* type mask (except storage) */
#define VT_STORAGE (VT_EXTERN | VT_STATIC | VT_TYPEDEF | VT_INLINE)