tcc.c

小而快的c编译器

    sec->sh_type = sh_type;
    sec->sh_flags = sh_flags;
    switch(sh_type) {
    case SHT_HASH:
    case SHT_REL:
    case SHT_DYNSYM:
    case SHT_SYMTAB:
    case SHT_DYNAMIC:
        sec->sh_addralign = 4;
        break;
    case SHT_STRTAB:
        sec->sh_addralign = 1;
        break;
    default:
        sec->sh_addralign = 32; /* default conservative alignment */
        break;
    }

    /* only add section if not private */
    if (!(sh_flags & SHF_PRIVATE)) {
        sec->sh_num = s1->nb_sections;
        dynarray_add((void ***)&s1->sections, &s1->nb_sections, sec);
    }
    return sec;
}

static void free_section(Section *s)
{
    tcc_free(s->data);
    tcc_free(s);
}

/* realloc section and set its content to zero */
static void section_realloc(Section *sec, unsigned long new_size)
{
    unsigned long size;
    unsigned char *data;
    
    size = sec->data_allocated;
    if (size == 0)
        size = 1;
    while (size < new_size)
        size = size * 2;
    data = tcc_realloc(sec->data, size);
    if (!data)
        error("memory full");
    memset(data + sec->data_allocated, 0, size - sec->data_allocated);
    sec->data = data;
    sec->data_allocated = size;
}

/* reserve at least 'size' bytes in section 'sec' from
   sec->data_offset. */
static void *section_ptr_add(Section *sec, unsigned long size)
{
    unsigned long offset, offset1;

    offset = sec->data_offset;
    offset1 = offset + size;
    if (offset1 > sec->data_allocated)
        section_realloc(sec, offset1);
    sec->data_offset = offset1;
    return sec->data + offset;
}

/* return a reference to a section, and create it if it does not
   exists */
Section *find_section(TCCState *s1, const char *name)
{
    Section *sec;
    int i;
    for(i = 1; i < s1->nb_sections; i++) {
        sec = s1->sections[i];
        if (!strcmp(name, sec->name)) 
            return sec;
    }
    /* sections are created as PROGBITS */
    return new_section(s1, name, SHT_PROGBITS, SHF_ALLOC);
}

/* update sym->c so that it points to an external symbol in section
   'section' with value 'value' */
static void put_extern_sym(Sym *sym, Section *section, 
                           unsigned long value, unsigned long size)
{
    int sym_type, sym_bind, sh_num, info;
    Elf32_Sym *esym;
    const char *name;

    if (section)
        sh_num = section->sh_num;
    else
        sh_num = SHN_UNDEF;
    if (!sym->c) {
        if ((sym->type.t & VT_BTYPE) == VT_FUNC)
            sym_type = STT_FUNC;
        else
            sym_type = STT_OBJECT;
        if (sym->type.t & VT_STATIC)
            sym_bind = STB_LOCAL;
        else
            sym_bind = STB_GLOBAL;
        
        name = get_tok_str(sym->v, NULL);
#ifdef CONFIG_TCC_BCHECK
        if (do_bounds_check) {
            char buf[32];

            /* XXX: avoid doing that for statics ? */
            /* if bound checking is activated, we change some function
               names by adding the "__bound" prefix */
            switch(sym->v) {
#if 0
            /* XXX: we rely only on malloc hooks */
            case TOK_malloc: 
            case TOK_free: 
            case TOK_realloc: 
            case TOK_memalign: 
            case TOK_calloc: 
#endif
            case TOK_memcpy: 
            case TOK_memmove:
            case TOK_memset:
            case TOK_strlen:
            case TOK_strcpy:
                strcpy(buf, "__bound_");
                strcat(buf, name);
                name = buf;
                break;
            }
        }
#endif
        info = ELF32_ST_INFO(sym_bind, sym_type);
        sym->c = add_elf_sym(symtab_section, value, size, info, sh_num, name);
    } else {
        esym = &((Elf32_Sym *)symtab_section->data)[sym->c];
        esym->st_value = value;
        esym->st_size = size;
        esym->st_shndx = sh_num;
    }
}

/* add a new relocation entry to symbol 'sym' in section 's' */
static void greloc(Section *s, Sym *sym, unsigned long offset, int type)
{
    if (!sym->c) 
        put_extern_sym(sym, NULL, 0, 0);
    /* now we can add ELF relocation info */
    put_elf_reloc(symtab_section, s, offset, type, sym->c);
}

static inline int isid(int c)
{
    return (c >= 'a' && c <= 'z') ||
        (c >= 'A' && c <= 'Z') ||
        c == '_';
}

static inline int isnum(int c)
{
    return c >= '0' && c <= '9';
}

static inline int isoct(int c)
{
    return c >= '0' && c <= '7';
}

static inline int toup(int c)
{
    if (c >= 'a' && c <= 'z')
        return c - 'a' + 'A';
    else
        return c;
}

static void strcat_vprintf(char *buf, int buf_size, const char *fmt, va_list ap)
{
    int len;
    len = strlen(buf);
    vsnprintf(buf + len, buf_size - len, fmt, ap);
}

static void strcat_printf(char *buf, int buf_size, const char *fmt, ...)
{
    va_list ap;
    va_start(ap, fmt);
    strcat_vprintf(buf, buf_size, fmt, ap);
    va_end(ap);
}

void error1(TCCState *s1, int is_warning, const char *fmt, va_list ap)
{
    char buf[2048];
    BufferedFile **f;
    
    buf[0] = '\0';
    if (file) {
        for(f = s1->include_stack; f < s1->include_stack_ptr; f++)
            strcat_printf(buf, sizeof(buf), "In file included from %s:%d:\n", 
                          (*f)->filename, (*f)->line_num);
        if (file->line_num > 0) {
            strcat_printf(buf, sizeof(buf), 
                          "%s:%d: ", file->filename, file->line_num);
        } else {
            strcat_printf(buf, sizeof(buf),
                          "%s: ", file->filename);
        }
    } else {
        strcat_printf(buf, sizeof(buf),
                      "tcc: ");
    }
    if (is_warning)
        strcat_printf(buf, sizeof(buf), "warning: ");
    strcat_vprintf(buf, sizeof(buf), fmt, ap);

    if (!s1->error_func) {
        /* default case: stderr */
        fprintf(stderr, "%s\n", buf);
    } else {
        s1->error_func(s1->error_opaque, buf);
    }
    if (!is_warning || s1->warn_error)
        s1->nb_errors++;
}

#ifdef LIBTCC
void tcc_set_error_func(TCCState *s, void *error_opaque,
                        void (*error_func)(void *opaque, const char *msg))
{
    s->error_opaque = error_opaque;
    s->error_func = error_func;
}
#endif

/* error without aborting current compilation */
void error_noabort(const char *fmt, ...)
{
    TCCState *s1 = tcc_state;
    va_list ap;

    va_start(ap, fmt);
    error1(s1, 0, fmt, ap);
    va_end(ap);
}

void error(const char *fmt, ...)
{
    TCCState *s1 = tcc_state;
    va_list ap;

    va_start(ap, fmt);
    error1(s1, 0, fmt, ap);
    va_end(ap);
    /* better than nothing: in some cases, we accept to handle errors */
    if (s1->error_set_jmp_enabled) {
        longjmp(s1->error_jmp_buf, 1);
    } else {
        /* XXX: eliminate this someday */
        exit(1);
    }
}

void expect(const char *msg)
{
    error("%s expected", msg);
}

void warning(const char *fmt, ...)
{
    TCCState *s1 = tcc_state;
    va_list ap;

    if (s1->warn_none)
        return;

    va_start(ap, fmt);
    error1(s1, 1, fmt, ap);
    va_end(ap);
}

void skip(int c)
{
    if (tok != c)
        error("'%c' expected", c);
    next();
}

static void test_lvalue(void)
{
    if (!(vtop->r & VT_LVAL))
        expect("lvalue");
}

/* allocate a new token */
static TokenSym *tok_alloc_new(TokenSym **pts, const char *str, int len)
{
    TokenSym *ts, **ptable;
    int i;

    if (tok_ident >= SYM_FIRST_ANOM) 
        error("memory full");

    /* expand token table if needed */
    i = tok_ident - TOK_IDENT;
    if ((i % TOK_ALLOC_INCR) == 0) {
        ptable = tcc_realloc(table_ident, (i + TOK_ALLOC_INCR) * sizeof(TokenSym *));
        if (!ptable)
            error("memory full");
        table_ident = ptable;
    }

    ts = tcc_malloc(sizeof(TokenSym) + len);
    table_ident[i] = ts;
    ts->tok = tok_ident++;
    ts->sym_define = NULL;
    ts->sym_label = NULL;
    ts->sym_struct = NULL;
    ts->sym_identifier = NULL;
    ts->len = len;
    ts->hash_next = NULL;
    memcpy(ts->str, str, len);
    ts->str[len] = '\0';
    *pts = ts;
    return ts;
}

#define TOK_HASH_INIT 1
#define TOK_HASH_FUNC(h, c) ((h) * 263 + (c))

/* find a token and add it if not found */
static TokenSym *tok_alloc(const char *str, int len)
{
    TokenSym *ts, **pts;
    int i;
    unsigned int h;
    
    h = TOK_HASH_INIT;
    for(i=0;i<len;i++)
        h = TOK_HASH_FUNC(h, ((unsigned char *)str)[i]);
    h &= (TOK_HASH_SIZE - 1);

    pts = &hash_ident[h];
    for(;;) {
        ts = *pts;
        if (!ts)
            break;
        if (ts->len == len && !memcmp(ts->str, str, len))
            return ts;
        pts = &(ts->hash_next);
    }
    return tok_alloc_new(pts, str, len);
}

/* CString handling */

static void cstr_realloc(CString *cstr, int new_size)
{
    int size;
    void *data;

    size = cstr->size_allocated;
    if (size == 0)
        size = 8; /* no need to allocate a too small first string */
    while (size < new_size)
        size = size * 2;
    data = tcc_realloc(cstr->data_allocated, size);
    if (!data)
        error("memory full");
    cstr->data_allocated = data;
    cstr->size_allocated = size;
    cstr->data = data;
}

/* add a byte */
static void cstr_ccat(CString *cstr, int ch)
{
    int size;
    size = cstr->size + 1;
    if (size > cstr->size_allocated)
        cstr_realloc(cstr, size);
    ((unsigned char *)cstr->data)[size - 1] = ch;
    cstr->size = size;
}

static void cstr_cat(CString *cstr, const char *str)
{
    int c;
    for(;;) {
        c = *str;
        if (c == '\0')
            break;
        cstr_ccat(cstr, c);
        str++;
    }
}

/* add a wide char */
static void cstr_wccat(CString *cstr, int ch)
{
    int size;
    size = cstr->size + sizeof(int);
    if (size > cstr->size_allocated)
        cstr_realloc(cstr, size);
    *(int *)(((unsigned char *)cstr->data) + size - sizeof(int)) = ch;
    cstr->size = size;
}

static void cstr_new(CString *cstr)
{
    memset(cstr, 0, sizeof(CString));
}

/* free string and reset it to NULL */
static void cstr_free(CString *cstr)
{
    tcc_free(cstr->data_allocated);
    cstr_new(cstr);
}

#define cstr_reset(cstr) cstr_free(cstr)

static CString *cstr_dup(CString *cstr1)
{
    CString *cstr;
    int size;

    cstr = tcc_malloc(sizeof(CString));
    size = cstr1->size;
    cstr->size = size;
    cstr->size_allocated = size;
    cstr->data_allocated = tcc_malloc(size);
    cstr->data = cstr->data_allocated;
    memcpy(cstr->data_allocated, cstr1->data_allocated, size);
    return cstr;
}

/* XXX: unicode ? */
static void add_char(CString *cstr, int c)
{
    if (c == '\'' || c == '\"' || c == '\\') {
        /* XXX: could be more precise if char or string */
        cstr_ccat(cstr, '\\');
    }
    if (c >= 32 && c <= 126) {
        cstr_ccat(cstr, c);
    } else {
        cstr_ccat(cstr, '\\');
        if (c == '\n') {
            cstr_ccat(cstr, 'n');
        } else {
            cstr_ccat(cstr, '0' + ((c >> 6) & 7));
            cstr_ccat(cstr, '0' + ((c >> 3) & 7));
            cstr_ccat(cstr, '0' + (c & 7));
        }
    }
}

/* XXX: buffer overflow */
/* XXX: float tokens */
char *get_tok_str(int v, CValue *cv)
{
    static char buf[STRING_MAX_SIZE + 1];
    static CString cstr_buf;
    CString *cstr;
    unsigned char *q;
    char *p;
    int i, len;

    /* NOTE: to go faster, we give a fixed buffer for small strings */
    cstr_reset(&cstr_buf);
    cstr_buf.data = buf;
    cstr_buf.size_allocated = sizeof(buf);
    p = buf;

    switch(v) {
    case TOK_CINT:
    case TOK_CUINT:
        /* XXX: not quite exact, but only useful for testing */
        sprintf(p, "%u", cv->ui);
        break;
    case TOK_CLLONG:
    case TOK_CULLONG:
        /* XXX: not quite exact, but only useful for testing  */