tinycc/libtcc.c

/*
 *  TCC - Tiny C Compiler
 * 
 *  Copyright (c) 2001-2004 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
 */

#include "tcc.h"

/********************************************************/
/* global variables */

/* display benchmark infos */
int total_lines;
int total_bytes;

/* 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 */
#define TOK_FLAG_EOF   0x0008 /* end of file */

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 */
#define PARSE_FLAG_ASM_COMMENTS 0x0008 /* '#' can be used for line comment */
#define PARSE_FLAG_SPACES     0x0010 /* next() returns space tokens (for -E) */
 
static Section *text_section, *data_section, *bss_section; /* predefined sections */
static Section *cur_text_section; /* current section where function code is
                              generated */
#ifdef CONFIG_TCC_ASM
static Section *last_text_section; /* to handle .previous asm directive */
#endif
/* 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;
/* symbol allocator */
#define SYM_POOL_NB (8192 / sizeof(Sym))
static Sym *sym_free_first;
static void **sym_pools;
static int nb_sym_pools;

static SValue vstack[VSTACK_SIZE], *vtop;
/* some predefined types */
static CType char_pointer_type, func_old_type, int_type;

/* 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 */
#ifdef CONFIG_TCC_BACKTRACE
int num_callers = 6;
const char **rt_bound_error_msg;
unsigned long rt_prog_main;
#endif

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

/********************************************************/
/* function prototypes */

/* tccpp.c */
static void next(void);
char *get_tok_str(int v, CValue *cv);

/* tccgen.c */
static void parse_expr_type(CType *type);
static void expr_type(CType *type);
static void unary_type(CType *type);
static void block(int *bsym, int *csym, int *case_sym, int *def_sym, 
                  int case_reg, int is_expr);
static int expr_const(void);
static void expr_eq(void);
static void gexpr(void);
static void gen_inline_functions(void);
static void decl(int l);
static void decl_initializer(CType *type, Section *sec, unsigned long c, 
                             int first, int size_only);
static void decl_initializer_alloc(CType *type, AttributeDef *ad, int r, 
                                   int has_init, int v, int scope);
int gv(int rc);
void gv2(int rc1, int rc2);
void move_reg(int r, int s);
void save_regs(int n);
void save_reg(int r);
void vpop(void);
void vswap(void);
void vdup(void);
int get_reg(int rc);
int get_reg_ex(int rc,int rc2);

void gen_op(int op);
void force_charshort_cast(int t);
static void gen_cast(CType *type);
void vstore(void);
static Sym *sym_find(int v);
static Sym *sym_push(int v, CType *type, int r, int c);

/* type handling */
static int type_size(CType *type, int *a);
static inline CType *pointed_type(CType *type);
static int pointed_size(CType *type);
static int lvalue_type(int t);
static int parse_btype(CType *type, AttributeDef *ad);
static void type_decl(CType *type, AttributeDef *ad, int *v, int td);
static int compare_types(CType *type1, CType *type2, int unqualified);
static int is_compatible_types(CType *type1, CType *type2);
static int is_compatible_parameter_types(CType *type1, CType *type2);

int ieee_finite(double d);
void vpushi(int v);
void vpushll(long long v);
void vrott(int n);
void vnrott(int n);
void lexpand_nr(void);
static void vpush_global_sym(CType *type, int v);
void vset(CType *type, int r, int v);
void type_to_str(char *buf, int buf_size, 
                 CType *type, const char *varstr);
static Sym *get_sym_ref(CType *type, Section *sec,
                        unsigned long offset, unsigned long size);
static Sym *external_global_sym(int v, CType *type, int r);

/* section generation */
static void section_realloc(Section *sec, unsigned long new_size);
static void *section_ptr_add(Section *sec, unsigned long size);
static void put_extern_sym(Sym *sym, Section *section, 
                           unsigned long value, unsigned long size);
static void greloc(Section *s, Sym *sym, unsigned long addr, int type);
static int put_elf_str(Section *s, const char *sym);
static int put_elf_sym(Section *s, 
                       unsigned long value, unsigned long size,
                       int info, int other, int shndx, const char *name);
static int add_elf_sym(Section *s, uplong value, unsigned long size,
                       int info, int other, int sh_num, const char *name);
static void put_elf_reloc(Section *symtab, Section *s, unsigned long offset,
                          int type, int symbol);
static void put_stabs(const char *str, int type, int other, int desc, 
                      unsigned long value);
static void put_stabs_r(const char *str, int type, int other, int desc, 
                        unsigned long value, Section *sec, int sym_index);
static void put_stabn(int type, int other, int desc, int value);
static void put_stabd(int type, int other, int desc);
static int tcc_add_dll(TCCState *s, const char *filename, int flags);

#define AFF_PRINT_ERROR     0x0001 /* print error if file not found */
#define AFF_REFERENCED_DLL  0x0002 /* load a referenced dll from another dll */
#define AFF_PREPROCESS      0x0004 /* preprocess file */
static int tcc_add_file_internal(TCCState *s, const char *filename, int flags);

/* tcccoff.c */
int tcc_output_coff(TCCState *s1, FILE *f);

/* tccpe.c */
int pe_load_file(struct TCCState *s1, const char *filename, int fd);
int pe_output_file(struct TCCState *s1, const char *filename);

/* tccasm.c */
#ifdef CONFIG_TCC_ASM
static void asm_expr(TCCState *s1, ExprValue *pe);
static int asm_int_expr(TCCState *s1);
static int find_constraint(ASMOperand *operands, int nb_operands, 
                           const char *name, const char **pp);

static int tcc_assemble(TCCState *s1, int do_preprocess);
#endif

static void asm_instr(void);
static void asm_global_instr(void);

/********************************************************/
/* libtcc.c */

static Sym *__sym_malloc(void);
static inline Sym *sym_malloc(void);
static inline void sym_free(Sym *sym);
Section *new_section(TCCState *s1, const char *name, int sh_type, int sh_flags);
static void free_section(Section *s);
static void section_realloc(Section *sec, unsigned long new_size);
static void *section_ptr_add(Section *sec, unsigned long size);
Section *find_section(TCCState *s1, const char *name);
static void put_extern_sym2(
    Sym *sym, Section *section,
    unsigned long value, unsigned long size, int can_add_underscore);
static void put_extern_sym(
    Sym *sym, Section *section,
    unsigned long value, unsigned long size);
static void greloc(Section *s, Sym *sym, unsigned long offset, int type);

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

/* CString handling */
static void cstr_realloc(CString *cstr, int new_size);
static inline void cstr_ccat(CString *cstr, int ch);
static void cstr_cat(CString *cstr, const char *str);
static void cstr_wccat(CString *cstr, int ch);
static void cstr_new(CString *cstr);
static void cstr_free(CString *cstr);
#define cstr_reset(cstr) cstr_free(cstr)
static void add_char(CString *cstr, int c);

static Sym *sym_push2(Sym **ps, int v, int t, long c);
static Sym *sym_find2(Sym *s, int v);
static inline Sym *struct_find(int v);
static inline Sym *sym_find(int v);
static Sym *sym_push(int v, CType *type, int r, int c);
static Sym *global_identifier_push(int v, int t, int c);
static void sym_pop(Sym **ptop, Sym *b);

BufferedFile *tcc_open(TCCState *s1, const char *filename);
void tcc_close(BufferedFile *bf);
static int tcc_compile(TCCState *s1);

void expect(const char *msg);
void skip(int c);
static void test_lvalue(void);
void *resolve_sym(TCCState *s1, const char *sym);

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;
}

/********************************************************/

#ifdef TCC_TARGET_I386
#include "i386-gen.c"
#endif

#ifdef TCC_TARGET_ARM
#include "arm-gen.c"
#endif

#ifdef TCC_TARGET_C67
#include "c67-gen.c"
#endif

#ifdef TCC_TARGET_X86_64
#include "x86_64-gen.c"
#endif

#include "tccpp.c"
#include "tccgen.c"

#ifdef CONFIG_TCC_ASM
#ifdef TCC_TARGET_I386
#include "i386-asm.c"
#endif
#include "tccasm.c"
#else
static void asm_instr(void)
{
    error("inline asm() not supported");
}
static void asm_global_instr(void)
{
    error("inline asm() not supported");
}
#endif

#include "tccelf.c"

#ifdef TCC_TARGET_COFF
#include "tcccoff.c"
#endif

#ifdef TCC_TARGET_PE
#include "tccpe.c"
#endif

/********************************************************/
#ifdef _WIN32
char *normalize_slashes(char *path)
{
    char *p;
    for (p = path; *p; ++p)
        if (*p == '\\')
            *p = '/';
    return path;
}

HMODULE tcc_module;

/* on win32, we suppose the lib and includes are at the location of 'tcc.exe' */
void tcc_set_lib_path_w32(TCCState *s)
{
    char path[1024], *p;
    GetModuleFileNameA(tcc_module, path, sizeof path);
    p = tcc_basename(normalize_slashes(strlwr(path)));
    if (p - 5 > path && 0 == strncmp(p - 5, "/bin/", 5))
        p -= 5;
    else if (p > path)
        p--;
    *p = 0;
    tcc_set_lib_path(s, path);
}

#ifdef LIBTCC_AS_DLL
BOOL WINAPI DllMain (HANDLE hDll, DWORD dwReason, LPVOID lpReserved)
{
    if (DLL_PROCESS_ATTACH == dwReason)
        tcc_module = hDll;
    return TRUE;
}
#endif
#endif

/********************************************************/
#ifdef CONFIG_TCC_STATIC

#define RTLD_LAZY       0x001
#define RTLD_NOW        0x002
#define RTLD_GLOBAL     0x100
#define RTLD_DEFAULT    NULL

/* dummy function for profiling */
void *dlopen(const char *filename, int flag)
{
    return NULL;
}

void dlclose(void *p)
{
}

const char *dlerror(void)
{
    return "error";
}

typedef struct TCCSyms {
    char *str;
    void *ptr;
} TCCSyms;

#define TCCSYM(a) { #a, &a, },

/* add the symbol you want here if no dynamic linking is done */
static TCCSyms tcc_syms[] = {
#if !defined(CONFIG_TCCBOOT)
    TCCSYM(printf)
    TCCSYM(fprintf)
    TCCSYM(fopen)
    TCCSYM(fclose)
#endif
    { NULL, NULL },
};

void *resolve_sym(TCCState *s1, const char *symbol)
{
    TCCSyms *p;
    p = tcc_syms;
    while (p->str != NULL) {
        if (!strcmp(p->str, symbol))
            return p->ptr;
        p++;
    }
    return NULL;
}

#elif defined(_WIN32)
#define dlclose FreeLibrary

#else
#include <dlfcn.h>

void *resolve_sym(TCCState *s1, const char *sym)
{
    return dlsym(RTLD_DEFAULT, sym);
}

#endif

/********************************************************/

/* we use our own 'finite' function to avoid potential problems with
   non standard math libs */
/* XXX: endianness dependent */
int ieee_finite(double d)
{
    int *p = (int *)&d;
    return ((unsigned)((p[1] | 0x800fffff) + 1)) >> 31;
}

/* copy a string and truncate it. */
char *pstrcpy(char *buf, int buf_size, const char *s)
{
    char *q, *q_end;
    int c;

    if (buf_size > 0) {
        q = buf;
        q_end = buf + buf_size - 1;
        while (q < q_end) {
            c = *s++;
            if (c == '\0')
                break;
            *q++ = c;
        }
        *q = '\0';
    }
    return buf;
}

/* strcat and truncate. */
char *pstrcat(char *buf, int buf_size, const char *s)
{
    int len;
    len = strlen(buf);
    if (len < buf_size) 
        pstrcpy(buf + len, buf_size - len, s);
    return buf;
}

/* extract the basename of a file */
char *tcc_basename(const char *name)
{
    char *p = strchr(name, 0);
    while (p > name && !IS_PATHSEP(p[-1]))
        --p;
    return p;
}

char *tcc_fileextension (const char *name)
{
    char *b = tcc_basename(name);
    char *e = strrchr(b, '.');
    return e ? e : strchr(b, 0);
}

void set_pages_executable(void *ptr, unsigned long length)
{
#ifdef _WIN32
    unsigned long old_protect;
    VirtualProtect(ptr, length, PAGE_EXECUTE_READWRITE, &old_protect);
#else
    unsigned long start, end;
    start = (unsigned long)ptr & ~(PAGESIZE - 1);
    end = (unsigned long)ptr + length;
    end = (end + PAGESIZE - 1) & ~(PAGESIZE - 1);
    mprotect((void *)start, end - start, PROT_READ | PROT_WRITE | PROT_EXEC);
#endif            
}

/* memory management */
#ifdef MEM_DEBUG
int mem_cur_size;
int mem_max_size;
unsigned malloc_usable_size(void*);
#endif

void tcc_free(void *ptr)
{
#ifdef MEM_DEBUG
    mem_cur_size -= malloc_usable_size(ptr);
#endif
    free(ptr);
}

void *tcc_malloc(unsigned long size)
{
    void *ptr;
    ptr = malloc(size);
    if (!ptr && size)
        error("memory full");
#ifdef MEM_DEBUG
    mem_cur_size += malloc_usable_size(ptr);
    if (mem_cur_size > mem_max_size)
        mem_max_size = mem_cur_size;
#endif
    return ptr;
}

void *tcc_mallocz(unsigned long size)
{
    void *ptr;
    ptr = tcc_malloc(size);
    memset(ptr, 0, size);
    return ptr;
}

void *tcc_realloc(void *ptr, unsigned long size)
{
    void *ptr1;
#ifdef MEM_DEBUG
    mem_cur_size -= malloc_usable_size(ptr);
#endif
    ptr1 = realloc(ptr, size);
#ifdef MEM_DEBUG
    /* NOTE: count not correct if alloc error, but not critical */
    mem_cur_size += malloc_usable_size(ptr1);
    if (mem_cur_size > mem_max_size)
        mem_max_size = mem_cur_size;
#endif
    return ptr1;
}

char *tcc_strdup(const char *str)
{
    char *ptr;
    ptr = tcc_malloc(strlen(str) + 1);
    strcpy(ptr, str);
    return ptr;
}

#define free(p) use_tcc_free(p)
#define malloc(s) use_tcc_malloc(s)
#define realloc(p, s) use_tcc_realloc(p, s)

void dynarray_add(void ***ptab, int *nb_ptr, void *data)
{
    int nb, nb_alloc;
    void **pp;
    
    nb = *nb_ptr;
    pp = *ptab;
    /* every power of two we double array size */
    if ((nb & (nb - 1)) == 0) {
        if (!nb)
            nb_alloc = 1;
        else
            nb_alloc = nb * 2;
        pp = tcc_realloc(pp, nb_alloc * sizeof(void *));
        if (!pp)
            error("memory full");
        *ptab = pp;
    }
    pp[nb++] = data;
    *nb_ptr = nb;
}

void dynarray_reset(void *pp, int *n)
{
    void **p;
    for (p = *(void***)pp; *n; ++p, --*n)
        if (*p)
            tcc_free(*p);
    tcc_free(*(void**)pp);
    *(void**)pp = NULL;
}

/* symbol allocator */
static Sym *__sym_malloc(void)
{
    Sym *sym_pool, *sym, *last_sym;
    int i;

    sym_pool = tcc_malloc(SYM_POOL_NB * sizeof(Sym));
    dynarray_add(&sym_pools, &nb_sym_pools, sym_pool);

    last_sym = sym_free_first;
    sym = sym_pool;
    for(i = 0; i < SYM_POOL_NB; i++) {
        sym->next = last_sym;
        last_sym = sym;
        sym++;
    }
    sym_free_first = last_sym;
    return last_sym;
}

static inline Sym *sym_malloc(void)
{
    Sym *sym;
    sym = sym_free_first;
    if (!sym)
        sym = __sym_malloc();
    sym_free_first = sym->next;
    return sym;
}

static inline void sym_free(Sym *sym)
{
    sym->next = sym_free_first;
    sym_free_first = sym;
}

Section *new_section(TCCState *s1, const char *name, int sh_type, int sh_flags)
{
    Section *sec;

    sec = tcc_mallocz(sizeof(Section) + strlen(name));
    strcpy(sec->name, name);
    sec->sh_type = sh_type;
    sec->sh_flags = sh_flags;
    switch(sh_type) {
    case SHT_HASH:
    case SHT_REL:
    case SHT_RELA:
    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;
    }

    if (sh_flags & SHF_PRIVATE) {
        dynarray_add((void ***)&s1->priv_sections, &s1->nb_priv_sections, sec);
    } else {
        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);
}

/* 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_sym2(Sym *sym, Section *section, 
                            unsigned long value, unsigned long size,
                            int can_add_underscore)
{
    int sym_type, sym_bind, sh_num, info, other, attr;
    ElfW(Sym) *esym;
    const char *name;
    char buf1[256];

    if (section == NULL)
        sh_num = SHN_UNDEF;
    else if (section == SECTION_ABS) 
        sh_num = SHN_ABS;
    else
        sh_num = section->sh_num;

    other = attr = 0;

    if ((sym->type.t & VT_BTYPE) == VT_FUNC) {
        sym_type = STT_FUNC;
#ifdef TCC_TARGET_PE
        if (sym->type.ref)
            attr = sym->type.ref->r;
        if (FUNC_EXPORT(attr))
            other |= 1;
        if (FUNC_CALL(attr) == FUNC_STDCALL)
            other |= 2;
#endif
    } else {
        sym_type = STT_OBJECT;
    }

    if (sym->type.t & VT_STATIC)
        sym_bind = STB_LOCAL;
    else
        sym_bind = STB_GLOBAL;

    if (!sym->c) {
        name = get_tok_str(sym->v, NULL);
#ifdef CONFIG_TCC_BCHECK
        if (tcc_state->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:
            case TOK_alloca:
                strcpy(buf, "__bound_");
                strcat(buf, name);
                name = buf;
                break;
            }
        }
#endif

#ifdef TCC_TARGET_PE
        if ((other & 2) && can_add_underscore) {
            sprintf(buf1, "_%s@%d", name, FUNC_ARGS(attr));
            name = buf1;
        } else
#endif
        if (tcc_state->leading_underscore && can_add_underscore) {
            buf1[0] = '_';
            pstrcpy(buf1 + 1, sizeof(buf1) - 1, name);
            name = buf1;
        }
        info = ELFW(ST_INFO)(sym_bind, sym_type);
        sym->c = add_elf_sym(symtab_section, value, size, info, other, sh_num, name);
    } else {
        esym = &((ElfW(Sym) *)symtab_section->data)[sym->c];
        esym->st_value = value;
        esym->st_size = size;
        esym->st_shndx = sh_num;
        esym->st_other |= other;
    }
}

static void put_extern_sym(Sym *sym, Section *section, 
                           unsigned long value, unsigned long size)
{
    put_extern_sym2(sym, section, value, size, 1);
}

/* 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 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: ");
    else
        strcat_printf(buf, sizeof(buf), "error: ");
    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++;
}

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;
}

/* 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");
}

/* 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 inline 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(nwchar_t);
    if (size > cstr->size_allocated)
        cstr_realloc(cstr, size);
    *(nwchar_t *)(((unsigned char *)cstr->data) + size - sizeof(nwchar_t)) = 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)

/* 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));
        }
    }
}

/* push, without hashing */
static Sym *sym_push2(Sym **ps, int v, int t, long c)
{
    Sym *s;
    s = sym_malloc();
    s->v = v;
    s->type.t = t;
#ifdef _WIN64
    s->d = NULL;
#endif
    s->c = c;
    s->next = NULL;
    /* add in stack */
    s->prev = *ps;
    *ps = s;
    return s;
}

/* find a symbol and return its associated structure. 's' is the top
   of the symbol stack */
static Sym *sym_find2(Sym *s, int v)
{
    while (s) {
        if (s->v == v)
            return s;
        s = s->prev;
    }
    return NULL;
}

/* structure lookup */
static inline Sym *struct_find(int v)
{
    v -= TOK_IDENT;
    if ((unsigned)v >= (unsigned)(tok_ident - TOK_IDENT))
        return NULL;
    return table_ident[v]->sym_struct;
}

/* find an identifier */
static inline Sym *sym_find(int v)
{
    v -= TOK_IDENT;
    if ((unsigned)v >= (unsigned)(tok_ident - TOK_IDENT))
        return NULL;
    return table_ident[v]->sym_identifier;
}

/* push a given symbol on the symbol stack */
static Sym *sym_push(int v, CType *type, int r, int c)
{
    Sym *s, **ps;
    TokenSym *ts;

    if (local_stack)
        ps = &local_stack;
    else
        ps = &global_stack;
    s = sym_push2(ps, v, type->t, c);
    s->type.ref = type->ref;
    s->r = r;
    /* don't record fields or anonymous symbols */
    /* XXX: simplify */
    if (!(v & SYM_FIELD) && (v & ~SYM_STRUCT) < SYM_FIRST_ANOM) {
        /* record symbol in token array */
        ts = table_ident[(v & ~SYM_STRUCT) - TOK_IDENT];
        if (v & SYM_STRUCT)
            ps = &ts->sym_struct;
        else
            ps = &ts->sym_identifier;
        s->prev_tok = *ps;
        *ps = s;
    }
    return s;
}

/* push a global identifier */
static Sym *global_identifier_push(int v, int t, int c)
{
    Sym *s, **ps;
    s = sym_push2(&global_stack, v, t, c);
    /* don't record anonymous symbol */
    if (v < SYM_FIRST_ANOM) {
        ps = &table_ident[v - TOK_IDENT]->sym_identifier;
        /* modify the top most local identifier, so that
           sym_identifier will point to 's' when popped */
        while (*ps != NULL)
            ps = &(*ps)->prev_tok;
        s->prev_tok = NULL;
        *ps = s;
    }
    return s;
}

/* pop symbols until top reaches 'b' */
static void sym_pop(Sym **ptop, Sym *b)
{
    Sym *s, *ss, **ps;
    TokenSym *ts;
    int v;

    s = *ptop;
    while(s != b) {
        ss = s->prev;
        v = s->v;
        /* remove symbol in token array */
        /* XXX: simplify */
        if (!(v & SYM_FIELD) && (v & ~SYM_STRUCT) < SYM_FIRST_ANOM) {
            ts = table_ident[(v & ~SYM_STRUCT) - TOK_IDENT];
            if (v & SYM_STRUCT)
                ps = &ts->sym_struct;
            else
                ps = &ts->sym_identifier;
            *ps = s->prev_tok;
        }
        sym_free(s);
        s = ss;
    }
    *ptop = b;
}

/* I/O layer */

BufferedFile *tcc_open(TCCState *s1, const char *filename)
{
    int fd;
    BufferedFile *bf;

    if (strcmp(filename, "-") == 0)
        fd = 0, filename = "stdin";
    else
        fd = open(filename, O_RDONLY | O_BINARY);
    if ((s1->verbose == 2 && fd >= 0) || s1->verbose == 3)
        printf("%s %*s%s\n", fd < 0 ? "nf":"->",
               (int)(s1->include_stack_ptr - s1->include_stack), "", filename);
    if (fd < 0)
        return NULL;
    bf = tcc_malloc(sizeof(BufferedFile));
    bf->fd = fd;
    bf->buf_ptr = bf->buffer;
    bf->buf_end = bf->buffer;
    bf->buffer[0] = CH_EOB; /* put eob symbol */
    pstrcpy(bf->filename, sizeof(bf->filename), filename);
#ifdef _WIN32
    normalize_slashes(bf->filename);
#endif
    bf->line_num = 1;
    bf->ifndef_macro = 0;
    bf->ifdef_stack_ptr = s1->ifdef_stack_ptr;
    //    printf("opening '%s'\n", filename);
    return bf;
}

void tcc_close(BufferedFile *bf)
{
    total_lines += bf->line_num;
    close(bf->fd);
    tcc_free(bf);
}

/* compile the C file opened in 'file'. Return non zero if errors. */
static int tcc_compile(TCCState *s1)
{
    Sym *define_start;
    char buf[512];
    volatile int section_sym;

#ifdef INC_DEBUG
    printf("%s: **** new file\n", file->filename);
#endif
    preprocess_init(s1);

    cur_text_section = NULL;
    funcname = "";
    anon_sym = SYM_FIRST_ANOM; 

    /* file info: full path + filename */
    section_sym = 0; /* avoid warning */
    if (s1->do_debug) {
        section_sym = put_elf_sym(symtab_section, 0, 0, 
                                  ELFW(ST_INFO)(STB_LOCAL, STT_SECTION), 0, 
                                  text_section->sh_num, NULL);
        getcwd(buf, sizeof(buf));
#ifdef _WIN32
        normalize_slashes(buf);
#endif
        pstrcat(buf, sizeof(buf), "/");
        put_stabs_r(buf, N_SO, 0, 0, 
                    text_section->data_offset, text_section, section_sym);
        put_stabs_r(file->filename, N_SO, 0, 0, 
                    text_section->data_offset, text_section, section_sym);
    }
    /* an elf symbol of type STT_FILE must be put so that STB_LOCAL
       symbols can be safely used */
    put_elf_sym(symtab_section, 0, 0, 
                ELFW(ST_INFO)(STB_LOCAL, STT_FILE), 0, 
                SHN_ABS, file->filename);

    /* define some often used types */
    int_type.t = VT_INT;

    char_pointer_type.t = VT_BYTE;
    mk_pointer(&char_pointer_type);

    func_old_type.t = VT_FUNC;
    func_old_type.ref = sym_push(SYM_FIELD, &int_type, FUNC_CDECL, FUNC_OLD);

#if defined(TCC_ARM_EABI) && defined(TCC_ARM_VFP)
    float_type.t = VT_FLOAT;
    double_type.t = VT_DOUBLE;

    func_float_type.t = VT_FUNC;
    func_float_type.ref = sym_push(SYM_FIELD, &float_type, FUNC_CDECL, FUNC_OLD);
    func_double_type.t = VT_FUNC;
    func_double_type.ref = sym_push(SYM_FIELD, &double_type, FUNC_CDECL, FUNC_OLD);
#endif

#if 0
    /* define 'void *alloca(unsigned int)' builtin function */
    {
        Sym *s1;

        p = anon_sym++;
        sym = sym_push(p, mk_pointer(VT_VOID), FUNC_CDECL, FUNC_NEW);
        s1 = sym_push(SYM_FIELD, VT_UNSIGNED | VT_INT, 0, 0);
        s1->next = NULL;
        sym->next = s1;
        sym_push(TOK_alloca, VT_FUNC | (p << VT_STRUCT_SHIFT), VT_CONST, 0);
    }
#endif

    define_start = define_stack;
    nocode_wanted = 1;

    if (setjmp(s1->error_jmp_buf) == 0) {
        s1->nb_errors = 0;
        s1->error_set_jmp_enabled = 1;

        ch = file->buf_ptr[0];
        tok_flags = TOK_FLAG_BOL | TOK_FLAG_BOF;
        parse_flags = PARSE_FLAG_PREPROCESS | PARSE_FLAG_TOK_NUM;
        next();
        decl(VT_CONST);
        if (tok != TOK_EOF)
            expect("declaration");

        /* end of translation unit info */
        if (s1->do_debug) {
            put_stabs_r(NULL, N_SO, 0, 0, 
                        text_section->data_offset, text_section, section_sym);
        }
    }
    s1->error_set_jmp_enabled = 0;

    /* reset define stack, but leave -Dsymbols (may be incorrect if
       they are undefined) */
    free_defines(define_start); 

    gen_inline_functions();

    sym_pop(&global_stack, NULL);
    sym_pop(&local_stack, NULL);

    return s1->nb_errors != 0 ? -1 : 0;
}

int tcc_compile_string(TCCState *s, const char *str)
{
    BufferedFile bf1, *bf = &bf1;
    int ret, len;
    char *buf;

    /* init file structure */
    bf->fd = -1;
    /* XXX: avoid copying */
    len = strlen(str);
    buf = tcc_malloc(len + 1);
    if (!buf)
        return -1;
    memcpy(buf, str, len);
    buf[len] = CH_EOB;
    bf->buf_ptr = buf;
    bf->buf_end = buf + len;
    pstrcpy(bf->filename, sizeof(bf->filename), "<string>");
    bf->line_num = 1;
    file = bf;
    ret = tcc_compile(s);
    file = NULL;
    tcc_free(buf);

    /* currently, no need to close */
    return ret;
}

/* define a preprocessor symbol. A value can also be provided with the '=' operator */
void tcc_define_symbol(TCCState *s1, const char *sym, const char *value)
{
    BufferedFile bf1, *bf = &bf1;

    pstrcpy(bf->buffer, IO_BUF_SIZE, sym);
    pstrcat(bf->buffer, IO_BUF_SIZE, " ");
    /* default value */
    if (!value) 
        value = "1";
    pstrcat(bf->buffer, IO_BUF_SIZE, value);
    
    /* init file structure */
    bf->fd = -1;
    bf->buf_ptr = bf->buffer;
    bf->buf_end = bf->buffer + strlen(bf->buffer);
    *bf->buf_end = CH_EOB;
    bf->filename[0] = '\0';
    bf->line_num = 1;
    file = bf;
    
    s1->include_stack_ptr = s1->include_stack;

    /* parse with define parser */
    ch = file->buf_ptr[0];
    next_nomacro();
    parse_define();
    file = NULL;
}

/* undefine a preprocessor symbol */
void tcc_undefine_symbol(TCCState *s1, const char *sym)
{
    TokenSym *ts;
    Sym *s;
    ts = tok_alloc(sym, strlen(sym));
    s = define_find(ts->tok);
    /* undefine symbol by putting an invalid name */
    if (s)
        define_undef(s);
}


#ifdef CONFIG_TCC_BACKTRACE
/* print the position in the source file of PC value 'pc' by reading
   the stabs debug information */
static unsigned long rt_printline(unsigned long wanted_pc)
{
    Stab_Sym *sym, *sym_end;
    char func_name[128], last_func_name[128];
    unsigned long func_addr, last_pc, pc;
    const char *incl_files[INCLUDE_STACK_SIZE];
    int incl_index, len, last_line_num, i;
    const char *str, *p;

    fprintf(stderr, "0x%08lx:", wanted_pc);

    func_name[0] = '\0';
    func_addr = 0;
    incl_index = 0;
    last_func_name[0] = '\0';
    last_pc = 0xffffffff;
    last_line_num = 1;
    sym = (Stab_Sym *)stab_section->data + 1;
    sym_end = (Stab_Sym *)(stab_section->data + stab_section->data_offset);
    while (sym < sym_end) {
        switch(sym->n_type) {
            /* function start or end */
        case N_FUN:
            if (sym->n_strx == 0) {
                /* we test if between last line and end of function */
                pc = sym->n_value + func_addr;
                if (wanted_pc >= last_pc && wanted_pc < pc)
                    goto found;
                func_name[0] = '\0';
                func_addr = 0;
            } else {
                str = stabstr_section->data + sym->n_strx;
                p = strchr(str, ':');
                if (!p) {
                    pstrcpy(func_name, sizeof(func_name), str);
                } else {
                    len = p - str;
                    if (len > sizeof(func_name) - 1)
                        len = sizeof(func_name) - 1;
                    memcpy(func_name, str, len);
                    func_name[len] = '\0';
                }
                func_addr = sym->n_value;
            }
            break;
            /* line number info */
        case N_SLINE:
            pc = sym->n_value + func_addr;
            if (wanted_pc >= last_pc && wanted_pc < pc)
                goto found;
            last_pc = pc;
            last_line_num = sym->n_desc;
            /* XXX: slow! */
            strcpy(last_func_name, func_name);
            break;
            /* include files */
        case N_BINCL:
            str = stabstr_section->data + sym->n_strx;
        add_incl:
            if (incl_index < INCLUDE_STACK_SIZE) {
                incl_files[incl_index++] = str;
            }
            break;
        case N_EINCL:
            if (incl_index > 1)
                incl_index--;
            break;
        case N_SO:
            if (sym->n_strx == 0) {
                incl_index = 0; /* end of translation unit */
            } else {
                str = stabstr_section->data + sym->n_strx;
                /* do not add path */
                len = strlen(str);
                if (len > 0 && str[len - 1] != '/')
                    goto add_incl;
            }
            break;
        }
        sym++;
    }

    /* second pass: we try symtab symbols (no line number info) */
    incl_index = 0;
    {
        ElfW(Sym) *sym, *sym_end;
        int type;

        sym_end = (ElfW(Sym) *)(symtab_section->data + symtab_section->data_offset);
        for(sym = (ElfW(Sym) *)symtab_section->data + 1; 
            sym < sym_end;
            sym++) {
            type = ELFW(ST_TYPE)(sym->st_info);
            if (type == STT_FUNC) {
                if (wanted_pc >= sym->st_value &&
                    wanted_pc < sym->st_value + sym->st_size) {
                    pstrcpy(last_func_name, sizeof(last_func_name),
                            strtab_section->data + sym->st_name);
                    func_addr = sym->st_value;
                    goto found;
                }
            }
        }
    }
    /* did not find any info: */
    fprintf(stderr, " ???\n");
    return 0;
 found:
    if (last_func_name[0] != '\0') {
        fprintf(stderr, " %s()", last_func_name);
    }
    if (incl_index > 0) {
        fprintf(stderr, " (%s:%d", 
                incl_files[incl_index - 1], last_line_num);
        for(i = incl_index - 2; i >= 0; i--)
            fprintf(stderr, ", included from %s", incl_files[i]);
        fprintf(stderr, ")");
    }
    fprintf(stderr, "\n");
    return func_addr;
}

#ifdef __i386__
/* fix for glibc 2.1 */
#ifndef REG_EIP
#define REG_EIP EIP
#define REG_EBP EBP
#endif

/* return the PC at frame level 'level'. Return non zero if not found */
static int rt_get_caller_pc(unsigned long *paddr, 
                            ucontext_t *uc, int level)
{
    unsigned long fp;
    int i;

    if (level == 0) {
#if defined(__FreeBSD__)
        *paddr = uc->uc_mcontext.mc_eip;
#elif defined(__dietlibc__)
        *paddr = uc->uc_mcontext.eip;
#else
        *paddr = uc->uc_mcontext.gregs[REG_EIP];
#endif
        return 0;
    } else {
#if defined(__FreeBSD__) 
        fp = uc->uc_mcontext.mc_ebp;
#elif defined(__dietlibc__)
        fp = uc->uc_mcontext.ebp;
#else
        fp = uc->uc_mcontext.gregs[REG_EBP];
#endif
        for(i=1;i<level;i++) {
            /* XXX: check address validity with program info */
            if (fp <= 0x1000 || fp >= 0xc0000000)
                return -1;
            fp = ((unsigned long *)fp)[0];
        }
        *paddr = ((unsigned long *)fp)[1];
        return 0;
    }
}
#elif defined(__x86_64__)
/* return the PC at frame level 'level'. Return non zero if not found */
static int rt_get_caller_pc(unsigned long *paddr,
                            ucontext_t *uc, int level)
{
    unsigned long fp;
    int i;

    if (level == 0) {
        /* XXX: only support linux */
        *paddr = uc->uc_mcontext.gregs[REG_RIP];
        return 0;
    } else {
        fp = uc->uc_mcontext.gregs[REG_RBP];
        for(i=1;i<level;i++) {
            /* XXX: check address validity with program info */
            if (fp <= 0x1000)
                return -1;
            fp = ((unsigned long *)fp)[0];
        }
        *paddr = ((unsigned long *)fp)[1];
        return 0;
    }
}
#else
#warning add arch specific rt_get_caller_pc()
static int rt_get_caller_pc(unsigned long *paddr,
                            ucontext_t *uc, int level)
{
    return -1;
}
#endif

/* emit a run time error at position 'pc' */
void rt_error(ucontext_t *uc, const char *fmt, ...)
{
    va_list ap;
    unsigned long pc;
    int i;

    va_start(ap, fmt);
    fprintf(stderr, "Runtime error: ");
    vfprintf(stderr, fmt, ap);
    fprintf(stderr, "\n");
    for(i=0;i<num_callers;i++) {
        if (rt_get_caller_pc(&pc, uc, i) < 0)
            break;
        if (i == 0)
            fprintf(stderr, "at ");
        else
            fprintf(stderr, "by ");
        pc = rt_printline(pc);
        if (pc == rt_prog_main && pc)
            break;
    }
    exit(255);
    va_end(ap);
}

/* signal handler for fatal errors */
static void sig_error(int signum, siginfo_t *siginf, void *puc)
{
    ucontext_t *uc = puc;

    switch(signum) {
    case SIGFPE:
        switch(siginf->si_code) {
        case FPE_INTDIV:
        case FPE_FLTDIV:
            rt_error(uc, "division by zero");
            break;
        default:
            rt_error(uc, "floating point exception");
            break;
        }
        break;
    case SIGBUS:
    case SIGSEGV:
        if (rt_bound_error_msg && *rt_bound_error_msg)
            rt_error(uc, *rt_bound_error_msg);
        else
            rt_error(uc, "dereferencing invalid pointer");
        break;
    case SIGILL:
        rt_error(uc, "illegal instruction");
        break;
    case SIGABRT:
        rt_error(uc, "abort() called");
        break;
    default:
        rt_error(uc, "caught signal %d", signum);
        break;
    }
    exit(255);
}

#endif

/* copy code into memory passed in by the caller and do all relocations
   (needed before using tcc_get_symbol()).
   returns -1 on error and required size if ptr is NULL */
int tcc_relocate(TCCState *s1, void *ptr)
{
    Section *s;
    unsigned long offset, length;
    uplong mem;
    int i;

    if (0 == s1->runtime_added) {
        s1->runtime_added = 1;
        s1->nb_errors = 0;
#ifdef TCC_TARGET_PE
        pe_output_file(s1, NULL);
#else
        tcc_add_runtime(s1);
        relocate_common_syms();
        tcc_add_linker_symbols(s1);
        build_got_entries(s1);
#endif
        if (s1->nb_errors)
            return -1;
    }

    offset = 0, mem = (uplong)ptr;
    for(i = 1; i < s1->nb_sections; i++) {
        s = s1->sections[i];
        if (0 == (s->sh_flags & SHF_ALLOC))
            continue;
        length = s->data_offset;
        s->sh_addr = mem ? (mem + offset + 15) & ~15 : 0;
        offset = (offset + length + 15) & ~15;
    }

    /* relocate symbols */
    relocate_syms(s1, 1);
    if (s1->nb_errors)
        return -1;

#ifndef TCC_TARGET_PE
#ifdef TCC_TARGET_X86_64
    s1->runtime_plt_and_got_offset = 0;
    s1->runtime_plt_and_got = (char *)(mem + offset);
    /* double the size of the buffer for got and plt entries
       XXX: calculate exact size for them? */
    offset *= 2;
#endif
#endif

    if (0 == mem)
        return offset + 15;

    /* relocate each section */
    for(i = 1; i < s1->nb_sections; i++) {
        s = s1->sections[i];
        if (s->reloc)
            relocate_section(s1, s);
    }

    for(i = 1; i < s1->nb_sections; i++) {
        s = s1->sections[i];
        if (0 == (s->sh_flags & SHF_ALLOC))
            continue;
        length = s->data_offset;
        // printf("%-12s %08x %04x\n", s->name, s->sh_addr, length);
        ptr = (void*)(uplong)s->sh_addr;
        if (NULL == s->data || s->sh_type == SHT_NOBITS)
            memset(ptr, 0, length);
        else
            memcpy(ptr, s->data, length);
        /* mark executable sections as executable in memory */
        if (s->sh_flags & SHF_EXECINSTR)
            set_pages_executable(ptr, length);
    }
#ifndef TCC_TARGET_PE
#ifdef TCC_TARGET_X86_64
    set_pages_executable(s1->runtime_plt_and_got,
                         s1->runtime_plt_and_got_offset);
#endif
#endif
    return 0;
}

/* launch the compiled program with the given arguments */
int tcc_run(TCCState *s1, int argc, char **argv)
{
    int (*prog_main)(int, char **);
    void *ptr;
    int ret;

    ret = tcc_relocate(s1, NULL);
    if (ret < 0)
        return -1;
    ptr = tcc_malloc(ret);
    tcc_relocate(s1, ptr);

    prog_main = tcc_get_symbol_err(s1, "main");
    
    if (s1->do_debug) {
#ifdef CONFIG_TCC_BACKTRACE
        struct sigaction sigact;
        /* install TCC signal handlers to print debug info on fatal
           runtime errors */
        sigact.sa_flags = SA_SIGINFO | SA_RESETHAND;
        sigact.sa_sigaction = sig_error;
        sigemptyset(&sigact.sa_mask);
        sigaction(SIGFPE, &sigact, NULL);
        sigaction(SIGILL, &sigact, NULL);
        sigaction(SIGSEGV, &sigact, NULL);
        sigaction(SIGBUS, &sigact, NULL);
        sigaction(SIGABRT, &sigact, NULL);
#else        
        error("debug mode not available");
#endif
    }

#ifdef CONFIG_TCC_BCHECK
    if (s1->do_bounds_check) {
        void (*bound_init)(void);
        void (*bound_exit)(void);
        /* set error function */
        rt_bound_error_msg = tcc_get_symbol_err(s1, "__bound_error_msg");
        rt_prog_main = (unsigned long)prog_main;
        /* XXX: use .init section so that it also work in binary ? */
        bound_init = tcc_get_symbol_err(s1, "__bound_init");
        bound_exit = tcc_get_symbol_err(s1, "__bound_exit");
        bound_init();
        ret = (*prog_main)(argc, argv);
        bound_exit();
    } else
#endif
    ret = (*prog_main)(argc, argv);
    tcc_free(ptr);
    return ret;
}

void tcc_memstats(void)
{
#ifdef MEM_DEBUG
    printf("memory in use: %d\n", mem_cur_size);
#endif
}

static void tcc_cleanup(void)
{
    int i, n;

    if (NULL == tcc_state)
        return;
    tcc_state = NULL;

    /* free -D defines */
    free_defines(NULL);

    /* free tokens */
    n = tok_ident - TOK_IDENT;
    for(i = 0; i < n; i++)
        tcc_free(table_ident[i]);
    tcc_free(table_ident);

    /* free sym_pools */
    dynarray_reset(&sym_pools, &nb_sym_pools);
    /* string buffer */
    cstr_free(&tokcstr);
    /* reset symbol stack */
    sym_free_first = NULL;
    /* cleanup from error/setjmp */
    macro_ptr = NULL;
}

TCCState *tcc_new(void)
{
    TCCState *s;

    tcc_cleanup();

    s = tcc_mallocz(sizeof(TCCState));
    if (!s)
        return NULL;
    tcc_state = s;
#ifdef _WIN32
    tcc_set_lib_path_w32(s);
#else
    tcc_set_lib_path(s, CONFIG_TCCDIR);
#endif
    s->output_type = TCC_OUTPUT_MEMORY;
    preprocess_new();

    /* we add dummy defines for some special macros to speed up tests
       and to have working defined() */
    define_push(TOK___LINE__, MACRO_OBJ, NULL, NULL);
    define_push(TOK___FILE__, MACRO_OBJ, NULL, NULL);
    define_push(TOK___DATE__, MACRO_OBJ, NULL, NULL);
    define_push(TOK___TIME__, MACRO_OBJ, NULL, NULL);

    /* standard defines */
    tcc_define_symbol(s, "__STDC__", NULL);
    tcc_define_symbol(s, "__STDC_VERSION__", "199901L");
#if defined(TCC_TARGET_I386)
    tcc_define_symbol(s, "__i386__", NULL);
#endif
#if defined(TCC_TARGET_X86_64)
    tcc_define_symbol(s, "__x86_64__", NULL);
#endif
#if defined(TCC_TARGET_ARM)
    tcc_define_symbol(s, "__ARM_ARCH_4__", NULL);
    tcc_define_symbol(s, "__arm_elf__", NULL);
    tcc_define_symbol(s, "__arm_elf", NULL);
    tcc_define_symbol(s, "arm_elf", NULL);
    tcc_define_symbol(s, "__arm__", NULL);
    tcc_define_symbol(s, "__arm", NULL);
    tcc_define_symbol(s, "arm", NULL);
    tcc_define_symbol(s, "__APCS_32__", NULL);
#endif
#ifdef TCC_TARGET_PE
    tcc_define_symbol(s, "_WIN32", NULL);
#ifdef TCC_TARGET_X86_64
    tcc_define_symbol(s, "_WIN64", NULL);
#endif
#else
    tcc_define_symbol(s, "__unix__", NULL);
    tcc_define_symbol(s, "__unix", NULL);
#if defined(__linux)
    tcc_define_symbol(s, "__linux__", NULL);
    tcc_define_symbol(s, "__linux", NULL);
#endif
#endif
    /* tiny C specific defines */
    tcc_define_symbol(s, "__TINYC__", NULL);

    /* tiny C & gcc defines */
    tcc_define_symbol(s, "__SIZE_TYPE__", "unsigned int");
    tcc_define_symbol(s, "__PTRDIFF_TYPE__", "int");
#ifdef TCC_TARGET_PE
    tcc_define_symbol(s, "__WCHAR_TYPE__", "unsigned short");
#else
    tcc_define_symbol(s, "__WCHAR_TYPE__", "int");
#endif
    
#ifndef TCC_TARGET_PE
    /* default library paths */
    tcc_add_library_path(s, CONFIG_SYSROOT "/usr/local/lib");
    tcc_add_library_path(s, CONFIG_SYSROOT "/usr/lib");
    tcc_add_library_path(s, CONFIG_SYSROOT "/lib");
#endif

    /* no section zero */
    dynarray_add((void ***)&s->sections, &s->nb_sections, NULL);

    /* create standard sections */
    text_section = new_section(s, ".text", SHT_PROGBITS, SHF_ALLOC | SHF_EXECINSTR);
    data_section = new_section(s, ".data", SHT_PROGBITS, SHF_ALLOC | SHF_WRITE);
    bss_section = new_section(s, ".bss", SHT_NOBITS, SHF_ALLOC | SHF_WRITE);

    /* symbols are always generated for linking stage */
    symtab_section = new_symtab(s, ".symtab", SHT_SYMTAB, 0,
                                ".strtab",
                                ".hashtab", SHF_PRIVATE); 
    strtab_section = symtab_section->link;
    
    /* private symbol table for dynamic symbols */
    s->dynsymtab_section = new_symtab(s, ".dynsymtab", SHT_SYMTAB, SHF_PRIVATE,
                                      ".dynstrtab", 
                                      ".dynhashtab", SHF_PRIVATE);
    s->alacarte_link = 1;

#ifdef CHAR_IS_UNSIGNED
    s->char_is_unsigned = 1;
#endif
#if defined(TCC_TARGET_PE) && 0
    /* XXX: currently the PE linker is not ready to support that */
    s->leading_underscore = 1;
#endif
    return s;
}

void tcc_delete(TCCState *s1)
{
    int i;

    tcc_cleanup();

    /* free all sections */
    for(i = 1; i < s1->nb_sections; i++)
        free_section(s1->sections[i]);
    dynarray_reset(&s1->sections, &s1->nb_sections);

    for(i = 0; i < s1->nb_priv_sections; i++)
        free_section(s1->priv_sections[i]);
    dynarray_reset(&s1->priv_sections, &s1->nb_priv_sections);
        
    /* free any loaded DLLs */
    for ( i = 0; i < s1->nb_loaded_dlls; i++) {
        DLLReference *ref = s1->loaded_dlls[i];
        if ( ref->handle )
            dlclose(ref->handle);
    }
    
    /* free loaded dlls array */
    dynarray_reset(&s1->loaded_dlls, &s1->nb_loaded_dlls);

    /* free library paths */
    dynarray_reset(&s1->library_paths, &s1->nb_library_paths);

    /* free include paths */
    dynarray_reset(&s1->cached_includes, &s1->nb_cached_includes);
    dynarray_reset(&s1->include_paths, &s1->nb_include_paths);
    dynarray_reset(&s1->sysinclude_paths, &s1->nb_sysinclude_paths);

    tcc_free(s1->tcc_lib_path);
    tcc_free(s1);
}

int tcc_add_include_path(TCCState *s1, const char *pathname)
{
    char *pathname1;
    
    pathname1 = tcc_strdup(pathname);
    dynarray_add((void ***)&s1->include_paths, &s1->nb_include_paths, pathname1);
    return 0;
}

int tcc_add_sysinclude_path(TCCState *s1, const char *pathname)
{
    char *pathname1;
    
    pathname1 = tcc_strdup(pathname);
    dynarray_add((void ***)&s1->sysinclude_paths, &s1->nb_sysinclude_paths, pathname1);
    return 0;
}

static int tcc_add_file_internal(TCCState *s1, const char *filename, int flags)
{
    const char *ext;
    ElfW(Ehdr) ehdr;
    int fd, ret, size;
    BufferedFile *saved_file;

    ret = -1;

    /* find source file type with extension */
    ext = tcc_fileextension(filename);
    if (ext[0])
        ext++;

    /* open the file */
    saved_file = file;
    file = tcc_open(s1, filename);
    if (!file) {
        if (flags & AFF_PRINT_ERROR)
            error_noabort("file '%s' not found", filename);
        goto the_end;
    }

    if (flags & AFF_PREPROCESS) {
        ret = tcc_preprocess(s1);
        goto the_end;
    }

    if (!ext[0] || !PATHCMP(ext, "c")) {
        /* C file assumed */
        ret = tcc_compile(s1);
        goto the_end;
    }

#ifdef CONFIG_TCC_ASM
    if (!strcmp(ext, "S")) {
        /* preprocessed assembler */
        ret = tcc_assemble(s1, 1);
        goto the_end;
    }

    if (!strcmp(ext, "s")) {
        /* non preprocessed assembler */
        ret = tcc_assemble(s1, 0);
        goto the_end;
    }
#endif

    fd = file->fd;
    /* assume executable format: auto guess file type */
    size = read(fd, &ehdr, sizeof(ehdr));
    lseek(fd, 0, SEEK_SET);
    if (size <= 0) {
        error_noabort("could not read header");
        goto the_end;
    }

    if (size == sizeof(ehdr) &&
        ehdr.e_ident[0] == ELFMAG0 &&
        ehdr.e_ident[1] == ELFMAG1 &&
        ehdr.e_ident[2] == ELFMAG2 &&
        ehdr.e_ident[3] == ELFMAG3) {

        /* do not display line number if error */
        file->line_num = 0;
        if (ehdr.e_type == ET_REL) {
            ret = tcc_load_object_file(s1, fd, 0);
            goto the_end;

        }
#ifndef TCC_TARGET_PE
        if (ehdr.e_type == ET_DYN) {
            if (s1->output_type == TCC_OUTPUT_MEMORY) {
                void *h;
                h = dlopen(filename, RTLD_GLOBAL | RTLD_LAZY);
                if (h)
                    ret = 0;
            } else {
                ret = tcc_load_dll(s1, fd, filename, 
                                   (flags & AFF_REFERENCED_DLL) != 0);
            }
            goto the_end;
        }
#endif
        error_noabort("unrecognized ELF file");
        goto the_end;
    }

    if (memcmp((char *)&ehdr, ARMAG, 8) == 0) {
        file->line_num = 0; /* do not display line number if error */
        ret = tcc_load_archive(s1, fd);
        goto the_end;
    }

#ifdef TCC_TARGET_COFF
    if (*(uint16_t *)(&ehdr) == COFF_C67_MAGIC) {
        ret = tcc_load_coff(s1, fd);
        goto the_end;
    }
#endif

#ifdef TCC_TARGET_PE
    ret = pe_load_file(s1, filename, fd);
#else
    /* as GNU ld, consider it is an ld script if not recognized */
    ret = tcc_load_ldscript(s1);
#endif
    if (ret < 0)
        error_noabort("unrecognized file type");

the_end:
    if (file)
        tcc_close(file);
    file = saved_file;
    return ret;
}

int tcc_add_file(TCCState *s, const char *filename)
{
    if (s->output_type == TCC_OUTPUT_PREPROCESS)
        return tcc_add_file_internal(s, filename, AFF_PRINT_ERROR | AFF_PREPROCESS);
    else
        return tcc_add_file_internal(s, filename, AFF_PRINT_ERROR);
}

int tcc_add_library_path(TCCState *s, const char *pathname)
{
    char *pathname1;
    
    pathname1 = tcc_strdup(pathname);
    dynarray_add((void ***)&s->library_paths, &s->nb_library_paths, pathname1);
    return 0;
}

/* find and load a dll. Return non zero if not found */
/* XXX: add '-rpath' option support ? */
static int tcc_add_dll(TCCState *s, const char *filename, int flags)
{
    char buf[1024];
    int i;

    for(i = 0; i < s->nb_library_paths; i++) {
        snprintf(buf, sizeof(buf), "%s/%s", 
                 s->library_paths[i], filename);
        if (tcc_add_file_internal(s, buf, flags) == 0)
            return 0;
    }
    return -1;
}

/* the library name is the same as the argument of the '-l' option */
int tcc_add_library(TCCState *s, const char *libraryname)
{
    char buf[1024];
    int i;
    
    /* first we look for the dynamic library if not static linking */
    if (!s->static_link) {
#ifdef TCC_TARGET_PE
        if (pe_add_dll(s, libraryname) == 0)
            return 0;
#else
        snprintf(buf, sizeof(buf), "lib%s.so", libraryname);
        if (tcc_add_dll(s, buf, 0) == 0)
            return 0;
#endif
    }
    /* then we look for the static library */
    for(i = 0; i < s->nb_library_paths; i++) {
        snprintf(buf, sizeof(buf), "%s/lib%s.a", 
                 s->library_paths[i], libraryname);
        if (tcc_add_file_internal(s, buf, 0) == 0)
            return 0;
    }
    return -1;
}

int tcc_add_symbol(TCCState *s, const char *name, void *val)
{
    add_elf_sym(symtab_section, (uplong)val, 0,
                ELFW(ST_INFO)(STB_GLOBAL, STT_NOTYPE), 0,
                SHN_ABS, name);
    return 0;
}

int tcc_set_output_type(TCCState *s, int output_type)
{
    char buf[1024];

    s->output_type = output_type;

    if (!s->nostdinc) {
        /* default include paths */
        /* XXX: reverse order needed if -isystem support */
#ifndef TCC_TARGET_PE
        tcc_add_sysinclude_path(s, CONFIG_SYSROOT "/usr/local/include");
        tcc_add_sysinclude_path(s, CONFIG_SYSROOT "/usr/include");
#endif
        snprintf(buf, sizeof(buf), "%s/include", s->tcc_lib_path);
        tcc_add_sysinclude_path(s, buf);
#ifdef TCC_TARGET_PE
        snprintf(buf, sizeof(buf), "%s/include/winapi", s->tcc_lib_path);
        tcc_add_sysinclude_path(s, buf);
#endif
    }

    /* if bound checking, then add corresponding sections */
#ifdef CONFIG_TCC_BCHECK
    if (s->do_bounds_check) {
        /* define symbol */
        tcc_define_symbol(s, "__BOUNDS_CHECKING_ON", NULL);
        /* create bounds sections */
        bounds_section = new_section(s, ".bounds", 
                                     SHT_PROGBITS, SHF_ALLOC);
        lbounds_section = new_section(s, ".lbounds", 
                                      SHT_PROGBITS, SHF_ALLOC);
    }
#endif

    if (s->char_is_unsigned) {
        tcc_define_symbol(s, "__CHAR_UNSIGNED__", NULL);
    }

    /* add debug sections */
    if (s->do_debug) {
        /* stab symbols */
        stab_section = new_section(s, ".stab", SHT_PROGBITS, 0);
        stab_section->sh_entsize = sizeof(Stab_Sym);
        stabstr_section = new_section(s, ".stabstr", SHT_STRTAB, 0);
        put_elf_str(stabstr_section, "");
        stab_section->link = stabstr_section;
        /* put first entry */
        put_stabs("", 0, 0, 0, 0);
    }

    /* add libc crt1/crti objects */
#ifndef TCC_TARGET_PE
    if ((output_type == TCC_OUTPUT_EXE || output_type == TCC_OUTPUT_DLL) &&
        !s->nostdlib) {
        if (output_type != TCC_OUTPUT_DLL)
            tcc_add_file(s, CONFIG_TCC_CRT_PREFIX "/crt1.o");
        tcc_add_file(s, CONFIG_TCC_CRT_PREFIX "/crti.o");
    }
#endif

#ifdef TCC_TARGET_PE
    snprintf(buf, sizeof(buf), "%s/lib", s->tcc_lib_path);
    tcc_add_library_path(s, buf);
#ifdef _WIN32
    if (GetSystemDirectory(buf, sizeof buf))
        tcc_add_library_path(s, buf);
#endif
#endif

    return 0;
}

#define WD_ALL    0x0001 /* warning is activated when using -Wall */
#define FD_INVERT 0x0002 /* invert value before storing */

typedef struct FlagDef {
    uint16_t offset;
    uint16_t flags;
    const char *name;
} FlagDef;

static const FlagDef warning_defs[] = {
    { offsetof(TCCState, warn_unsupported), 0, "unsupported" },
    { offsetof(TCCState, warn_write_strings), 0, "write-strings" },
    { offsetof(TCCState, warn_error), 0, "error" },
    { offsetof(TCCState, warn_implicit_function_declaration), WD_ALL,
      "implicit-function-declaration" },
};

static int set_flag(TCCState *s, const FlagDef *flags, int nb_flags,
                    const char *name, int value)
{
    int i;
    const FlagDef *p;
    const char *r;

    r = name;
    if (r[0] == 'n' && r[1] == 'o' && r[2] == '-') {
        r += 3;
        value = !value;
    }
    for(i = 0, p = flags; i < nb_flags; i++, p++) {
        if (!strcmp(r, p->name))
            goto found;
    }
    return -1;
 found:
    if (p->flags & FD_INVERT)
        value = !value;
    *(int *)((uint8_t *)s + p->offset) = value;
    return 0;
}


/* set/reset a warning */
int tcc_set_warning(TCCState *s, const char *warning_name, int value)
{
    int i;
    const FlagDef *p;

    if (!strcmp(warning_name, "all")) {
        for(i = 0, p = warning_defs; i < countof(warning_defs); i++, p++) {
            if (p->flags & WD_ALL)
                *(int *)((uint8_t *)s + p->offset) = 1;
        }
        return 0;
    } else {
        return set_flag(s, warning_defs, countof(warning_defs),
                        warning_name, value);
    }
}

static const FlagDef flag_defs[] = {
    { offsetof(TCCState, char_is_unsigned), 0, "unsigned-char" },
    { offsetof(TCCState, char_is_unsigned), FD_INVERT, "signed-char" },
    { offsetof(TCCState, nocommon), FD_INVERT, "common" },
    { offsetof(TCCState, leading_underscore), 0, "leading-underscore" },
};

/* set/reset a flag */
int tcc_set_flag(TCCState *s, const char *flag_name, int value)
{
    return set_flag(s, flag_defs, countof(flag_defs),
                    flag_name, value);
}

/* set CONFIG_TCCDIR at runtime */
void tcc_set_lib_path(TCCState *s, const char *path)
{
    tcc_free(s->tcc_lib_path);
    s->tcc_lib_path = tcc_strdup(path);
}

void tcc_print_stats(TCCState *s, int64_t total_time)
{
    double tt;
    tt = (double)total_time / 1000000.0;
    if (tt < 0.001)
        tt = 0.001;
    if (total_bytes < 1)
        total_bytes = 1;
    printf("%d idents, %d lines, %d bytes, %0.3f s, %d lines/s, %0.1f MB/s\n", 
           tok_ident - TOK_IDENT, total_lines, total_bytes,
           tt, (int)(total_lines / tt),
           total_bytes / tt / 1000000.0);
}