i386-link.c

   1 #ifdef TARGET_DEFS_ONLY
   2
   3 #define EM_TCC_TARGET EM_386
   4
   5 /* relocation type for 32 bit data relocation */
   6 #define R_DATA_32   R_386_32
   7 #define R_DATA_PTR  R_386_32
   8 #define R_JMP_SLOT  R_386_JMP_SLOT
   9 #define R_GLOB_DAT  R_386_GLOB_DAT
  10 #define R_COPY      R_386_COPY
  11
  12 #define R_NUM       R_386_NUM
  13
  14 #define ELF_START_ADDR 0x08048000
  15 #define ELF_PAGE_SIZE  0x1000
  16
  17 #define HAVE_SECTION_RELOC
  18 #define PCRELATIVE_DLLPLT 0
  19
  20 #else /* !TARGET_DEFS_ONLY */
  21
  22 #include "tcc.h"
  23
  24 /* Returns 1 for a code relocation, 0 for a data relocation. For unknown
  25    relocations, returns -1. */
  26 int code_reloc (int reloc_type)
  27 {
  28     switch (reloc_type) {
  29         case R_386_16:
  30         case R_386_32:
  31         case R_386_GOTPC:
  32         case R_386_GOTOFF:
  33         case R_386_GOT32:
  34         case R_386_GOT32X:
  35         case R_386_GLOB_DAT:
  36         case R_386_COPY:
  37             return 0;
  38
  39         case R_386_PC16:
  40         case R_386_PC32:
  41         case R_386_PLT32:
  42         case R_386_JMP_SLOT:
  43             return 1;
  44     }
  45
  46     tcc_error ("Unknown relocation type: %d", reloc_type);
  47     return -1;
  48 }
  49
  50 /* Returns an enumerator to describe wether and when the relocation needs a
  51    GOT and/or PLT entry to be created. See tcc.h for a description of the
  52    different values. */
  53 int gotplt_entry_type (int reloc_type)
  54 {
  55     switch (reloc_type) {
  56         case R_386_16:
  57         case R_386_32:
  58         case R_386_GLOB_DAT:
  59         case R_386_JMP_SLOT:
  60         case R_386_COPY:
  61             return NO_GOTPLT_ENTRY;
  62
  63         case R_386_PC16:
  64         case R_386_PC32:
  65             return AUTO_GOTPLT_ENTRY;
  66
  67         case R_386_GOTPC:
  68         case R_386_GOTOFF:
  69             return BUILD_GOT_ONLY;
  70
  71         case R_386_GOT32:
  72         case R_386_GOT32X:
  73         case R_386_PLT32:
  74             return ALWAYS_GOTPLT_ENTRY;
  75     }
  76
  77     tcc_error ("Unknown relocation type: %d", reloc_type);
  78     return -1;
  79 }
  80
  81 static ElfW_Rel *qrel; /* ptr to next reloc entry reused */
  82
  83 void relocate_init(Section *sr)
  84 {
  85     qrel = (ElfW_Rel *) sr->data;
  86 }
  87
  88 void relocate(TCCState *s1, ElfW_Rel *rel, int type, char *ptr, addr_t addr, addr_t val)
  89 {
  90     int sym_index, esym_index;
  91
  92     sym_index = ELFW(R_SYM)(rel->r_info);
  93
  94     switch (type) {
  95         case R_386_32:
  96             if (s1->output_type == TCC_OUTPUT_DLL) {
  97                 esym_index = s1->symtab_to_dynsym[sym_index];
  98                 qrel->r_offset = rel->r_offset;
  99                 if (esym_index) {
 100                     qrel->r_info = ELFW(R_INFO)(esym_index, R_386_32);
 101                     qrel++;
 102                     return;
 103                 } else {
 104                     qrel->r_info = ELFW(R_INFO)(0, R_386_RELATIVE);
 105                     qrel++;
 106                 }
 107             }
 108             add32le(ptr, val);
 109             return;
 110         case R_386_PC32:
 111             if (s1->output_type == TCC_OUTPUT_DLL) {
 112                 /* DLL relocation */
 113                 esym_index = s1->symtab_to_dynsym[sym_index];
 114                 if (esym_index) {
 115                     qrel->r_offset = rel->r_offset;
 116                     qrel->r_info = ELFW(R_INFO)(esym_index, R_386_PC32);
 117                     qrel++;
 118                     return;
 119                 }
 120             }
 121             add32le(ptr, val - addr);
 122             return;
 123         case R_386_PLT32:
 124             add32le(ptr, val - addr);
 125             return;
 126         case R_386_GLOB_DAT:
 127         case R_386_JMP_SLOT:
 128             write32le(ptr, val);
 129             return;
 130         case R_386_GOTPC:
 131             add32le(ptr, s1->got->sh_addr - addr);
 132             return;
 133         case R_386_GOTOFF:
 134             add32le(ptr, val - s1->got->sh_addr);
 135             return;
 136         case R_386_GOT32:
 137         case R_386_GOT32X:
 138             /* we load the got offset */
 139             add32le(ptr, s1->sym_attrs[sym_index].got_offset);
 140             return;
 141         case R_386_16:
 142             if (s1->output_format != TCC_OUTPUT_FORMAT_BINARY) {
 143             output_file:
 144                 tcc_error("can only produce 16-bit binary files");
 145             }
 146             write16le(ptr, read16le(ptr) + val);
 147             return;
 148         case R_386_PC16:
 149             if (s1->output_format != TCC_OUTPUT_FORMAT_BINARY)
 150                 goto output_file;
 151             write16le(ptr, read16le(ptr) + val - addr);
 152             return;
 153         case R_386_RELATIVE:
 154             /* do nothing */
 155             return;
 156         case R_386_COPY:
 157             /* This reloction must copy initialized data from the library
 158             to the program .bss segment. Currently made like for ARM
 159             (to remove noise of defaukt case). Is this true?
 160             */
 161             return;
 162         default:
 163             fprintf(stderr,"FIXME: handle reloc type %d at %x [%p] to %x\n",
 164                 type, (unsigned)addr, ptr, (unsigned)val);
 165             return;
 166     }
 167 }
 168
 169 #endif /* !TARGET_DEFS_ONLY */