emit.c

   1 #include "all.h"
   2
   3 enum {
   4         SecText,
   5         SecData,
   6         SecBss,
   7 };
   8
   9 void
  10 emitlnk(char *n, Lnk *l, int s, FILE *f)
  11 {
  12         static char *sec[2][3] = {
  13                 [0][SecText] = ".text",
  14                 [0][SecData] = ".data",
  15                 [0][SecBss] = ".bss",
  16                 [1][SecText] = ".abort \"unreachable\"",
  17                 [1][SecData] = ".section .tdata,\"awT\"",
  18                 [1][SecBss] = ".section .tbss,\"awT\"",
  19         };
  20         char *pfx, *sfx;
  21
  22         pfx = n[0] == '"' ? "" : T.assym;
  23         sfx = "";
  24         if (T.apple && l->thread) {
  25                 l->sec = "__DATA";
  26                 l->secf = "__thread_data,thread_local_regular";
  27                 sfx = "$tlv$init";
  28                 fputs(
  29                         ".section __DATA,__thread_vars,"
  30                         "thread_local_variables\n",
  31                         f
  32                 );
  33                 fprintf(f, "%s%s:\n", pfx, n);
  34                 fprintf(f,
  35                         "\t.quad __tlv_bootstrap\n"
  36                         "\t.quad 0\n"
  37                         "\t.quad %s%s%s\n\n",
  38                         pfx, n, sfx
  39                 );
  40         }
  41         if (l->sec) {
  42                 fprintf(f, ".section %s", l->sec);
  43                 if (l->secf)
  44                         fprintf(f, ",%s", l->secf);
  45         } else
  46                 fputs(sec[l->thread != 0][s], f);
  47         fputc('\n', f);
  48         if (l->align)
  49                 fprintf(f, ".balign %d\n", l->align);
  50         if (l->export)
  51                 fprintf(f, ".globl %s%s\n", pfx, n);
  52         fprintf(f, "%s%s%s:\n", pfx, n, sfx);
  53 }
  54
  55 void
  56 emitfnlnk(char *n, Lnk *l, FILE *f)
  57 {
  58         emitlnk(n, l, SecText, f);
  59 }
  60
  61 void
  62 emitdat(Dat *d, FILE *f)
  63 {
  64         static char *dtoa[] = {
  65                 [DB] = "\t.byte",
  66                 [DH] = "\t.short",
  67                 [DW] = "\t.int",
  68                 [DL] = "\t.quad"
  69         };
  70         static int64_t zero;
  71         char *p;
  72
  73         switch (d->type) {
  74         case DStart:
  75                 zero = 0;
  76                 break;
  77         case DEnd:
  78                 if (zero != -1) {
  79                         emitlnk(d->name, d->lnk, SecBss, f);
  80                         fprintf(f, "\t.fill %"PRId64",1,0\n", zero);
  81                 }
  82                 break;
  83         case DZ:
  84                 if (zero != -1)
  85                         zero += d->u.num;
  86                 else
  87                         fprintf(f, "\t.fill %"PRId64",1,0\n", d->u.num);
  88                 break;
  89         default:
  90                 if (zero != -1) {
  91                         emitlnk(d->name, d->lnk, SecData, f);
  92                         if (zero > 0)
  93                                 fprintf(f, "\t.fill %"PRId64",1,0\n", zero);
  94                         zero = -1;
  95                 }
  96                 if (d->isstr) {
  97                         if (d->type != DB)
  98                                 err("strings only supported for 'b' currently");
  99                         fprintf(f, "\t.ascii %s\n", d->u.str);
 100                 }
 101                 else if (d->isref) {
 102                         p = d->u.ref.name[0] == '"' ? "" : T.assym;
 103                         fprintf(f, "%s %s%s%+"PRId64"\n",
 104                                 dtoa[d->type], p, d->u.ref.name,
 105                                 d->u.ref.off);
 106                 }
 107                 else {
 108                         fprintf(f, "%s %"PRId64"\n",
 109                                 dtoa[d->type], d->u.num);
 110                 }
 111                 break;
 112         }
 113 }
 114
 115 typedef struct Asmbits Asmbits;
 116
 117 struct Asmbits {
 118         char bits[16];
 119         int size;
 120         Asmbits *link;
 121 };
 122
 123 static Asmbits *stash;
 124
 125 int
 126 stashbits(void *bits, int size)
 127 {
 128         Asmbits **pb, *b;
 129         int i;
 130
 131         assert(size == 4 || size == 8 || size == 16);
 132         for (pb=&stash, i=0; (b=*pb); pb=&b->link, i++)
 133                 if (size <= b->size)
 134                 if (memcmp(bits, b->bits, size) == 0)
 135                         return i;
 136         b = emalloc(sizeof *b);
 137         memcpy(b->bits, bits, size);
 138         b->size = size;
 139         b->link = 0;
 140         *pb = b;
 141         return i;
 142 }
 143
 144 static void
 145 emitfin(FILE *f, char *sec[3])
 146 {
 147         Asmbits *b;
 148         char *p;
 149         int lg, i;
 150         double d;
 151
 152         if (!stash)
 153                 return;
 154         fprintf(f, "/* floating point constants */\n");
 155         for (lg=4; lg>=2; lg--)
 156                 for (b=stash, i=0; b; b=b->link, i++) {
 157                         if (b->size == (1<<lg)) {
 158                                 fprintf(f,
 159                                         ".section %s\n"
 160                                         ".p2align %d\n"
 161                                         "%sfp%d:",
 162                                         sec[lg-2], lg, T.asloc, i
 163                                 );
 164                                 for (p=b->bits; p<&b->bits[b->size]; p+=4)
 165                                         fprintf(f, "\n\t.int %"PRId32,
 166                                                 *(int32_t *)p);
 167                                 if (lg <= 3) {
 168                                         if (lg == 2)
 169                                                 d = *(float *)b->bits;
 170                                         else
 171                                                 d = *(double *)b->bits;
 172                                         fprintf(f, " /* %f */\n\n", d);
 173                                 } else
 174                                         fprintf(f, "\n\n");
 175                         }
 176                 }
 177         while ((b=stash)) {
 178                 stash = b->link;
 179                 free(b);
 180         }
 181 }
 182
 183 void
 184 elf_emitfin(FILE *f)
 185 {
 186         static char *sec[3] = { ".rodata", ".rodata", ".rodata" };
 187
 188         emitfin(f ,sec);
 189         fprintf(f, ".section .note.GNU-stack,\"\",@progbits\n");
 190 }
 191
 192 void
 193 elf_emitfnfin(char *fn, FILE *f)
 194 {
 195         fprintf(f, ".type %s, @function\n", fn);
 196         fprintf(f, ".size %s, .-%s\n", fn, fn);
 197 }
 198
 199 void
 200 macho_emitfin(FILE *f)
 201 {
 202         static char *sec[3] = {
 203                 "__TEXT,__literal4,4byte_literals",
 204                 "__TEXT,__literal8,8byte_literals",
 205                 ".abort \"unreachable\"",
 206         };
 207
 208         emitfin(f, sec);
 209 }