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Fixed bug in tc-i386.c which in rare but unpredictable circumstances would 

screw up PC relative offsets to _GLOBAL_SYMBOL_TABLE_ (caused by me not quite
understanding the inner workings of this phenomenon called `obstack').
Thanks to Thomas Eberhardt for creating rare and unpredictable circumstances.

Changes to obj-aout.c to handle non-absolute `.size' expressions and to set
the `n_other' field of symbols to the symbols type, as given by `.type'
directives.
This commit is contained in:
pk 1993-11-20 22:15:54 +00:00
parent facd69a0ee
commit 7895f44731
4 changed files with 99 additions and 36 deletions
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6
gnu/usr.bin/gas/config/aout.h
View File

@ -64,6 +64,12 @@ enum reloc_type {
#endif /* not TC_SPARC */ #endif /* not TC_SPARC */
NO_RELOC, NO_RELOC,
#ifdef TC_I386
/* Used internally by gas */
RELOC_GOT,
RELOC_GOTOFF,
#endif
#endif /* not TC_I860 */ #endif /* not TC_I860 */
#endif /* not TC_M88K */ #endif /* not TC_M88K */
}; };

74
gnu/usr.bin/gas/config/obj-aout.c
View File

@ -99,7 +99,7 @@ const pseudo_typeS obj_pseudo_table[] = {
{ "scl", s_ignore, 0 }, { "scl", s_ignore, 0 },
{ "size", s_size, 0 }, { "size", s_size, 0 },
{ "tag", s_ignore, 0 }, { "tag", s_ignore, 0 },
{ "type", s_ignore, 0 }, { "type", s_type, 0 },
{ "val", s_ignore, 0 }, { "val", s_ignore, 0 },
{ "version", s_ignore, 0 }, { "version", s_ignore, 0 },
@ -228,8 +228,42 @@ symbolS *symbol_rootP;
temp = S_GET_NAME(symbolP); temp = S_GET_NAME(symbolP);
S_SET_OFFSET(symbolP, symbolP->sy_name_offset); S_SET_OFFSET(symbolP, symbolP->sy_name_offset);
/*
* Put aux info in lower four bits of `n_other' field
* Do this only now, because things like S_IS_DEFINED()
* depend on S_GET_OTHER() for some unspecified reason.
*/
if (symbolP->sy_aux)
S_SET_OTHER(symbolP, (symbolP->sy_aux & 0xf));
/* Any symbol still undefined and is not a dbg symbol is made N_EXT. */ /* Any symbol still undefined and is not a dbg symbol is made N_EXT. */
if (!S_IS_DEBUG(symbolP) && !S_IS_DEFINED(symbolP)) S_SET_EXTERNAL(symbolP); if (!S_IS_DEBUG(symbolP) && !S_IS_DEFINED(symbolP))
S_SET_EXTERNAL(symbolP);
if (S_GET_TYPE(symbolP) == N_SIZE) {
expressionS *exp = (expressionS*)symbolP->sy_sizexp;
long size = 0;
if (exp == NULL) {
as_bad("Internal error: no size expression");
return;
}
switch (exp->X_seg) {
case SEG_ABSOLUTE:
size = exp->X_add_number;
break;
case SEG_DIFFERENCE:
size = S_GET_VALUE(exp->X_add_symbol) -
S_GET_VALUE(exp->X_subtract_symbol) +
exp->X_add_number;
break;
default:
as_bad("Unsupported .size expression");
break;
}
S_SET_VALUE(symbolP, size);
}
obj_symbol_to_chars(where, symbolP); obj_symbol_to_chars(where, symbolP);
S_SET_NAME(symbolP,temp); S_SET_NAME(symbolP,temp);
@ -458,6 +492,8 @@ object_headers *headers;
* symbols with no name (stabd's?) * symbols with no name (stabd's?)
* symbols with debug info in their N_TYPE * symbols with debug info in their N_TYPE
* symbols marked "forceout" (to force out local `L'
symbols in PIC code)
Symbols that don't are: Symbols that don't are:
* symbols that are registers * symbols that are registers
@ -506,31 +542,39 @@ object_headers *headers;
/* /*
* If symbol has a known size, output an extra symbol * If symbol has a known size, output an extra symbol
* of type N_SIZE and with the same name. * of type N_SIZE and with the same name.
* We cannot evaluate the size expression just yet, as
* some its terms may not have had their final values
* set. We defer this until `obj_emit_symbols()'
*/ */
if (symbolP->sy_size && flagseen['k']) { if (flagseen['k'] &&
S_GET_TYPE(symbolP) != N_SIZE &&
#ifndef GRACE_PERIOD_EXPIRED
/*Can be enabled when no more old ld's around*/
(symbolP->sy_aux == AUX_OBJECT) &&
#endif
symbolP->sy_sizexp) {
symbolS *addme; symbolS *addme;
#ifdef USE_NSIZE_PREFIX /*XXX*/
/* Put a new symbol on the chain */
#ifdef NSIZE_PREFIX /*XXX*/
char buf[BUFSIZ]; char buf[BUFSIZ];
/* buf[0] = NSIZE_PREFIX;
* Changed my mind, make name: "=symbol"
*/
buf[0] = '=';
strncpy(buf+1, S_GET_NAME(symbolP), BUFSIZ-2); strncpy(buf+1, S_GET_NAME(symbolP), BUFSIZ-2);
addme = symbol_make(buf); addme = symbol_make(buf);
#else #else
addme = symbol_make(S_GET_NAME(symbolP)); addme = symbol_make(S_GET_NAME(symbolP));
#endif #endif
#if 0 /* Set type and transfer size expression */
S_SET_SEGMENT(addme, SEG_SIZE);
#endif
addme->sy_symbol.n_type = N_SIZE; addme->sy_symbol.n_type = N_SIZE;
S_SET_VALUE(addme, symbolP->sy_size); addme->sy_sizexp = symbolP->sy_sizexp;
/* Set external if symbolP is ? */ symbolP->sy_sizexp = NULL;
#if 1
/* Set external if symbolP is */
if (S_IS_EXTERN(symbolP)) if (S_IS_EXTERN(symbolP))
S_SET_EXTERNAL(addme); S_SET_EXTERNAL(addme);
#endif
} }
symbolPP = &(symbol_next(symbolP)); symbolPP = &(symbol_next(symbolP));
} else { } else {

5
gnu/usr.bin/gas/config/obj-aout.h
View File

@ -17,7 +17,7 @@
License along with GAS; see the file COPYING. If not, write License along with GAS; see the file COPYING. If not, write
to the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */ to the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */
/* /*
* $Id: obj-aout.h,v 1.1 1993/10/02 20:58:55 pk Exp $ * $Id: obj-aout.h,v 1.2 1993/11/20 22:15:59 pk Exp $
*/ */
@ -39,6 +39,9 @@ extern const segT N_TYPE_seg[];
#define DEFAULT_MAGIC_NUMBER_FOR_OBJECT_FILE (OMAGIC) #define DEFAULT_MAGIC_NUMBER_FOR_OBJECT_FILE (OMAGIC)
#endif /* DEFAULT_MAGIC_NUMBER_FOR_OBJECT_FILE */ #endif /* DEFAULT_MAGIC_NUMBER_FOR_OBJECT_FILE */
/* First character of operand in `.type' directives */
#define TYPE_OPERAND_FMT '@'
/* SYMBOL TABLE */ /* SYMBOL TABLE */
/* Symbol table entry data type */ /* Symbol table entry data type */

46
gnu/usr.bin/gas/config/tc-i386.c
View File

@ -25,7 +25,7 @@
*/ */
#ifndef lint #ifndef lint
static char rcsid[] = "$Id: tc-i386.c,v 1.3 1993/10/27 00:14:50 pk Exp $"; static char rcsid[] = "$Id: tc-i386.c,v 1.4 1993/11/20 22:16:01 pk Exp $";
#endif #endif
#include "as.h" #include "as.h"
@ -1191,30 +1191,35 @@ char *line;
* Remember # of opcode bytes to put in pcrel_adjust * Remember # of opcode bytes to put in pcrel_adjust
* for use in _GLOBAL_OFFSET_TABLE_ expressions. * for use in _GLOBAL_OFFSET_TABLE_ expressions.
*/ */
long opoffset = 0; int nopbytes = 0;
if (flagseen['k'])
opoffset = obstack_next_free(&frags) - frag_now->fr_literal;
#endif #endif
/* First the prefix bytes. */ /* First the prefix bytes. */
for (q = i.prefix; q < i.prefix + i.prefixes; q++) { for (q = i.prefix; q < i.prefix + i.prefixes; q++) {
p = frag_more (1); p = frag_more (1);
nopbytes += 1;
md_number_to_chars (p, (unsigned int) *q, 1); md_number_to_chars (p, (unsigned int) *q, 1);
} }
/* Now the opcode; be careful about word order here! */ /* Now the opcode; be careful about word order here! */
if (fits_in_unsigned_byte(t->base_opcode)) { if (fits_in_unsigned_byte(t->base_opcode)) {
nopbytes += 1;
FRAG_APPEND_1_CHAR (t->base_opcode); FRAG_APPEND_1_CHAR (t->base_opcode);
} else if (fits_in_unsigned_word(t->base_opcode)) { } else if (fits_in_unsigned_word(t->base_opcode)) {
p = frag_more (2); p = frag_more (2);
nopbytes += 2;
/* put out high byte first: can't use md_number_to_chars! */ /* put out high byte first: can't use md_number_to_chars! */
*p++ = (t->base_opcode >> 8) & 0xff; *p++ = (t->base_opcode >> 8) & 0xff;
*p = t->base_opcode & 0xff; *p = t->base_opcode & 0xff;
} else { /* opcode is either 3 or 4 bytes */ } else { /* opcode is either 3 or 4 bytes */
if (t->base_opcode & 0xff000000) { if (t->base_opcode & 0xff000000) {
p = frag_more (4); p = frag_more (4);
nopbytes += 4;
*p++ = (t->base_opcode >> 24) & 0xff; *p++ = (t->base_opcode >> 24) & 0xff;
} else p = frag_more (3); } else {
p = frag_more (3);
nopbytes += 3;
}
*p++ = (t->base_opcode >> 16) & 0xff; *p++ = (t->base_opcode >> 16) & 0xff;
*p++ = (t->base_opcode >> 8) & 0xff; *p++ = (t->base_opcode >> 8) & 0xff;
*p = (t->base_opcode ) & 0xff; *p = (t->base_opcode ) & 0xff;
@ -1223,20 +1228,18 @@ char *line;
/* Now the modrm byte and base index byte (if present). */ /* Now the modrm byte and base index byte (if present). */
if (t->opcode_modifier & Modrm) { if (t->opcode_modifier & Modrm) {
p = frag_more (1); p = frag_more (1);
nopbytes += 1;
/* md_number_to_chars (p, i.rm, 1); */ /* md_number_to_chars (p, i.rm, 1); */
md_number_to_chars (p, (i.rm.regmem<<0 | i.rm.reg<<3 | i.rm.mode<<6), 1); md_number_to_chars (p, (i.rm.regmem<<0 | i.rm.reg<<3 | i.rm.mode<<6), 1);
/* If i.rm.regmem == ESP (4) && i.rm.mode != Mode 3 (Register mode) /* If i.rm.regmem == ESP (4) && i.rm.mode != Mode 3 (Register mode)
==> need second modrm byte. */ ==> need second modrm byte. */
if (i.rm.regmem == ESCAPE_TO_TWO_BYTE_ADDRESSING && i.rm.mode != 3) { if (i.rm.regmem == ESCAPE_TO_TWO_BYTE_ADDRESSING && i.rm.mode != 3) {
p = frag_more (1); p = frag_more (1);
nopbytes += 1;
/* md_number_to_chars (p, i.bi, 1); */ /* md_number_to_chars (p, i.bi, 1); */
md_number_to_chars (p,(i.bi.base<<0 | i.bi.index<<3 | i.bi.scale<<6), 1); md_number_to_chars (p,(i.bi.base<<0 | i.bi.index<<3 | i.bi.scale<<6), 1);
} }
} }
#ifdef PIC
if (flagseen['k'])
opoffset = obstack_next_free(&frags) - frag_now->fr_literal - opoffset;
#endif
if (i.disp_operands) { if (i.disp_operands) {
register unsigned int n; register unsigned int n;
@ -1264,8 +1267,7 @@ char *line;
i.disps[n]->X_add_number, 0, i.disp_reloc[n], i.disps[n]->X_got_symbol); i.disps[n]->X_add_number, 0, i.disp_reloc[n], i.disps[n]->X_got_symbol);
#ifdef PIC #ifdef PIC
if (i.disps[n]->X_got_symbol) { if (i.disps[n]->X_got_symbol) {
fixP->fx_pcrel_adjust = opoffset; fixP->fx_pcrel_adjust = nopbytes;
opoffset = 0;
} }
#endif #endif
} }
@ -1307,8 +1309,7 @@ char *line;
i.imms[n]->X_add_number, 0, NO_RELOC, i.imms[n]->X_got_symbol); i.imms[n]->X_add_number, 0, NO_RELOC, i.imms[n]->X_got_symbol);
#ifdef PIC #ifdef PIC
if (i.imms[n]->X_got_symbol) { if (i.imms[n]->X_got_symbol) {
fixP->fx_pcrel_adjust = opoffset; fixP->fx_pcrel_adjust = nopbytes;
opoffset = 0;
} }
#endif #endif
} }
@ -1615,13 +1616,13 @@ char *operand_string;
strcat(tmpbuf, cp+1+3); strcat(tmpbuf, cp+1+3);
*cp = '@'; *cp = '@';
} else if (strncmp(cp+1, "GOTOFF", 6) == 0) { } else if (strncmp(cp+1, "GOTOFF", 6) == 0) {
i.disp_reloc[this_operand] = RELOC_GLOB_DAT; i.disp_reloc[this_operand] = RELOC_GOTOFF;
*cp = '\0'; *cp = '\0';
strcpy(tmpbuf, input_line_pointer); strcpy(tmpbuf, input_line_pointer);
strcat(tmpbuf, cp+1+6); strcat(tmpbuf, cp+1+6);
*cp = '@'; *cp = '@';
} else if (strncmp(cp+1, "GOT", 3) == 0) { } else if (strncmp(cp+1, "GOT", 3) == 0) {
i.disp_reloc[this_operand] = RELOC_GLOB_DAT; i.disp_reloc[this_operand] = RELOC_GOT;
*cp = '\0'; *cp = '\0';
strcpy(tmpbuf, input_line_pointer); strcpy(tmpbuf, input_line_pointer);
strcat(tmpbuf, cp+1+3); strcat(tmpbuf, cp+1+3);
@ -1634,7 +1635,7 @@ char *operand_string;
#endif #endif
exp_seg = expression(exp); exp_seg = expression(exp);
#ifdef PIC #ifdef PIC
if (i.disp_reloc[this_operand] == RELOC_GLOB_DAT) if (i.disp_reloc[this_operand] == RELOC_GOTOFF)
exp->X_add_symbol->sy_forceout = 1; exp->X_add_symbol->sy_forceout = 1;
#endif #endif
if (*input_line_pointer) if (*input_line_pointer)
@ -2044,12 +2045,21 @@ relax_addressT segment_address_in_file;
r_symbolnum = fixP->fx_addsy->sy_number; r_symbolnum = fixP->fx_addsy->sy_number;
extrn_bit = 1; extrn_bit = 1;
break; break;
case RELOC_GLOB_DAT: case RELOC_GOT:
extra_bits = (1 << 4) & 0x10; /* r_baserel */ extra_bits = (1 << 4) & 0x10; /* r_baserel */
r_symbolnum = fixP->fx_addsy->sy_number; r_symbolnum = fixP->fx_addsy->sy_number;
if (S_IS_EXTERNAL(fixP->fx_addsy)) if (!extrn_bit && !S_IS_EXTERNAL(fixP->fx_addsy))
as_warn("GOT relocation burb: `%s' should be global",
S_GET_NAME(fixP->fx_addsy));
extrn_bit = 1; extrn_bit = 1;
break; break;
case RELOC_GOTOFF:
extra_bits = (1 << 4) & 0x10; /* r_baserel */
r_symbolnum = fixP->fx_addsy->sy_number;
if (extrn_bit || S_IS_EXTERNAL(fixP->fx_addsy))
as_warn("GOT relocation burb: `%s' should be static",
S_GET_NAME(fixP->fx_addsy));
break;
case RELOC_JMP_TBL: case RELOC_JMP_TBL:
extra_bits = (1 << 5) & 0x20; /* r_jmptable */ extra_bits = (1 << 5) & 0x20; /* r_jmptable */
break; break;