Replace libdisasm with capstone

src/third_party/libdisasm/ia32_modrm.c

Index: src/third_party/libdisasm/ia32_modrm.c
diff --git a/src/third_party/libdisasm/ia32_modrm.c b/src/third_party/libdisasm/ia32_modrm.c
deleted file mode 100644
index b0fe2ed3d3520e40fa217a3a84c2e22df9e812b4..0000000000000000000000000000000000000000
--- a/src/third_party/libdisasm/ia32_modrm.c
+++ /dev/null
@@ -1,310 +0,0 @@
-#include "ia32_modrm.h"
-#include "ia32_reg.h"
-#include "x86_imm.h"
-
-/* NOTE: when decoding ModR/M and SIB, we have to add 1 to all register
- * values obtained from decoding the ModR/M or SIB byte, since they
- * are encoded with eAX = 0 and the tables in ia32_reg.c use eAX = 1.
- * ADDENDUM: this is only the case when the register value is used
- * directly as an index into the register table, not when it is added to
- * a genregs offset. */
-
-/* -------------------------------- ModR/M, SIB */
-/* ModR/M flags */
-#define MODRM_RM_SIB            0x04    /* R/M == 100 */
-#define MODRM_RM_NOREG          0x05    /* R/B == 101 */
-
-/* if (MODRM.MOD_NODISP && MODRM.RM_NOREG) then just disp32 */
-#define MODRM_MOD_NODISP        0x00    /* mod == 00 */
-#define MODRM_MOD_DISP8         0x01    /* mod == 01 */
-#define MODRM_MOD_DISP32        0x02    /* mod == 10 */
-#define MODRM_MOD_NOEA          0x03    /* mod == 11 */
-
-/* 16-bit modrm flags */
-#define MOD16_MOD_NODISP      0
-#define MOD16_MOD_DISP8       1
-#define MOD16_MOD_DISP16      2
-#define MOD16_MOD_REG         3
-
-#define MOD16_RM_BXSI         0
-#define MOD16_RM_BXDI         1
-#define MOD16_RM_BPSI         2
-#define MOD16_RM_BPDI         3
-#define MOD16_RM_SI           4
-#define MOD16_RM_DI           5
-#define MOD16_RM_BP           6
-#define MOD16_RM_BX           7
-
-/* SIB flags */
-#define SIB_INDEX_NONE       0x04
-#define SIB_BASE_EBP       0x05
-#define SIB_SCALE_NOBASE    0x00
-
-/* Convenience struct for modR/M bitfield */
-struct modRM_byte {  
-   unsigned int mod : 2;
-   unsigned int reg : 3;
-   unsigned int rm  : 3; 
-};
-
-/* Convenience struct for SIB bitfield */
-struct SIB_byte {
-   unsigned int scale : 2;
-   unsigned int index : 3;
-   unsigned int base  : 3;
-};
-
-
-#if 0
-int modrm_rm[] = {0,1,2,3,MODRM_RM_SIB,MODRM_MOD_DISP32,6,7};
-int modrm_reg[] = {0, 1, 2, 3, 4, 5, 6, 7};
-int modrm_mod[]  = {0, MODRM_MOD_DISP8, MODRM_MOD_DISP32, MODRM_MOD_NOEA};
-int sib_scl[] = {0, 2, 4, 8};
-int sib_idx[] = {0, 1, 2, 3, SIB_INDEX_NONE, 5, 6, 7 };
-int sib_bas[] = {0, 1, 2, 3, 4, SIB_SCALE_NOBASE, 6, 7 };
-#endif
-
-/* this is needed to replace x86_imm_signsized() which does not sign-extend
- * to dest */
-static unsigned int imm32_signsized( unsigned char *buf, size_t buf_len,
-				     int32_t *dest, unsigned int size ) {
-	if ( size > buf_len ) {
-		return 0;
-	}
-
-	switch (size) {
-		case 1:
-			*dest = *((signed char *) buf);
-			break;
-		case 2:
-			*dest = *((signed short *) buf);
-			break;
-		case 4:
-		default:
-			*dest = *((signed int *) buf);
-			break;
-	}
-
-	return size;
-}
-
-
-
-static void byte_decode(unsigned char b, struct modRM_byte *modrm) {
-	/* generic bitfield-packing routine */
-
-	modrm->mod = b >> 6;	/* top 2 bits */
-	modrm->reg = (b & 56) >> 3;	/* middle 3 bits */
-	modrm->rm = b & 7;	/* bottom 3 bits */
-}
-
-
-static size_t sib_decode( unsigned char *buf, size_t buf_len, x86_ea_t *ea, 
-			  unsigned int mod ) {
-	/* set Address Expression fields (scale, index, base, disp) 
-	 * according to the contents of the SIB byte.
-	 *  b points to the SIB byte in the instruction-stream buffer; the
-	 *    byte after b[0] is therefore the byte after the SIB
-	 *  returns number of bytes 'used', including the SIB byte */
-	size_t size = 1;		/* start at 1 for SIB byte */
-	struct SIB_byte sib;
-
-	if ( buf_len < 1 ) {
-		return 0;
-	}
-
-	byte_decode( *buf, (struct modRM_byte *)(void*)&sib );  /* get bit-fields */
-
-	if ( sib.base == SIB_BASE_EBP && ! mod ) {  /* if base == 101 (ebp) */
-	    /* IF BASE == EBP, deal with exception */
-		/* IF (ModR/M did not create a Disp */
-		/* ... create a 32-bit Displacement */
-		imm32_signsized( &buf[1], buf_len, &ea->disp, sizeof(int32_t));
-		ea->disp_size = sizeof(int32_t);
-		ea->disp_sign = (ea->disp < 0) ? 1 : 0;
-		size += 4;	/* add sizeof disp to count */
-
-	} else {
-		/* ELSE BASE refers to a General Register */
-		ia32_handle_register( &ea->base, sib.base + 1 );
-	}
-
-	/* set scale to 1, 2, 4, 8 */
-	ea->scale = 1 << sib.scale;
-
-	if (sib.index != SIB_INDEX_NONE) {
-		/* IF INDEX is not 'ESP' (100) */
-		ia32_handle_register( &ea->index, sib.index + 1 );
-	}
-
-	return (size);		/* return number of bytes processed */
-}
-
-static size_t modrm_decode16( unsigned char *buf, unsigned int buf_len,
-			    x86_op_t *op, struct modRM_byte *modrm ) {
-	/* 16-bit mode: hackish, but not as hackish as 32-bit mode ;) */
-	size_t size = 1; /* # of bytes decoded [1 for modR/M byte] */
-	x86_ea_t * ea = &op->data.expression;
-
-	switch( modrm->rm ) {
-		case MOD16_RM_BXSI:
-			ia32_handle_register(&ea->base, REG_WORD_OFFSET + 3);
-			ia32_handle_register(&ea->index, REG_WORD_OFFSET + 6);
-			break;
-		case MOD16_RM_BXDI:
-			ia32_handle_register(&ea->base, REG_WORD_OFFSET + 3);
-			ia32_handle_register(&ea->index, REG_WORD_OFFSET + 7);
-		case MOD16_RM_BPSI:
-			op->flags |= op_ss_seg;
-			ia32_handle_register(&ea->base, REG_WORD_OFFSET + 5);
-			ia32_handle_register(&ea->index, REG_WORD_OFFSET + 6);
-			break;
-		case MOD16_RM_BPDI:
-			op->flags |= op_ss_seg;
-			ia32_handle_register(&ea->base, REG_WORD_OFFSET + 5);
-			ia32_handle_register(&ea->index, REG_WORD_OFFSET + 7);
-			break;
-		case MOD16_RM_SI:
-			ia32_handle_register(&ea->base, REG_WORD_OFFSET + 6);
-			break;
-		case MOD16_RM_DI:
-			ia32_handle_register(&ea->base, REG_WORD_OFFSET + 7);
-			break;
-		case MOD16_RM_BP:
-			if ( modrm->mod != MOD16_MOD_NODISP ) {
-				op->flags |= op_ss_seg;
-				ia32_handle_register(&ea->base, 
-						     REG_WORD_OFFSET + 5);
-			}
-			break;
-		case MOD16_RM_BX:
-			ia32_handle_register(&ea->base, REG_WORD_OFFSET + 3);
-			break;
-	}
-
-	/* move to byte after ModR/M */
-	++buf;
-	--buf_len;
-
-	if ( modrm->mod == MOD16_MOD_DISP8 ) {
-		imm32_signsized( buf, buf_len, &ea->disp, sizeof(char) );
-		ea->disp_sign = (ea->disp < 0) ? 1 : 0;
-		ea->disp_size = sizeof(char);
-		size += sizeof(char);
-	} else if ( modrm->mod == MOD16_MOD_DISP16 ) {
-		imm32_signsized( buf, buf_len, &ea->disp, sizeof(short) );
-		ea->disp_sign = (ea->disp < 0) ? 1 : 0;
-		ea->disp_size = sizeof(short);
-		size += sizeof(short);
-	} 
-
-	return size;
-}
-
-/* TODO : Mark index modes
-    Use addressing mode flags to imply arrays (index), structure (disp),
-    two-dimensional arrays [disp + index], classes [ea reg], and so on.
-*/
-size_t ia32_modrm_decode( unsigned char *buf, unsigned int buf_len,
-			    x86_op_t *op, x86_insn_t *insn, size_t gen_regs ) {
-	/* create address expression and/or fill operand based on value of
-	 * ModR/M byte. Calls sib_decode as appropriate.
-	 *    flags specifies whether Reg or mod+R/M fields are being decoded
-	 *  returns the number of bytes in the instruction, including modR/M */
-	struct modRM_byte modrm;
-	size_t size = 1;	/* # of bytes decoded [1 for modR/M byte] */
-	x86_ea_t * ea;
-
-
-	byte_decode(*buf, &modrm);	/* get bitfields */
-
-	/* first, handle the case where the mod field is a register only */
-	if ( modrm.mod == MODRM_MOD_NOEA ) {
-		op->type = op_register;
-		ia32_handle_register(&op->data.reg, modrm.rm + gen_regs);
-                /* increase insn size by 1 for modrm byte */
- 		return 1;
- 	}
- 
-	/* then deal with cases where there is an effective address */
-	ea = &op->data.expression;
-	op->type = op_expression;
-	op->flags |= op_pointer;
-
-	if ( insn->addr_size == 2 ) {
-		/* gah! 16 bit mode! */
-		return modrm_decode16( buf, buf_len, op, &modrm);
-	}
-
-	/* move to byte after ModR/M */
-	++buf;
-	--buf_len;
-
-	if (modrm.mod == MODRM_MOD_NODISP) {	/* if mod == 00 */
-
-		/* IF MOD == No displacement, just Indirect Register */
-		if (modrm.rm == MODRM_RM_NOREG) {	/* if r/m == 101 */
-			/* IF RM == No Register, just Displacement */
-			/* This is an Intel Moronic Exception TM */
-			imm32_signsized( buf, buf_len, &ea->disp, 
-					sizeof(int32_t) );
-			ea->disp_size = sizeof(int32_t);
-			ea->disp_sign = (ea->disp < 0) ? 1 : 0;
-			size += 4;	/* add sizeof disp to count */
-
-		} else if (modrm.rm == MODRM_RM_SIB) {	/* if r/m == 100 */
-			/* ELSE IF an SIB byte is present */
-			/* TODO: check for 0 retval */
-			size += sib_decode( buf, buf_len, ea, modrm.mod);
-			/* move to byte after SIB for displacement */
-			++buf;
-			--buf_len;
-		} else {	/* modR/M specifies base register */
-			/* ELSE RM encodes a general register */
-			ia32_handle_register( &ea->base, modrm.rm + 1 );
-		}
-	} else { 					/* mod is 01 or 10 */
-		if (modrm.rm == MODRM_RM_SIB) {	/* rm == 100 */
-			/* IF base is an AddrExpr specified by an SIB byte */
-			/* TODO: check for 0 retval */
-			size += sib_decode( buf, buf_len, ea, modrm.mod);
-			/* move to byte after SIB for displacement */
-			++buf;
-			--buf_len;
-		} else {
-			/* ELSE base is a general register */
-			ia32_handle_register( &ea->base, modrm.rm + 1 );
-		}
-
-		/* ELSE mod + r/m specify a disp##[base] or disp##(SIB) */
-		if (modrm.mod == MODRM_MOD_DISP8) {		/* mod == 01 */
-			/* If this is an 8-bit displacement */
-			imm32_signsized( buf, buf_len, &ea->disp, 
-					sizeof(char));
-			ea->disp_size = sizeof(char);
-			ea->disp_sign = (ea->disp < 0) ? 1 : 0;
-			size += 1;	/* add sizeof disp to count */
-
-		} else {
-			/* Displacement is dependent on address size */
-			imm32_signsized( buf, buf_len, &ea->disp, 
-					insn->addr_size);
-			ea->disp_size = insn->addr_size;
-			ea->disp_sign = (ea->disp < 0) ? 1 : 0;
-			size += 4;
-		}
-	}
-
-	return size;		/* number of bytes found in instruction */
-}
-
-void ia32_reg_decode( unsigned char byte, x86_op_t *op, size_t gen_regs ) {
-	struct modRM_byte modrm;
-	byte_decode( byte, &modrm );	/* get bitfields */
-
- 	/* set operand to register ID */
-	op->type = op_register;
-	ia32_handle_register(&op->data.reg, modrm.reg + gen_regs);
-
-	return;
-}