Changes: Edwin Steiner
- $Id: stack.c 787 2003-12-15 18:20:31Z edwin $
+ $Id: stack.c 868 2004-01-10 20:12:10Z edwin $
*/
#include <string.h>
#include "stack.h"
#include "global.h"
+#include "main.h"
#include "jit.h"
#include "builtin.h"
#include "disass.h"
/* from codegen.inc */
extern int dseglen;
+/**********************************************************************/
+/* Macros used internally by analyse_stack */
+/**********************************************************************/
#ifdef STATISTICS
#define COUNT(cnt) cnt++
#define COUNT(cnt)
#endif
-#define STACKRESET {curstack=0;stackdepth=0;}
-
-#define TYPEPANIC {show_icmd_method();panic("Stack type mismatch");}
-#define UNDERFLOW {show_icmd_method();panic("Stack underflow");} /* XXX why isn't this caught in parse.c? */
+/* convenient abbreviations */
#define CURKIND curstack->varkind
#define CURTYPE curstack->type
+/*--------------------------------------------------*/
+/* SIGNALING ERRORS */
+/*--------------------------------------------------*/
+
+#define TYPEPANIC {show_icmd_method();panic("Stack type mismatch");}
+#define UNDERFLOW {show_icmd_method();panic("Operand stack underflow");}
+#define OVERFLOW {show_icmd_method();panic("Operand stack overflow");}
+
+/*--------------------------------------------------*/
+/* STACK UNDERFLOW/OVERFLOW CHECKS */
+/*--------------------------------------------------*/
+
+/* underflow checks */
#define REQUIRE(num) do { if (stackdepth<(num)) {UNDERFLOW;} } while(0)
#define REQUIRE_1 REQUIRE(1)
#define REQUIRE_2 REQUIRE(2)
#define REQUIRE_3 REQUIRE(3)
#define REQUIRE_4 REQUIRE(4)
+/* overflow check */
+/* XXX we allow ACONST instructions inserted as arguments to builtin
+ * functions to exceed the maximum stack depth. Maybe we should check
+ * against maximum stack depth only at block boundaries?
+ */
+#define CHECKOVERFLOW \
+ do { \
+ if (stackdepth > maxstack) { \
+ if (iptr[0].opc != ICMD_ACONST \
+ || iptr[0].op1 == 0) \
+ {OVERFLOW;} \
+ } \
+ } while(0)
+
+/*--------------------------------------------------*/
+/* ALLOCATING STACK SLOTS */
+/*--------------------------------------------------*/
+
#define NEWSTACK(s,v,n) {new->prev=curstack;new->type=s;new->flags=0; \
new->varkind=v;new->varnum=n;curstack=new;new++;}
#define NEWSTACKn(s,n) NEWSTACK(s,UNDEFVAR,n)
#define NEWSTACK0(s) NEWSTACK(s,UNDEFVAR,0)
+
+/* allocate the input stack for an exception handler */
#define NEWXSTACK {NEWSTACK(TYPE_ADR,STACKVAR,0);curstack=0;}
+/*--------------------------------------------------*/
+/* STACK MANIPULATION */
+/*--------------------------------------------------*/
+
+/* resetting to an empty operand stack */
+#define STACKRESET {curstack=0;stackdepth=0;}
+
+/* set the output stack of the current instruction */
#define SETDST {iptr->dst=curstack;}
-/* The following macros do NOT check stackdepth, set stackdepth and iptr->dst */
+/* The following macros do NOT check stackdepth, set stackdepth or iptr->dst */
#define POP(s) {if(s!=curstack->type){TYPEPANIC;} \
if(curstack->varkind==UNDEFVAR)curstack->varkind=TEMPVAR;\
curstack=curstack->prev;}
curstack=curstack->prev;}
#define COPY(s,d) {(d)->flags=0;(d)->type=(s)->type;\
(d)->varkind=(s)->varkind;(d)->varnum=(s)->varnum;}
-/******************************/
-/* The following macros check stackdepth, set stackdepth and itpr->dst */
+/*--------------------------------------------------*/
+/* STACK OPERATIONS MODELING */
+/*--------------------------------------------------*/
+
+/* The following macros are used to model the stack manipulations of
+ * different kinds of instructions.
+ *
+ * These macros check the input stackdepth and they set the output
+ * stackdepth and the output stack of the instruction (iptr->dst).
+ *
+ * These macros do *not* check for stack overflows!
+ */
+
#define PUSHCONST(s){NEWSTACKn(s,stackdepth);SETDST;stackdepth++;}
#define LOAD(s,v,n) {NEWSTACK(s,v,n);SETDST;stackdepth++;}
#define STORE(s) {REQUIRE_1;POP(s);SETDST;stackdepth--;}
new[2].prev=new+1;new[3].prev=new+2;\
new[4].prev=new+3;new[5].prev=new+4;\
curstack=new+5;new+=6;SETDST;stackdepth+=2;}
-/******************************/
+/*--------------------------------------------------*/
+/* MACROS FOR HANDLING BASIC BLOCKS */
+/*--------------------------------------------------*/
+
+/* COPYCURSTACK makes a copy of the current operand stack (curstack)
+ * and returns it in the variable copy.
+ *
+ * This macro is used to propagate the operand stack from one basic
+ * block to another. The destination block receives the copy as its
+ * input stack.
+ */
#define COPYCURSTACK(copy) {\
int d;\
stackptr s;\
copy=NULL;\
}
+/* BBEND is called at the end of each basic block (after the last
+ * instruction of the block has been processed).
+ */
#define BBEND(s,i){\
i=stackdepth-1;\
}\
}
-
-#define MARKREACHED(b,c) {\
- if(b->flags<0)\
- {COPYCURSTACK(c);b->flags=0;b->instack=c;b->indepth=stackdepth;}\
- else {stackptr s=curstack;stackptr t=b->instack;\
- if(b->indepth!=stackdepth)\
- {show_icmd_method();panic("Stack depth mismatch");}\
- while(s){if (s->type!=t->type)\
- TYPEPANIC\
- s=s->prev;t=t->prev;\
- }\
- }\
+
+/* MARKREACHED marks the destination block <b> as reached. If this
+ * block has been reached before we check if stack depth and types
+ * match. Otherwise the destination block receives a copy of the
+ * current stack as its input stack.
+ *
+ * b...destination block
+ * c...current stack
+ */
+#define MARKREACHED(b,c) { \
+ if(b->flags<0) \
+ {COPYCURSTACK(c);b->flags=0;b->instack=c;b->indepth=stackdepth;} \
+ else {stackptr s=curstack;stackptr t=b->instack; \
+ if(b->indepth!=stackdepth) \
+ {show_icmd_method();panic("Stack depth mismatch");} \
+ while(s){if (s->type!=t->type) \
+ TYPEPANIC \
+ s=s->prev;t=t->prev; \
+ } \
+ } \
}
+/**********************************************************************/
+/* analyse_stack */
+/**********************************************************************/
+
+/* analyse_stack uses the intermediate code created by parse.c to
+ * build a model of the JVM operand stack for the current method.
+ *
+ * The following checks are performed:
+ * - check for operand stack underflow (before each instruction)
+ * - check for operand stack overflow (after[1] each instruction)
+ * - check for matching stack depth at merging points
+ * - check for matching basic types[2] at merging points
+ * - check basic types for instruction input (except for BUILTIN*
+ * opcodes, INVOKE* opcodes and MULTIANEWARRAY)
+ *
+ * [1]) XXX Checking this after the instruction should be ok. parse.c
+ * counts the number of required stack slots in such a way that it is
+ * only vital that we don't exceed `maxstack` at basic block
+ * boundaries.
+ *
+ * [2]) 'basic types' means the distinction between INT, LONG, FLOAT,
+ * DOUBLE and ADDRESS types. Subtypes of INT and different ADDRESS
+ * types are not discerned.
+ */
+
void analyse_stack()
{
int b_count;
log_text(logtext);
}
- argren = DMNEW(int, maxlocals);
- //int *argren = (int *)alloca(maxlocals * sizeof(int)); /* table for argument renaming */
+ argren = DMNEW(int, maxlocals);
+ /*int *argren = (int *)alloca(maxlocals * sizeof(int));*/ /* table for argument renaming */
for (i = 0; i < maxlocals; i++)
argren[i] = i;
/* pop 1 push 0 */
case ICMD_POP:
+#ifdef TYPECHECK_STACK_COMPCAT
+ if (opt_verify) {
+ REQUIRE_1;
+ if (IS_2_WORD_TYPE(curstack->type))
+ panic("Illegal instruction: POP on category 2 type");
+ }
+#endif
OP1_0ANY;
break;
case ICMD_POP2:
REQUIRE_1;
if (! IS_2_WORD_TYPE(curstack->type)) {
+ /* ..., cat1 */
+#ifdef TYPECHECK_STACK_COMPCAT
+ if (opt_verify) {
+ REQUIRE_2;
+ if (IS_2_WORD_TYPE(curstack->prev->type))
+ panic("Illegal instruction: POP2 on cat2, cat1 types");
+ }
+#endif
OP1_0ANY; /* second pop */
}
else
/* pop 0 push 1 dup */
case ICMD_DUP:
+#ifdef TYPECHECK_STACK_COMPCAT
+ if (opt_verify) {
+ REQUIRE_1;
+ if (IS_2_WORD_TYPE(curstack->type))
+ panic("Illegal instruction: DUP on category 2 type");
+ }
+#endif
COUNT(count_dup_instruction);
DUP;
break;
case ICMD_DUP2:
REQUIRE_1;
if (IS_2_WORD_TYPE(curstack->type)) {
+ /* ..., cat2 */
iptr->opc = ICMD_DUP;
DUP;
}
else {
REQUIRE_2;
+ /* ..., ????, cat1 */
+#ifdef TYPECHECK_STACK_COMPCAT
+ if (opt_verify) {
+ if (IS_2_WORD_TYPE(curstack->prev->type))
+ panic("Illegal instruction: DUP2 on cat2, cat1 types");
+ }
+#endif
copy = curstack;
NEWSTACK(copy->prev->type, copy->prev->varkind,
copy->prev->varnum);
/* pop 2 push 3 dup */
case ICMD_DUP_X1:
+#ifdef TYPECHECK_STACK_COMPCAT
+ if (opt_verify) {
+ REQUIRE_2;
+ if (IS_2_WORD_TYPE(curstack->type) ||
+ IS_2_WORD_TYPE(curstack->prev->type))
+ panic("Illegal instruction: DUP_X1 on cat 2 type");
+ }
+#endif
DUP_X1;
break;
case ICMD_DUP2_X1:
REQUIRE_2;
if (IS_2_WORD_TYPE(curstack->type)) {
+ /* ..., ????, cat2 */
+#ifdef TYPECHECK_STACK_COMPCAT
+ if (opt_verify) {
+ if (IS_2_WORD_TYPE(curstack->prev->type))
+ panic("Illegal instruction: DUP2_X1 on cat2, cat2 types");
+ }
+#endif
iptr->opc = ICMD_DUP_X1;
DUP_X1;
}
else {
+ /* ..., ????, cat1 */
+#ifdef TYPECHECK_STACK_COMPCAT
+ if (opt_verify) {
+ REQUIRE_3;
+ if (IS_2_WORD_TYPE(curstack->prev->type)
+ || IS_2_WORD_TYPE(curstack->prev->prev->type))
+ panic("Illegal instruction: DUP2_X1 on invalid types");
+ }
+#endif
DUP2_X1;
}
break;
case ICMD_DUP_X2:
REQUIRE_2;
if (IS_2_WORD_TYPE(curstack->prev->type)) {
+ /* ..., cat2, ???? */
+#ifdef TYPECHECK_STACK_COMPCAT
+ if (opt_verify) {
+ if (IS_2_WORD_TYPE(curstack->type))
+ panic("Illegal instruction: DUP_X2 on cat2, cat2 types");
+ }
+#endif
iptr->opc = ICMD_DUP_X1;
DUP_X1;
}
else {
+ /* ..., cat1, ???? */
+#ifdef TYPECHECK_STACK_COMPCAT
+ if (opt_verify) {
+ REQUIRE_3;
+ if (IS_2_WORD_TYPE(curstack->type)
+ || IS_2_WORD_TYPE(curstack->prev->prev->type))
+ panic("Illegal instruction: DUP_X2 on invalid types");
+ }
+#endif
DUP_X2;
}
break;
case ICMD_DUP2_X2:
REQUIRE_2;
if (IS_2_WORD_TYPE(curstack->type)) {
+ /* ..., ????, cat2 */
if (IS_2_WORD_TYPE(curstack->prev->type)) {
+ /* ..., cat2, cat2 */
iptr->opc = ICMD_DUP_X1;
DUP_X1;
}
else {
+ /* ..., cat1, cat2 */
+#ifdef TYPECHECK_STACK_COMPCAT
+ if (opt_verify) {
+ REQUIRE_3;
+ if (IS_2_WORD_TYPE(curstack->prev->prev->type))
+ panic("Illegal instruction: DUP2_X2 on invalid types");
+ }
+#endif
iptr->opc = ICMD_DUP_X2;
DUP_X2;
}
}
else {
REQUIRE_3;
+ /* ..., ????, ????, cat1 */
if (IS_2_WORD_TYPE(curstack->prev->prev->type)) {
+ /* ..., cat2, ????, cat1 */
+#ifdef TYPECHECK_STACK_COMPCAT
+ if (opt_verify) {
+ if (IS_2_WORD_TYPE(curstack->prev->type))
+ panic("Illegal instruction: DUP2_X2 on invalid types");
+ }
+#endif
iptr->opc = ICMD_DUP2_X1;
DUP2_X1;
}
else {
+ /* ..., cat1, ????, cat1 */
+#ifdef TYPECHECK_STACK_COMPCAT
+ if (opt_verify) {
+ REQUIRE_4;
+ if (IS_2_WORD_TYPE(curstack->prev->type)
+ || IS_2_WORD_TYPE(curstack->prev->prev->prev->type))
+ panic("Illegal instruction: DUP2_X2 on invalid types");
+ }
+#endif
DUP2_X2;
}
}
/* pop 2 push 2 swap */
case ICMD_SWAP:
+#ifdef TYPECHECK_STACK_COMPCAT
+ if (opt_verify) {
+ REQUIRE_2;
+ if (IS_2_WORD_TYPE(curstack->type)
+ || IS_2_WORD_TYPE(curstack->prev->type))
+ panic("Illegal instruction: SWAP on category 2 type");
+ }
+#endif
SWAP;
break;
* needs it because the OP1_0ANY below
* overwrites iptr->dst.
*/
- iptr->val.a = (void*) iptr->dst;
+ iptr->val.a = (void *) iptr->dst;
- tbptr->type=BBTYPE_SBR;
+ tbptr->type = BBTYPE_SBR;
+
+ /* We need to check for overflow right here because
+ * the pushed value is poped after MARKREACHED. */
+ CHECKOVERFLOW;
MARKREACHED(tbptr, copy);
OP1_0ANY;
break;
arguments_num = i + intreg_argnum;
copy = curstack;
while (--i >= 0) {
+ /* XXX check INT type here? Currently typecheck does this. */
if (! (copy->flags & SAVEDVAR)) {
copy->varkind = ARGVAR;
copy->varnum = i + intreg_argnum;
printf("ICMD %d at %d\n", iptr->opc, (int)(iptr-instr));
panic("Missing ICMD code during stack analysis");
} /* switch */
+
+ CHECKOVERFLOW;
+
/* XXX DEBUG */ /*dolog("iptr++");*/
iptr++;
} /* while instructions */
}
+/**********************************************************************/
+/* DEBUGGING HELPERS */
+/**********************************************************************/
+
void icmd_print_stack(stackptr s)
{
int i, j;
void show_icmd_method()
{
int i, j;
- int deadcode;
- s4 *s4ptr;
- instruction *iptr;
+ s4 *s4ptr; /* used */
basicblock *bptr;
- void **tptr;
xtable *ex;
printf("\n");
{
int i, j;
int deadcode;
- s4 *s4ptr;
+ s4 *s4ptr; /* used */
instruction *iptr;
if (bptr->flags != BBDELETED) {
case ICMD_PUTSTATIC:
case ICMD_GETSTATIC:
printf(" ");
- utf_fprint(stdout,
- ((fieldinfo *) iptr->val.a)->class->name);
+ utf_fprint(stdout, ((fieldinfo *) iptr->val.a)->class->name);
printf(".");
- utf_fprint(stdout,
- ((fieldinfo *) iptr->val.a)->name);
+ utf_fprint(stdout, ((fieldinfo *) iptr->val.a)->name);
printf(" (type ");
- utf_fprint(stdout,
- ((fieldinfo *) iptr->val.a)->descriptor);
+ utf_fprint(stdout, ((fieldinfo *) iptr->val.a)->descriptor);
printf(")");
break;
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