#include "TSO.h"
#include "Schedule.h"
#include "RtsFlags.h"
-#include "Storage.h"
#include "LdvProfile.h"
#include "Updates.h"
#include "Sanity.h"
#include "Liveness.h"
+#include "Prelude.h"
#include "Bytecodes.h"
#include "Printer.h"
#include <errno.h>
#endif
+#include "ffi.h"
/* --------------------------------------------------------------------------
* The bytecode interpreter
/* Sp points to the lowest live word on the stack. */
#define BCO_NEXT instrs[bciPtr++]
+#define BCO_NEXT_32 (bciPtr += 2, (((StgWord) instrs[bciPtr-2]) << 16) + ((StgWord) instrs[bciPtr-1]))
+#define BCO_NEXT_64 (bciPtr += 4, (((StgWord) instrs[bciPtr-4]) << 48) + (((StgWord) instrs[bciPtr-3]) << 32) + (((StgWord) instrs[bciPtr-2]) << 16) + ((StgWord) instrs[bciPtr-1]))
+#if WORD_SIZE_IN_BITS == 32
+#define BCO_NEXT_WORD BCO_NEXT_32
+#elif WORD_SIZE_IN_BITS == 64
+#define BCO_NEXT_WORD BCO_NEXT_64
+#else
+#error Cannot cope with WORD_SIZE_IN_BITS being nether 32 nor 64
+#endif
+#define BCO_GET_LARGE_ARG ((bci & bci_FLAG_LARGE_ARGS) ? BCO_NEXT_WORD : BCO_NEXT)
+
#define BCO_PTR(n) (W_)ptrs[n]
#define BCO_LIT(n) literals[n]
-#define BCO_ITBL(n) itbls[n]
#define LOAD_STACK_POINTERS \
Sp = cap->r.rCurrentTSO->sp; \
return allocate(stg_max(sizeofW(StgHeader)+MIN_PAYLOAD_SIZE, n_words));
}
+int rts_stop_next_breakpoint = 0;
+int rts_stop_on_exception = 0;
#ifdef INTERP_STATS
int it_oofreq[27][27];
int it_lastopc;
+
#define INTERP_TICK(n) (n)++
void interp_startup ( void )
(W_)&stg_ap_pppppp_info,
};
+HsStablePtr rts_breakpoint_io_action; // points to the IO action which is executed on a breakpoint
+ // it is set in main/GHC.hs:runStmt
+
Capability *
interpretBCO (Capability* cap)
{
// that these entities are non-aliasable.
register StgPtr Sp; // local state -- stack pointer
register StgPtr SpLim; // local state -- stack lim pointer
- register StgClosure* obj;
+ register StgClosure *tagged_obj = 0, *obj;
nat n, m;
LOAD_STACK_POINTERS;
// +---------------+
//
if (Sp[0] == (W_)&stg_enter_info) {
- Sp++;
- goto eval;
+ Sp++;
+ goto eval;
}
// ------------------------------------------------------------------------
// +---------------+
//
else if (Sp[0] == (W_)&stg_apply_interp_info) {
- obj = (StgClosure *)Sp[1];
+ obj = UNTAG_CLOSURE((StgClosure *)Sp[1]);
Sp += 2;
goto run_BCO_fun;
}
// Evaluate the object on top of the stack.
eval:
- obj = (StgClosure*)Sp[0]; Sp++;
+ tagged_obj = (StgClosure*)Sp[0]; Sp++;
eval_obj:
+ obj = UNTAG_CLOSURE(tagged_obj);
INTERP_TICK(it_total_evals);
IF_DEBUG(interpreter,
case IND_OLDGEN_PERM:
case IND_STATIC:
{
- obj = ((StgInd*)obj)->indirectee;
+ tagged_obj = ((StgInd*)obj)->indirectee;
goto eval_obj;
}
break;
case BCO:
+ {
ASSERT(((StgBCO *)obj)->arity > 0);
break;
+ }
case AP: /* Copied from stg_AP_entry. */
{
// Stack check
if (Sp - (words+sizeofW(StgUpdateFrame)) < SpLim) {
Sp -= 2;
- Sp[1] = (W_)obj;
+ Sp[1] = (W_)tagged_obj;
Sp[0] = (W_)&stg_enter_info;
RETURN_TO_SCHEDULER(ThreadInterpret, StackOverflow);
}
Sp[i] = (W_)ap->payload[i];
}
- obj = (StgClosure*)ap->fun;
+ obj = UNTAG_CLOSURE((StgClosure*)ap->fun);
ASSERT(get_itbl(obj)->type == BCO);
goto run_BCO_fun;
}
printObj(obj);
);
Sp -= 2;
- Sp[1] = (W_)obj;
+ Sp[1] = (W_)tagged_obj;
Sp[0] = (W_)&stg_enter_info;
RETURN_TO_SCHEDULER_NO_PAUSE(ThreadRunGHC, ThreadYielding);
}
}
// ------------------------------------------------------------------------
- // We now have an evaluated object (obj). The next thing to
+ // We now have an evaluated object (tagged_obj). The next thing to
// do is return it to the stack frame on top of the stack.
do_return:
+ obj = UNTAG_CLOSURE(tagged_obj);
ASSERT(closure_HNF(obj));
IF_DEBUG(interpreter,
case UPDATE_FRAME:
// Returning to an update frame: do the update, pop the update
// frame, and continue with the next stack frame.
+ //
+ // NB. we must update with the *tagged* pointer. Some tags
+ // are not optional, and if we omit the tag bits when updating
+ // then bad things can happen (albeit very rarely). See #1925.
+ // What happened was an indirection was created with an
+ // untagged pointer, and this untagged pointer was propagated
+ // to a PAP by the GC, violating the invariant that PAPs
+ // always contain a tagged pointer to the function.
INTERP_TICK(it_retto_UPDATE);
- UPD_IND(((StgUpdateFrame *)Sp)->updatee, obj);
+ UPD_IND(((StgUpdateFrame *)Sp)->updatee, tagged_obj);
Sp += sizeofW(StgUpdateFrame);
goto do_return;
INTERP_TICK(it_retto_BCO);
Sp--;
Sp[0] = (W_)obj;
+ // NB. return the untagged object; the bytecode expects it to
+ // be untagged. XXX this doesn't seem right.
obj = (StgClosure*)Sp[2];
ASSERT(get_itbl(obj)->type == BCO);
goto run_BCO_return;
printStackChunk(Sp,cap->r.rCurrentTSO->stack+cap->r.rCurrentTSO->stack_size);
);
Sp -= 2;
- Sp[1] = (W_)obj;
+ Sp[1] = (W_)tagged_obj;
Sp[0] = (W_)&stg_enter_info;
RETURN_TO_SCHEDULER_NO_PAUSE(ThreadRunGHC, ThreadYielding);
}
// Application...
do_apply:
+ ASSERT(obj == UNTAG_CLOSURE(tagged_obj));
// we have a function to apply (obj), and n arguments taking up m
// words on the stack. The info table (stg_ap_pp_info or whatever)
// is on top of the arguments on the stack.
pap = (StgPAP *)obj;
// we only cope with PAPs whose function is a BCO
- if (get_itbl(pap->fun)->type != BCO) {
+ if (get_itbl(UNTAG_CLOSURE(pap->fun))->type != BCO) {
goto defer_apply_to_sched;
}
for (i = 0; i < pap->n_args; i++) {
Sp[i] = (W_)pap->payload[i];
}
- obj = pap->fun;
+ obj = UNTAG_CLOSURE(pap->fun);
goto run_BCO_fun;
}
else if (arity == n) {
for (i = 0; i < pap->n_args; i++) {
Sp[i] = (W_)pap->payload[i];
}
- obj = pap->fun;
+ obj = UNTAG_CLOSURE(pap->fun);
goto run_BCO_fun;
}
else /* arity > n */ {
for (i = 0; i < m; i++) {
new_pap->payload[pap->n_args + i] = (StgClosure *)Sp[i];
}
- obj = (StgClosure *)new_pap;
+ tagged_obj = (StgClosure *)new_pap;
Sp += m;
goto do_return;
}
for (i = 0; i < m; i++) {
pap->payload[i] = (StgClosure *)Sp[i];
}
- obj = (StgClosure *)pap;
+ tagged_obj = (StgClosure *)pap;
Sp += m;
goto do_return;
}
default:
defer_apply_to_sched:
Sp -= 2;
- Sp[1] = (W_)obj;
+ Sp[1] = (W_)tagged_obj;
Sp[0] = (W_)&stg_enter_info;
RETURN_TO_SCHEDULER_NO_PAUSE(ThreadRunGHC, ThreadYielding);
}
// Sadly we have three different kinds of stack/heap/cswitch check
// to do:
+
run_BCO_return:
// Heap check
if (doYouWantToGC()) {
}
// Stack checks aren't necessary at return points, the stack use
// is aggregated into the enclosing function entry point.
+
goto run_BCO;
run_BCO_return_unboxed:
}
// Stack checks aren't necessary at return points, the stack use
// is aggregated into the enclosing function entry point.
+
goto run_BCO;
run_BCO_fun:
Sp[0] = (W_)&stg_apply_interp_info; // placeholder, really
RETURN_TO_SCHEDULER(ThreadInterpret, StackOverflow);
}
+
goto run_BCO;
// Now, actually interpret the BCO... (no returning to the
INTERP_TICK(it_BCO_entries);
{
register int bciPtr = 1; /* instruction pointer */
+ register StgWord16 bci;
register StgBCO* bco = (StgBCO*)obj;
register StgWord16* instrs = (StgWord16*)(bco->instrs->payload);
register StgWord* literals = (StgWord*)(&bco->literals->payload[0]);
register StgPtr* ptrs = (StgPtr*)(&bco->ptrs->payload[0]);
- register StgInfoTable** itbls = (StgInfoTable**)
- (&bco->itbls->payload[0]);
#ifdef INTERP_STATS
it_lastopc = 0; /* no opcode */
//if (do_print_stack) checkStack(Sp,cap->r.rCurrentTSO->stack+cap->r.rCurrentTSO->stack_size,iSu);
);
+
INTERP_TICK(it_insns);
#ifdef INTERP_STATS
it_lastopc = (int)instrs[bciPtr];
#endif
- switch (BCO_NEXT) {
+ bci = BCO_NEXT;
+ /* We use the high 8 bits for flags, only the highest of which is
+ * currently allocated */
+ ASSERT((bci & 0xFF00) == (bci & 0x8000));
+
+ switch (bci & 0xFF) {
+
+ /* check for a breakpoint on the beginning of a let binding */
+ case bci_BRK_FUN:
+ {
+ int arg1_brk_array, arg2_array_index, arg3_freeVars;
+ StgArrWords *breakPoints;
+ int returning_from_break; // are we resuming execution from a breakpoint?
+ // if yes, then don't break this time around
+ StgClosure *ioAction; // the io action to run at a breakpoint
+
+ StgAP_STACK *new_aps; // a closure to save the top stack frame on the heap
+ int i;
+ int size_words;
+
+ arg1_brk_array = BCO_NEXT; // 1st arg of break instruction
+ arg2_array_index = BCO_NEXT; // 2nd arg of break instruction
+ arg3_freeVars = BCO_NEXT; // 3rd arg of break instruction
+
+ // check if we are returning from a breakpoint - this info
+ // is stored in the flags field of the current TSO
+ returning_from_break = cap->r.rCurrentTSO->flags & TSO_STOPPED_ON_BREAKPOINT;
+
+ // if we are returning from a break then skip this section
+ // and continue executing
+ if (!returning_from_break)
+ {
+ breakPoints = (StgArrWords *) BCO_PTR(arg1_brk_array);
+
+ // stop the current thread if either the
+ // "rts_stop_next_breakpoint" flag is true OR if the
+ // breakpoint flag for this particular expression is
+ // true
+ if (rts_stop_next_breakpoint == rtsTrue ||
+ breakPoints->payload[arg2_array_index] == rtsTrue)
+ {
+ // make sure we don't automatically stop at the
+ // next breakpoint
+ rts_stop_next_breakpoint = rtsFalse;
+
+ // allocate memory for a new AP_STACK, enough to
+ // store the top stack frame plus an
+ // stg_apply_interp_info pointer and a pointer to
+ // the BCO
+ size_words = BCO_BITMAP_SIZE(obj) + 2;
+ new_aps = (StgAP_STACK *) allocate (AP_STACK_sizeW(size_words));
+ SET_HDR(new_aps,&stg_AP_STACK_info,CCS_SYSTEM);
+ new_aps->size = size_words;
+ new_aps->fun = &stg_dummy_ret_closure;
+
+ // fill in the payload of the AP_STACK
+ new_aps->payload[0] = (StgClosure *)&stg_apply_interp_info;
+ new_aps->payload[1] = (StgClosure *)obj;
+
+ // copy the contents of the top stack frame into the AP_STACK
+ for (i = 2; i < size_words; i++)
+ {
+ new_aps->payload[i] = (StgClosure *)Sp[i-2];
+ }
+
+ // prepare the stack so that we can call the
+ // rts_breakpoint_io_action and ensure that the stack is
+ // in a reasonable state for the GC and so that
+ // execution of this BCO can continue when we resume
+ ioAction = (StgClosure *) deRefStablePtr (rts_breakpoint_io_action);
+ Sp -= 9;
+ Sp[8] = (W_)obj;
+ Sp[7] = (W_)&stg_apply_interp_info;
+ Sp[6] = (W_)&stg_noforceIO_info; // see [unreg] below
+ Sp[5] = (W_)new_aps; // the AP_STACK
+ Sp[4] = (W_)BCO_PTR(arg3_freeVars); // the info about local vars of the breakpoint
+ Sp[3] = (W_)False_closure; // True <=> a breakpoint
+ Sp[2] = (W_)&stg_ap_pppv_info;
+ Sp[1] = (W_)ioAction; // apply the IO action to its two arguments above
+ Sp[0] = (W_)&stg_enter_info; // get ready to run the IO action
+ // Note [unreg]: in unregisterised mode, the return
+ // convention for IO is different. The
+ // stg_noForceIO_info stack frame is necessary to
+ // account for this difference.
+
+ // set the flag in the TSO to say that we are now
+ // stopping at a breakpoint so that when we resume
+ // we don't stop on the same breakpoint that we
+ // already stopped at just now
+ cap->r.rCurrentTSO->flags |= TSO_STOPPED_ON_BREAKPOINT;
+
+ // stop this thread and return to the scheduler -
+ // eventually we will come back and the IO action on
+ // the top of the stack will be executed
+ RETURN_TO_SCHEDULER_NO_PAUSE(ThreadRunGHC, ThreadYielding);
+ }
+ }
+ // record that this thread is not stopped at a breakpoint anymore
+ cap->r.rCurrentTSO->flags &= ~TSO_STOPPED_ON_BREAKPOINT;
+
+ // continue normal execution of the byte code instructions
+ goto nextInsn;
+ }
case bci_STKCHECK: {
// Explicit stack check at the beginning of a function
// *only* (stack checks in case alternatives are
// propagated to the enclosing function).
- int stk_words_reqd = BCO_NEXT + 1;
+ StgWord stk_words_reqd = BCO_GET_LARGE_ARG + 1;
if (Sp - stk_words_reqd < SpLim) {
Sp -= 2;
Sp[1] = (W_)obj;
goto nextInsn;
}
+ case bci_ALLOC_AP_NOUPD: {
+ StgAP* ap;
+ int n_payload = BCO_NEXT;
+ ap = (StgAP*)allocate(AP_sizeW(n_payload));
+ Sp[-1] = (W_)ap;
+ ap->n_args = n_payload;
+ SET_HDR(ap, &stg_AP_NOUPD_info, CCS_SYSTEM/*ToDo*/)
+ Sp --;
+ goto nextInsn;
+ }
+
case bci_ALLOC_PAP: {
StgPAP* pap;
int arity = BCO_NEXT;
int i;
int o_itbl = BCO_NEXT;
int n_words = BCO_NEXT;
- StgInfoTable* itbl = INFO_PTR_TO_STRUCT(BCO_ITBL(o_itbl));
+ StgInfoTable* itbl = INFO_PTR_TO_STRUCT(BCO_LIT(o_itbl));
int request = CONSTR_sizeW( itbl->layout.payload.ptrs,
itbl->layout.payload.nptrs );
StgClosure* con = (StgClosure*)allocate_NONUPD(request);
ASSERT( itbl->layout.payload.ptrs + itbl->layout.payload.nptrs > 0);
- SET_HDR(con, BCO_ITBL(o_itbl), CCS_SYSTEM/*ToDo*/);
+ SET_HDR(con, (StgInfoTable*)BCO_LIT(o_itbl), CCS_SYSTEM/*ToDo*/);
for (i = 0; i < n_words; i++) {
con->payload[i] = (StgClosure*)Sp[i];
}
goto eval;
case bci_RETURN:
- obj = (StgClosure *)Sp[0];
+ tagged_obj = (StgClosure *)Sp[0];
Sp++;
goto do_return;
RET_DYN_BITMAP_SIZE + RET_DYN_NONPTR_REGS_SIZE
+ sizeofW(StgRetDyn);
-#ifdef THREADED_RTS
- // Threaded RTS:
- // Arguments on the TSO stack are not good, because garbage
- // collection might move the TSO as soon as we call
- // suspendThread below.
-
- W_ arguments[stk_offset];
-
- memcpy(arguments, Sp, sizeof(W_) * stk_offset);
-#endif
+ /* the stack looks like this:
+
+ | | <- Sp + stk_offset
+ +-------------+
+ | |
+ | args |
+ | | <- Sp + ret_size + 1
+ +-------------+
+ | C fun | <- Sp + ret_size
+ +-------------+
+ | ret | <- Sp
+ +-------------+
+
+ ret is a placeholder for the return address, and may be
+ up to 2 words.
+
+ We need to copy the args out of the TSO, because when
+ we call suspendThread() we no longer own the TSO stack,
+ and it may move at any time - indeed suspendThread()
+ itself may do stack squeezing and move our args.
+ So we make a copy of the argument block.
+ */
+
+#define ROUND_UP_WDS(p) ((((StgWord)(p)) + sizeof(W_)-1)/sizeof(W_))
+
+ ffi_cif *cif = (ffi_cif *)marshall_fn;
+ nat nargs = cif->nargs;
+ nat ret_size;
+ nat i;
+ StgPtr p;
+ W_ ret[2]; // max needed
+ W_ *arguments[stk_offset]; // max needed
+ void *argptrs[nargs];
+ void (*fn)(void);
+
+ if (cif->rtype->type == FFI_TYPE_VOID) {
+ // necessary because cif->rtype->size == 1 for void,
+ // but the bytecode generator has not pushed a
+ // placeholder in this case.
+ ret_size = 0;
+ } else {
+ ret_size = ROUND_UP_WDS(cif->rtype->size);
+ }
+
+ memcpy(arguments, Sp+ret_size+1,
+ sizeof(W_) * (stk_offset-1-ret_size));
+
+ // libffi expects the args as an array of pointers to
+ // values, so we have to construct this array before making
+ // the call.
+ p = (StgPtr)arguments;
+ for (i = 0; i < nargs; i++) {
+ argptrs[i] = (void *)p;
+ // get the size from the cif
+ p += ROUND_UP_WDS(cif->arg_types[i]->size);
+ }
+
+ // this is the function we're going to call
+ fn = (void(*)(void))Sp[ret_size];
// Restore the Haskell thread's current value of errno
errno = cap->r.rCurrentTSO->saved_errno;
// on the stack frame to describe this chunk of stack.
//
Sp -= ret_dyn_size;
- ((StgRetDyn *)Sp)->liveness = NO_PTRS | N_NONPTRS(stk_offset);
+ ((StgRetDyn *)Sp)->liveness = R1_PTR | N_NONPTRS(stk_offset);
((StgRetDyn *)Sp)->info = (StgInfoTable *)&stg_gc_gen_info;
+ // save obj (pointer to the current BCO), since this
+ // might move during the call. We use the R1 slot in the
+ // RET_DYN frame for this, hence R1_PTR above.
+ ((StgRetDyn *)Sp)->payload[0] = (StgClosure *)obj;
+
SAVE_STACK_POINTERS;
tok = suspendThread(&cap->r);
-#ifndef THREADED_RTS
- // Careful:
- // suspendThread might have shifted the stack
- // around (stack squeezing), so we have to grab the real
- // Sp out of the TSO to find the ccall args again.
-
- marshall_fn ( (void*)(cap->r.rCurrentTSO->sp + ret_dyn_size) );
-#else
- // Threaded RTS:
// We already made a copy of the arguments above.
-
- marshall_fn ( arguments );
-#endif
+ ffi_call(cif, fn, ret, argptrs);
// And restart the thread again, popping the RET_DYN frame.
cap = (Capability *)((void *)((unsigned char*)resumeThread(tok) - sizeof(StgFunTable)));
LOAD_STACK_POINTERS;
+
+ // Re-load the pointer to the BCO from the RET_DYN frame,
+ // it might have moved during the call. Also reload the
+ // pointers to the components of the BCO.
+ obj = ((StgRetDyn *)Sp)->payload[0];
+ bco = (StgBCO*)obj;
+ instrs = (StgWord16*)(bco->instrs->payload);
+ literals = (StgWord*)(&bco->literals->payload[0]);
+ ptrs = (StgPtr*)(&bco->ptrs->payload[0]);
+
Sp += ret_dyn_size;
// Save the Haskell thread's current value of errno
cap->r.rCurrentTSO->saved_errno = errno;
-#ifdef THREADED_RTS
- // Threaded RTS:
- // Copy the "arguments", which might include a return value,
- // back to the TSO stack. It would of course be enough to
- // just copy the return value, but we don't know the offset.
- memcpy(Sp, arguments, sizeof(W_) * stk_offset);
-#endif
+ // Copy the return value back to the TSO stack. It is at
+ // most 2 words large, and resides at arguments[0].
+ memcpy(Sp, ret, sizeof(W_) * stg_min(stk_offset,ret_size));
goto nextInsn;
}
bciPtr = nextpc;
goto nextInsn;
}
-
+
case bci_CASEFAIL:
barf("interpretBCO: hit a CASEFAIL");
// Errors
default:
- barf("interpretBCO: unknown or unimplemented opcode");
+ barf("interpretBCO: unknown or unimplemented opcode %d",
+ (int)(bci & 0xFF));
} /* switch on opcode */
}
projects / ghc-hetmet.git / blobdiff