/*
* Clean up a frame and return.
*/
static void
InlineReturn(VMFrame &f)
{
JSContext *cx = f.cx;
JSStackFrame *fp = f.regs.fp;
JS_ASSERT(f.fp() != f.entryfp);
JS_ASSERT(!js_IsActiveWithOrBlock(cx, &fp->scopeChain(), 0));
Value *newsp = fp->actualArgs() - 1;
newsp[-1] = fp->returnValue();
cx->stack().popInlineFrame(cx, fp->prev(), newsp);
}
/*
* This function must only be called after the early prologue, since it depends
* on fp->exec.fun.
*/
void * JS_FASTCALL
stubs::FixupArity(VMFrame &f, uint32 nactual)
{
JSContext *cx = f.cx;
JSStackFrame *oldfp = f.fp();
JS_ASSERT(nactual != oldfp->numFormalArgs());
/*
* Grossssss! *move* the stack frame. If this ends up being perf-critical,
* we can figure out how to spot-optimize it. Be careful to touch only the
* members that have been initialized by initCallFrameCallerHalf and the
* early prologue.
*/
uint32 flags = oldfp->isConstructingFlag();
JSFunction *fun = oldfp->fun();
void *ncode = oldfp->nativeReturnAddress();
/* Pop the inline frame. */
f.fp() = oldfp->prev();
f.regs.sp = (Value*) oldfp;
/* Reserve enough space for a callee frame. */
JSStackFrame *newfp = cx->stack().getInlineFrameWithinLimit(cx, (Value*) oldfp, nactual,
fun, fun->script(), &flags,
f.entryfp, &f.stackLimit);
if (!newfp) {
/*
* The PC is not coherent with the current frame, so fix it up for
* exception handling.
*/
f.regs.pc = f.jit()->nativeToPC(ncode);
THROWV(NULL);
}
/* Reset the part of the stack frame set by the caller. */
newfp->initCallFrameCallerHalf(cx, flags, ncode);
/* Reset the part of the stack frame set by the prologue up to now. */
newfp->initCallFrameEarlyPrologue(fun, nactual);
/* The caller takes care of assigning fp to regs. */
return newfp;
}
/*
* The strategy for this goes as follows:
*
* 1) Scan the stack, looking at all return addresses that could go into JIT
* code.
* 2) If an address corresponds to a call site registered by |callSite| during
* the last compilation, remember it.
* 3) Purge the old compiled state and return if there were no active frames of
* this script on the stack.
* 4) Fix up the stack by replacing all saved addresses with the addresses the
* new compiler gives us for the call sites.
*/
bool
Recompiler::recompile()
{
JS_ASSERT(script->hasJITCode());
Vector<PatchableAddress> normalPatches(cx);
Vector<PatchableAddress> ctorPatches(cx);
JSStackFrame *firstCtorFrame = NULL;
JSStackFrame *firstNormalFrame = NULL;
// Find all JIT'd stack frames to account for return addresses that will
// need to be patched after recompilation.
for (VMFrame *f = script->compartment->jaegerCompartment->activeFrame();
f != NULL;
f = f->previous) {
// Scan all frames owned by this VMFrame.
JSStackFrame *end = f->entryfp->prev();
for (JSStackFrame *fp = f->fp(); fp != end; fp = fp->prev()) {
// Remember the latest frame for each type of JIT'd code, so the
// compiler will have a frame to re-JIT from.
if (!firstCtorFrame && fp->script() == script && fp->isConstructing())
firstCtorFrame = fp;
else if (!firstNormalFrame && fp->script() == script && !fp->isConstructing())
firstNormalFrame = fp;
void **addr = fp->addressOfNativeReturnAddress();
if (script->jitCtor && script->jitCtor->isValidCode(*addr)) {
if (!ctorPatches.append(findPatch(script->jitCtor, addr)))
return false;
} else if (script->jitNormal && script->jitNormal->isValidCode(*addr)) {
if (!normalPatches.append(findPatch(script->jitNormal, addr)))
return false;
}
}
void **addr = f->returnAddressLocation();
if (script->jitCtor && script->jitCtor->isValidCode(*addr)) {
if (!ctorPatches.append(findPatch(script->jitCtor, addr)))
return false;
} else if (script->jitNormal && script->jitNormal->isValidCode(*addr)) {
if (!normalPatches.append(findPatch(script->jitNormal, addr)))
return false;
}
}
Vector<CallSite> normalSites(cx);
Vector<CallSite> ctorSites(cx);
if (script->jitNormal && !saveTraps(script->jitNormal, &normalSites))
return false;
if (script->jitCtor && !saveTraps(script->jitCtor, &ctorSites))
return false;
ReleaseScriptCode(cx, script);
if (normalPatches.length() &&
!recompile(firstNormalFrame, normalPatches, normalSites)) {
return false;
}
if (ctorPatches.length() &&
!recompile(firstCtorFrame, ctorPatches, ctorSites)) {
return false;
}
return true;
}