package org.luaj.vm2.luajc;
import java.io.ByteArrayOutputStream;
import java.io.PrintStream;
import org.luaj.vm2.Lua;
import org.luaj.vm2.Print;
import org.luaj.vm2.Prototype;
/**
* Prototype information for static single-assignment analysis
*/
public class ProtoInfo {
public final String name;
public final Prototype prototype; // the prototype that this info is about
public final ProtoInfo[] subprotos; // one per enclosed prototype, or null
public final BasicBlock[] blocks; // basic block analysis of code branching
public final BasicBlock[] blocklist; // blocks in breadth-first order
public final VarInfo[] params; // Parameters and initial values of stack variables
public final VarInfo[][] vars; // Each variable
public final UpvalInfo[] upvals; // from outer scope
public final UpvalInfo[][] openups; // per slot, upvalues allocated by this prototype
public ProtoInfo(Prototype p, String name) {
this(p,name,null);
}
private ProtoInfo(Prototype p, String name, UpvalInfo[] u) {
this.name = name;
this.prototype = p;
this.upvals = u;
this.subprotos = p.p!=null&&p.p.length>0? new ProtoInfo[p.p.length]: null;
// find basic blocks
this.blocks = BasicBlock.findBasicBlocks(p);
this.blocklist = BasicBlock.findLiveBlocks(blocks);
// params are inputs to first block
this.params = new VarInfo[p.maxstacksize];
for ( int slot=0; slot<p.maxstacksize; slot++ ) {
VarInfo v = VarInfo.PARAM(slot);
params[slot] = v;
}
// find variables
this.vars = findVariables();
replaceTrivialPhiVariables();
// find upvalues, create sub-prototypes
this.openups = new UpvalInfo[p.maxstacksize][];
findUpvalues();
}
public String toString() {
StringBuffer sb = new StringBuffer();
// prototpye name
sb.append( "proto '"+name+"'\n" );
// upvalues from outer scopes
for ( int i=0, n=(upvals!=null? upvals.length: 0); i<n; i++ )
sb.append( " up["+i+"]: "+upvals[i]+"\n" );
// basic blocks
for ( int i=0; i<blocklist.length; i++ ) {
BasicBlock b = blocklist[i];
int pc0 = b.pc0;
sb.append( " block "+b.toString() );
appendOpenUps( sb, -1 );
// instructions
for ( int pc=pc0; pc<=b.pc1; pc++ ) {
// open upvalue storage
appendOpenUps( sb, pc );
// opcode
sb.append( " " );
for ( int j=0; j<prototype.maxstacksize; j++ ) {
VarInfo v = vars[j][pc];
String u = (v==null? "": v.upvalue!=null? !v.upvalue.rw? "[C] ": (v.allocupvalue&&v.pc==pc? "[*] ": "[] "): " ");
String s = v==null? "null ": String.valueOf(v);
sb.append( s+u);
}
sb.append( " " );
ByteArrayOutputStream baos = new ByteArrayOutputStream();
PrintStream ops = Print.ps;
Print.ps = new PrintStream(baos);
try {
Print.printOpCode(prototype, pc);
} finally {
Print.ps.close();
Print.ps = ops;
}
sb.append( baos.toString() );
sb.append( "\n" );
}
}
// nested functions
for ( int i=0, n=subprotos!=null? subprotos.length: 0; i<n; i++ ) {
sb.append( subprotos[i].toString() );
}
return sb.toString();
}
private void appendOpenUps(StringBuffer sb, int pc) {
for ( int j=0; j<prototype.maxstacksize; j++ ) {
VarInfo v = (pc<0? params[j]: vars[j][pc]);
if ( v != null && v.pc == pc && v.allocupvalue ) {
sb.append( " open: "+v.upvalue+"\n" );
}
}
}
private VarInfo[][] findVariables() {
// create storage for variables.
int n = prototype.code.length;
int m = prototype.maxstacksize;
VarInfo[][] v = new VarInfo[m][];
for ( int i=0; i<v.length; i++ )
v[i] = new VarInfo[n];
// process instructions
for ( int bi=0; bi<blocklist.length; bi++ ) {
BasicBlock b0 = blocklist[bi];
// input from previous blocks
int nprev = b0.prev!=null? b0.prev.length: 0;
for ( int slot=0; slot<m; slot++ ) {
VarInfo var = null;
if ( nprev == 0 )
var = params[slot];
else if ( nprev == 1 )
var = v[slot][b0.prev[0].pc1];
else {
for ( int i=0; i<nprev; i++ ) {
BasicBlock bp = b0.prev[i];
if ( v[slot][bp.pc1] == VarInfo.INVALID )
var = VarInfo.INVALID;
}
}
if ( var == null )
var = VarInfo.PHI(this, slot, b0.pc0);
v[slot][b0.pc0] = var;
}
// process instructions for this basic block
for ( int pc=b0.pc0; pc<=b0.pc1; pc++ ) {
// propogate previous values except at block boundaries
if ( pc > b0.pc0 )
propogateVars( v, pc-1, pc );
int a,b,c,nups;
int ins = prototype.code[pc];
int op = Lua.GET_OPCODE(ins);
// account for assignments, references and invalidations
switch ( op ) {
case Lua.OP_LOADK:/* A Bx R(A) := Kst(Bx) */
case Lua.OP_LOADBOOL:/* A B C R(A) := (Bool)B; if (C) pc++ */
case Lua.OP_GETUPVAL: /* A B R(A) := UpValue[B] */
case Lua.OP_GETGLOBAL: /* A Bx R(A) := Gbl[Kst(Bx)] */
case Lua.OP_NEWTABLE: /* A B C R(A) := {} (size = B,C) */
a = Lua.GETARG_A( ins );
v[a][pc] = new VarInfo(a,pc);
break;
case Lua.OP_MOVE:/* A B R(A) := R(B) */
case Lua.OP_UNM: /* A B R(A) := -R(B) */
case Lua.OP_NOT: /* A B R(A) := not R(B) */
case Lua.OP_LEN: /* A B R(A) := length of R(B) */
case Lua.OP_TESTSET: /* A B C if (R(B) <=> C) then R(A) := R(B) else pc++ */
a = Lua.GETARG_A( ins );
b = Lua.GETARG_B( ins );
v[b][pc].isreferenced = true;
v[a][pc] = new VarInfo(a,pc);
break;
case Lua.OP_ADD: /* A B C R(A) := RK(B) + RK(C) */
case Lua.OP_SUB: /* A B C R(A) := RK(B) - RK(C) */
case Lua.OP_MUL: /* A B C R(A) := RK(B) * RK(C) */
case Lua.OP_DIV: /* A B C R(A) := RK(B) / RK(C) */
case Lua.OP_MOD: /* A B C R(A) := RK(B) % RK(C) */
case Lua.OP_POW: /* A B C R(A) := RK(B) ^ RK(C) */
a = Lua.GETARG_A( ins );
b = Lua.GETARG_B( ins );
c = Lua.GETARG_C( ins );
if (!Lua.ISK(b)) v[b][pc].isreferenced = true;
if (!Lua.ISK(c)) v[c][pc].isreferenced = true;
v[a][pc] = new VarInfo(a,pc);
break;
case Lua.OP_SETTABLE: /* A B C R(A)[RK(B)]:= RK(C) */
a = Lua.GETARG_A( ins );
b = Lua.GETARG_B( ins );
c = Lua.GETARG_C( ins );
v[a][pc].isreferenced = true;
if (!Lua.ISK(b)) v[b][pc].isreferenced = true;
if (!Lua.ISK(c)) v[c][pc].isreferenced = true;
break;
case Lua.OP_CONCAT: /* A B C R(A) := R(B).. ... ..R(C) */
a = Lua.GETARG_A( ins );
b = Lua.GETARG_B( ins );
c = Lua.GETARG_C( ins );
for ( ; b<=c; b++ )
v[b][pc].isreferenced = true;
v[a][pc] = new VarInfo(a,pc);
break;
case Lua.OP_FORPREP: /* A sBx R(A)-=R(A+2); pc+=sBx */
a = Lua.GETARG_A( ins );
v[a+2][pc].isreferenced = true;
v[a][pc] = new VarInfo(a,pc);
break;
case Lua.OP_GETTABLE: /* A B C R(A) := R(B)[RK(C)] */
a = Lua.GETARG_A( ins );
b = Lua.GETARG_B( ins );
c = Lua.GETARG_C( ins );
v[b][pc].isreferenced = true;
if (!Lua.ISK(c)) v[c][pc].isreferenced = true;
v[a][pc] = new VarInfo(a,pc);
break;
case Lua.OP_SELF: /* A B C R(A+1) := R(B); R(A) := R(B)[RK(C)] */
a = Lua.GETARG_A( ins );
b = Lua.GETARG_B( ins );
c = Lua.GETARG_C( ins );
v[b][pc].isreferenced = true;
if (!Lua.ISK(c)) v[c][pc].isreferenced = true;
v[a][pc] = new VarInfo(a,pc);
v[a+1][pc] = new VarInfo(a+1,pc);
break;
case Lua.OP_FORLOOP: /* A sBx R(A)+=R(A+2);
if R(A) <?= R(A+1) then { pc+=sBx; R(A+3)=R(A) }*/
a = Lua.GETARG_A( ins );
v[a][pc].isreferenced = true;
v[a+2][pc].isreferenced = true;
v[a][pc] = new VarInfo(a,pc);
v[a][pc].isreferenced = true;
v[a+1][pc].isreferenced = true;
v[a+3][pc] = new VarInfo(a+3,pc);
break;
case Lua.OP_LOADNIL: /* A B R(A) := ... := R(B) := nil */
a = Lua.GETARG_A( ins );
b = Lua.GETARG_B( ins );
for ( ; a<=b; a++ )
v[a][pc] = new VarInfo(a,pc);
break;
case Lua.OP_VARARG: /* A B R(A), R(A+1), ..., R(A+B-1) = vararg */
a = Lua.GETARG_A( ins );
b = Lua.GETARG_B( ins );
for ( int j=1; j<b; j++, a++ )
v[a][pc] = new VarInfo(a,pc);
if ( b == 0 )
for ( ; a<m; a++ )
v[a][pc] = VarInfo.INVALID;
break;
case Lua.OP_CALL: /* A B C R(A), ... ,R(A+C-2) := R(A)(R(A+1), ... ,R(A+B-1)) */
a = Lua.GETARG_A( ins );
b = Lua.GETARG_B( ins );
c = Lua.GETARG_C( ins );
v[a][pc].isreferenced = true;
v[a][pc].isreferenced = true;
for ( int i=1; i<=b-1; i++ )
v[a+i][pc].isreferenced = true;
for ( int j=0; j<=c-2; j++, a++ )
v[a][pc] = new VarInfo(a,pc);
for ( ; a<m; a++ )
v[a][pc] = VarInfo.INVALID;
break;
case Lua.OP_TAILCALL: /* A B C return R(A)(R(A+1), ... ,R(A+B-1)) */
a = Lua.GETARG_A( ins );
b = Lua.GETARG_B( ins );
v[a][pc].isreferenced = true;
for ( int i=1; i<=b-1; i++ )
v[a+i][pc].isreferenced = true;
break;
case Lua.OP_RETURN: /* A B return R(A), ... ,R(A+B-2) (see note) */
a = Lua.GETARG_A( ins );
b = Lua.GETARG_B( ins );
for ( int i=0; i<=b-2; i++ )
v[a+i][pc].isreferenced = true;
break;
case Lua.OP_TFORLOOP: /* A C R(A+3), ... ,R(A+2+C) := R(A)(R(A+1), R(A+2));
if R(A+3) ~= nil then R(A+2)=R(A+3) else pc++ */
a = Lua.GETARG_A( ins );
c = Lua.GETARG_C( ins );
v[a++][pc].isreferenced = true;
v[a++][pc].isreferenced = true;
v[a++][pc].isreferenced = true;
for ( int j=0; j<c; j++, a++ )
v[a][pc] = new VarInfo(a,pc);
for ( ; a<m; a++ )
v[a][pc] = VarInfo.INVALID;
break;
case Lua.OP_CLOSURE: /* A Bx R(A) := closure(KPROTO[Bx], R(A), ... ,R(A+n)) */
a = Lua.GETARG_A( ins );
b = Lua.GETARG_Bx( ins );
nups = prototype.p[b].nups;
for ( int k=1; k<=nups; ++k ) {
int i = prototype.code[pc+k];
if ( (i&4) == 0 ) {
b = Lua.GETARG_B(i);
v[b][pc].isreferenced = true;
}
}
v[a][pc] = new VarInfo(a,pc);
for ( int k=1; k<=nups; k++ )
propogateVars( v, pc, pc+k );
pc += nups;
break;
case Lua.OP_CLOSE: /* A close all variables in the stack up to (>=) R(A)*/
a = Lua.GETARG_A( ins );
for ( ; a<m; a++ )
v[a][pc] = VarInfo.INVALID;
break;
case Lua.OP_SETLIST: /* A B C R(A)[(C-1)*FPF+i]:= R(A+i), 1 <= i <= B */
a = Lua.GETARG_A( ins );
b = Lua.GETARG_B( ins );
v[a][pc].isreferenced = true;
for ( int i=1; i<=b; i++ )
v[a+i][pc].isreferenced = true;
break;
case Lua.OP_SETGLOBAL: /* A Bx Gbl[Kst(Bx)]:= R(A) */
case Lua.OP_SETUPVAL: /* A B UpValue[B]:= R(A) */
case Lua.OP_TEST: /* A C if not (R(A) <=> C) then pc++ */
a = Lua.GETARG_A( ins );
v[a][pc].isreferenced = true;
break;
case Lua.OP_EQ: /* A B C if ((RK(B) == RK(C)) ~= A) then pc++ */
case Lua.OP_LT: /* A B C if ((RK(B) < RK(C)) ~= A) then pc++ */
case Lua.OP_LE: /* A B C if ((RK(B) <= RK(C)) ~= A) then pc++ */
b = Lua.GETARG_B( ins );
c = Lua.GETARG_C( ins );
if (!Lua.ISK(b)) v[b][pc].isreferenced = true;
if (!Lua.ISK(c)) v[c][pc].isreferenced = true;
break;
case Lua.OP_JMP: /* sBx pc+=sBx */
break;
default:
throw new IllegalStateException("unhandled opcode: "+ins);
}
}
}
return v;
}
private static void propogateVars(VarInfo[][] v, int pcfrom, int pcto) {
for ( int j=0, m=v.length; j<m; j++ )
v[j][pcto] = v[j][pcfrom];
}
private void replaceTrivialPhiVariables() {
for ( int i=0; i<blocklist.length; i++ ) {
BasicBlock b0 = blocklist[i];
for ( int slot=0; slot<prototype.maxstacksize; slot++ ) {
VarInfo vold = vars[slot][b0.pc0];
VarInfo vnew = vold.resolvePhiVariableValues();
if ( vnew != null )
substituteVariable( slot, vold, vnew );
}
}
}
private void substituteVariable(int slot, VarInfo vold, VarInfo vnew) {
for ( int i=0, n=prototype.code.length; i<n; i++ )
replaceAll( vars[slot], vars[slot].length, vold, vnew );
}
private void replaceAll(VarInfo[] v, int n, VarInfo vold, VarInfo vnew) {
for ( int i=0; i<n; i++ )
if ( v[i] == vold )
v[i] = vnew;
}
private void findUpvalues() {
int[] code = prototype.code;
int n = code.length;
// propogate to inner prototypes
for ( int pc=0; pc<n; pc++ ) {
if ( Lua.GET_OPCODE(code[pc]) == Lua.OP_CLOSURE ) {
int bx = Lua.GETARG_Bx(code[pc]);
Prototype newp = prototype.p[bx];
UpvalInfo[] newu = newp.nups>0? new UpvalInfo[newp.nups]: null;
String newname = name + "$" + bx;
for ( int j=0; j<newp.nups; ++j ) {
int i = code[++pc];
int b = Lua.GETARG_B(i);
newu[j] = (i&4) != 0? upvals[b]: findOpenUp(pc,b);
}
subprotos[bx] = new ProtoInfo(newp, newname, newu);
}
}
// mark all upvalues that are written locally as read/write
for ( int pc=0; pc<n; pc++ ) {
if ( Lua.GET_OPCODE(code[pc]) == Lua.OP_SETUPVAL )
upvals[Lua.GETARG_B(code[pc])].rw = true;
}
}
private UpvalInfo findOpenUp(int pc, int slot) {
if ( openups[slot] == null )
openups[slot] = new UpvalInfo[prototype.code.length];
if ( openups[slot][pc] != null )
return openups[slot][pc];
UpvalInfo u = new UpvalInfo(this, pc, slot);
for ( int i=0, n=prototype.code.length; i<n; ++i )
if ( vars[slot][i] != null && vars[slot][i].upvalue == u )
openups[slot][i] = u;
return u;
}
public boolean isUpvalueAssign(int pc, int slot) {
VarInfo v = pc<0? params[slot]: vars[slot][pc];
return v != null && v.upvalue != null && v.upvalue.rw;
}
public boolean isUpvalueCreate(int pc, int slot) {
VarInfo v = pc<0? params[slot]: vars[slot][pc];
return v != null && v.upvalue != null && v.upvalue.rw && v.allocupvalue && pc == v.pc;
}
public boolean isUpvalueRefer(int pc, int slot) {
// special case when both refer and assign in same instruction
if ( pc > 0 && vars[slot][pc] != null && vars[slot][pc].pc == pc && vars[slot][pc-1] != null )
pc -= 1;
VarInfo v = pc<0? params[slot]: vars[slot][pc];
return v != null && v.upvalue != null && v.upvalue.rw;
}
public boolean isInitialValueUsed(int slot) {
VarInfo v = params[slot];
return v.isreferenced;
}
public boolean isReadWriteUpvalue(UpvalInfo u) {
return u.rw;
}
}