// (C) Copyright 2001 Samuele Pedroni
package org.python.compiler;
import java.util.Enumeration;
import java.util.LinkedHashMap;
import java.util.Map;
import java.util.Hashtable;
import java.util.Vector;
import org.python.antlr.ParseException;
import org.python.antlr.PythonTree;
import org.python.antlr.ast.Return;
import org.python.antlr.base.expr;
public class ScopeInfo extends Object implements ScopeConstants {
public PythonTree scope_node;
public String scope_name;
public int level;
public int func_level;
public void dump() { // for debugging
if (org.python.core.Options.verbose < org.python.core.Py.DEBUG)
return;
for(int i=0; i<level; i++) System.err.print(' ');
System.err.print(((kind != CLASSSCOPE)?scope_name:"class "+
scope_name)+": ");
for (Map.Entry<String, SymInfo> entry : tbl.entrySet()) {
String name = entry.getKey();
SymInfo info = entry.getValue();
int flags = info.flags;
System.err.print(name);
if ((flags&BOUND) != 0) System.err.print('=');
// func scope global (affect nested scopes)
// vs. class scope global
if ((flags&NGLOBAL) != 0) System.err.print('G');
else if ((flags&CLASS_GLOBAL) != 0) System.err.print('g');
if ((flags&PARAM) != 0) System.err.print('P');
else if ((flags&FROM_PARAM) != 0) System.err.print('p');
if ((flags&CELL) != 0) System.err.print('!');
if ((flags&FREE) != 0) System.err.print(",f");
System.err.print(" ");
}
System.err.println();
}
public ScopeInfo(String name, PythonTree node, int level, int kind,
int func_level, ArgListCompiler ac) {
scope_name = name;
scope_node = node;
this.level = level;
this.kind = kind;
this.func_level = func_level;
this.ac = ac;
}
public int kind;
public boolean unqual_exec;
public boolean exec;
public boolean from_import_star;
public boolean contains_ns_free_vars;
public boolean generator;
private boolean hasReturnWithValue;
public int yield_count;
public int max_with_count;
public ArgListCompiler ac;
public Map<String, SymInfo> tbl = new LinkedHashMap<String, SymInfo>();
public Vector<String> names = new Vector<String>();
public int addGlobal(String name) {
// global kind = func vs. class
int global = kind==CLASSSCOPE?CLASS_GLOBAL:NGLOBAL;
SymInfo info = tbl.get(name);
if (info == null) {
tbl.put(name,new SymInfo(global|BOUND));
return -1;
}
int prev = info.flags;
info.flags |= global|BOUND;
return prev;
}
public int local = 0;
public void addParam(String name) {
//System.out.println("addParam " + name);
tbl.put(name, new SymInfo(PARAM|BOUND,local++));
names.addElement(name);
}
public void markFromParam() {
for (SymInfo info : tbl.values()) {
info.flags |= FROM_PARAM;
}
}
public void addBound(String name) {
SymInfo info = tbl.get(name);
if (info == null) {
tbl.put(name, new SymInfo(BOUND));
return;
}
info.flags |= BOUND;
}
public void addUsed(String name) {
if (tbl.get(name) == null) {
tbl.put(name, new SymInfo(0));
return;
}
}
private final static Object PRESENT = new Object();
public Hashtable<String,Object> inner_free = new Hashtable<String,Object>();
public Vector<String> cellvars = new Vector<String>();
public Vector<String> jy_paramcells = new Vector<String>();
public int jy_npurecell;
public int cell, distance;
public ScopeInfo up;
//Resolve the names used in the given scope, and mark any freevars used in the up scope
public void cook(ScopeInfo up, int distance, CompilationContext ctxt) throws Exception {
if(up == null)
return; // top level => nop
this.up = up;
this.distance = distance;
boolean func = kind == FUNCSCOPE;
Vector<String> purecells = new Vector<String>();
cell = 0;
boolean some_inner_free = inner_free.size() > 0;
for (Enumeration e = inner_free.keys(); e.hasMoreElements(); ) {
String name = (String)e.nextElement();
SymInfo info = tbl.get(name);
if (info == null) {
tbl.put(name,new SymInfo(FREE));
continue;
}
int flags = info.flags;
if (func) {
// not func global and bound ?
if ((flags&NGLOBAL) == 0 && (flags&BOUND) != 0) {
info.flags |= CELL;
if ((info.flags&PARAM) != 0)
jy_paramcells.addElement(name);
cellvars.addElement(name);
info.env_index = cell++;
if ((flags&PARAM) == 0) purecells.addElement(name);
continue;
}
} else {
info.flags |= FREE;
}
}
boolean some_free = false;
boolean nested = up.kind != TOPSCOPE;
for (Map.Entry<String, SymInfo> entry : tbl.entrySet()) {
String name = entry.getKey();
SymInfo info = entry.getValue();
int flags = info.flags;
if (nested && (flags&FREE) != 0) up.inner_free.put(name,PRESENT);
if ((flags&(GLOBAL|PARAM|CELL)) == 0) {
if ((flags&BOUND) != 0) { // ?? only func
// System.err.println("local: "+name);
names.addElement(name);
info.locals_index = local++;
continue;
}
info.flags |= FREE;
some_free = true;
if (nested) up.inner_free.put(name,PRESENT);
}
}
if ((jy_npurecell = purecells.size()) > 0) {
int sz = purecells.size();
for (int i = 0; i < sz; i++) {
names.addElement(purecells.elementAt(i));
}
}
if (some_free && nested) {
up.contains_ns_free_vars = true;
}
// XXX - this doesn't catch all cases - may depend subtly
// on how visiting NOW works with antlr compared to javacc
if ((unqual_exec || from_import_star)) {
if(some_inner_free) dynastuff_trouble(true, ctxt);
else if(func_level > 1 && some_free)
dynastuff_trouble(false, ctxt);
}
}
private void dynastuff_trouble(boolean inner_free, CompilationContext ctxt) throws Exception {
StringBuilder illegal = new StringBuilder();
if (unqual_exec && from_import_star) {
illegal.append("function '")
.append(scope_name)
.append("' uses import * and bare exec, which are illegal");
} else if (unqual_exec) {
illegal.append("unqualified exec is not allowed in function '")
.append(scope_name)
.append("'");
} else {
illegal.append("import * is not allowed in function '").append(scope_name).append("'");
}
if (inner_free) {
illegal.append(" because it contains a function with free variables");
} else {
illegal.append(" because it contains free variables");
}
ctxt.error(illegal.toString(), true, scope_node);
}
public Vector<String> freevars = new Vector<String>();
/**
* setup the closure on this scope using the scope passed into cook as up as
* the containing scope
*/
public void setup_closure() {
setup_closure(up);
}
/**
* setup the closure on this scope using the passed in scope. This is used
* by jythonc to setup its closures.
*/
public void setup_closure(ScopeInfo up){
int free = cell; // env = cell...,free...
Map<String, SymInfo> up_tbl = up.tbl;
boolean nested = up.kind != TOPSCOPE;
for (Map.Entry<String, SymInfo> entry : tbl.entrySet()) {
String name = entry.getKey();
SymInfo info = entry.getValue();
int flags = info.flags;
if ((flags&FREE) != 0) {
SymInfo up_info = up_tbl.get(name);
// ?? differs from CPython -- what is the intended behaviour?
if (up_info != null) {
int up_flags = up_info.flags;
if ((up_flags&(CELL|FREE)) != 0) {
info.env_index = free++;
freevars.addElement(name);
continue;
}
// ! func global affect nested scopes
if (nested && (up_flags&NGLOBAL) != 0) {
info.flags = NGLOBAL|BOUND;
continue;
}
}
info.flags &= ~FREE;
}
}
}
@Override
public String toString() {
return "ScopeInfo[" + scope_name + " " + kind + "]@" +
System.identityHashCode(this);
}
public void defineAsGenerator(expr node) {
generator = true;
if (hasReturnWithValue) {
throw new ParseException("'return' with argument " +
"inside generator", node);
}
}
public void noteReturnValue(Return node) {
if (generator) {
throw new ParseException("'return' with argument " +
"inside generator", node);
}
hasReturnWithValue = true;
}
}