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-rw-r--r--src/libexpr/eval-test.cc662
1 files changed, 1 insertions, 661 deletions
diff --git a/src/libexpr/eval-test.cc b/src/libexpr/eval-test.cc
index 543a9cf85..d37014a73 100644
--- a/src/libexpr/eval-test.cc
+++ b/src/libexpr/eval-test.cc
@@ -10,668 +10,13 @@
using namespace nix;
-struct Env;
-struct Value;
-
-typedef ATerm Sym;
-
-typedef std::map<Sym, Value> Bindings;
-
-
-struct Env
-{
- Env * up;
- Bindings bindings;
-};
-
-
-typedef enum {
- tInt = 1,
- tBool,
- tString,
- tPath,
- tNull,
- tAttrs,
- tList,
- tThunk,
- tLambda,
- tCopy,
- tBlackhole,
- tPrimOp,
- tPrimOpApp,
-} ValueType;
-
-
-typedef void (* PrimOp_) (Value * * args, Value & v);
-
-
-struct Value
-{
- ValueType type;
- union
- {
- int integer;
- bool boolean;
- struct {
- const char * s;
- const char * * context;
- } string;
- Bindings * attrs;
- struct {
- unsigned int length;
- Value * elems;
- } list;
- struct {
- Env * env;
- Expr expr;
- } thunk;
- struct {
- Env * env;
- Pattern pat;
- Expr body;
- } lambda;
- Value * val;
- struct {
- PrimOp_ fun;
- unsigned int arity;
- } primOp;
- struct {
- Value * left, * right;
- unsigned int argsLeft;
- } primOpApp;
- };
-};
-
-
-static void mkThunk(Value & v, Env & env, Expr expr)
-{
- v.type = tThunk;
- v.thunk.env = &env;
- v.thunk.expr = expr;
-}
-
-
-static void mkInt(Value & v, int n)
-{
- v.type = tInt;
- v.integer = n;
-}
-
-
-static void mkBool(Value & v, bool b)
-{
- v.type = tBool;
- v.boolean = b;
-}
-
-
-static void mkString(Value & v, const char * s)
-{
- v.type = tString;
- v.string.s = s;
- v.string.context = 0;
-}
-
-
-std::ostream & operator << (std::ostream & str, Value & v)
-{
- switch (v.type) {
- case tInt:
- str << v.integer;
- break;
- case tBool:
- str << (v.boolean ? "true" : "false");
- break;
- case tString:
- str << "\"" << v.string.s << "\""; // !!! escaping
- break;
- case tNull:
- str << "true";
- break;
- case tAttrs:
- str << "{ ";
- foreach (Bindings::iterator, i, *v.attrs)
- str << aterm2String(i->first) << " = " << i->second << "; ";
- str << "}";
- break;
- case tList:
- str << "[ ";
- for (unsigned int n = 0; n < v.list.length; ++n)
- str << v.list.elems[n] << " ";
- str << "]";
- break;
- case tThunk:
- str << "<CODE>";
- break;
- case tLambda:
- str << "<LAMBDA>";
- break;
- case tPrimOp:
- str << "<PRIMOP>";
- break;
- case tPrimOpApp:
- str << "<PRIMOP-APP>";
- break;
- default:
- abort();
- }
- return str;
-}
-
-
-static void eval(Env & env, Expr e, Value & v);
-
-
-string showType(Value & v)
-{
- switch (v.type) {
- case tString: return "a string";
- case tPath: return "a path";
- case tNull: return "null";
- case tInt: return "an integer";
- case tBool: return "a boolean";
- case tLambda: return "a function";
- case tAttrs: return "an attribute set";
- case tList: return "a list";
- case tPrimOpApp: return "a partially applied built-in function";
- default: throw Error("unknown type");
- }
-}
-
-
-static void forceValue(Value & v)
-{
- if (v.type == tThunk) {
- v.type = tBlackhole;
- eval(*v.thunk.env, v.thunk.expr, v);
- }
- else if (v.type == tCopy) {
- forceValue(*v.val);
- v = *v.val;
- }
- else if (v.type == tBlackhole)
- throw EvalError("infinite recursion encountered");
-}
-
-
-static void forceInt(Value & v)
-{
- forceValue(v);
- if (v.type != tInt)
- throw TypeError(format("value is %1% while an integer was expected") % showType(v));
-}
-
-
-static void forceAttrs(Value & v)
-{
- forceValue(v);
- if (v.type != tAttrs)
- throw TypeError(format("value is %1% while an attribute set was expected") % showType(v));
-}
-
-
-static void forceList(Value & v)
-{
- forceValue(v);
- if (v.type != tList)
- throw TypeError(format("value is %1% while a list was expected") % showType(v));
-}
-
-
-static Value * lookupWith(Env * env, Sym name)
-{
- if (!env) return 0;
- Value * v = lookupWith(env->up, name);
- if (v) return v;
- Bindings::iterator i = env->bindings.find(sWith);
- if (i == env->bindings.end()) return 0;
- Bindings::iterator j = i->second.attrs->find(name);
- if (j != i->second.attrs->end()) return &j->second;
- return 0;
-}
-
-
-static Value * lookupVar(Env * env, Sym name)
-{
- /* First look for a regular variable binding for `name'. */
- for (Env * env2 = env; env2; env2 = env2->up) {
- Bindings::iterator i = env2->bindings.find(name);
- if (i != env2->bindings.end()) return &i->second;
- }
-
- /* Otherwise, look for a `with' attribute set containing `name'.
- Outer `withs' take precedence (i.e. `with {x=1;}; with {x=2;};
- x' evaluates to 1). */
- Value * v = lookupWith(env, name);
- if (v) return v;
-
- /* Alternative implementation where the inner `withs' take
- precedence (i.e. `with {x=1;}; with {x=2;}; x' evaluates to
- 2). */
-#if 0
- for (Env * env2 = env; env2; env2 = env2->up) {
- Bindings::iterator i = env2->bindings.find(sWith);
- if (i == env2->bindings.end()) continue;
- Bindings::iterator j = i->second.attrs->find(name);
- if (j != i->second.attrs->end()) return &j->second;
- }
-#endif
-
- throw Error("undefined variable");
-}
-
-
-static bool eqValues(Value & v1, Value & v2)
-{
- forceValue(v1);
- forceValue(v2);
- switch (v1.type) {
-
- case tInt:
- return v2.type == tInt && v1.integer == v2.integer;
-
- case tBool:
- return v2.type == tBool && v1.boolean == v2.boolean;
-
- case tList:
- if (v2.type != tList || v1.list.length != v2.list.length) return false;
- for (unsigned int n = 0; n < v1.list.length; ++n)
- if (!eqValues(v1.list.elems[n], v2.list.elems[n])) return false;
- return true;
-
- case tAttrs: {
- if (v2.type != tAttrs || v1.attrs->size() != v2.attrs->size()) return false;
- Bindings::iterator i, j;
- for (i = v1.attrs->begin(), j = v2.attrs->begin(); i != v1.attrs->end(); ++i, ++j)
- if (!eqValues(i->second, j->second)) return false;
- return true;
- }
-
- default:
- throw Error("cannot compare given values");
- }
-}
-
-
-unsigned long nrValues = 0, nrEnvs = 0, nrEvaluated = 0;
-
-static Value * allocValues(unsigned int count)
-{
- nrValues += count;
- return new Value[count]; // !!! check destructor
-}
-
-static Env & allocEnv()
-{
- nrEnvs++;
- return *(new Env);
-}
-
-
-char * p1 = 0, * p2 = 0;
-
-
-static bool evalBool(Env & env, Expr e)
-{
- Value v;
- eval(env, e, v);
- if (v.type != tBool)
- throw TypeError(format("value is %1% while a Boolean was expected") % showType(v));
- return v.boolean;
-}
-
-
-static void eval(Env & env, Expr e, Value & v)
-{
- char c;
- if (!p1) p1 = &c; else if (!p2) p2 = &c;
-
- printMsg(lvlError, format("eval: %1%") % e);
-
- nrEvaluated++;
-
- Sym name;
- if (matchVar(e, name)) {
- Value * v2 = lookupVar(&env, name);
- forceValue(*v2);
- v = *v2;
- return;
- }
-
- int n;
- if (matchInt(e, n)) {
- mkInt(v, n);
- return;
- }
-
- ATerm s; ATermList context;
- if (matchStr(e, s, context)) {
- assert(context == ATempty);
- mkString(v, ATgetName(ATgetAFun(s)));
- return;
- }
-
- ATermList es;
- if (matchAttrs(e, es)) {
- v.type = tAttrs;
- v.attrs = new Bindings;
- ATerm e2, pos;
- for (ATermIterator i(es); i; ++i) {
- if (!matchBind(*i, name, e2, pos)) abort(); /* can't happen */
- Value & v2 = (*v.attrs)[name];
- nrValues++;
- mkThunk(v2, env, e2);
- }
- return;
- }
-
- ATermList rbnds, nrbnds;
- if (matchRec(e, rbnds, nrbnds)) {
- Env & env2(allocEnv());
- env2.up = &env;
-
- v.type = tAttrs;
- v.attrs = &env2.bindings;
- ATerm name, e2, pos;
- for (ATermIterator i(rbnds); i; ++i) {
- if (!matchBind(*i, name, e2, pos)) abort(); /* can't happen */
- Value & v2 = env2.bindings[name];
- nrValues++;
- mkThunk(v2, env2, e2);
- }
-
- return;
- }
-
- Expr e1, e2;
- if (matchSelect(e, e2, name)) {
- eval(env, e2, v);
- forceAttrs(v); // !!! eval followed by force is slightly inefficient
- Bindings::iterator i = v.attrs->find(name);
- if (i == v.attrs->end()) throw TypeError("attribute not found");
- forceValue(i->second);
- v = i->second;
- return;
- }
-
- Pattern pat; Expr body; Pos pos;
- if (matchFunction(e, pat, body, pos)) {
- v.type = tLambda;
- v.lambda.env = &env;
- v.lambda.pat = pat;
- v.lambda.body = body;
- return;
- }
-
- Expr fun, arg;
- if (matchCall(e, fun, arg)) {
- eval(env, fun, v);
-
- if (v.type == tPrimOp || v.type == tPrimOpApp) {
- unsigned int argsLeft =
- v.type == tPrimOp ? v.primOp.arity : v.primOpApp.argsLeft;
- if (argsLeft == 1) {
- /* We have all the arguments, so call the primop.
- First find the primop. */
- Value * primOp = &v;
- while (primOp->type == tPrimOpApp) primOp = primOp->primOpApp.left;
- assert(primOp->type == tPrimOp);
- unsigned int arity = primOp->primOp.arity;
-
- Value vLastArg;
- mkThunk(vLastArg, env, arg);
-
- /* Put all the arguments in an array. */
- Value * vArgs[arity];
- unsigned int n = arity - 1;
- vArgs[n--] = &vLastArg;
- for (Value * arg = &v; arg->type == tPrimOpApp; arg = arg->primOpApp.left)
- vArgs[n--] = arg->primOpApp.right;
-
- /* And call the primop. */
- primOp->primOp.fun(vArgs, v);
- } else {
- Value * v2 = allocValues(2);
- v2[0] = v;
- mkThunk(v2[1], env, arg);
- v.type = tPrimOpApp;
- v.primOpApp.left = &v2[0];
- v.primOpApp.right = &v2[1];
- v.primOpApp.argsLeft = argsLeft - 1;
- }
- return;
- }
-
- if (v.type != tLambda) throw TypeError("expected function");
-
- Env & env2(allocEnv());
- env2.up = &env;
-
- ATermList formals; ATerm ellipsis;
-
- if (matchVarPat(v.lambda.pat, name)) {
- Value & vArg = env2.bindings[name];
- nrValues++;
- mkThunk(vArg, env, arg);
- }
-
- else if (matchAttrsPat(v.lambda.pat, formals, ellipsis, name)) {
- Value * vArg;
- Value vArg_;
-
- if (name == sNoAlias)
- vArg = &vArg_;
- else {
- vArg = &env2.bindings[name];
- nrValues++;
- }
-
- eval(env, arg, *vArg);
- forceAttrs(*vArg);
-
- /* For each formal argument, get the actual argument. If
- there is no matching actual argument but the formal
- argument has a default, use the default. */
- unsigned int attrsUsed = 0;
- for (ATermIterator i(formals); i; ++i) {
- Expr def; Sym name;
- DefaultValue def2;
- if (!matchFormal(*i, name, def2)) abort(); /* can't happen */
-
- Bindings::iterator j = vArg->attrs->find(name);
-
- Value & v = env2.bindings[name];
- nrValues++;
-
- if (j == vArg->attrs->end()) {
- if (!matchDefaultValue(def2, def)) def = 0;
- if (def == 0) throw TypeError(format("the argument named `%1%' required by the function is missing")
- % aterm2String(name));
- mkThunk(v, env2, def);
- } else {
- attrsUsed++;
- v.type = tCopy;
- v.val = &j->second;
- }
- }
-
- /* Check that each actual argument is listed as a formal
- argument (unless the attribute match specifies a
- `...'). TODO: show the names of the
- expected/unexpected arguments. */
- if (ellipsis == eFalse && attrsUsed != vArg->attrs->size())
- throw TypeError("function called with unexpected argument");
- }
-
- else abort();
-
- eval(env2, v.lambda.body, v);
- return;
- }
-
- Expr attrs;
- if (matchWith(e, attrs, body, pos)) {
- Env & env2(allocEnv());
- env2.up = &env;
-
- Value & vAttrs = env2.bindings[sWith];
- nrValues++;
- eval(env, attrs, vAttrs);
- forceAttrs(vAttrs);
-
- eval(env2, body, v);
- return;
- }
-
- if (matchList(e, es)) {
- v.type = tList;
- v.list.length = ATgetLength(es);
- v.list.elems = allocValues(v.list.length);
- for (unsigned int n = 0; n < v.list.length; ++n, es = ATgetNext(es))
- mkThunk(v.list.elems[n], env, ATgetFirst(es));
- return;
- }
-
- if (matchOpEq(e, e1, e2)) {
- Value v1; eval(env, e1, v1);
- Value v2; eval(env, e2, v2);
- mkBool(v, eqValues(v1, v2));
- return;
- }
-
- if (matchOpNEq(e, e1, e2)) {
- Value v1; eval(env, e1, v1);
- Value v2; eval(env, e2, v2);
- mkBool(v, !eqValues(v1, v2));
- return;
- }
-
- if (matchOpConcat(e, e1, e2)) {
- Value v1; eval(env, e1, v1);
- forceList(v1);
- Value v2; eval(env, e2, v2);
- forceList(v2);
- v.type = tList;
- v.list.length = v1.list.length + v2.list.length;
- v.list.elems = allocValues(v.list.length);
- /* !!! This loses sharing with the original lists. We could
- use a tCopy node, but that would use more memory. */
- for (unsigned int n = 0; n < v1.list.length; ++n)
- v.list.elems[n] = v1.list.elems[n];
- for (unsigned int n = 0; n < v2.list.length; ++n)
- v.list.elems[n + v1.list.length] = v2.list.elems[n];
- return;
- }
-
- if (matchConcatStrings(e, es)) {
- unsigned int n = ATgetLength(es), j = 0;
- Value vs[n];
- unsigned int len = 0;
- for (ATermIterator i(es); i; ++i, ++j) {
- eval(env, *i, vs[j]);
- if (vs[j].type != tString) throw TypeError("string expected");
- len += strlen(vs[j].string.s);
- }
- char * s = new char[len + 1], * t = s;
- for (unsigned int i = 0; i < j; ++i) {
- strcpy(t, vs[i].string.s);
- t += strlen(vs[i].string.s);
- }
- *t = 0;
- mkString(v, s);
- return;
- }
-
- Expr e3;
- if (matchIf(e, e1, e2, e3)) {
- eval(env, evalBool(env, e1) ? e2 : e3, v);
- return;
- }
-
- if (matchOpOr(e, e1, e2)) {
- mkBool(v, evalBool(env, e1) || evalBool(env, e2));
- return;
- }
-
- throw Error("unsupported term");
-}
-
-
-static void strictEval(Env & env, Expr e, Value & v)
-{
- eval(env, e, v);
-
- if (v.type == tAttrs) {
- foreach (Bindings::iterator, i, *v.attrs)
- forceValue(i->second);
- }
-
- else if (v.type == tList) {
- for (unsigned int n = 0; n < v.list.length; ++n)
- forceValue(v.list.elems[n]);
- }
-}
-
-
-static void prim_head(Value * * args, Value & v)
-{
- forceList(*args[0]);
- if (args[0]->list.length == 0)
- throw Error("`head' called on an empty list");
- forceValue(args[0]->list.elems[0]);
- v = args[0]->list.elems[0];
-}
-
-
-static void prim_add(Value * * args, Value & v)
-{
- forceInt(*args[0]);
- forceInt(*args[1]);
- mkInt(v, args[0]->integer + args[1]->integer);
-}
-
-
-static void addPrimOp(Env & env, const string & name, unsigned int arity, PrimOp_ fun)
-{
- Value & v = env.bindings[toATerm(name)];
- nrValues++;
- v.type = tPrimOp;
- v.primOp.arity = arity;
- v.primOp.fun = fun;
-}
-
-
void doTest(string s)
{
- Env baseEnv;
- baseEnv.up = 0;
-
- /* Add global constants such as `true' to the base environment. */
- {
- Value & v = baseEnv.bindings[toATerm("true")];
- v.type = tBool;
- v.boolean = true;
- }
- {
- Value & v = baseEnv.bindings[toATerm("false")];
- v.type = tBool;
- v.boolean = false;
- }
- {
- Value & v = baseEnv.bindings[toATerm("null")];
- v.type = tNull;
- }
-
- /* Add primops to the base environment. */
- addPrimOp(baseEnv, "__head", 1, prim_head);
- addPrimOp(baseEnv, "__add", 2, prim_add);
-
- p1 = p2 = 0;
EvalState state;
Expr e = parseExprFromString(state, s, "/");
printMsg(lvlError, format(">>>>> %1%") % e);
Value v;
- strictEval(baseEnv, e, v);
+ state.strictEval(e, v);
printMsg(lvlError, format("result: %1%") % v);
}
@@ -721,11 +66,6 @@ void run(Strings args)
doTest("if false then 1 else 2");
doTest("if false || true then 1 else 2");
doTest("let x = x; in if true || x then 1 else 2");
-
- printMsg(lvlError, format("alloced %1% values") % nrValues);
- printMsg(lvlError, format("alloced %1% environments") % nrEnvs);
- printMsg(lvlError, format("evaluated %1% expressions") % nrEvaluated);
- printMsg(lvlError, format("each eval() uses %1% bytes of stack space") % (p1 - p2));
}