diff options
Diffstat (limited to 'src/libexpr/eval.cc')
| -rw-r--r-- | src/libexpr/eval.cc | 296 |
1 files changed, 170 insertions, 126 deletions
diff --git a/src/libexpr/eval.cc b/src/libexpr/eval.cc index db1e7e56d..402de78ad 100644 --- a/src/libexpr/eval.cc +++ b/src/libexpr/eval.cc @@ -583,14 +583,20 @@ Value * EvalState::addConstant(const string & name, Value & v) { Value * v2 = allocValue(); *v2 = v; - staticBaseEnv.vars[symbols.create(name)] = baseEnvDispl; - baseEnv.values[baseEnvDispl++] = v2; - string name2 = string(name, 0, 2) == "__" ? string(name, 2) : name; - baseEnv.values[0]->attrs->push_back(Attr(symbols.create(name2), v2)); + addConstant(name, v2); return v2; } +void EvalState::addConstant(const string & name, Value * v) +{ + staticBaseEnv.vars.emplace_back(symbols.create(name), baseEnvDispl); + baseEnv.values[baseEnvDispl++] = v; + string name2 = string(name, 0, 2) == "__" ? string(name, 2) : name; + baseEnv.values[0]->attrs->push_back(Attr(symbols.create(name2), v)); +} + + Value * EvalState::addPrimOp(const string & name, size_t arity, PrimOpFun primOp) { @@ -609,7 +615,7 @@ Value * EvalState::addPrimOp(const string & name, Value * v = allocValue(); v->mkPrimOp(new PrimOp { .fun = primOp, .arity = arity, .name = sym }); - staticBaseEnv.vars[symbols.create(name)] = baseEnvDispl; + staticBaseEnv.vars.emplace_back(symbols.create(name), baseEnvDispl); baseEnv.values[baseEnvDispl++] = v; baseEnv.values[0]->attrs->push_back(Attr(sym, v)); return v; @@ -635,7 +641,7 @@ Value * EvalState::addPrimOp(PrimOp && primOp) Value * v = allocValue(); v->mkPrimOp(new PrimOp(std::move(primOp))); - staticBaseEnv.vars[envName] = baseEnvDispl; + staticBaseEnv.vars.emplace_back(envName, baseEnvDispl); baseEnv.values[baseEnvDispl++] = v; baseEnv.values[0]->attrs->push_back(Attr(primOp.name, v)); return v; @@ -785,7 +791,7 @@ void mkPath(Value & v, const char * s) inline Value * EvalState::lookupVar(Env * env, const ExprVar & var, bool noEval) { - for (size_t l = var.level; l; --l, env = env->up) ; + for (auto l = var.level; l; --l, env = env->up) ; if (!var.fromWith) return env->values[var.displ]; @@ -1058,7 +1064,7 @@ void ExprAttrs::eval(EvalState & state, Env & env, Value & v) /* The recursive attributes are evaluated in the new environment, while the inherited attributes are evaluated in the original environment. */ - size_t displ = 0; + Displacement displ = 0; for (auto & i : attrs) { Value * vAttr; if (hasOverrides && !i.second.inherited) { @@ -1134,7 +1140,7 @@ void ExprLet::eval(EvalState & state, Env & env, Value & v) /* The recursive attributes are evaluated in the new environment, while the inherited attributes are evaluated in the original environment. */ - size_t displ = 0; + Displacement displ = 0; for (auto & i : attrs->attrs) env2.values[displ++] = i.second.e->maybeThunk(state, i.second.inherited ? env : env2); @@ -1251,144 +1257,182 @@ void ExprLambda::eval(EvalState & state, Env & env, Value & v) } -void ExprApp::eval(EvalState & state, Env & env, Value & v) +void EvalState::callFunction(Value & fun, size_t nrArgs, Value * * args, Value & vRes, const Pos & pos) { - /* FIXME: vFun prevents GCC from doing tail call optimisation. */ - Value vFun; - e1->eval(state, env, vFun); - state.callFunction(vFun, *(e2->maybeThunk(state, env)), v, pos); -} + auto trace = evalSettings.traceFunctionCalls ? std::make_unique<FunctionCallTrace>(pos) : nullptr; + forceValue(fun, pos); -void EvalState::callPrimOp(Value & fun, Value & arg, Value & v, const Pos & pos) -{ - /* Figure out the number of arguments still needed. */ - size_t argsDone = 0; - Value * primOp = &fun; - while (primOp->isPrimOpApp()) { - argsDone++; - primOp = primOp->primOpApp.left; - } - assert(primOp->isPrimOp()); - auto arity = primOp->primOp->arity; - auto argsLeft = arity - argsDone; - - if (argsLeft == 1) { - /* We have all the arguments, so call the primop. */ - - /* Put all the arguments in an array. */ - Value * vArgs[arity]; - auto n = arity - 1; - vArgs[n--] = &arg; - for (Value * arg = &fun; arg->isPrimOpApp(); arg = arg->primOpApp.left) - vArgs[n--] = arg->primOpApp.right; - - /* And call the primop. */ - nrPrimOpCalls++; - if (countCalls) primOpCalls[primOp->primOp->name]++; - primOp->primOp->fun(*this, pos, vArgs, v); - } else { - Value * fun2 = allocValue(); - *fun2 = fun; - v.mkPrimOpApp(fun2, &arg); - } -} + Value vCur(fun); -void EvalState::callFunction(Value & fun, Value & arg, Value & v, const Pos & pos) -{ - auto trace = evalSettings.traceFunctionCalls ? std::make_unique<FunctionCallTrace>(pos) : nullptr; + auto makeAppChain = [&]() + { + vRes = vCur; + for (size_t i = 0; i < nrArgs; ++i) { + auto fun2 = allocValue(); + *fun2 = vRes; + vRes.mkPrimOpApp(fun2, args[i]); + } + }; - forceValue(fun, pos); + while (nrArgs > 0) { - if (fun.isPrimOp() || fun.isPrimOpApp()) { - callPrimOp(fun, arg, v, pos); - return; - } + if (vCur.isLambda()) { - if (fun.type() == nAttrs) { - auto found = fun.attrs->find(sFunctor); - if (found != fun.attrs->end()) { - /* fun may be allocated on the stack of the calling function, - * but for functors we may keep a reference, so heap-allocate - * a copy and use that instead. - */ - auto & fun2 = *allocValue(); - fun2 = fun; - /* !!! Should we use the attr pos here? */ - Value v2; - callFunction(*found->value, fun2, v2, pos); - return callFunction(v2, arg, v, pos); - } - } + ExprLambda & lambda(*vCur.lambda.fun); - if (!fun.isLambda()) - throwTypeError(pos, "attempt to call something which is not a function but %1%", fun); + auto size = + (lambda.arg.empty() ? 0 : 1) + + (lambda.hasFormals() ? lambda.formals->formals.size() : 0); + Env & env2(allocEnv(size)); + env2.up = vCur.lambda.env; - ExprLambda & lambda(*fun.lambda.fun); + Displacement displ = 0; - auto size = - (lambda.arg.empty() ? 0 : 1) + - (lambda.hasFormals() ? lambda.formals->formals.size() : 0); - Env & env2(allocEnv(size)); - env2.up = fun.lambda.env; + if (!lambda.hasFormals()) + env2.values[displ++] = args[0]; - size_t displ = 0; + else { + forceAttrs(*args[0], pos); - if (!lambda.hasFormals()) - env2.values[displ++] = &arg; + if (!lambda.arg.empty()) + env2.values[displ++] = args[0]; - else { - forceAttrs(arg, pos); - - if (!lambda.arg.empty()) - env2.values[displ++] = &arg; - - /* 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. */ - size_t attrsUsed = 0; - for (auto & i : lambda.formals->formals) { - Bindings::iterator j = arg.attrs->find(i.name); - if (j == arg.attrs->end()) { - if (!i.def) throwTypeError(pos, "%1% called without required argument '%2%'", - lambda, i.name); - env2.values[displ++] = i.def->maybeThunk(*this, env2); + /* 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. */ + size_t attrsUsed = 0; + for (auto & i : lambda.formals->formals) { + auto j = args[0]->attrs->get(i.name); + if (!j) { + if (!i.def) throwTypeError(pos, "%1% called without required argument '%2%'", + lambda, i.name); + env2.values[displ++] = i.def->maybeThunk(*this, env2); + } else { + attrsUsed++; + env2.values[displ++] = j->value; + } + } + + /* Check that each actual argument is listed as a formal + argument (unless the attribute match specifies a `...'). */ + if (!lambda.formals->ellipsis && attrsUsed != args[0]->attrs->size()) { + /* Nope, so show the first unexpected argument to the + user. */ + for (auto & i : *args[0]->attrs) + if (lambda.formals->argNames.find(i.name) == lambda.formals->argNames.end()) + throwTypeError(pos, "%1% called with unexpected argument '%2%'", lambda, i.name); + abort(); // can't happen + } + } + + nrFunctionCalls++; + if (countCalls) incrFunctionCall(&lambda); + + /* Evaluate the body. */ + try { + lambda.body->eval(*this, env2, vCur); + } catch (Error & e) { + if (loggerSettings.showTrace.get()) { + addErrorTrace(e, lambda.pos, "while evaluating %s", + (lambda.name.set() + ? "'" + (string) lambda.name + "'" + : "anonymous lambda")); + addErrorTrace(e, pos, "from call site%s", ""); + } + throw; + } + + nrArgs--; + args += 1; + } + + else if (vCur.isPrimOp()) { + + size_t argsLeft = vCur.primOp->arity; + + if (nrArgs < argsLeft) { + /* We don't have enough arguments, so create a tPrimOpApp chain. */ + makeAppChain(); + return; + } else { + /* We have all the arguments, so call the primop. */ + nrPrimOpCalls++; + if (countCalls) primOpCalls[vCur.primOp->name]++; + vCur.primOp->fun(*this, pos, args, vCur); + + nrArgs -= argsLeft; + args += argsLeft; + } + } + + else if (vCur.isPrimOpApp()) { + /* Figure out the number of arguments still needed. */ + size_t argsDone = 0; + Value * primOp = &vCur; + while (primOp->isPrimOpApp()) { + argsDone++; + primOp = primOp->primOpApp.left; + } + assert(primOp->isPrimOp()); + auto arity = primOp->primOp->arity; + auto argsLeft = arity - argsDone; + + if (nrArgs < argsLeft) { + /* We still don't have enough arguments, so extend the tPrimOpApp chain. */ + makeAppChain(); + return; } else { - attrsUsed++; - env2.values[displ++] = j->value; + /* We have all the arguments, so call the primop with + the previous and new arguments. */ + + Value * vArgs[arity]; + auto n = argsDone; + for (Value * arg = &vCur; arg->isPrimOpApp(); arg = arg->primOpApp.left) + vArgs[--n] = arg->primOpApp.right; + + for (size_t i = 0; i < argsLeft; ++i) + vArgs[argsDone + i] = args[i]; + + nrPrimOpCalls++; + if (countCalls) primOpCalls[primOp->primOp->name]++; + primOp->primOp->fun(*this, pos, vArgs, vCur); + + nrArgs -= argsLeft; + args += argsLeft; } } - /* Check that each actual argument is listed as a formal - argument (unless the attribute match specifies a `...'). */ - if (!lambda.formals->ellipsis && attrsUsed != arg.attrs->size()) { - /* Nope, so show the first unexpected argument to the - user. */ - for (auto & i : *arg.attrs) - if (lambda.formals->argNames.find(i.name) == lambda.formals->argNames.end()) - throwTypeError(pos, "%1% called with unexpected argument '%2%'", lambda, i.name); - abort(); // can't happen + else if (vCur.type() == nAttrs) { + if (auto functor = vCur.attrs->get(sFunctor)) { + /* 'vCur" may be allocated on the stack of the calling + function, but for functors we may keep a reference, + so heap-allocate a copy and use that instead. */ + Value * args2[] = {allocValue()}; + *args2[0] = vCur; + /* !!! Should we use the attr pos here? */ + callFunction(*functor->value, 1, args2, vCur, pos); + } } + + else + throwTypeError(pos, "attempt to call something which is not a function but %1%", vCur); } - nrFunctionCalls++; - if (countCalls) incrFunctionCall(&lambda); + vRes = vCur; +} - /* Evaluate the body. This is conditional on showTrace, because - catching exceptions makes this function not tail-recursive. */ - if (loggerSettings.showTrace.get()) - try { - lambda.body->eval(*this, env2, v); - } catch (Error & e) { - addErrorTrace(e, lambda.pos, "while evaluating %s", - (lambda.name.set() - ? "'" + (string) lambda.name + "'" - : "anonymous lambda")); - addErrorTrace(e, pos, "from call site%s", ""); - throw; - } - else - fun.lambda.fun->body->eval(*this, env2, v); + +void ExprCall::eval(EvalState & state, Env & env, Value & v) +{ + Value vFun; + fun->eval(state, env, vFun); + + Value * vArgs[args.size()]; + for (size_t i = 0; i < args.size(); ++i) + vArgs[i] = args[i]->maybeThunk(state, env); + + state.callFunction(vFun, args.size(), vArgs, v, pos); } |