forked from lix-project/lix
1424 lines
40 KiB
C++
1424 lines
40 KiB
C++
#include "eval.hh"
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#include "parser.hh"
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#include "hash.hh"
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#include "util.hh"
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#include "store-api.hh"
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#include "derivations.hh"
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#include "nixexpr-ast.hh"
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#include "globals.hh"
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#include <cstring>
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#define LocalNoInline(f) static f __attribute__((noinline)); f
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#define LocalNoInlineNoReturn(f) static f __attribute__((noinline, noreturn)); f
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namespace nix {
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std::ostream & operator << (std::ostream & str, Value & v)
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{
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switch (v.type) {
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case tInt:
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str << v.integer;
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break;
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case tBool:
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str << (v.boolean ? "true" : "false");
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break;
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case tString:
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str << "\"" << v.string.s << "\""; // !!! escaping
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break;
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case tPath:
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str << v.path; // !!! escaping?
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break;
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case tNull:
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str << "true";
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break;
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case tAttrs:
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str << "{ ";
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foreach (Bindings::iterator, i, *v.attrs)
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str << aterm2String(i->first) << " = " << i->second << "; ";
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str << "}";
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break;
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case tList:
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str << "[ ";
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for (unsigned int n = 0; n < v.list.length; ++n)
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str << v.list.elems[n] << " ";
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str << "]";
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break;
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case tThunk:
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str << "<CODE>";
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break;
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case tLambda:
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str << "<LAMBDA>";
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break;
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case tPrimOp:
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str << "<PRIMOP>";
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break;
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case tPrimOpApp:
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str << "<PRIMOP-APP>";
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break;
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default:
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throw Error("invalid value");
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}
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return str;
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}
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string showType(Value & v)
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{
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switch (v.type) {
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case tInt: return "an integer";
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case tBool: return "a boolean";
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case tString: return "a string";
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case tPath: return "a path";
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case tAttrs: return "an attribute set";
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case tList: return "a list";
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case tNull: return "null";
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case tLambda: return "a function";
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case tPrimOp: return "a built-in function";
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case tPrimOpApp: return "a partially applied built-in function";
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default: throw Error(format("unknown type: %1%") % v.type);
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}
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}
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EvalState::EvalState() : baseEnv(allocEnv())
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{
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nrValues = nrEnvs = nrEvaluated = 0;
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initNixExprHelpers();
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createBaseEnv();
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allowUnsafeEquality = getEnv("NIX_NO_UNSAFE_EQ", "") == "";
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}
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void EvalState::addConstant(const string & name, Value & v)
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{
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baseEnv.bindings[toATerm(name)] = v;
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string name2 = string(name, 0, 2) == "__" ? string(name, 2) : name;
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(*baseEnv.bindings[toATerm("builtins")].attrs)[toATerm(name2)] = v;
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nrValues += 2;
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}
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void EvalState::addPrimOp(const string & name,
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unsigned int arity, PrimOp primOp)
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{
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Value v;
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v.type = tPrimOp;
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v.primOp.arity = arity;
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v.primOp.fun = primOp;
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baseEnv.bindings[toATerm(name)] = v;
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string name2 = string(name, 0, 2) == "__" ? string(name, 2) : name;
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(*baseEnv.bindings[toATerm("builtins")].attrs)[toATerm(name2)] = v;
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nrValues += 2;
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}
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/* Every "format" object (even temporary) takes up a few hundred bytes
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of stack space, which is a real killer in the recursive
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evaluator. So here are some helper functions for throwing
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exceptions. */
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LocalNoInlineNoReturn(void throwEvalError(const char * s))
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{
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throw EvalError(s);
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}
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LocalNoInlineNoReturn(void throwEvalError(const char * s, const string & s2))
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{
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throw EvalError(format(s) % s2);
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}
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LocalNoInlineNoReturn(void throwTypeError(const char * s))
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{
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throw TypeError(s);
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}
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LocalNoInlineNoReturn(void throwTypeError(const char * s, const string & s2))
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{
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throw TypeError(format(s) % s2);
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}
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LocalNoInline(void addErrorPrefix(Error & e, const char * s))
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{
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e.addPrefix(s);
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}
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LocalNoInline(void addErrorPrefix(Error & e, const char * s, const string & s2))
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{
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e.addPrefix(format(s) % s2);
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}
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LocalNoInline(void addErrorPrefix(Error & e, const char * s, const string & s2, const string & s3))
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{
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e.addPrefix(format(s) % s2 % s3);
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}
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void mkString(Value & v, const char * s)
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{
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v.type = tString;
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v.string.s = strdup(s);
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v.string.context = 0;
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}
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void mkString(Value & v, const string & s, const PathSet & context)
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{
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mkString(v, s.c_str());
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if (!context.empty()) {
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unsigned int n = 0;
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v.string.context = new const char *[context.size() + 1];
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foreach (PathSet::const_iterator, i, context)
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v.string.context[n++] = strdup(i->c_str());
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v.string.context[n] = 0;
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}
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}
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void mkPath(Value & v, const char * s)
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{
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v.type = tPath;
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v.path = strdup(s);
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}
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static Value * lookupWith(Env * env, Sym name)
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{
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if (!env) return 0;
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Value * v = lookupWith(env->up, name);
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if (v) return v;
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Bindings::iterator i = env->bindings.find(sWith);
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if (i == env->bindings.end()) return 0;
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Bindings::iterator j = i->second.attrs->find(name);
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if (j != i->second.attrs->end()) return &j->second;
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return 0;
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}
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static Value * lookupVar(Env * env, Sym name)
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{
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/* First look for a regular variable binding for `name'. */
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for (Env * env2 = env; env2; env2 = env2->up) {
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Bindings::iterator i = env2->bindings.find(name);
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if (i != env2->bindings.end()) return &i->second;
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}
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/* Otherwise, look for a `with' attribute set containing `name'.
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Outer `withs' take precedence (i.e. `with {x=1;}; with {x=2;};
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x' evaluates to 1). */
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Value * v = lookupWith(env, name);
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if (v) return v;
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/* Alternative implementation where the inner `withs' take
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precedence (i.e. `with {x=1;}; with {x=2;}; x' evaluates to
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2). */
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#if 0
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for (Env * env2 = env; env2; env2 = env2->up) {
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Bindings::iterator i = env2->bindings.find(sWith);
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if (i == env2->bindings.end()) continue;
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Bindings::iterator j = i->second.attrs->find(name);
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if (j != i->second.attrs->end()) return &j->second;
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}
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#endif
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throw Error(format("undefined variable `%1%'") % aterm2String(name));
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}
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Value * EvalState::allocValues(unsigned int count)
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{
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nrValues += count;
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return new Value[count]; // !!! check destructor
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}
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Env & EvalState::allocEnv()
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{
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nrEnvs++;
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return *(new Env);
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}
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void EvalState::mkList(Value & v, unsigned int length)
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{
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v.type = tList;
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v.list.length = length;
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v.list.elems = allocValues(length);
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}
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void EvalState::mkAttrs(Value & v)
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{
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v.type = tAttrs;
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v.attrs = new Bindings;
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}
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void EvalState::cloneAttrs(Value & src, Value & dst)
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{
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mkAttrs(dst);
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foreach (Bindings::iterator, i, *src.attrs)
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mkCopy((*dst.attrs)[i->first], i->second);
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}
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void EvalState::evalFile(const Path & path, Value & v)
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{
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startNest(nest, lvlTalkative, format("evaluating file `%1%'") % path);
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Expr e = parseTrees.get(toATerm(path));
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if (!e) {
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e = parseExprFromFile(*this, path);
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parseTrees.set(toATerm(path), e);
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}
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try {
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eval(e, v);
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} catch (Error & e) {
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e.addPrefix(format("while evaluating the file `%1%':\n")
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% path);
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throw;
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}
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}
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static char * deepestStack = (char *) -1; /* for measuring stack usage */
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void EvalState::eval(Env & env, Expr e, Value & v)
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{
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/* When changing this function, make sure that you don't cause a
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(large) increase in stack consumption! */
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char x;
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if (&x < deepestStack) deepestStack = &x;
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//debug(format("eval: %1%") % e);
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checkInterrupt();
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nrEvaluated++;
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Sym name;
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int n;
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ATerm s; ATermList context, es;
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ATermList rbnds, nrbnds;
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Expr e1, e2, e3, fun, arg, attrs;
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Pattern pat; Expr body; Pos pos;
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if (matchVar(e, name)) {
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Value * v2 = lookupVar(&env, name);
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forceValue(*v2);
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v = *v2;
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}
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else if (matchInt(e, n))
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mkInt(v, n);
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else if (matchStr(e, s, context)) {
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assert(context == ATempty);
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mkString(v, ATgetName(ATgetAFun(s)));
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}
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else if (matchPath(e, s))
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mkPath(v, ATgetName(ATgetAFun(s)));
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else if (matchAttrs(e, es)) {
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mkAttrs(v);
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ATerm e2, pos;
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for (ATermIterator i(es); i; ++i) {
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if (!matchBind(*i, name, e2, pos)) abort(); /* can't happen */
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Value & v2 = (*v.attrs)[name];
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nrValues++;
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mkThunk(v2, env, e2);
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}
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}
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else if (matchRec(e, rbnds, nrbnds)) {
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/* Create a new environment that contains the attributes in
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this `rec'. */
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Env & env2(allocEnv());
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env2.up = &env;
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v.type = tAttrs;
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v.attrs = &env2.bindings;
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/* The recursive attributes are evaluated in the new
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environment. */
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ATerm name, e2, pos;
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for (ATermIterator i(rbnds); i; ++i) {
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if (!matchBind(*i, name, e2, pos)) abort(); /* can't happen */
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Value & v2 = env2.bindings[name];
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nrValues++;
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mkThunk(v2, env2, e2);
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}
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/* The non-recursive attributes, on the other hand, are
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evaluated in the original environment. */
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for (ATermIterator i(nrbnds); i; ++i) {
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if (!matchBind(*i, name, e2, pos)) abort(); /* can't happen */
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Value & v2 = env2.bindings[name];
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nrValues++;
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mkThunk(v2, env, e2);
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}
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}
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else if (matchSelect(e, e2, name)) {
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Value v2;
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eval(env, e2, v2);
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forceAttrs(v2); // !!! eval followed by force is slightly inefficient
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Bindings::iterator i = v2.attrs->find(name);
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if (i == v2.attrs->end())
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throwEvalError("attribute `%1%' missing", aterm2String(name));
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try {
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forceValue(i->second);
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} catch (Error & e) {
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addErrorPrefix(e, "while evaluating the attribute `%1%':\n", aterm2String(name));
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throw;
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}
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v = i->second;
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}
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else if (matchFunction(e, pat, body, pos)) {
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v.type = tLambda;
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v.lambda.env = &env;
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v.lambda.pat = pat;
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v.lambda.body = body;
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}
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else if (matchCall(e, fun, arg)) {
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Value vFun;
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eval(env, fun, vFun);
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Value vArg;
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mkThunk(vArg, env, arg); // !!! should this be on the heap?
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callFunction(vFun, vArg, v);
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}
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else if (matchWith(e, attrs, body, pos)) {
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Env & env2(allocEnv());
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env2.up = &env;
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Value & vAttrs = env2.bindings[sWith];
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nrValues++;
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eval(env, attrs, vAttrs);
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forceAttrs(vAttrs);
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eval(env2, body, v);
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}
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else if (matchList(e, es)) {
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mkList(v, ATgetLength(es));
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for (unsigned int n = 0; n < v.list.length; ++n, es = ATgetNext(es))
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mkThunk(v.list.elems[n], env, ATgetFirst(es));
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}
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else if (matchOpEq(e, e1, e2)) {
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Value v1; eval(env, e1, v1);
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Value v2; eval(env, e2, v2);
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mkBool(v, eqValues(v1, v2));
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}
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else if (matchOpNEq(e, e1, e2)) {
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Value v1; eval(env, e1, v1);
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Value v2; eval(env, e2, v2);
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mkBool(v, !eqValues(v1, v2));
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}
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else if (matchOpConcat(e, e1, e2)) {
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Value v1; eval(env, e1, v1);
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forceList(v1);
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Value v2; eval(env, e2, v2);
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forceList(v2);
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mkList(v, v1.list.length + v2.list.length);
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/* !!! This loses sharing with the original lists. We could
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use a tCopy node, but that would use more memory. */
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for (unsigned int n = 0; n < v1.list.length; ++n)
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v.list.elems[n] = v1.list.elems[n];
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for (unsigned int n = 0; n < v2.list.length; ++n)
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v.list.elems[n + v1.list.length] = v2.list.elems[n];
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}
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else if (matchConcatStrings(e, es)) {
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PathSet context;
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std::ostringstream s;
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bool first = true, isPath = false;
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Value vStr;
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for (ATermIterator i(es); i; ++i) {
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eval(env, *i, vStr);
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/* If the first element is a path, then the result will
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also be a path, we don't copy anything (yet - that's
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done later, since paths are copied when they are used
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in a derivation), and none of the strings are allowed
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to have contexts. */
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if (first) {
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isPath = vStr.type == tPath;
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first = false;
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}
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s << coerceToString(vStr, context, false, !isPath);
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}
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if (isPath && !context.empty())
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throw EvalError(format("a string that refers to a store path cannot be appended to a path, in `%1%'")
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% s.str());
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if (isPath)
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mkPath(v, s.str().c_str());
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else
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mkString(v, s.str(), context);
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}
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/* Conditionals. */
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else if (matchIf(e, e1, e2, e3))
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eval(env, evalBool(env, e1) ? e2 : e3, v);
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/* Assertions. */
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else if (matchAssert(e, e1, e2, pos)) {
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if (!evalBool(env, e1))
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throw AssertionError(format("assertion failed at %1%") % showPos(pos));
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eval(env, e2, v);
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}
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/* Negation. */
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else if (matchOpNot(e, e1))
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mkBool(v, !evalBool(env, e1));
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/* Implication. */
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else if (matchOpImpl(e, e1, e2))
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return mkBool(v, !evalBool(env, e1) || evalBool(env, e2));
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/* Conjunction (logical AND). */
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else if (matchOpAnd(e, e1, e2))
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mkBool(v, evalBool(env, e1) && evalBool(env, e2));
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/* Disjunction (logical OR). */
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else if (matchOpOr(e, e1, e2))
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mkBool(v, evalBool(env, e1) || evalBool(env, e2));
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/* Attribute set update (//). */
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else if (matchOpUpdate(e, e1, e2)) {
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Value v2;
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eval(env, e1, v2);
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cloneAttrs(v2, v);
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eval(env, e2, v2);
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foreach (Bindings::iterator, i, *v2.attrs)
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(*v.attrs)[i->first] = i->second; // !!! sharing
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}
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/* Attribute existence test (?). */
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else if (matchOpHasAttr(e, e1, name)) {
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Value vAttrs;
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eval(env, e1, vAttrs);
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forceAttrs(vAttrs);
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mkBool(v, vAttrs.attrs->find(name) != vAttrs.attrs->end());
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}
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else throw Error("unsupported term");
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}
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void EvalState::callFunction(Value & fun, Value & arg, Value & v)
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{
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if (fun.type == tPrimOp || fun.type == tPrimOpApp) {
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unsigned int argsLeft =
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fun.type == tPrimOp ? fun.primOp.arity : fun.primOpApp.argsLeft;
|
|
if (argsLeft == 1) {
|
|
/* We have all the arguments, so call the primop. First
|
|
find the primop. */
|
|
Value * primOp = &fun;
|
|
while (primOp->type == tPrimOpApp) primOp = primOp->primOpApp.left;
|
|
assert(primOp->type == tPrimOp);
|
|
unsigned int arity = primOp->primOp.arity;
|
|
|
|
/* Put all the arguments in an array. */
|
|
Value * vArgs[arity];
|
|
unsigned int n = arity - 1;
|
|
vArgs[n--] = &arg;
|
|
for (Value * arg = &fun; arg->type == tPrimOpApp; arg = arg->primOpApp.left)
|
|
vArgs[n--] = arg->primOpApp.right;
|
|
|
|
/* And call the primop. */
|
|
primOp->primOp.fun(*this, vArgs, v);
|
|
} else {
|
|
Value * v2 = allocValues(2);
|
|
v2[0] = fun;
|
|
v2[1] = arg;
|
|
v.type = tPrimOpApp;
|
|
v.primOpApp.left = &v2[0];
|
|
v.primOpApp.right = &v2[1];
|
|
v.primOpApp.argsLeft = argsLeft - 1;
|
|
}
|
|
return;
|
|
}
|
|
|
|
if (fun.type != tLambda)
|
|
throwTypeError("attempt to call something which is neither a function nor a primop (built-in operation) but %1%",
|
|
showType(fun));
|
|
|
|
Env & env2(allocEnv());
|
|
env2.up = fun.lambda.env;
|
|
|
|
ATermList formals; ATerm ellipsis, name;
|
|
|
|
if (matchVarPat(fun.lambda.pat, name)) {
|
|
Value & vArg = env2.bindings[name];
|
|
nrValues++;
|
|
vArg = arg;
|
|
}
|
|
|
|
else if (matchAttrsPat(fun.lambda.pat, formals, ellipsis, name)) {
|
|
forceAttrs(arg);
|
|
|
|
if (name != sNoAlias) {
|
|
env2.bindings[name] = arg;
|
|
nrValues++;
|
|
}
|
|
|
|
/* 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 = arg.attrs->find(name);
|
|
|
|
Value & v = env2.bindings[name];
|
|
nrValues++;
|
|
|
|
if (j == arg.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++;
|
|
mkCopy(v, 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 != arg.attrs->size())
|
|
throw TypeError("function called with unexpected argument");
|
|
}
|
|
|
|
else abort();
|
|
|
|
eval(env2, fun.lambda.body, v);
|
|
}
|
|
|
|
|
|
void EvalState::eval(Expr e, Value & v)
|
|
{
|
|
eval(baseEnv, e, v);
|
|
}
|
|
|
|
|
|
bool EvalState::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;
|
|
}
|
|
|
|
|
|
void EvalState::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 == tApp)
|
|
callFunction(*v.app.left, *v.app.right, v);
|
|
else if (v.type == tBlackhole)
|
|
throw EvalError("infinite recursion encountered");
|
|
}
|
|
|
|
|
|
void EvalState::strictForceValue(Value & v)
|
|
{
|
|
forceValue(v);
|
|
|
|
if (v.type == tAttrs) {
|
|
foreach (Bindings::iterator, i, *v.attrs)
|
|
strictForceValue(i->second);
|
|
}
|
|
|
|
else if (v.type == tList) {
|
|
for (unsigned int n = 0; n < v.list.length; ++n)
|
|
strictForceValue(v.list.elems[n]);
|
|
}
|
|
}
|
|
|
|
|
|
int EvalState::forceInt(Value & v)
|
|
{
|
|
forceValue(v);
|
|
if (v.type != tInt)
|
|
throw TypeError(format("value is %1% while an integer was expected") % showType(v));
|
|
return v.integer;
|
|
}
|
|
|
|
|
|
bool EvalState::forceBool(Value & v)
|
|
{
|
|
forceValue(v);
|
|
if (v.type != tBool)
|
|
throw TypeError(format("value is %1% while a Boolean was expected") % showType(v));
|
|
return v.boolean;
|
|
}
|
|
|
|
|
|
void EvalState::forceAttrs(Value & v)
|
|
{
|
|
forceValue(v);
|
|
if (v.type != tAttrs)
|
|
throw TypeError(format("value is %1% while an attribute set was expected") % showType(v));
|
|
}
|
|
|
|
|
|
void EvalState::forceList(Value & v)
|
|
{
|
|
forceValue(v);
|
|
if (v.type != tList)
|
|
throw TypeError(format("value is %1% while a list was expected") % showType(v));
|
|
}
|
|
|
|
|
|
void EvalState::forceFunction(Value & v)
|
|
{
|
|
forceValue(v);
|
|
if (v.type != tLambda && v.type != tPrimOp && v.type != tPrimOpApp)
|
|
throw TypeError(format("value is %1% while a function was expected") % showType(v));
|
|
}
|
|
|
|
|
|
string EvalState::forceString(Value & v)
|
|
{
|
|
forceValue(v);
|
|
if (v.type != tString)
|
|
throw TypeError(format("value is %1% while a string was expected") % showType(v));
|
|
return string(v.string.s);
|
|
}
|
|
|
|
|
|
string EvalState::forceString(Value & v, PathSet & context)
|
|
{
|
|
string s = forceString(v);
|
|
if (v.string.context) {
|
|
for (const char * * p = v.string.context; *p; ++p)
|
|
context.insert(*p);
|
|
}
|
|
return s;
|
|
}
|
|
|
|
|
|
string EvalState::forceStringNoCtx(Value & v)
|
|
{
|
|
string s = forceString(v);
|
|
if (v.string.context)
|
|
throw EvalError(format("the string `%1%' is not allowed to refer to a store path (such as `%2%')")
|
|
% v.string.s % v.string.context[0]);
|
|
return s;
|
|
}
|
|
|
|
|
|
bool EvalState::isDerivation(Value & v)
|
|
{
|
|
if (v.type != tAttrs) return false;
|
|
Bindings::iterator i = v.attrs->find(toATerm("type"));
|
|
return i != v.attrs->end() && forceStringNoCtx(i->second) == "derivation";
|
|
}
|
|
|
|
|
|
string EvalState::coerceToString(Value & v, PathSet & context,
|
|
bool coerceMore, bool copyToStore)
|
|
{
|
|
forceValue(v);
|
|
|
|
string s;
|
|
|
|
if (v.type == tString) {
|
|
if (v.string.context)
|
|
for (const char * * p = v.string.context; *p; ++p)
|
|
context.insert(*p);
|
|
return v.string.s;
|
|
}
|
|
|
|
if (v.type == tPath) {
|
|
Path path(canonPath(v.path));
|
|
|
|
if (!copyToStore) return path;
|
|
|
|
if (nix::isDerivation(path))
|
|
throw EvalError(format("file names are not allowed to end in `%1%'")
|
|
% drvExtension);
|
|
|
|
Path dstPath;
|
|
if (srcToStore[path] != "")
|
|
dstPath = srcToStore[path];
|
|
else {
|
|
dstPath = readOnlyMode
|
|
? computeStorePathForPath(path).first
|
|
: store->addToStore(path);
|
|
srcToStore[path] = dstPath;
|
|
printMsg(lvlChatty, format("copied source `%1%' -> `%2%'")
|
|
% path % dstPath);
|
|
}
|
|
|
|
context.insert(dstPath);
|
|
return dstPath;
|
|
}
|
|
|
|
if (v.type == tAttrs) {
|
|
Bindings::iterator i = v.attrs->find(toATerm("outPath"));
|
|
if (i == v.attrs->end())
|
|
throwTypeError("cannot coerce an attribute set (except a derivation) to a string");
|
|
return coerceToString(i->second, context, coerceMore, copyToStore);
|
|
}
|
|
|
|
if (coerceMore) {
|
|
|
|
/* Note that `false' is represented as an empty string for
|
|
shell scripting convenience, just like `null'. */
|
|
if (v.type == tBool && v.boolean) return "1";
|
|
if (v.type == tBool && !v.boolean) return "";
|
|
if (v.type == tInt) return int2String(v.integer);
|
|
if (v.type == tNull) return "";
|
|
|
|
if (v.type == tList) {
|
|
string result;
|
|
for (unsigned int n = 0; n < v.list.length; ++n) {
|
|
result += coerceToString(v.list.elems[n],
|
|
context, coerceMore, copyToStore);
|
|
if (n < v.list.length - 1
|
|
/* !!! not quite correct */
|
|
&& (v.list.elems[n].type != tList || v.list.elems[n].list.length != 0))
|
|
result += " ";
|
|
}
|
|
return result;
|
|
}
|
|
}
|
|
|
|
throwTypeError("cannot coerce %1% to a string", showType(v));
|
|
}
|
|
|
|
|
|
Path EvalState::coerceToPath(Value & v, PathSet & context)
|
|
{
|
|
string path = coerceToString(v, context, false, false);
|
|
if (path == "" || path[0] != '/')
|
|
throw EvalError(format("string `%1%' doesn't represent an absolute path") % path);
|
|
return path;
|
|
}
|
|
|
|
|
|
bool EvalState::eqValues(Value & v1, Value & v2)
|
|
{
|
|
forceValue(v1);
|
|
forceValue(v2);
|
|
|
|
if (v1.type != v2.type) return false;
|
|
|
|
switch (v1.type) {
|
|
|
|
case tInt:
|
|
return v1.integer == v2.integer;
|
|
|
|
case tBool:
|
|
return v1.boolean == v2.boolean;
|
|
|
|
case tString:
|
|
/* !!! contexts */
|
|
return strcmp(v1.string.s, v2.string.s) == 0;
|
|
|
|
case tPath:
|
|
return strcmp(v1.path, v2.path) == 0;
|
|
|
|
case tNull:
|
|
return true;
|
|
|
|
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;
|
|
}
|
|
|
|
/* Functions are incomparable. */
|
|
case tLambda:
|
|
case tPrimOp:
|
|
case tPrimOpApp:
|
|
return false;
|
|
|
|
default:
|
|
throw Error(format("cannot compare %1% with %2%") % showType(v1) % showType(v2));
|
|
}
|
|
}
|
|
|
|
|
|
#if 0
|
|
/* Pattern-match `pat' against `arg'. The result is a set of
|
|
substitutions (`subs') and a set of recursive substitutions
|
|
(`subsRecursive'). The latter can refer to the variables bound by
|
|
both `subs' and `subsRecursive'. */
|
|
static void patternMatch(EvalState & state,
|
|
Pattern pat, Expr arg, ATermMap & subs, ATermMap & subsRecursive)
|
|
{
|
|
ATerm name;
|
|
ATermList formals;
|
|
ATermBool ellipsis;
|
|
|
|
if (matchVarPat(pat, name))
|
|
subs.set(name, arg);
|
|
|
|
else if (matchAttrsPat(pat, formals, ellipsis, name)) {
|
|
|
|
arg = evalExpr(state, arg);
|
|
|
|
if (name != sNoAlias) subs.set(name, arg);
|
|
|
|
/* Get the actual arguments. */
|
|
ATermMap attrs;
|
|
queryAllAttrs(arg, attrs);
|
|
unsigned int nrAttrs = attrs.size();
|
|
|
|
/* 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 name, def;
|
|
DefaultValue def2;
|
|
if (!matchFormal(*i, name, def2)) abort(); /* can't happen */
|
|
|
|
Expr value = attrs[name];
|
|
|
|
if (value == 0) {
|
|
if (!matchDefaultValue(def2, def)) def = 0;
|
|
if (def == 0) throw TypeError(format("the argument named `%1%' required by the function is missing")
|
|
% aterm2String(name));
|
|
subsRecursive.set(name, def);
|
|
} else {
|
|
attrsUsed++;
|
|
attrs.remove(name);
|
|
subs.set(name, value);
|
|
}
|
|
|
|
}
|
|
|
|
/* Check that each actual argument is listed as a formal
|
|
argument (unless the attribute match specifies a `...'). */
|
|
if (ellipsis == eFalse && attrsUsed != nrAttrs)
|
|
throw TypeError(format("the function does not expect an argument named `%1%'")
|
|
% aterm2String(attrs.begin()->key));
|
|
}
|
|
|
|
else abort();
|
|
}
|
|
|
|
|
|
/* Substitute an argument set into the body of a function. */
|
|
static Expr substArgs(EvalState & state,
|
|
Expr body, Pattern pat, Expr arg)
|
|
{
|
|
ATermMap subs(16), subsRecursive(16);
|
|
|
|
patternMatch(state, pat, arg, subs, subsRecursive);
|
|
|
|
/* If we used any default values, make a recursive attribute set
|
|
out of the (argument-name, value) tuples. This is so that we
|
|
can support default values that refer to each other, e.g. ({x,
|
|
y ? x + x}: y) {x = "foo";} evaluates to "foofoo". */
|
|
if (subsRecursive.size() != 0) {
|
|
ATermList recAttrs = ATempty;
|
|
foreach (ATermMap::const_iterator, i, subs)
|
|
recAttrs = ATinsert(recAttrs, makeBind(i->key, i->value, makeNoPos()));
|
|
foreach (ATermMap::const_iterator, i, subsRecursive)
|
|
recAttrs = ATinsert(recAttrs, makeBind(i->key, i->value, makeNoPos()));
|
|
Expr rec = makeRec(recAttrs, ATempty);
|
|
foreach (ATermMap::const_iterator, i, subsRecursive)
|
|
subs.set(i->key, makeSelect(rec, i->key));
|
|
}
|
|
|
|
return substitute(Substitution(0, &subs), body);
|
|
}
|
|
|
|
|
|
/* Transform a mutually recursive set into a non-recursive set. Each
|
|
attribute is transformed into an expression that has all references
|
|
to attributes substituted with selection expressions on the
|
|
original set. E.g., e = `rec {x = f x y; y = x;}' becomes `{x = f
|
|
(e.x) (e.y); y = e.x;}'. */
|
|
LocalNoInline(ATerm expandRec(EvalState & state, ATerm e, ATermList rbnds, ATermList nrbnds))
|
|
{
|
|
ATerm name;
|
|
Expr e2;
|
|
Pos pos;
|
|
Expr eOverrides = 0;
|
|
|
|
/* Create the substitution list. */
|
|
ATermMap subs(ATgetLength(rbnds) + ATgetLength(nrbnds));
|
|
for (ATermIterator i(rbnds); i; ++i) {
|
|
if (!matchBind(*i, name, e2, pos)) abort(); /* can't happen */
|
|
subs.set(name, makeSelect(e, name));
|
|
}
|
|
for (ATermIterator i(nrbnds); i; ++i) {
|
|
if (!matchBind(*i, name, e2, pos)) abort(); /* can't happen */
|
|
if (name == sOverrides) eOverrides = e2;
|
|
subs.set(name, e2);
|
|
}
|
|
|
|
/* If the rec contains an attribute called `__overrides', then
|
|
evaluate it, and add the attributes in that set to the rec.
|
|
This allows overriding of recursive attributes, which is
|
|
otherwise not possible. (You can use the // operator to
|
|
replace an attribute, but other attributes in the rec will
|
|
still reference the original value, because that value has been
|
|
substituted into the bodies of the other attributes. Hence we
|
|
need __overrides.) */
|
|
ATermMap overrides;
|
|
if (eOverrides) {
|
|
eOverrides = evalExpr(state, eOverrides);
|
|
queryAllAttrs(eOverrides, overrides, false);
|
|
foreach (ATermMap::const_iterator, i, overrides)
|
|
subs.set(i->key, i->value);
|
|
}
|
|
|
|
Substitution subs_(0, &subs);
|
|
|
|
/* Create the non-recursive set. */
|
|
ATermMap as(ATgetLength(rbnds) + ATgetLength(nrbnds));
|
|
for (ATermIterator i(rbnds); i; ++i) {
|
|
if (!matchBind(*i, name, e2, pos)) abort(); /* can't happen */
|
|
as.set(name, makeAttrRHS(substitute(subs_, e2), pos));
|
|
}
|
|
|
|
if (eOverrides)
|
|
foreach (ATermMap::const_iterator, i, overrides)
|
|
as.set(i->key, makeAttrRHS(i->value, makeNoPos()));
|
|
|
|
/* Copy the non-recursive bindings. !!! inefficient */
|
|
for (ATermIterator i(nrbnds); i; ++i) {
|
|
if (!matchBind(*i, name, e2, pos)) abort(); /* can't happen */
|
|
as.set(name, makeAttrRHS(e2, pos));
|
|
}
|
|
|
|
return makeAttrs(as);
|
|
}
|
|
|
|
|
|
static void flattenList(EvalState & state, Expr e, ATermList & result)
|
|
{
|
|
ATermList es;
|
|
e = evalExpr(state, e);
|
|
if (matchList(e, es))
|
|
for (ATermIterator i(es); i; ++i)
|
|
flattenList(state, *i, result);
|
|
else
|
|
result = ATinsert(result, e);
|
|
}
|
|
|
|
|
|
ATermList flattenList(EvalState & state, Expr e)
|
|
{
|
|
ATermList result = ATempty;
|
|
flattenList(state, e, result);
|
|
return ATreverse(result);
|
|
}
|
|
|
|
|
|
Expr autoCallFunction(Expr e, const ATermMap & args)
|
|
{
|
|
Pattern pat;
|
|
ATerm body, pos, name;
|
|
ATermList formals;
|
|
ATermBool ellipsis;
|
|
|
|
if (matchFunction(e, pat, body, pos) && matchAttrsPat(pat, formals, ellipsis, name)) {
|
|
ATermMap actualArgs(ATgetLength(formals));
|
|
|
|
for (ATermIterator i(formals); i; ++i) {
|
|
Expr name, def, value; ATerm def2;
|
|
if (!matchFormal(*i, name, def2)) abort();
|
|
if ((value = args.get(name)))
|
|
actualArgs.set(name, makeAttrRHS(value, makeNoPos()));
|
|
else if (!matchDefaultValue(def2, def))
|
|
throw TypeError(format("cannot auto-call a function that has an argument without a default value (`%1%')")
|
|
% aterm2String(name));
|
|
}
|
|
|
|
e = makeCall(e, makeAttrs(actualArgs));
|
|
}
|
|
|
|
return e;
|
|
}
|
|
|
|
|
|
/* Evaluation of various language constructs. These have been taken
|
|
out of evalExpr2 to reduce stack space usage. (GCC is really dumb
|
|
about stack space: it just adds up all the local variables and
|
|
temporaries of every scope into one huge stack frame. This is
|
|
really bad for deeply recursive functions.) */
|
|
|
|
|
|
LocalNoInline(Expr evalVar(EvalState & state, ATerm name))
|
|
{
|
|
ATerm primOp = state.primOps.get(name);
|
|
if (!primOp)
|
|
throw EvalError(format("impossible: undefined variable `%1%'") % aterm2String(name));
|
|
int arity;
|
|
ATermBlob fun;
|
|
if (!matchPrimOpDef(primOp, arity, fun)) abort();
|
|
if (arity == 0)
|
|
/* !!! backtrace for primop call */
|
|
return ((PrimOp) ATgetBlobData(fun)) (state, ATermVector());
|
|
else
|
|
return makePrimOp(arity, fun, ATempty);
|
|
}
|
|
|
|
|
|
LocalNoInline(Expr evalCall(EvalState & state, Expr fun, Expr arg))
|
|
{
|
|
Pattern pat;
|
|
ATerm pos;
|
|
Expr body;
|
|
|
|
/* Evaluate the left-hand side. */
|
|
fun = evalExpr(state, fun);
|
|
|
|
/* Is it a primop or a function? */
|
|
int arity;
|
|
ATermBlob funBlob;
|
|
ATermList args;
|
|
if (matchPrimOp(fun, arity, funBlob, args)) {
|
|
args = ATinsert(args, arg);
|
|
if (ATgetLength(args) == arity) {
|
|
/* Put the arguments in a vector in reverse (i.e.,
|
|
actual) order. */
|
|
ATermVector args2(arity);
|
|
for (ATermIterator i(args); i; ++i)
|
|
args2[--arity] = *i;
|
|
/* !!! backtrace for primop call */
|
|
return ((PrimOp) ATgetBlobData(funBlob))
|
|
(state, args2);
|
|
} else
|
|
/* Need more arguments, so propagate the primop. */
|
|
return makePrimOp(arity, funBlob, args);
|
|
}
|
|
|
|
else if (matchFunction(fun, pat, body, pos)) {
|
|
try {
|
|
return evalExpr(state, substArgs(state, body, pat, arg));
|
|
} catch (Error & e) {
|
|
addErrorPrefix(e, "while evaluating the function at %1%:\n",
|
|
showPos(pos));
|
|
throw;
|
|
}
|
|
}
|
|
|
|
else throwTypeError(
|
|
"attempt to call something which is neither a function nor a primop (built-in operation) but %1%",
|
|
showType(fun));
|
|
}
|
|
|
|
|
|
LocalNoInline(Expr evalWith(EvalState & state, Expr defs, Expr body, ATerm pos))
|
|
{
|
|
ATermMap attrs;
|
|
try {
|
|
defs = evalExpr(state, defs);
|
|
queryAllAttrs(defs, attrs);
|
|
} catch (Error & e) {
|
|
addErrorPrefix(e, "while evaluating the `with' definitions at %1%:\n",
|
|
showPos(pos));
|
|
throw;
|
|
}
|
|
try {
|
|
body = substitute(Substitution(0, &attrs), body);
|
|
checkVarDefs(state.primOps, body);
|
|
return evalExpr(state, body);
|
|
} catch (Error & e) {
|
|
addErrorPrefix(e, "while evaluating the `with' body at %1%:\n",
|
|
showPos(pos));
|
|
throw;
|
|
}
|
|
}
|
|
|
|
|
|
/* Implementation of the `==' and `!=' operators. */
|
|
LocalNoInline(bool areEqual(EvalState & state, Expr e1, Expr e2))
|
|
{
|
|
e1 = evalExpr(state, e1);
|
|
e2 = evalExpr(state, e2);
|
|
|
|
/* We cannot test functions/primops for equality, and we currently
|
|
don't support testing equality between attribute sets or lists
|
|
- that would have to be a deep equality test to be sound. */
|
|
AFun sym1 = ATgetAFun(e1);
|
|
AFun sym2 = ATgetAFun(e2);
|
|
|
|
if (sym1 != sym2) return false;
|
|
|
|
/* Functions are incomparable. */
|
|
if (sym1 == symFunction || sym1 == symPrimOp) return false;
|
|
|
|
if (!state.allowUnsafeEquality && sym1 == symAttrs)
|
|
throw EvalError("comparison of attribute sets is not implemented");
|
|
|
|
/* !!! This allows comparisons of infinite data structures to
|
|
succeed, such as `let x = [x]; in x == x'. This is
|
|
undesirable, since equivalent (?) terms such as `let x = [x]; y
|
|
= [y]; in x == y' don't terminate. */
|
|
if (e1 == e2) return true;
|
|
|
|
if (sym1 == symList) {
|
|
ATermList es1; matchList(e1, es1);
|
|
ATermList es2; matchList(e2, es2);
|
|
if (ATgetLength(es1) != ATgetLength(es2)) return false;
|
|
ATermIterator i(es1), j(es2);
|
|
while (*i) {
|
|
if (!areEqual(state, *i, *j)) return false;
|
|
++i; ++j;
|
|
}
|
|
return true;
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
|
|
Expr evalExpr2(EvalState & state, Expr e)
|
|
{
|
|
/* When changing this function, make sure that you don't cause a
|
|
(large) increase in stack consumption! */
|
|
|
|
char x;
|
|
if (&x < deepestStack) deepestStack = &x;
|
|
|
|
Expr e1, e2, e3;
|
|
ATerm name, pos;
|
|
AFun sym = ATgetAFun(e);
|
|
|
|
/* Normal forms. */
|
|
if (sym == symStr ||
|
|
sym == symPath ||
|
|
sym == symNull ||
|
|
sym == symInt ||
|
|
sym == symBool ||
|
|
sym == symFunction ||
|
|
sym == symAttrs ||
|
|
sym == symList ||
|
|
sym == symPrimOp)
|
|
return e;
|
|
|
|
/* The `Closed' constructor is just a way to prevent substitutions
|
|
into expressions not containing free variables. */
|
|
if (matchClosed(e, e1))
|
|
return evalExpr(state, e1);
|
|
|
|
/* Any encountered variables must be primops (since undefined
|
|
variables are detected after parsing). */
|
|
if (matchVar(e, name)) return evalVar(state, name);
|
|
|
|
/* Function application. */
|
|
if (matchCall(e, e1, e2)) return evalCall(state, e1, e2);
|
|
|
|
/* Attribute selection. */
|
|
if (matchSelect(e, e1, name)) return evalSelect(state, e1, name);
|
|
|
|
/* Mutually recursive sets. */
|
|
ATermList rbnds, nrbnds;
|
|
if (matchRec(e, rbnds, nrbnds))
|
|
return expandRec(state, e, rbnds, nrbnds);
|
|
|
|
/* Conditionals. */
|
|
if (matchIf(e, e1, e2, e3))
|
|
return evalExpr(state, evalBool(state, e1) ? e2 : e3);
|
|
|
|
/* Assertions. */
|
|
if (matchAssert(e, e1, e2, pos)) return evalAssert(state, e1, e2, pos);
|
|
|
|
/* Withs. */
|
|
if (matchWith(e, e1, e2, pos)) return evalWith(state, e1, e2, pos);
|
|
|
|
/* Generic equality/inequality. Note that the behaviour on
|
|
composite data (lists, attribute sets) and functions is
|
|
undefined, since the subterms of those terms are not evaluated.
|
|
However, we don't want to make (==) strict, because that would
|
|
make operations like `big_derivation == null' very slow (unless
|
|
we were to evaluate them side-by-side). */
|
|
if (matchOpEq(e, e1, e2)) return makeBool(areEqual(state, e1, e2));
|
|
|
|
if (matchOpNEq(e, e1, e2)) return makeBool(!areEqual(state, e1, e2));
|
|
|
|
/* Negation. */
|
|
if (matchOpNot(e, e1))
|
|
return makeBool(!evalBool(state, e1));
|
|
|
|
/* Implication. */
|
|
if (matchOpImpl(e, e1, e2))
|
|
return makeBool(!evalBool(state, e1) || evalBool(state, e2));
|
|
|
|
/* Conjunction (logical AND). */
|
|
if (matchOpAnd(e, e1, e2))
|
|
return makeBool(evalBool(state, e1) && evalBool(state, e2));
|
|
|
|
/* Disjunction (logical OR). */
|
|
if (matchOpOr(e, e1, e2))
|
|
return makeBool(evalBool(state, e1) || evalBool(state, e2));
|
|
|
|
/* Attribute set update (//). */
|
|
if (matchOpUpdate(e, e1, e2))
|
|
return updateAttrs(evalExpr(state, e1), evalExpr(state, e2));
|
|
|
|
/* Attribute existence test (?). */
|
|
if (matchOpHasAttr(e, e1, name)) return evalHasAttr(state, e1, name);
|
|
|
|
/* String or path concatenation. */
|
|
if (sym == symOpPlus || sym == symConcatStrings)
|
|
return evalPlusConcat(state, e);
|
|
|
|
/* Backwards compatability: subpath operator (~). */
|
|
if (matchSubPath(e, e1, e2)) return evalSubPath(state, e1, e2);
|
|
|
|
/* List concatenation. */
|
|
if (matchOpConcat(e, e1, e2)) return evalOpConcat(state, e1, e2);
|
|
|
|
/* Barf. */
|
|
abort();
|
|
}
|
|
|
|
|
|
Expr evalExpr(EvalState & state, Expr e)
|
|
{
|
|
checkInterrupt();
|
|
|
|
#if 0
|
|
startNest(nest, lvlVomit,
|
|
format("evaluating expression: %1%") % e);
|
|
#endif
|
|
|
|
state.nrEvaluated++;
|
|
|
|
/* Consult the memo table to quickly get the normal form of
|
|
previously evaluated expressions. */
|
|
Expr nf = state.normalForms.get(e);
|
|
if (nf) {
|
|
if (nf == makeBlackHole())
|
|
throwEvalError("infinite recursion encountered");
|
|
state.nrCached++;
|
|
return nf;
|
|
}
|
|
|
|
/* Otherwise, evaluate and memoize. */
|
|
state.normalForms.set(e, makeBlackHole());
|
|
try {
|
|
nf = evalExpr2(state, e);
|
|
} catch (Error & err) {
|
|
state.normalForms.remove(e);
|
|
throw;
|
|
}
|
|
state.normalForms.set(e, nf);
|
|
return nf;
|
|
}
|
|
|
|
|
|
static Expr strictEvalExpr(EvalState & state, Expr e, ATermMap & nfs);
|
|
|
|
|
|
static Expr strictEvalExpr_(EvalState & state, Expr e, ATermMap & nfs)
|
|
{
|
|
e = evalExpr(state, e);
|
|
|
|
ATermList as;
|
|
if (matchAttrs(e, as)) {
|
|
ATermList as2 = ATempty;
|
|
for (ATermIterator i(as); i; ++i) {
|
|
ATerm name; Expr e; ATerm pos;
|
|
if (!matchBind(*i, name, e, pos)) abort(); /* can't happen */
|
|
as2 = ATinsert(as2, makeBind(name, strictEvalExpr(state, e, nfs), pos));
|
|
}
|
|
return makeAttrs(ATreverse(as2));
|
|
}
|
|
|
|
ATermList es;
|
|
if (matchList(e, es)) {
|
|
ATermList es2 = ATempty;
|
|
for (ATermIterator i(es); i; ++i)
|
|
es2 = ATinsert(es2, strictEvalExpr(state, *i, nfs));
|
|
return makeList(ATreverse(es2));
|
|
}
|
|
|
|
return e;
|
|
}
|
|
|
|
|
|
static Expr strictEvalExpr(EvalState & state, Expr e, ATermMap & nfs)
|
|
{
|
|
Expr nf = nfs.get(e);
|
|
if (nf) return nf;
|
|
|
|
nf = strictEvalExpr_(state, e, nfs);
|
|
|
|
nfs.set(e, nf);
|
|
|
|
return nf;
|
|
}
|
|
|
|
|
|
Expr strictEvalExpr(EvalState & state, Expr e)
|
|
{
|
|
ATermMap strictNormalForms;
|
|
return strictEvalExpr(state, e, strictNormalForms);
|
|
}
|
|
#endif
|
|
|
|
|
|
void EvalState::printStats()
|
|
{
|
|
char x;
|
|
bool showStats = getEnv("NIX_SHOW_STATS", "0") != "0";
|
|
printMsg(showStats ? lvlInfo : lvlDebug,
|
|
format("evaluated %1% expressions, used %2% bytes of stack space, allocated %3% values, allocated %4% environments")
|
|
% nrEvaluated
|
|
% (&x - deepestStack)
|
|
% nrValues
|
|
% nrEnvs);
|
|
if (showStats)
|
|
printATermMapStats();
|
|
}
|
|
|
|
|
|
}
|