forked from lix-project/lix
c34e6d71bc
broken, but now the evaluator checks for it to prevent Nix
expressions from relying on undefined behaviour. Equality tests are
implemented using a shallow pointer equality test between ATerms.
However, because attribute sets are lazy and contain position
information, this can give false positives. For instance,
previously
let y = {x = 1;}; in y == y
evaluated to true, while the equivalent expression
{x = 1;} == {x = 1;}
evaluated to false. So disallow these tests for now. (Eventually
we may want to implement deep equality tests for attribute sets,
like lib.eqStrict.)
* Idem: disallow comparisons between functions.
* Implemented deep comparisons of lists. This had the same problem as
attribute sets - the elements in the list weren't evaluated. For
instance,
["xy"] == [("x" + "y")]
evaluated to false. Now it works properly.
909 lines
26 KiB
C++
909 lines
26 KiB
C++
#include "eval.hh"
|
|
#include "parser.hh"
|
|
#include "hash.hh"
|
|
#include "util.hh"
|
|
#include "store-api.hh"
|
|
#include "derivations.hh"
|
|
#include "nixexpr-ast.hh"
|
|
#include "globals.hh"
|
|
|
|
|
|
#define LocalNoInline(f) static f __attribute__((noinline)); f
|
|
#define LocalNoInlineNoReturn(f) static f __attribute__((noinline, noreturn)); f
|
|
|
|
|
|
namespace nix {
|
|
|
|
|
|
EvalState::EvalState()
|
|
: normalForms(32768), primOps(128)
|
|
{
|
|
nrEvaluated = nrCached = 0;
|
|
|
|
initNixExprHelpers();
|
|
|
|
addPrimOps();
|
|
}
|
|
|
|
|
|
void EvalState::addPrimOp(const string & name,
|
|
unsigned int arity, PrimOp primOp)
|
|
{
|
|
primOps.set(toATerm(name), makePrimOpDef(arity, ATmakeBlob(0, (void *) primOp)));
|
|
}
|
|
|
|
|
|
/* Every "format" object (even temporary) takes up a few hundred bytes
|
|
of stack space, which is a real killer in the recursive
|
|
evaluator. So here are some helper functions for throwing
|
|
exceptions. */
|
|
|
|
LocalNoInlineNoReturn(void throwEvalError(const char * s))
|
|
{
|
|
throw EvalError(s);
|
|
}
|
|
|
|
LocalNoInlineNoReturn(void throwEvalError(const char * s, const string & s2))
|
|
{
|
|
throw EvalError(format(s) % s2);
|
|
}
|
|
|
|
LocalNoInlineNoReturn(void throwTypeError(const char * s))
|
|
{
|
|
throw TypeError(s);
|
|
}
|
|
|
|
LocalNoInlineNoReturn(void throwTypeError(const char * s, const string & s2))
|
|
{
|
|
throw TypeError(format(s) % s2);
|
|
}
|
|
|
|
LocalNoInline(void addErrorPrefix(Error & e, const char * s))
|
|
{
|
|
e.addPrefix(s);
|
|
}
|
|
|
|
LocalNoInline(void addErrorPrefix(Error & e, const char * s, const string & s2))
|
|
{
|
|
e.addPrefix(format(s) % s2);
|
|
}
|
|
|
|
LocalNoInline(void addErrorPrefix(Error & e, const char * s, const string & s2, const string & s3))
|
|
{
|
|
e.addPrefix(format(s) % s2 % s3);
|
|
}
|
|
|
|
|
|
/* 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;
|
|
Pattern pat1, pat2;
|
|
ATermBool ellipsis;
|
|
|
|
if (matchVarPat(pat, name))
|
|
subs.set(name, arg);
|
|
|
|
else if (matchAttrsPat(pat, formals, ellipsis)) {
|
|
|
|
arg = evalExpr(state, 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 if (matchAtPat(pat, pat1, pat2)) {
|
|
patternMatch(state, pat1, arg, subs, subsRecursive);
|
|
patternMatch(state, pat2, arg, subs, subsRecursive);
|
|
}
|
|
|
|
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);
|
|
}
|
|
|
|
|
|
LocalNoInline(Expr updateAttrs(Expr e1, Expr e2))
|
|
{
|
|
/* Note: e1 and e2 should be in normal form. */
|
|
|
|
ATermMap attrs;
|
|
queryAllAttrs(e1, attrs, true);
|
|
queryAllAttrs(e2, attrs, true);
|
|
|
|
return makeAttrs(attrs);
|
|
}
|
|
|
|
|
|
string evalString(EvalState & state, Expr e, PathSet & context)
|
|
{
|
|
e = evalExpr(state, e);
|
|
string s;
|
|
if (!matchStr(e, s, context))
|
|
throwTypeError("value is %1% while a string was expected", showType(e));
|
|
return s;
|
|
}
|
|
|
|
|
|
string evalStringNoCtx(EvalState & state, Expr e)
|
|
{
|
|
PathSet context;
|
|
string s = evalString(state, e, context);
|
|
if (!context.empty())
|
|
throw EvalError(format("the string `%1%' is not allowed to refer to a store path (such as `%2%')")
|
|
% s % *(context.begin()));
|
|
return s;
|
|
}
|
|
|
|
|
|
int evalInt(EvalState & state, Expr e)
|
|
{
|
|
e = evalExpr(state, e);
|
|
int i;
|
|
if (!matchInt(e, i))
|
|
throwTypeError("value is %1% while an integer was expected", showType(e));
|
|
return i;
|
|
}
|
|
|
|
|
|
bool evalBool(EvalState & state, Expr e)
|
|
{
|
|
e = evalExpr(state, e);
|
|
if (e == eTrue) return true;
|
|
else if (e == eFalse) return false;
|
|
else throwTypeError("value is %1% while a boolean was expected", showType(e));
|
|
}
|
|
|
|
|
|
ATermList evalList(EvalState & state, Expr e)
|
|
{
|
|
e = evalExpr(state, e);
|
|
ATermList list;
|
|
if (!matchList(e, list))
|
|
throwTypeError("value is %1% while a list was expected", showType(e));
|
|
return list;
|
|
}
|
|
|
|
|
|
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);
|
|
}
|
|
|
|
|
|
string coerceToString(EvalState & state, Expr e, PathSet & context,
|
|
bool coerceMore, bool copyToStore)
|
|
{
|
|
e = evalExpr(state, e);
|
|
|
|
string s;
|
|
|
|
if (matchStr(e, s, context)) return s;
|
|
|
|
ATerm s2;
|
|
if (matchPath(e, s2)) {
|
|
Path path(canonPath(aterm2String(s2)));
|
|
|
|
if (!copyToStore) return path;
|
|
|
|
if (isDerivation(path))
|
|
throw EvalError(format("file names are not allowed to end in `%1%'")
|
|
% drvExtension);
|
|
|
|
Path dstPath;
|
|
if (state.srcToStore[path] != "")
|
|
dstPath = state.srcToStore[path];
|
|
else {
|
|
dstPath = readOnlyMode
|
|
? computeStorePathForPath(path).first
|
|
: store->addToStore(path);
|
|
state.srcToStore[path] = dstPath;
|
|
printMsg(lvlChatty, format("copied source `%1%' -> `%2%'")
|
|
% path % dstPath);
|
|
}
|
|
|
|
context.insert(dstPath);
|
|
return dstPath;
|
|
}
|
|
|
|
ATermList es;
|
|
if (matchAttrs(e, es)) {
|
|
Expr e2 = queryAttr(e, "outPath");
|
|
if (!e2) throwTypeError("cannot coerce an attribute set (except a derivation) to a string");
|
|
return coerceToString(state, e2, context, coerceMore, copyToStore);
|
|
}
|
|
|
|
if (coerceMore) {
|
|
|
|
/* Note that `false' is represented as an empty string for
|
|
shell scripting convenience, just like `null'. */
|
|
if (e == eTrue) return "1";
|
|
if (e == eFalse) return "";
|
|
int n;
|
|
if (matchInt(e, n)) return int2String(n);
|
|
if (matchNull(e)) return "";
|
|
|
|
if (matchList(e, es)) {
|
|
string result;
|
|
es = flattenList(state, e);
|
|
bool first = true;
|
|
for (ATermIterator i(es); i; ++i) {
|
|
if (!first) result += " "; else first = false;
|
|
result += coerceToString(state, *i,
|
|
context, coerceMore, copyToStore);
|
|
}
|
|
return result;
|
|
}
|
|
}
|
|
|
|
throwTypeError("cannot coerce %1% to a string", showType(e));
|
|
}
|
|
|
|
|
|
/* Common implementation of `+', ConcatStrings and `~'. */
|
|
static ATerm concatStrings(EvalState & state, ATermVector & args,
|
|
string separator = "")
|
|
{
|
|
if (args.empty()) return makeStr("", PathSet());
|
|
|
|
PathSet context;
|
|
std::ostringstream s;
|
|
|
|
/* If the first element is a path, then the result will also be a
|
|
path, we don't copy anything (yet - that's done later, since
|
|
paths are copied when they are used in a derivation), and none
|
|
of the strings are allowed to have contexts. */
|
|
ATerm dummy;
|
|
args.front() = evalExpr(state, args.front());
|
|
bool isPath = matchPath(args.front(), dummy);
|
|
|
|
for (ATermVector::const_iterator i = args.begin(); i != args.end(); ++i) {
|
|
if (i != args.begin()) s << separator;
|
|
s << coerceToString(state, *i, context, false, !isPath);
|
|
}
|
|
|
|
if (isPath && !context.empty())
|
|
throw EvalError(format("a string that refers to a store path cannot be appended to a path, in `%1%'")
|
|
% s.str());
|
|
|
|
return isPath
|
|
? makePath(toATerm(s.str()))
|
|
: makeStr(s.str(), context);
|
|
}
|
|
|
|
|
|
Path coerceToPath(EvalState & state, Expr e, PathSet & context)
|
|
{
|
|
string path = coerceToString(state, e, context, false, false);
|
|
if (path == "" || path[0] != '/')
|
|
throw EvalError(format("string `%1%' doesn't represent an absolute path") % path);
|
|
return path;
|
|
}
|
|
|
|
|
|
Expr autoCallFunction(Expr e, const ATermMap & args)
|
|
{
|
|
Pattern pat;
|
|
ATerm body, pos;
|
|
ATermList formals;
|
|
ATermBool ellipsis;
|
|
|
|
/* !!! this should be more general */
|
|
if (matchFunction(e, pat, body, pos) && matchAttrsPat(pat, formals, ellipsis)) {
|
|
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 evalSelect(EvalState & state, Expr e, ATerm name))
|
|
{
|
|
ATerm pos;
|
|
string s = aterm2String(name);
|
|
Expr a = queryAttr(evalExpr(state, e), s, pos);
|
|
if (!a) throwEvalError("attribute `%1%' missing", s);
|
|
try {
|
|
return evalExpr(state, a);
|
|
} catch (Error & e) {
|
|
addErrorPrefix(e, "while evaluating the attribute `%1%' at %2%:\n",
|
|
s, showPos(pos));
|
|
throw;
|
|
}
|
|
}
|
|
|
|
|
|
LocalNoInline(Expr evalAssert(EvalState & state, Expr cond, Expr body, ATerm pos))
|
|
{
|
|
if (!evalBool(state, cond))
|
|
throw AssertionError(format("assertion failed at %1%") % showPos(pos));
|
|
return evalExpr(state, body);
|
|
}
|
|
|
|
|
|
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;
|
|
}
|
|
}
|
|
|
|
|
|
LocalNoInline(Expr evalHasAttr(EvalState & state, Expr e, ATerm name))
|
|
{
|
|
ATermMap attrs;
|
|
queryAllAttrs(evalExpr(state, e), attrs);
|
|
return makeBool(attrs.get(name) != 0);
|
|
}
|
|
|
|
|
|
LocalNoInline(Expr evalPlusConcat(EvalState & state, Expr e))
|
|
{
|
|
Expr e1, e2;
|
|
ATermList es;
|
|
|
|
ATermVector args;
|
|
|
|
if (matchOpPlus(e, e1, e2)) {
|
|
|
|
/* !!! Awful compatibility hack for `drv + /path'.
|
|
According to regular concatenation, /path should be
|
|
copied to the store and its store path should be
|
|
appended to the string. However, in Nix <= 0.10, /path
|
|
was concatenated. So handle that case separately, but
|
|
do print out a warning. This code can go in Nix 0.12,
|
|
maybe. */
|
|
e1 = evalExpr(state, e1);
|
|
e2 = evalExpr(state, e2);
|
|
|
|
ATermList as;
|
|
ATerm p;
|
|
if (matchAttrs(e1, as) && matchPath(e2, p)) {
|
|
static bool haveWarned = false;
|
|
warnOnce(haveWarned, format(
|
|
"concatenation of a derivation and a path is deprecated; "
|
|
"you should write `drv + \"%1%\"' instead of `drv + %1%'")
|
|
% aterm2String(p));
|
|
PathSet context;
|
|
return makeStr(
|
|
coerceToString(state, makeSelect(e1, toATerm("outPath")), context)
|
|
+ aterm2String(p), context);
|
|
}
|
|
|
|
args.push_back(e1);
|
|
args.push_back(e2);
|
|
}
|
|
|
|
else if (matchConcatStrings(e, es))
|
|
for (ATermIterator i(es); i; ++i) args.push_back(*i);
|
|
|
|
try {
|
|
return concatStrings(state, args);
|
|
} catch (Error & e) {
|
|
addErrorPrefix(e, "in a string concatenation:\n");
|
|
throw;
|
|
}
|
|
}
|
|
|
|
|
|
LocalNoInline(Expr evalSubPath(EvalState & state, Expr e1, Expr e2))
|
|
{
|
|
static bool haveWarned = false;
|
|
warnOnce(haveWarned, "the subpath operator (~) is deprecated, use string concatenation (+) instead");
|
|
ATermVector args;
|
|
args.push_back(e1);
|
|
args.push_back(e2);
|
|
return concatStrings(state, args, "/");
|
|
}
|
|
|
|
|
|
LocalNoInline(Expr evalOpConcat(EvalState & state, Expr e1, Expr e2))
|
|
{
|
|
try {
|
|
ATermList l1 = evalList(state, e1);
|
|
ATermList l2 = evalList(state, e2);
|
|
return makeList(ATconcat(l1, l2));
|
|
} catch (Error & e) {
|
|
addErrorPrefix(e, "in a list concatenation:\n");
|
|
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 (sym1 == symAttrs)
|
|
throw EvalError("comparison of attribute sets is not implemented");
|
|
|
|
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;
|
|
}
|
|
|
|
|
|
static char * deepestStack = (char *) -1; /* for measuring stack usage */
|
|
|
|
|
|
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;
|
|
}
|
|
|
|
|
|
Expr evalFile(EvalState & state, const Path & path)
|
|
{
|
|
startNest(nest, lvlTalkative, format("evaluating file `%1%'") % path);
|
|
Expr e = parseExprFromFile(state, path);
|
|
try {
|
|
return evalExpr(state, e);
|
|
} catch (Error & e) {
|
|
e.addPrefix(format("while evaluating the file `%1%':\n")
|
|
% path);
|
|
throw;
|
|
}
|
|
}
|
|
|
|
|
|
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);
|
|
}
|
|
|
|
|
|
/* Yes, this is a really bad idea... */
|
|
extern "C" {
|
|
unsigned long AT_calcAllocatedSize();
|
|
}
|
|
|
|
void printEvalStats(EvalState & state)
|
|
{
|
|
char x;
|
|
bool showStats = getEnv("NIX_SHOW_STATS", "0") != "0";
|
|
printMsg(showStats ? lvlInfo : lvlDebug,
|
|
format("evaluated %1% expressions, %2% cache hits, %3%%% efficiency, used %4% ATerm bytes, used %5% bytes of stack space")
|
|
% state.nrEvaluated % state.nrCached
|
|
% ((float) state.nrCached / (float) state.nrEvaluated * 100)
|
|
% AT_calcAllocatedSize()
|
|
% (&x - deepestStack));
|
|
if (showStats)
|
|
printATermMapStats();
|
|
}
|
|
|
|
|
|
}
|