* Work around problems with the ATerm library.

The ATerm library doesn't search the heap for pointers to ATerms
  when garbage collecting.  As a result, C++ containers such as
  `map<ATerm, ATerm>' will cause pointer to be hidden from the garbage
  collector, causing crashes.  Instead, we now use ATermTables.
This commit is contained in:
Eelco Dolstra 2003-11-03 20:30:40 +00:00
parent ff31324278
commit 0690c1c9c0
5 changed files with 182 additions and 55 deletions

View file

@ -5,6 +5,7 @@
EvalState::EvalState()
: normalForms(32768, 75)
{
blackHole = ATmake("BlackHole()");
if (!blackHole) throw Error("cannot build black hole");
@ -20,32 +21,43 @@ Expr getAttr(EvalState & state, Expr e, const string & name)
/* Substitute an argument set into the body of a function. */
static Expr substArgs(Expr body, ATermList formals, Expr arg)
{
Subs subs;
ATermMap subs;
Expr undefined = ATmake("Undefined");
/* Get the formal arguments. */
while (!ATisEmpty(formals)) {
ATerm t = ATgetFirst(formals);
char * s;
if (!ATmatch(ATgetFirst(formals), "<str>", &s))
if (!ATmatch(t, "<str>", &s))
abort(); /* can't happen */
subs[s] = undefined;
subs.set(t, undefined);
formals = ATgetNext(formals);
}
/* Get the actual arguments, and check that they match with the
formals. */
Attrs args;
ATermMap args;
queryAllAttrs(arg, args);
for (Attrs::iterator i = args.begin(); i != args.end(); i++) {
if (subs.find(i->first) == subs.end())
throw badTerm(format("argument `%1%' not declared") % i->first, arg);
subs[i->first] = i->second;
for (ATermList keys = args.keys(); !ATisEmpty(keys);
keys = ATgetNext(keys))
{
Expr key = ATgetFirst(keys);
Expr cur = subs.get(key);
if (!cur)
throw badTerm(format("argument `%1%' not declared")
% aterm2String(key), arg);
subs.set(key, args.get(key));
}
/* Check that all arguments are defined. */
for (Subs::iterator i = subs.begin(); i != subs.end(); i++)
if (i->second == undefined)
throw badTerm(format("formal argument `%1%' missing") % i->first, arg);
for (ATermList keys = subs.keys(); !ATisEmpty(keys);
keys = ATgetNext(keys))
{
Expr key = ATgetFirst(keys);
if (subs.get(key) == undefined)
throw badTerm(format("formal argument `%1%' missing")
% aterm2String(key), arg);
}
return substitute(subs, body);
}
@ -59,26 +71,26 @@ static Expr substArgs(Expr body, ATermList formals, Expr arg)
ATerm expandRec(ATerm e, ATermList bnds)
{
/* Create the substitution list. */
Subs subs;
ATermMap subs;
ATermList bs = bnds;
while (!ATisEmpty(bs)) {
char * s;
Expr e2;
if (!ATmatch(ATgetFirst(bs), "Bind(<str>, <term>)", &s, &e2))
abort(); /* can't happen */
subs[s] = ATmake("Select(<term>, <str>)", e, s);
subs.set(s, ATmake("Select(<term>, <str>)", e, s));
bs = ATgetNext(bs);
}
/* Create the non-recursive set. */
Attrs as;
ATermMap as;
bs = bnds;
while (!ATisEmpty(bs)) {
char * s;
Expr e2;
if (!ATmatch(ATgetFirst(bs), "Bind(<str>, <term>)", &s, &e2))
abort(); /* can't happen */
as[s] = substitute(subs, e2);
as.set(s, substitute(subs, e2));
bs = ATgetNext(bs);
}
@ -205,18 +217,18 @@ Expr evalExpr(EvalState & state, Expr e)
/* Consult the memo table to quickly get the normal form of
previously evaluated expressions. */
NormalForms::iterator i = state.normalForms.find(e);
if (i != state.normalForms.end()) {
if (i->second == state.blackHole)
Expr nf = state.normalForms.get(e);
if (nf) {
if (nf == state.blackHole)
throw badTerm("infinite recursion", e);
state.nrCached++;
return i->second;
return nf;
}
/* Otherwise, evaluate and memoize. */
state.normalForms[e] = state.blackHole;
Expr nf = evalExpr2(state, e);
state.normalForms[e] = nf;
state.normalForms.set(e, state.blackHole);
nf = evalExpr2(state, e);
state.normalForms.set(e, nf);
return nf;
}

View file

@ -7,13 +7,12 @@
#include "expr.hh"
typedef map<Expr, Expr> NormalForms;
typedef map<Path, PathSet> DrvPaths;
typedef map<Path, Hash> DrvHashes;
struct EvalState
{
NormalForms normalForms;
ATermMap normalForms;
DrvPaths drvPaths;
DrvHashes drvHashes; /* normalised derivation hashes */
Expr blackHole;

View file

@ -2,6 +2,91 @@
#include "expr.hh"
ATermMap::ATermMap(unsigned int initialSize, unsigned int maxLoadPct)
{
table = ATtableCreate(initialSize, maxLoadPct);
if (!table) throw Error("cannot create ATerm table");
}
ATermMap::ATermMap(const ATermMap & map)
: table(0)
{
ATermList keys = map.keys();
/* !!! adjust allocation for load pct */
table = ATtableCreate(ATgetLength(keys), map.maxLoadPct);
if (!table) throw Error("cannot create ATerm table");
for (; !ATisEmpty(keys); keys = ATgetNext(keys)) {
ATerm key = ATgetFirst(keys);
set(key, map.get(key));
}
}
ATermMap::~ATermMap()
{
if (table) ATtableDestroy(table);
}
void ATermMap::set(ATerm key, ATerm value)
{
return ATtablePut(table, key, value);
}
void ATermMap::set(const string & key, ATerm value)
{
set(string2ATerm(key), value);
}
ATerm ATermMap::get(ATerm key) const
{
return ATtableGet(table, key);
}
ATerm ATermMap::get(const string & key) const
{
return get(string2ATerm(key));
}
void ATermMap::remove(ATerm key)
{
ATtableRemove(table, key);
}
void ATermMap::remove(const string & key)
{
remove(string2ATerm(key));
}
ATermList ATermMap::keys() const
{
ATermList keys = ATtableKeys(table);
if (!keys) throw Error("cannot query aterm map keys");
return keys;
}
ATerm string2ATerm(const string & s)
{
return (ATerm) ATmakeAppl0(ATmakeAFun((char *) s.c_str(), 0, ATtrue));
}
string aterm2String(ATerm t)
{
return ATgetName(ATgetAFun(t));
}
ATerm bottomupRewrite(TermFun & f, ATerm e)
{
if (ATgetType(e) == AT_APPL) {
@ -31,7 +116,7 @@ ATerm bottomupRewrite(TermFun & f, ATerm e)
}
void queryAllAttrs(Expr e, Attrs & attrs)
void queryAllAttrs(Expr e, ATermMap & attrs)
{
ATermList bnds;
if (!ATmatch(e, "Attrs([<list>])", &bnds))
@ -42,7 +127,7 @@ void queryAllAttrs(Expr e, Attrs & attrs)
Expr e;
if (!ATmatch(ATgetFirst(bnds), "Bind(<str>, <term>)", &s, &e))
abort(); /* can't happen */
attrs[s] = e;
attrs.set(s, e);
bnds = ATgetNext(bnds);
}
}
@ -50,33 +135,32 @@ void queryAllAttrs(Expr e, Attrs & attrs)
Expr queryAttr(Expr e, const string & name)
{
Attrs attrs;
ATermMap attrs;
queryAllAttrs(e, attrs);
Attrs::iterator i = attrs.find(name);
return i == attrs.end() ? 0 : i->second;
return attrs.get(name);
}
Expr makeAttrs(const Attrs & attrs)
Expr makeAttrs(const ATermMap & attrs)
{
ATermList bnds = ATempty;
for (Attrs::const_iterator i = attrs.begin(); i != attrs.end(); i++)
ATermList bnds = ATempty, keys = attrs.keys();
while (!ATisEmpty(keys)) {
Expr key = ATgetFirst(keys);
bnds = ATinsert(bnds,
ATmake("Bind(<str>, <term>)", i->first.c_str(), i->second));
ATmake("Bind(<term>, <term>)", key, attrs.get(key)));
keys = ATgetNext(keys);
}
return ATmake("Attrs(<term>)", ATreverse(bnds));
}
ATerm substitute(Subs & subs, ATerm e)
Expr substitute(const ATermMap & subs, Expr e)
{
char * s;
if (ATmatch(e, "Var(<str>)", &s)) {
Subs::iterator i = subs.find(s);
if (i == subs.end())
return e;
else
return i->second;
Expr sub = subs.get(s);
return sub ? sub : e;
}
/* In case of a function, filter out all variables bound by this
@ -84,11 +168,11 @@ ATerm substitute(Subs & subs, ATerm e)
ATermList formals;
ATerm body;
if (ATmatch(e, "Function([<list>], <term>)", &formals, &body)) {
Subs subs2(subs);
ATermMap subs2(subs);
ATermList fs = formals;
while (!ATisEmpty(fs)) {
if (!ATmatch(ATgetFirst(fs), "<str>", &s)) abort();
subs2.erase(s);
subs2.remove(s);
fs = ATgetNext(fs);
}
return ATmake("Function(<term>, <term>)", formals,
@ -98,13 +182,13 @@ ATerm substitute(Subs & subs, ATerm e)
/* Idem for a mutually recursive attribute set. */
ATermList bindings;
if (ATmatch(e, "Rec([<list>])", &bindings)) {
Subs subs2(subs);
ATermMap subs2(subs);
ATermList bnds = bindings;
while (!ATisEmpty(bnds)) {
Expr e;
if (!ATmatch(ATgetFirst(bnds), "Bind(<str>, <term>)", &s, &e))
abort(); /* can't happen */
subs2.erase(s);
subs2.remove(s);
bnds = ATgetNext(bnds);
}
return ATmake("Rec(<term>)", substitute(subs2, (ATerm) bindings));

View file

@ -14,6 +14,38 @@
typedef ATerm Expr;
/* Mappings from ATerms to ATerms. This is just a wrapper around
ATerm tables. */
class ATermMap
{
private:
unsigned int maxLoadPct;
ATermTable table;
public:
ATermMap(unsigned int initialSize = 16, unsigned int maxLoadPct = 75);
ATermMap(const ATermMap & map);
~ATermMap();
void set(ATerm key, ATerm value);
void set(const string & key, ATerm value);
ATerm get(ATerm key) const;
ATerm get(const string & key) const;
void remove(ATerm key);
void remove(const string & key);
ATermList keys() const;
};
/* Convert a string to an ATerm (i.e., a quoted nullary function
applicaton). */
ATerm string2ATerm(const string & s);
string aterm2String(ATerm t);
/* Generic bottomup traversal over ATerms. The traversal first
recursively descends into subterms, and then applies the given term
function to the resulting term. */
@ -25,19 +57,17 @@ ATerm bottomupRewrite(TermFun & f, ATerm e);
/* Query all attributes in an attribute set expression. The
expression must be in normal form. */
typedef map<string, Expr> Attrs;
void queryAllAttrs(Expr e, Attrs & attrs);
void queryAllAttrs(Expr e, ATermMap & attrs);
/* Query a specific attribute from an attribute set expression. The
expression must be in normal form. */
Expr queryAttr(Expr e, const string & name);
/* Create an attribute set expression from an Attrs value. */
Expr makeAttrs(const Attrs & attrs);
Expr makeAttrs(const ATermMap & attrs);
/* Perform a set of substitutions on an expression. */
typedef map<string, Expr> Subs;
ATerm substitute(Subs & subs, ATerm e);
Expr substitute(const ATermMap & subs, Expr e);
#endif /* !__FIXEXPR_H */

View file

@ -123,7 +123,7 @@ Expr primDerivation(EvalState & state, Expr args)
{
Nest nest(lvlVomit, "evaluating derivation");
Attrs attrs;
ATermMap attrs;
args = evalExpr(state, args);
queryAllAttrs(args, attrs);
@ -136,9 +136,11 @@ Expr primDerivation(EvalState & state, Expr args)
Hash outHash;
bool outHashGiven = false;
for (Attrs::iterator i = attrs.begin(); i != attrs.end(); i++) {
string key = i->first;
Expr value = i->second;
for (ATermList keys = attrs.keys(); !ATisEmpty(keys);
keys = ATgetNext(keys))
{
string key = aterm2String(ATgetFirst(keys));
Expr value = attrs.get(key);
Nest nest(lvlVomit, format("processing attribute `%1%'") % key);
/* The `args' attribute is special: it supplies the
@ -198,9 +200,9 @@ Expr primDerivation(EvalState & state, Expr args)
msg(lvlChatty, format("instantiated `%1%' -> `%2%'")
% drvName % drvPath);
attrs["outPath"] = ATmake("Path(<str>)", outPath.c_str());
attrs["drvPath"] = ATmake("Path(<str>)", drvPath.c_str());
attrs["type"] = ATmake("Str(\"derivation\")");
attrs.set("outPath", ATmake("Path(<str>)", outPath.c_str()));
attrs.set("drvPath", ATmake("Path(<str>)", drvPath.c_str()));
attrs.set("type", ATmake("Str(\"derivation\")"));
return makeAttrs(attrs);
}