lix/src/libexpr/value-to-xml.cc
Andreas Rammhold cae41eebff libexpr: remove matchAttrs boolean from ExprLambda
The boolean is only used to determine if the formals are set to a
non-null pointer in all our cases. We can get rid of that allocation and
instead just compare the pointer value with NULL. Saving up to
sizeof(bool) + platform specific alignment per ExprLambda instace.
Probably not a lot of memory but perhaps a few kilobyte with nixpkgs?

This also gets rid of a potential issue with dereferencing formals based on
the value of the boolean that didn't have to be aligned with the formals
pointer but was in all our cases.
2021-10-06 17:24:06 +02:00

183 lines
5.4 KiB
C++

#include "value-to-xml.hh"
#include "xml-writer.hh"
#include "eval-inline.hh"
#include "util.hh"
#include <cstdlib>
namespace nix {
static XMLAttrs singletonAttrs(const string & name, const string & value)
{
XMLAttrs attrs;
attrs[name] = value;
return attrs;
}
static void printValueAsXML(EvalState & state, bool strict, bool location,
Value & v, XMLWriter & doc, PathSet & context, PathSet & drvsSeen);
static void posToXML(XMLAttrs & xmlAttrs, const Pos & pos)
{
xmlAttrs["path"] = pos.file;
xmlAttrs["line"] = (format("%1%") % pos.line).str();
xmlAttrs["column"] = (format("%1%") % pos.column).str();
}
static void showAttrs(EvalState & state, bool strict, bool location,
Bindings & attrs, XMLWriter & doc, PathSet & context, PathSet & drvsSeen)
{
StringSet names;
for (auto & i : attrs)
names.insert(i.name);
for (auto & i : names) {
Attr & a(*attrs.find(state.symbols.create(i)));
XMLAttrs xmlAttrs;
xmlAttrs["name"] = i;
if (location && a.pos != ptr(&noPos)) posToXML(xmlAttrs, *a.pos);
XMLOpenElement _(doc, "attr", xmlAttrs);
printValueAsXML(state, strict, location,
*a.value, doc, context, drvsSeen);
}
}
static void printValueAsXML(EvalState & state, bool strict, bool location,
Value & v, XMLWriter & doc, PathSet & context, PathSet & drvsSeen)
{
checkInterrupt();
if (strict) state.forceValue(v);
switch (v.type()) {
case nInt:
doc.writeEmptyElement("int", singletonAttrs("value", (format("%1%") % v.integer).str()));
break;
case nBool:
doc.writeEmptyElement("bool", singletonAttrs("value", v.boolean ? "true" : "false"));
break;
case nString:
/* !!! show the context? */
copyContext(v, context);
doc.writeEmptyElement("string", singletonAttrs("value", v.string.s));
break;
case nPath:
doc.writeEmptyElement("path", singletonAttrs("value", v.path));
break;
case nNull:
doc.writeEmptyElement("null");
break;
case nAttrs:
if (state.isDerivation(v)) {
XMLAttrs xmlAttrs;
Bindings::iterator a = v.attrs->find(state.symbols.create("derivation"));
Path drvPath;
a = v.attrs->find(state.sDrvPath);
if (a != v.attrs->end()) {
if (strict) state.forceValue(*a->value);
if (a->value->type() == nString)
xmlAttrs["drvPath"] = drvPath = a->value->string.s;
}
a = v.attrs->find(state.sOutPath);
if (a != v.attrs->end()) {
if (strict) state.forceValue(*a->value);
if (a->value->type() == nString)
xmlAttrs["outPath"] = a->value->string.s;
}
XMLOpenElement _(doc, "derivation", xmlAttrs);
if (drvPath != "" && drvsSeen.insert(drvPath).second)
showAttrs(state, strict, location, *v.attrs, doc, context, drvsSeen);
else
doc.writeEmptyElement("repeated");
}
else {
XMLOpenElement _(doc, "attrs");
showAttrs(state, strict, location, *v.attrs, doc, context, drvsSeen);
}
break;
case nList: {
XMLOpenElement _(doc, "list");
for (unsigned int n = 0; n < v.listSize(); ++n)
printValueAsXML(state, strict, location, *v.listElems()[n], doc, context, drvsSeen);
break;
}
case nFunction: {
if (!v.isLambda()) {
// FIXME: Serialize primops and primopapps
doc.writeEmptyElement("unevaluated");
break;
}
XMLAttrs xmlAttrs;
if (location) posToXML(xmlAttrs, v.lambda.fun->pos);
XMLOpenElement _(doc, "function", xmlAttrs);
if (v.lambda.fun->hasFormals()) {
XMLAttrs attrs;
if (!v.lambda.fun->arg.empty()) attrs["name"] = v.lambda.fun->arg;
if (v.lambda.fun->formals->ellipsis) attrs["ellipsis"] = "1";
XMLOpenElement _(doc, "attrspat", attrs);
for (auto & i : v.lambda.fun->formals->formals)
doc.writeEmptyElement("attr", singletonAttrs("name", i.name));
} else
doc.writeEmptyElement("varpat", singletonAttrs("name", v.lambda.fun->arg));
break;
}
case nExternal:
v.external->printValueAsXML(state, strict, location, doc, context, drvsSeen);
break;
case nFloat:
doc.writeEmptyElement("float", singletonAttrs("value", (format("%1%") % v.fpoint).str()));
break;
case nThunk:
doc.writeEmptyElement("unevaluated");
}
}
void ExternalValueBase::printValueAsXML(EvalState & state, bool strict,
bool location, XMLWriter & doc, PathSet & context, PathSet & drvsSeen) const
{
doc.writeEmptyElement("unevaluated");
}
void printValueAsXML(EvalState & state, bool strict, bool location,
Value & v, std::ostream & out, PathSet & context)
{
XMLWriter doc(true, out);
XMLOpenElement root(doc, "expr");
PathSet drvsSeen;
printValueAsXML(state, strict, location, v, doc, context, drvsSeen);
}
}