Merge branch 'register-constant' of https://github.com/shlevy/nix

This commit is contained in:
Eelco Dolstra 2018-02-13 12:24:48 +01:00
commit 7828dca9e8
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GPG key ID: 8170B4726D7198DE
6 changed files with 15 additions and 6 deletions

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@ -750,7 +750,7 @@ builtins.fetchurl {
files will be dlopened by Nix, allowing them to affect
execution through static initialization. In particular, these
plugins may construct static instances of RegisterPrimOp to
add new primops to the expression language,
add new primops or constants to the expression language,
RegisterStoreImplementation to add new store implementations,
and RegisterCommand to add new subcommands to the
<literal>nix</literal> command. See the constructors for those

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@ -404,7 +404,7 @@ Path EvalState::toRealPath(const Path & path, const PathSet & context)
};
void EvalState::addConstant(const string & name, Value & v)
Value * EvalState::addConstant(const string & name, Value & v)
{
Value * v2 = allocValue();
*v2 = v;
@ -412,12 +412,18 @@ void EvalState::addConstant(const string & name, Value & v)
baseEnv.values[baseEnvDispl++] = v2;
string name2 = string(name, 0, 2) == "__" ? string(name, 2) : name;
baseEnv.values[0]->attrs->push_back(Attr(symbols.create(name2), v2));
return v2;
}
Value * EvalState::addPrimOp(const string & name,
unsigned int arity, PrimOpFun primOp)
{
if (arity == 0) {
Value v;
primOp(*this, noPos, nullptr, v);
return addConstant(name, v);
}
Value * v = allocValue();
string name2 = string(name, 0, 2) == "__" ? string(name, 2) : name;
Symbol sym = symbols.create(name2);

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@ -210,7 +210,7 @@ private:
void createBaseEnv();
void addConstant(const string & name, Value & v);
Value * addConstant(const string & name, Value & v);
Value * addPrimOp(const string & name,
unsigned int arity, PrimOpFun primOp);

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@ -9,6 +9,9 @@ struct RegisterPrimOp
{
typedef std::vector<std::tuple<std::string, size_t, PrimOpFun>> PrimOps;
static PrimOps * primOps;
/* You can register a constant by passing an arity of 0. fun
will get called during EvalState initialization, so there
may be primops not yet added and builtins is not yet sorted. */
RegisterPrimOp(std::string name, size_t arity, PrimOpFun fun);
};

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@ -2,6 +2,6 @@ source common.sh
set -o pipefail
res=$(nix eval '(builtins.constNull true)' --option plugin-files $PWD/plugins/plugintest.so)
res=$(nix eval '(builtins.anotherNull)' --option plugin-files $PWD/plugins/plugintest.so)
[ "$res"x = "nullx" ]

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@ -2,9 +2,9 @@
using namespace nix;
static void prim_constNull (EvalState & state, const Pos & pos, Value ** args, Value & v)
static void prim_anotherNull (EvalState & state, const Pos & pos, Value ** args, Value & v)
{
mkNull(v);
}
static RegisterPrimOp r("constNull", 1, prim_constNull);
static RegisterPrimOp r("anotherNull", 0, prim_anotherNull);