From e583df52800b4baa1564b027fe3b83a21756c2cc Mon Sep 17 00:00:00 2001 From: Robin Gloster Date: Sun, 27 Oct 2019 10:15:51 +0100 Subject: [PATCH] builtins.toJSON: fix __toString usage --- src/libexpr/eval.cc | 23 +++++++++++++++++------ src/libexpr/eval.hh | 4 ++++ src/libexpr/value-to-json.cc | 7 ++++++- tests/lang/eval-okay-tojson.exp | 2 +- tests/lang/eval-okay-tojson.nix | 1 + 5 files changed, 29 insertions(+), 8 deletions(-) diff --git a/src/libexpr/eval.cc b/src/libexpr/eval.cc index d8e10d9f2..8f728b906 100644 --- a/src/libexpr/eval.cc +++ b/src/libexpr/eval.cc @@ -1565,6 +1565,19 @@ bool EvalState::isDerivation(Value & v) } +std::optional EvalState::tryAttrsToString(const Pos & pos, Value & v, + PathSet & context, bool coerceMore, bool copyToStore) +{ + auto i = v.attrs->find(sToString); + if (i != v.attrs->end()) { + Value v1; + callFunction(*i->value, v, v1, pos); + return coerceToString(pos, v1, context, coerceMore, copyToStore); + } + + return {}; +} + string EvalState::coerceToString(const Pos & pos, Value & v, PathSet & context, bool coerceMore, bool copyToStore) { @@ -1583,13 +1596,11 @@ string EvalState::coerceToString(const Pos & pos, Value & v, PathSet & context, } if (v.type == tAttrs) { - auto i = v.attrs->find(sToString); - if (i != v.attrs->end()) { - Value v1; - callFunction(*i->value, v, v1, pos); - return coerceToString(pos, v1, context, coerceMore, copyToStore); + auto maybeString = tryAttrsToString(pos, v, context, coerceMore, copyToStore); + if (maybeString) { + return *maybeString; } - i = v.attrs->find(sOutPath); + auto i = v.attrs->find(sOutPath); if (i == v.attrs->end()) throwTypeError("cannot coerce a set to a string, at %1%", pos); return coerceToString(pos, *i->value, context, coerceMore, copyToStore); } diff --git a/src/libexpr/eval.hh b/src/libexpr/eval.hh index a314e01e0..82e6ca877 100644 --- a/src/libexpr/eval.hh +++ b/src/libexpr/eval.hh @@ -8,6 +8,7 @@ #include "config.hh" #include +#include #include @@ -195,6 +196,9 @@ public: set with attribute `type = "derivation"'). */ bool isDerivation(Value & v); + std::optional tryAttrsToString(const Pos & pos, Value & v, + PathSet & context, bool coerceMore = false, bool copyToStore = true); + /* String coercion. Converts strings, paths and derivations to a string. If `coerceMore' is set, also converts nulls, integers, booleans and lists to a string. If `copyToStore' is set, diff --git a/src/libexpr/value-to-json.cc b/src/libexpr/value-to-json.cc index 72e413e44..5fe8570ad 100644 --- a/src/libexpr/value-to-json.cc +++ b/src/libexpr/value-to-json.cc @@ -40,7 +40,12 @@ void printValueAsJSON(EvalState & state, bool strict, break; case tAttrs: { - Bindings::iterator i = v.attrs->find(state.sOutPath); + auto maybeString = state.tryAttrsToString(noPos, v, context, false, false); + if (maybeString) { + out.write(*maybeString); + break; + } + auto i = v.attrs->find(state.sOutPath); if (i == v.attrs->end()) { auto obj(out.object()); StringSet names; diff --git a/tests/lang/eval-okay-tojson.exp b/tests/lang/eval-okay-tojson.exp index 33588493f..e92aae323 100644 --- a/tests/lang/eval-okay-tojson.exp +++ b/tests/lang/eval-okay-tojson.exp @@ -1 +1 @@ -"{\"a\":123,\"b\":-456,\"c\":\"foo\",\"d\":\"foo\\n\\\"bar\\\"\",\"e\":true,\"f\":false,\"g\":[1,2,3],\"h\":[\"a\",[\"b\",{\"foo\\nbar\":{}}]],\"i\":3,\"j\":1.44}" +"{\"a\":123,\"b\":-456,\"c\":\"foo\",\"d\":\"foo\\n\\\"bar\\\"\",\"e\":true,\"f\":false,\"g\":[1,2,3],\"h\":[\"a\",[\"b\",{\"foo\\nbar\":{}}]],\"i\":3,\"j\":1.44,\"k\":\"foo\"}" diff --git a/tests/lang/eval-okay-tojson.nix b/tests/lang/eval-okay-tojson.nix index c046ba4ae..ce67943be 100644 --- a/tests/lang/eval-okay-tojson.nix +++ b/tests/lang/eval-okay-tojson.nix @@ -9,4 +9,5 @@ builtins.toJSON h = [ "a" [ "b" { "foo\nbar" = {}; } ] ]; i = 1 + 2; j = 1.44; + k = { __toString = self: self.a; a = "foo"; }; }