diff --git a/src/libexpr-c/nix_api_value.cc b/src/libexpr-c/nix_api_value.cc index a3686022d..0d61292c4 100644 --- a/src/libexpr-c/nix_api_value.cc +++ b/src/libexpr-c/nix_api_value.cc @@ -20,7 +20,7 @@ # include "gc_cpp.h" #endif -// Helper function to throw an exception if value is null or in an invalid state +// Internal helper functions to check [in] and [out] `Value *` parameters static const nix::Value & check_value_not_null(const Value * value) { if (!value) { @@ -37,18 +37,31 @@ static nix::Value & check_value_not_null(Value * value) return *((nix::Value *) value); } -static void check_value_initialized(const nix::Value & value) +static const nix::Value & check_value_in(const Value * value) { - if (!value.isValid()) { + auto & v = check_value_not_null(value); + if (!v.isValid()) { throw std::runtime_error("Uninitialized Value"); } + return v; } -static void check_value_uninitialized(const nix::Value & value) +static nix::Value & check_value_in(Value * value) { - if (value.isValid()) { + auto & v = check_value_not_null(value); + if (!v.isValid()) { + throw std::runtime_error("Uninitialized Value"); + } + return v; +} + +static nix::Value & check_value_out(Value * value) +{ + auto & v = check_value_not_null(value); + if (v.isValid()) { throw std::runtime_error("Value already initialized. Variables are immutable"); } + return v; } /** @@ -125,8 +138,7 @@ ValueType nix_get_type(nix_c_context * context, const Value * value) if (context) context->last_err_code = NIX_OK; try { - auto & v = check_value_not_null(value); - check_value_initialized(v); + auto & v = check_value_in(value); using namespace nix; switch (v.type()) { case nThunk: @@ -162,8 +174,7 @@ const char * nix_get_typename(nix_c_context * context, const Value * value) if (context) context->last_err_code = NIX_OK; try { - auto & v = check_value_not_null(value); - check_value_initialized(v); + auto & v = check_value_in(value); auto s = nix::showType(v); return strdup(s.c_str()); } @@ -175,8 +186,7 @@ bool nix_get_bool(nix_c_context * context, const Value * value) if (context) context->last_err_code = NIX_OK; try { - auto & v = check_value_not_null(value); - check_value_initialized(v); + auto & v = check_value_in(value); assert(v.type() == nix::nBool); return v.boolean(); } @@ -188,8 +198,7 @@ nix_err nix_get_string(nix_c_context * context, const Value * value, nix_get_str if (context) context->last_err_code = NIX_OK; try { - auto & v = check_value_not_null(value); - check_value_initialized(v); + auto & v = check_value_in(value); assert(v.type() == nix::nString); call_nix_get_string_callback(v.c_str(), callback, user_data); } @@ -201,8 +210,7 @@ const char * nix_get_path_string(nix_c_context * context, const Value * value) if (context) context->last_err_code = NIX_OK; try { - auto & v = check_value_not_null(value); - check_value_initialized(v); + auto & v = check_value_in(value); assert(v.type() == nix::nPath); // NOTE (from @yorickvP) // v._path.path should work but may not be how Eelco intended it. @@ -221,8 +229,7 @@ unsigned int nix_get_list_size(nix_c_context * context, const Value * value) if (context) context->last_err_code = NIX_OK; try { - auto & v = check_value_not_null(value); - check_value_initialized(v); + auto & v = check_value_in(value); assert(v.type() == nix::nList); return v.listSize(); } @@ -234,8 +241,7 @@ unsigned int nix_get_attrs_size(nix_c_context * context, const Value * value) if (context) context->last_err_code = NIX_OK; try { - auto & v = check_value_not_null(value); - check_value_initialized(v); + auto & v = check_value_in(value); assert(v.type() == nix::nAttrs); return v.attrs()->size(); } @@ -247,8 +253,7 @@ double nix_get_float(nix_c_context * context, const Value * value) if (context) context->last_err_code = NIX_OK; try { - auto & v = check_value_not_null(value); - check_value_initialized(v); + auto & v = check_value_in(value); assert(v.type() == nix::nFloat); return v.fpoint(); } @@ -260,8 +265,7 @@ int64_t nix_get_int(nix_c_context * context, const Value * value) if (context) context->last_err_code = NIX_OK; try { - auto & v = check_value_not_null(value); - check_value_initialized(v); + auto & v = check_value_in(value); assert(v.type() == nix::nInt); return v.integer(); } @@ -273,8 +277,7 @@ ExternalValue * nix_get_external(nix_c_context * context, Value * value) if (context) context->last_err_code = NIX_OK; try { - auto & v = check_value_not_null(value); - check_value_initialized(v); + auto & v = check_value_out(value); assert(v.type() == nix::nExternal); return (ExternalValue *) v.external(); } @@ -286,8 +289,7 @@ Value * nix_get_list_byidx(nix_c_context * context, const Value * value, EvalSta if (context) context->last_err_code = NIX_OK; try { - auto & v = check_value_not_null(value); - check_value_initialized(v); + auto & v = check_value_in(value); assert(v.type() == nix::nList); auto * p = v.listElems()[ix]; nix_gc_incref(nullptr, p); @@ -303,8 +305,7 @@ Value * nix_get_attr_byname(nix_c_context * context, const Value * value, EvalSt if (context) context->last_err_code = NIX_OK; try { - auto & v = check_value_not_null(value); - check_value_initialized(v); + auto & v = check_value_in(value); assert(v.type() == nix::nAttrs); nix::Symbol s = state->state.symbols.create(name); auto attr = v.attrs()->get(s); @@ -324,8 +325,7 @@ bool nix_has_attr_byname(nix_c_context * context, const Value * value, EvalState if (context) context->last_err_code = NIX_OK; try { - auto & v = check_value_not_null(value); - check_value_initialized(v); + auto & v = check_value_in(value); assert(v.type() == nix::nAttrs); nix::Symbol s = state->state.symbols.create(name); auto attr = v.attrs()->get(s); @@ -342,8 +342,7 @@ nix_get_attr_byidx(nix_c_context * context, const Value * value, EvalState * sta if (context) context->last_err_code = NIX_OK; try { - auto & v = check_value_not_null(value); - check_value_initialized(v); + auto & v = check_value_in(value); const nix::Attr & a = (*v.attrs())[i]; *name = ((const std::string &) (state->state.symbols[a.name])).c_str(); nix_gc_incref(nullptr, a.value); @@ -358,8 +357,7 @@ const char * nix_get_attr_name_byidx(nix_c_context * context, const Value * valu if (context) context->last_err_code = NIX_OK; try { - auto & v = check_value_not_null(value); - check_value_initialized(v); + auto & v = check_value_in(value); const nix::Attr & a = (*v.attrs())[i]; return ((const std::string &) (state->state.symbols[a.name])).c_str(); } @@ -371,8 +369,7 @@ nix_err nix_init_bool(nix_c_context * context, Value * value, bool b) if (context) context->last_err_code = NIX_OK; try { - auto & v = check_value_not_null(value); - check_value_uninitialized(v); + auto & v = check_value_out(value); v.mkBool(b); } NIXC_CATCH_ERRS @@ -384,8 +381,7 @@ nix_err nix_init_string(nix_c_context * context, Value * value, const char * str if (context) context->last_err_code = NIX_OK; try { - auto & v = check_value_not_null(value); - check_value_uninitialized(v); + auto & v = check_value_out(value); v.mkString(std::string_view(str)); } NIXC_CATCH_ERRS @@ -396,8 +392,7 @@ nix_err nix_init_path_string(nix_c_context * context, EvalState * s, Value * val if (context) context->last_err_code = NIX_OK; try { - auto & v = check_value_not_null(value); - check_value_uninitialized(v); + auto & v = check_value_out(value); v.mkPath(s->state.rootPath(nix::CanonPath(str))); } NIXC_CATCH_ERRS @@ -408,8 +403,7 @@ nix_err nix_init_float(nix_c_context * context, Value * value, double d) if (context) context->last_err_code = NIX_OK; try { - auto & v = check_value_not_null(value); - check_value_uninitialized(v); + auto & v = check_value_out(value); v.mkFloat(d); } NIXC_CATCH_ERRS @@ -420,8 +414,7 @@ nix_err nix_init_int(nix_c_context * context, Value * value, int64_t i) if (context) context->last_err_code = NIX_OK; try { - auto & v = check_value_not_null(value); - check_value_uninitialized(v); + auto & v = check_value_out(value); v.mkInt(i); } NIXC_CATCH_ERRS @@ -432,8 +425,7 @@ nix_err nix_init_null(nix_c_context * context, Value * value) if (context) context->last_err_code = NIX_OK; try { - auto & v = check_value_not_null(value); - check_value_uninitialized(v); + auto & v = check_value_out(value); v.mkNull(); } NIXC_CATCH_ERRS @@ -457,8 +449,7 @@ nix_err nix_init_external(nix_c_context * context, Value * value, ExternalValue if (context) context->last_err_code = NIX_OK; try { - auto & v = check_value_not_null(value); - check_value_uninitialized(v); + auto & v = check_value_out(value); auto r = (nix::ExternalValueBase *) val; v.mkExternal(r); } @@ -486,7 +477,6 @@ nix_err nix_list_builder_insert(nix_c_context * context, ListBuilder * list_buil context->last_err_code = NIX_OK; try { auto & e = check_value_not_null(value); - check_value_initialized(e); list_builder->builder[index] = &e; } NIXC_CATCH_ERRS @@ -506,8 +496,7 @@ nix_err nix_make_list(nix_c_context * context, ListBuilder * list_builder, Value if (context) context->last_err_code = NIX_OK; try { - auto & v = check_value_not_null(value); - check_value_uninitialized(v); + auto & v = check_value_out(value); v.mkList(list_builder->builder); } NIXC_CATCH_ERRS @@ -518,8 +507,7 @@ nix_err nix_init_primop(nix_c_context * context, Value * value, PrimOp * p) if (context) context->last_err_code = NIX_OK; try { - auto & v = check_value_not_null(value); - check_value_uninitialized(v); + auto & v = check_value_out(value); v.mkPrimOp((nix::PrimOp *) p); } NIXC_CATCH_ERRS @@ -530,10 +518,8 @@ nix_err nix_copy_value(nix_c_context * context, Value * value, Value * source) if (context) context->last_err_code = NIX_OK; try { - auto & v = check_value_not_null(value); - check_value_uninitialized(v); - auto & s = check_value_not_null(source); - check_value_initialized(s); + auto & v = check_value_out(value); + auto & s = check_value_in(source); v = s; } NIXC_CATCH_ERRS @@ -544,8 +530,7 @@ nix_err nix_make_attrs(nix_c_context * context, Value * value, BindingsBuilder * if (context) context->last_err_code = NIX_OK; try { - auto & v = check_value_not_null(value); - check_value_uninitialized(v); + auto & v = check_value_out(value); v.mkAttrs(b->builder); } NIXC_CATCH_ERRS @@ -572,7 +557,6 @@ nix_err nix_bindings_builder_insert(nix_c_context * context, BindingsBuilder * b context->last_err_code = NIX_OK; try { auto & v = check_value_not_null(value); - check_value_initialized(v); nix::Symbol s = bb->builder.state.symbols.create(name); bb->builder.insert(s, &v); } @@ -593,8 +577,7 @@ nix_realised_string * nix_string_realise(nix_c_context * context, EvalState * st if (context) context->last_err_code = NIX_OK; try { - auto & v = check_value_not_null(value); - check_value_initialized(v); + auto & v = check_value_in(value); nix::NixStringContext stringContext; auto rawStr = state->state.coerceToString(nix::noPos, v, stringContext, "while realising a string").toOwned(); nix::StorePathSet storePaths; diff --git a/tests/unit/libexpr/nix_api_value.cc b/tests/unit/libexpr/nix_api_value.cc index 7c8e82c50..6e209695e 100644 --- a/tests/unit/libexpr/nix_api_value.cc +++ b/tests/unit/libexpr/nix_api_value.cc @@ -139,13 +139,20 @@ TEST_F(nix_api_expr_test, nix_build_and_init_list) ListBuilder * builder = nix_make_list_builder(ctx, state, size); Value * intValue = nix_alloc_value(ctx, state); + Value * intValue2 = nix_alloc_value(ctx, state); + + // `init` and `insert` can be called in any order nix_init_int(ctx, intValue, 42); nix_list_builder_insert(ctx, builder, 0, intValue); + nix_list_builder_insert(ctx, builder, 1, intValue2); + nix_init_int(ctx, intValue2, 43); + nix_make_list(ctx, builder, value); nix_list_builder_free(builder); ASSERT_EQ(42, nix_get_int(ctx, nix_get_list_byidx(ctx, value, state, 0))); - ASSERT_EQ(nullptr, nix_get_list_byidx(ctx, value, state, 1)); + ASSERT_EQ(43, nix_get_int(ctx, nix_get_list_byidx(ctx, value, state, 1))); + ASSERT_EQ(nullptr, nix_get_list_byidx(ctx, value, state, 2)); ASSERT_EQ(10, nix_get_list_size(ctx, value)); ASSERT_STREQ("a list", nix_get_typename(ctx, value));