//: Spaces help isolate recipes from each other. You can create them at will, //: and all addresses in arguments are implicitly based on the 'default-space' //: (unless they have the /raw property) //: //: Spaces are often called 'scopes' in other languages. Stack frames are a //: limited form of space that can't outlive callers. //: //: Warning: messing with 'default-space' can corrupt memory. Don't share //: default-space between recipes. Later we'll see how to chain spaces safely. //: //: Tests in this layer can write to a location as part of one type, and read //: it as part of another. This is unsafe and insecure, and we'll stop doing //: this once we switch to variable names. //: Under the hood, a space is an array of locations in memory. :(before "End Mu Types Initialization") put(Type_abbreviations, "space", new_type_tree("address:array:location")); :(code) void test_set_default_space() { run( "def main [\n" // prepare default-space address " 10:num/alloc-id, 11:num <- copy 0, 1000\n" // prepare default-space payload " 1000:num <- copy 0\n" // alloc id of payload " 1001:num <- copy 5\n" // length // actual start of this recipe " default-space:space <- copy 10:&:@:location\n" // if default-space is 1000, then: // 1000: alloc id // 1001: array size // 1002: location 0 (space for the chaining slot; described later; often unused) // 1003: location 1 (space for the chaining slot; described later; often unused) // 1004: local 2 (assuming it is a scalar) " 2:num <- copy 93\n" "]\n" ); CHECK_TRACE_CONTENTS( "mem: storing 93 in location 1004\n" ); } void test_lookup_sidesteps_default_space() { run( "def main [\n" // prepare default-space address " 10:num/alloc-id, 11:num <- copy 0, 1000\n" // prepare default-space payload " 1000:num <- copy 0\n" // alloc id of payload " 1001:num <- copy 5\n" // length // prepare payload outside the local scope " 2000:num/alloc-id, 2001:num <- copy 0, 34\n" // actual start of this recipe " default-space:space <- copy 10:&:@:location\n" // a local address " 2:num, 3:num <- copy 0, 2000\n" " 20:num/raw <- copy *2:&:num\n" "]\n" ); CHECK_TRACE_CONTENTS( "mem: storing 2000 in location 1005\n" "mem: storing 34 in location 20\n" ); } //: precondition: disable name conversion for 'default-space' void test_convert_names_passes_default_space() { Hide_errors = true; transform( "def main [\n" " default-space:num <- copy 0\n" " x:num <- copy 1\n" "]\n" ); CHECK_TRACE_CONTENTS( "name: assign x 2\n" ); CHECK_TRACE_DOESNT_CONTAIN("name: assign default-space 1"); CHECK_TRACE_DOESNT_CONTAIN("name: assign default-space 2"); } :(before "End is_disqualified Special-cases") if (x.name == "default-space") x.initialized = true; :(before "End is_special_name Special-cases") if (s == "default-space") return true; //: core implementation :(before "End call Fields") int default_space; :(before "End call Constructor") default_space = 0; :(before "Begin canonize(x) Lookups") absolutize(x); :(code) void absolutize(reagent& x) { if (is_raw(x) || is_dummy(x)) return; if (x.name == "default-space") return; if (!x.initialized) raise << to_original_string(current_instruction()) << ": reagent not initialized: '" << x.original_string << "'\n" << end(); x.set_value(address(x.value, space_base(x))); x.properties.push_back(pair("raw", NULL)); assert(is_raw(x)); } //: hook replaced in a later layer int space_base(const reagent& x) { return current_call().default_space ? (current_call().default_space + /*skip alloc id*/1) : 0; } int address(int offset, int base) { assert(offset >= 0); if (base == 0) return offset; // raw int size = get_or_insert(Memory, base); if (offset >= size) { // todo: test raise << current_recipe_name() << ": location " << offset << " is out of bounds " << size << " at " << base << '\n' << end(); DUMP(""); exit(1); return 0; } return base + /*skip length*/1 + offset; } //: reads and writes to the 'default-space' variable have special behavior :(after "Begin Preprocess write_memory(x, data)") if (x.name == "default-space") { if (!is_mu_space(x)) raise << maybe(current_recipe_name()) << "'default-space' should be of type address:array:location, but is " << to_string(x.type) << '\n' << end(); if (SIZE(data) != 2) raise << maybe(current_recipe_name()) << "'default-space' getting data from non-address\n" << end(); current_call().default_space = data.at(/*skip alloc id*/1); return; } :(code) bool is_mu_space(reagent/*copy*/ x) { canonize_type(x); if (!is_compound_type_starting_with(x.type, "address")) return false; drop_from_type(x, "address"); if (!is_compound_type_starting_with(x.type, "array")) return false; drop_from_type(x, "array"); return x.type && x.type->atom && x.type->name == "location"; } void test_get_default_space() { run( "def main [\n" // prepare default-space address " 10:num/alloc-id, 11:num <- copy 0, 1000\n" // prepare default-space payload " 1000:num <- copy 0\n" // alloc id of payload " 1001:num <- copy 5\n" // length // actual start of this recipe " default-space:space <- copy 10:space\n" " 2:space/raw <- copy default-space:space\n" "]\n" ); CHECK_TRACE_CONTENTS( "mem: storing 1000 in location 3\n" ); } :(after "Begin Preprocess read_memory(x)") if (x.name == "default-space") { vector result; result.push_back(/*alloc id*/0); result.push_back(current_call().default_space); return result; } //:: fix 'get' :(code) void test_lookup_sidesteps_default_space_in_get() { run( "def main [\n" // prepare default-space address " 10:num/alloc-id, 11:num <- copy 0,