//: 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) //: A space is just an array of any scalar location. :(before "End Mu Types Initialization") put(Type_abbreviations, "space", new_type_tree("address:array:location")); //: Spaces are often called 'scopes' in other languages. put(Type_abbreviations, "scope", new_type_tree("address:array:location")); :(scenario set_default_space) # if default-space is 10, and if an array of 5 locals lies from location 12 to 16 (inclusive), # then local 0 is really location 12, local 1 is really location 13, and so on. def main [ # pretend address:array:location; in practice we'll use new 10:num <- copy 0 # refcount 11:num <- copy 5 # length default-space:space <- copy 10/unsafe 1:num <- copy 23 ] +mem: storing 23 in location 13 :(scenario lookup_sidesteps_default_space) def main [ # pretend pointer from outside (2000 reserved for refcount) 2001:num <- copy 34 # pretend address:array:location; in practice we'll use new 1000:num <- copy 0 # refcount 1001:num <- copy 5 # length # actual start of this recipe default-space:space <- copy 1000/unsafe 1:&:num <- copy 2000/unsafe # even local variables always contain raw addresses 8:num/raw <- copy *1:&:num ] +mem: storing 34 in location 8 //:: first disable name conversion for 'default-space' :(scenario convert_names_passes_default_space) % Hide_errors = true; def main [ default-space:num, x:num <- copy 0, 1 ] +name: assign x 1 -name: assign default-space 1 :(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; //:: now implement space support :(before "End call Fields") int default_space; :(before "End call Constructor") default_space = 0; :(before "End canonize(x) Special-cases") 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 refcount*/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 << "location " << offset << " is out of bounds " << size << " at " << base << '\n' << end(); 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 (!scalar(data) || !is_space(x)) raise << maybe(current_recipe_name()) << "'default-space' should be of type address:array:location, but is " << to_string(x.type) << '\n' << end(); current_call().default_space = data.at(0); return; } :(code) bool is_space(const reagent& r) { return is_address_of_array_of_numbers(r); } :(scenario get_default_space) def main [ default-space:space <- copy 10/unsafe 1:space/raw <- copy default-space:space ] +mem: storing 10 in location 1 :(after "Begin Preprocess read_memory(x)") if (x.name == "default-space") { vector result; result.push_back(current_call().default_space); return result; } //:: fix 'get' :(scenario lookup_sidesteps_default_space_in_get) def main [ # pretend pointer to container from outside (2000 reserved for refcount) 2001:num <- copy 34 2002:num <- copy 35 # pretend address:array:location; in practice we'll use new 1000:num <- copy 0 # refcount 1001:num <- copy 5 # length # actual start of this recipe default-space:space <- copy 1000/unsafe 1:&:point <- copy 2000/unsafe 9:num/raw <- get *1:&:point, 1:offset ] +mem: storing 35 in location 9 :(before "Read element" following "case GET:") element.properties.push_back(pair("raw", NULL)); //:: fix 'index' :(scenario lookup_sidesteps_default_space_in_index) def main [ # pretend pointer to array from outside (2000 reserved for refcount) 2001:num <- copy 2 # length 2002:num <- copy 34 2003:num <- copy 35 # pretend address:array:location; in practice we'll use new 1000:num <- copy 0 # refcount 1001:num <- copy 5 # length # actual start of this recipe default-space:space <- copy 1000/unsafe 1:&:@:num <- copy 2000/unsafe 9:num/raw <- index *1:&:@:num, 1 ] +mem: storing 35 in location 9 :(before "Read element" following "case INDEX:") element.properties.push_back(pair("raw", NULL)); //:: convenience operation to automatically deduce the amount of space to //:: allocate in a default space with names :(scenario new_default_space) def main [ new-default-space x:num <- copy 0 y:num <- copy 3 ] # allocate space for x and y, as well as the chaining slot at 0 +mem: array length is 3 :(before "End is_disqualified Special-cases") if (x.name == "number-of-locals") x.initialized = true; :(before "End is_special_name Special-cases") if (s == "number-of-locals") return true; :(before "End Rewrite Instruction(curr, recipe result)") // rewrite `new-default-space` to // `default-space:space <- new location:type, number-of-locals:literal` // where N is Name[recipe][""] if (curr.name == "new-default-space") { rewrite_default_space_instruction(curr); } :(after "Begin Preprocess read_memory(x)") if (x.name == "number-of-locals") { vector result; result.push_back(Name[get(Recipe_ordinal, current_recipe_name())][""]); if (result.back() == 0) raise << "no space allocated for default-space in recipe " << current_recipe_name() << "; are you using names?\n" << end(); return result; } :(after "Begin Preprocess write_memory(x, data)") if (x.name == "number-of-locals") { raise << maybe(current_recipe_name()) << "can't write to special name 'number-of-locals'\n" << end(); return; } //:: 'local-scope' is like 'new-default-space' except that we'll reclaim the //:: default-space when the routine exits :(scenario local_scope) def main [ 1:&:@:location <- foo 2:&:@:location <- foo 3:bool <- equal 1:&, 2:& ] def foo [ local-scope x:num <- copy 34 return default-space:space ] # both calls to foo should have received the same default-space +mem: storing 1 in location 3 :(scenario local_scope_frees_up_addresses) def main [ local-scope x:text <- new [abc] ] +mem: clearing x:text :(before "End Rewrite Instruction(curr, recipe result)") if (curr.name == "local-scope") { rewrite_default_space_instruction(curr); } //: todo: do this in a transform, rather than magically in the 'return' instruction :(after "Falling Through End Of Recipe") try_reclaim_locals(); :(after "Starting Reply") try_reclaim_locals(); :(code) void try_reclaim_locals() { if (!Reclaim_memory) return; // only reclaim routines starting with 'local-scope' const recipe_ordinal r = get(Recipe_ordinal, current_recipe_name()); const recipe& exiting_recipe = get(Recipe, r); if (exiting_recipe.steps.empty()) return; const instruction& inst = exiting_recipe.steps.at(0); if (inst.name_before_rewrite != "local-scope") return; // reclaim any local variables unless they're being returned vector zeros; for (int i = /*leave default space for last*/1; i < SIZE(exiting_recipe.steps); ++i) { const instruction& inst = exiting_recipe.steps.at(i); for (int i = 0; i < SIZE(inst.products); ++i) { const reagent& product = inst.products.at(i); // local variables only if (has_property(product, "lookup")) continue; if (has_property(product, "raw")) continue; // tests often want to check such locations after they run if (escaping(product)) continue; // End Checks For Reclaiming Locals trace(9999, "mem") << "clearing " << product.original_string << end(); zeros.resize(size_of(product)); write_memory(product, zeros); } } trace(9999, "mem") << "automatically abandoning " << current_call().default_space << end(); abandon(current_call().default_space, inst.products.at(0).type->right, /*refcount*/1 + /*array length*/1 + /*number-of-locals*/Name[r][""]); } //: Reclaiming local variables above requires remembering what name an //: instruction had before any rewrites or transforms. :(before "End instruction Fields") string name_before_rewrite; :(before "End instruction Clear") name_before_rewrite.clear(); :(before "End next_instruction(curr)") curr->name_before_rewrite = curr->name; :(code) // is this reagent one of the values returned by the current (return) instruction? // is the corresponding ingredient saved in the caller? bool escaping(const reagent& r) { assert(Current_routine); // run-time only // nothing escapes when you fall through past end of recipe if (current_step_index() >= SIZE(Current_routine->steps())) return false; for (long long i = 0; i < SIZE(current_instruction().ingredients); ++i) { if (r == current_instruction().ingredients.at(i)) { if

# Helper to check an array's bounds, and to abort if they're violated.
# Really only intended to be called from code generated by mu.subx.

== code

__check-mu-array-bounds:  # index: int, elem-size: int, arr-size: