1 files changed, 126 insertions, 0 deletions
diff --git a/cpp/042new.cc b/cpp/042new.cc
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index 00000000..d268e6ca
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+++ b/cpp/042new.cc
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+//: A simple memory allocator to create space for new variables at runtime.
+
+:(scenarios run)
+:(scenario new)
+# call new two times with identical arguments; you should get back different results
+recipe main [
+  1:address:integer/raw <- new integer:type
+  2:address:integer/raw <- new integer:type
+  3:boolean/raw <- equal 1:address:integer/raw, 2:address:integer/raw
+]
++mem: storing 0 in location 3
+
+:(before "End Globals")
+size_t Memory_allocated_until = 1000;
+:(before "End Setup")
+Memory_allocated_until = 1000;
+:(before "End routine Fields")
+size_t alloc;
+:(replace{} "routine::routine(recipe_number r)")
+routine::routine(recipe_number r) :alloc(Memory_allocated_until) {
+  calls.push(call(r));
+}
+
+//:: First handle 'type' operands.
+
+:(before "End Mu Types Initialization")
+Type_number["type"] = 0;
+:(after "Per-recipe Transforms")
+// replace type names with type_numbers
+if (inst.operation == Recipe_number["new"]) {
+  // first arg must be of type 'type'
+  assert(inst.ingredients.size() >= 1);
+//?   cout << inst.ingredients[0].to_string() << '\n'; //? 1
+  assert(isa_literal(inst.ingredients[0]));
+  if (inst.ingredients[0].properties[0].second[0] == "type") {
+    inst.ingredients[0].set_value(Type_number[inst.ingredients[0].name]);
+  }
+  trace("new") << inst.ingredients[0].name << " -> " << inst.ingredients[0].value;
+}
+
+//:: Now implement the primitive recipe.
+
+:(before "End Primitive Recipe Declarations")
+NEW,
+:(before "End Primitive Recipe Numbers")
+Recipe_number["new"] = NEW;
+:(before "End Primitive Recipe Implementations")
+case NEW: {
+  vector<int> result;
+  trace("mem") << "new alloc: " << Current_routine->alloc;
+  result.push_back(Current_routine->alloc);
+  write_memory(current_instruction().products[0], result);
+  vector<int> types;
+  types.push_back(current_instruction().ingredients[0].value);
+  if (current_instruction().ingredients.size() > 1) {
+    // array
+    vector<int> capacity = read_memory(current_instruction().ingredients[1]);
+    trace("mem") << "array size is " << capacity[0];
+    Memory[Current_routine->alloc] = capacity[0];
+    Current_routine->alloc += capacity[0]*size_of(types);
+  }
+  else {
+    // scalar
+    Current_routine->alloc += size_of(types);
+  }
+  break;
+}
+
+:(scenario new_array)
+recipe main [
+  1:address:array:integer/raw <- new integer:type, 5:literal
+  2:address:integer/raw <- new integer:type
+  3:integer/raw <- subtract 2:address:integer/raw, 1:address:array:integer/raw
+]
++run: instruction main/0
++mem: array size is 5
++run: instruction main/1
++run: instruction main/2
++mem: storing 5 in location 3
+
+//:: Next, extend 'new' to handle a string literal argument.
+
+:(scenario new_string)
+recipe main [
+  1:address:array:character <- new [abc def]
+  2:character <- index 1:address:array:character/deref, 5:literal
+]
+# integer code for 'e'
++mem: storing 101 in location 2
+
+:(after "case NEW" following "Primitive Recipe Implementations")
+if (current_instruction().ingredients[0].properties[0].second[0] == "literal-string") {
+  // allocate an array just large enough for it
+  vector<int> result;
+  result.push_back(Current_routine->alloc);
+  write_memory(current_instruction().products[0], result);
+  // assume that all characters fit in a single location
+//?   cout << "new string literal: " << current_instruction().ingredients[0].name << '\n'; //? 1
+  Memory[Current_routine->alloc++] = current_instruction().ingredients[0].name.size();
+  for (size_t i = 0; i < current_instruction().ingredients[0].name.size(); ++i) {
+    Memory[Current_routine->alloc++] = current_instruction().ingredients[0].name[i];
+  }
+  // mu strings are not null-terminated in memory
+  break;
+}
+
+//:: Make sure that each routine gets a different alloc to start.
+
+:(scenario new_concurrent)
+recipe f1 [
+  run f2:recipe
+  1:address:integer <- new integer:type
+]
+recipe f2 [
+  2:address:integer <- new integer:type
+  # hack: assumes scheduler implementation
+  3:boolean <- equal 1:address:integer, 2:address:integer
+]
++mem: storing 0 in location 3
+
+:(before "End Globals")
+size_t Initial_memory_per_routine = 100000;
+:(before "End Setup")
+Initial_memory_per_routine = 100000;
+:(after "routine::routine(recipe_number r)")
+  Memory_allocated_until += Initial_memory_per_routine;