1 //: Writing to a literal (not computed) address of 0 in a recipe chains two
  2 //: spaces together. When a variable has a property of /space:1, it looks up
  3 //: the variable in the chained/surrounding space. /space:2 looks up the
  4 //: surrounding space of the surrounding space, etc.
  5 //:
  6 //: todo: warn on default-space abuse. default-space for one recipe should
  7 //: never come from another, otherwise memory will be corrupted.
  8 
  9 :(scenario closure)
 10 def main [
 11   default-space:space <- new location:type, 30
 12   2:space/names:new-counter <- new-counter
 13   10:num/raw <- increment-counter 2:space/names:new-counter
 14   11:num/raw <- increment-counter 2:space/names:new-counter
 15 ]
 16 def new-counter [
 17   default-space:space <- new location:type, 30
 18   x:num <- copy 23
 19   y:num <- copy 13  # variable that will be incremented
 20   return default-space:space
 21 ]
 22 def increment-counter [
 23   default-space:space <- new location:type, 30
 24   0:space/names:new-counter <- next-ingredient  # outer space must be created by 'new-counter' above
 25   y:num/space:1 <- add y:num/space:1, 1  # increment
 26   y:num <- copy 234  # dummy
 27   return y:num/space:1
 28 ]
 29 +name: lexically surrounding space for recipe increment-counter comes from new-counter
 30 +mem: storing 15 in location 11
 31 
 32 //: To make this work, compute the recipe that provides names for the
 33 //: surrounding space of each recipe.
 34 
 35 :(before "End Globals")
 36 map<recipe_ordinal, recipe_ordinal> Surrounding_space;  // internal to transform; no need to snapshot
 37 :(before "End Reset")
 38 Surrounding_space.clear();
 39 
 40 :(before "Begin Type Modifying Transforms")
 41 Transform.push_back(collect_surrounding_spaces);  // idempotent
 42 
 43 :(code)
 44 void collect_surrounding_spaces(const recipe_ordinal r) {
 45   trace(9991, "transform") << "--- collect surrounding spaces for recipe " << get(Recipe, r).name << end();
 46   for (int i = 0;  i < SIZE(get(Recipe, r).steps);  ++i) {
 47     const instruction& inst = get(Recipe, r).steps.at(i);
 48     if (inst.is_label) continue;
 49     for (int j = 0;  j < SIZE(inst.products);  ++j) {
 50       if (is_literal(inst.products.at(j))) continue;
 51       if (inst.products.at(j).name != "0") continue;
 52       if (!is_mu_space(inst.products.at(j))) {
 53         raise << "slot 0 should always have type address:array:location, but is '" << to_string(inst.products.at(j)) << "'\n" << end();
 54         continue;
 55       }
 56       string_tree* s = property(inst.products.at(j), "names");
 57       if (!s) {
 58         raise << "slot 0 requires a /names property in recipe '" << get(Recipe, r).name << "'\n" << end();
 59         continue;
 60       }
 61       if (!s->atom) raise << "slot 0 should have a single value in /names, but got '" << to_string(inst.products.at(j)) << "'\n" << end();
 62       const string& surrounding_recipe_name = s->value;
 63       if (surrounding_recipe_name.empty()) {
 64         raise << "slot 0 doesn't initialize its /names property in recipe '" << get(Recipe, r).name << "'\n" << end();
 65         continue;
 66       }
 67       if (contains_key(Surrounding_space, r)
 68           && get(Surrounding_space, r) != get(Recipe_ordinal, surrounding_recipe_name)) {
 69         raise << "recipe '" << get(Recipe, r).name << "' can have only one 'surrounding' recipe but has '" << get(Recipe, get(Surrounding_space, r)).name << "' and '" << surrounding_recipe_name << "'\n" << end();
 70         continue;
 71       }
 72       trace(9993, "name") << "lexically surrounding space for recipe " << get(Recipe, r).name << " comes from " << surrounding_recipe_name << end();
 73       if (!contains_key(Recipe_ordinal, surrounding_recipe_name)) {
 74         raise << "can't find recipe providing surrounding space for '" << get(Recipe, r).name << "'; looking for '" << surrounding_recipe_name << "'\n" << end();
 75         continue;
 76       }
 77       put(Surrounding_space, r, get(Recipe_ordinal, surrounding_recipe_name));
 78     }
 79   }
 80 }
 81 
 82 //: Once surrounding spaces are available, transform_names uses them to handle
 83 //: /space properties.
 84 
 85 :(replace{} "int lookup_name(const reagent& r, const recipe_ordinal default_recipe)")
 86 int lookup_name(const reagent& x, const recipe_ordinal default_recipe) {
 87   if (!has_property(x, "space")) {
 88     if (Name[default_recipe].empty()) raise << "name not found: " << x.name << '\n' << end();
 89     return Name[default_recipe][x.name];
 90   }
 91   string_tree* p = property(x, "space");
 92   if (!p || !p->atom) raise << "/space property should have exactly one (non-negative integer) value\n" << end();
 93   int n = to_integer(p->value);
 94   assert(n >= 0);
 95   recipe_ordinal surrounding_recipe = lookup_surrounding_recipe(default_recipe, n);
 96   if (surrounding_recipe == -1) return -1;
 97   set<recipe_ordinal> done;
 98   vector<recipe_ordinal> path;
 99   return lookup_name(x, surrounding_recipe, done, path);
100 }
101 
102 // If the recipe we need to lookup this name in doesn't have names done yet,
103 // recursively call transform_names on it.
104 int lookup_name(const reagent& x, const recipe_ordinal r, set<recipe_ordinal>& done, vector<recipe_ordinal>& path) {
105   if (!Name[r].empty()) return Name[r][x.name];
106   if (contains_key(done, r)) {
107     raise << "can't compute address of '" << to_string(x) << "' because\n" << end();
108     for (int i = 1;  i < SIZE(path);  ++i) {
109       raise << path.at(i-1) << " requires computing names of " << path.at(i) << '\n' << end();
110     }
111     raise << path.at(SIZE(path)-1) << " requires computing names of " << r << "..ad infinitum\n" << end();
112     return -1;
113   }
114   done.insert(r);
115   path.push_back(r);
116   transform_names(r);  // Not passing 'done' through. Might this somehow cause an infinite loop?
117   assert(!Name[r].empty());
118   return Name[r][x.name];
119 }
120 
121 recipe_ordinal lookup_surrounding_recipe(const recipe_ordinal r, int n) {
122   if (n == 0) return r;
123   if (!contains_key(Surrounding_space, r)) {
124     raise << "don't know surrounding recipe of '" << get(Recipe, r).name << "'\n" << end();
125     return -1;
126   }
127   assert(contains_key(Surrounding_space, r));
128   return lookup_surrounding_recipe(get(Surrounding_space, r), n-1);
129 }
130 
131 //: weaken use-before-set detection just a tad
132 :(replace{} "bool already_transformed(const reagent& r, const map<string, int>& names)")
133 bool already_transformed(const reagent& r, const map<string, int>& names) {
134   if (has_property(r, "space")) {
135     string_tree* p = property(r, "space");
136     if (!p || !p->atom) {
137       raise << "/space property should have exactly one (non-negative integer) value in '" << r.original_string << "'\n" << end();
138       return false;
139     }
140     if (p->value != "0") return true;
141   }
142   return contains_key(names, r.name);
143 }
144 
145 :(scenario missing_surrounding_space)
146 % Hide_errors = true;
147 def f [
148   local-scope
149   x:num/space:1 <- copy 34
150 ]
151 +error: don't know surrounding recipe of 'f'
152 +error: f: can't find a place to store 'x'
153 
154 //: extra test for try_reclaim_locals() from previous layers
155 :(scenario local_scope_ignores_nonlocal_spaces)
156 def new-scope [
157   local-scope
158   x:&:num <- new number:type
159   *x:&:num <- copy 34
160   return default-space:space
161 ]
162 def use-scope [
163   local-scope
164   outer:space/names:new-scope <- next-ingredient
165   0:space/names:new-scope <- copy outer:space
166   return *x:&:num/space:1
167 ]
168 def main [
169   1:space/raw <- new-scope
170   3:num/raw <- use-scope 1:space/raw
171 ]
172 +mem: storing 34 in location 3
173 
174 :(scenario recursive_transform_names)
175 def foo [
176   local-scope
177   x:num <- copy 0
178   return default-space:space/names:foo
179 ]
180 def main [
181   local-scope
182   0:space/names:foo <- foo
183   x:num/space:1 <- copy 34
184 ]
185 $error: 0