Updated circgen with explainatory comments. Added a hard coded defini…

…tion of Bob and Alice's inputs so that when people use this as an implementation model they will be able to be agnostic towards circuit input sizes during circuit construction.

pcflib/cirgen.c

@@ -10,9 +10,6 @@
 
 void read_instr(const char * line);
 
-uint32_t key0 = 0;
-uint32_t key1 = 1;
-
 void * copy_key(void * k)
 {
   uint32_t * ret = (uint32_t*)malloc(sizeof(uint32_t));
@@ -27,8 +24,19 @@ void delete_key(void* k)
     free(k);
 }
 
-uint32_t wcnt = 0;
-
+/* Wire IDs for the constant '0' value and the constant '1' value. */
+uint32_t key0 = 0;
+uint32_t key1 = 1;
+/* wcnt should start at 1. If set to 0 it will clobber the constant '1' value wire id in the circuit. */
+uint32_t wcnt = 1;
+
+/* This function is called every time a gate is processed in PCFLib. All implementations of this callback
+ * function require the same signature. The following callback assigns unique wire IDs for 
+ * every wire in the circuit. 
+ *
+ * NOTE: The following callback does not gurantee that any output wires are used elsewhere in the
+ * circuit.
+ */
 void * m_callback(struct PCFState * st, struct PCFGate * gate)
 {
   // We just want to associate a unique ID with each wire
@@ -47,17 +55,18 @@ void * m_callback(struct PCFState * st, struct PCFGate * gate)
   else if(gate->tag == TAG_INPUT_A)
     {
       wcnt++;
-      printf("Input -> %u\n", wcnt);
+      printf("Alice Input -> %u\n", wcnt);
     }
 
   else if(gate->tag == TAG_INPUT_B)
     {
       wcnt++;
-      printf("Input -> %u\n", wcnt);
+      printf("Bob Input -> %u\n", wcnt);
     }
 
   else 
     {
+      /** Outputs should always be considered Alice's outputs. */
       printf("%u -> Output\n", *((uint32_t*)(get_wire_key(st,gate->wire1))));
     }
   return &wcnt;
@@ -101,6 +110,9 @@ void setup_bob_inputs_from_string(struct PCFState * st, const char * inputs)
   st->bob_in_size = 8 * strlen(inputs);
 }
 
+/**
+ * Example function for setting Alice's binary circuit inputs from a hexidecimal string.
+ */
 void setup_alice_inputs_from_hex_string(struct PCFState * st, const char * inputs)
 {
   uint32_t i, j;
@@ -129,6 +141,9 @@ void setup_alice_inputs_from_hex_string(struct PCFState * st, const char * input
   st->alice_in_size = 4 * strlen(inputs);
 }
 
+/**
+ * Example function for setting Bob's binary circuit inputs from a hexidecimal string.
+ */
 void setup_bob_inputs_from_hex_string(struct PCFState * st, const char * inputs)
 {
   uint32_t i, j;
@@ -161,12 +176,25 @@ int main(int argc, char**argv)
 {
   struct PCFState * st;
   struct PCFGate * g;
-
+
+
   st = load_pcf_file(argv[1], &key0, &key1, copy_key);
+
+  /*
+   * Required for circuit construction to generate an accurate number of input wires for any
+   * given circuit without having to know how many input _bits_ the circuit actually has.
+   */
+  st->alice_in_size = sizeof(st->alice_in_size)*8;
+  st->bob_in_size = sizeof(st->bob_in_size)*8;
+
   st->delete_key = delete_key;
+
+  /*
+   * Assigns a function that is executed for each gate PCFLib generates during circuit
+   * construction.
+   *
+   */
   st->callback = m_callback;
-  setup_alice_inputs_from_string(st, "AC000000");
-  setup_bob_inputs_from_string(st, "xy(S//NF)000000");
 
   g = get_next_gate(st);
   while(g != 0)