block walk in irouts.

[libfirm] / testprograms / empty.c

diff --git a/testprograms/empty.c b/testprograms/empty.c
index 238da87..0b4624c 100644 (file)
--- a/testprograms/empty.c
+++ b/testprograms/empty.c
@@ -3,7 +3,6 @@
 **
 ** Authors: Christian Schaefer, Goetz Lindenmaier
 **
-** testprogram.
 */
 
 #include <stdio.h>
@@ -11,70 +10,73 @@
 # include "irdump.h"
 # include "firm.h"
 
-/*
- * das leere FIRM Programm
- */
-
 /**
+***  An empty Firm program.
+***
 ***  This file constructs the ir for the following pseudo-program:
 ***
 ***  main() {
 ***    return;
 ***  }
+***
+***
 **/
 
 int main(int argc, char **argv)
 {
-  ir_graph *irg;          /* this variable contains the irgraph */
-  type_class *owner;      /* the class in which this method is defined */
-  type_method *proc_main; /* type information for the method main */
-  entity *ent;            /* represents this method as entity of owner */
-  ir_node *x;
+  ir_graph *irg;        /* this variable contains the irgraph */
+  type     *owner;      /* the class in which this method is defined */
+  type     *proc_main;  /* type information for the method main */
+  entity   *ent;        /* represents this method as entity of owner */
+  ir_node  *x;          /* to build control flow */
 
   printf("\nCreating an IR graph: EMPTY...\n");
 
   /* init library */
   init_firm ();
 
-  /* Don't optimize anything */
-  set_optimize(1);
+  /** Build type information for the procedure. **/
 
   /* FIRM was designed for oo languages where all methods belong to a class.
    * For imperative languages like C we view a file as a large class containing
-   * all functions as methods in this file.
-   * This class now is automatically generated.
+   * all functions in this file as methods.
+   * This clas is generated automatically.
    */
+  owner = get_glob_type();
+
 #define METHODNAME "main"
 #define NRARGS 0
 #define NRES 0
-
-  owner = get_glob_type();
+  /* The type of the method */
   proc_main = new_type_method(id_from_str(METHODNAME, strlen(METHODNAME)),
                               NRARGS, NRES);
+  /* An entity representing the method.  Owner of the entity is the global class
+     type mentioned above. */
   ent = new_entity ((type *)owner,
                     id_from_str (METHODNAME, strlen(METHODNAME)),
                     (type *)proc_main);
 
+  /** Build code for the procedure. **/
+
   /* Generates the basic graph for the method represented by entity ent, that
    * is, generates start and end blocks and nodes and a first, initial block.
-   * The constructor needs to know how many local variables the method has.
+   * The constructor needs to know the number of local variables (including
+   * the arguments) in the method.
    */
 #define NUM_OF_LOCAL_VARS 0
-
   irg = new_ir_graph (ent, NUM_OF_LOCAL_VARS);
 
-
   /* The constructor new_ir_graph() generated a region to place nodes in.
    * This region is accessible via the attribut current_block of irg and
    * it is not matured.
    * Generate the return node into this region. The Return node is needed to
-   * return at least the store. */
+   * return at least the memory. */
   {
     ir_node *in[0]; /* this is the array containing the return parameters */
     x = new_Return (get_store(), 0, in);
   }
-  /* Now generate all instructions for this block and all its predecessor blocks
-   * so we can mature it. */
+  /* Now we generated all instructions for this block and all its predecessor
+   * blocks so we can mature it.  (There are not too much.) */
   mature_block (get_irg_current_block(irg));
 
   /* This adds the in edge of the end block which originates at the return statement.
@@ -83,17 +85,13 @@ int main(int argc, char **argv)
   /* Now we can mature the end block as all it's predecessors are known. */
   mature_block (get_irg_end_block(irg));
 
-  /* verify the graph */
+  /* Verify the graph.  Finds some very bad errors in the graph. */
   irg_vrfy(irg);
-
-  printf("Optimizing ...\n");
-  dead_node_elimination(irg);
+  finalize_cons (irg);
 
   printf("Done building the graph.  Dumping it.\n");
   dump_ir_block_graph (irg);
 
-  dump_all_types();
-
   printf("use xvcg to view this graph:\n");
   printf("/ben/goetz/bin/xvcg GRAPHNAME\n\n");