1 /* Copyright (C) 1998 - 2000 by Universitaet Karlsruhe
2 ** All rights reserved.
4 ** Authors: Christian Schaefer, Goetz Lindenmaier
14 *** An empty Firm program.
16 *** This file constructs the ir for the following pseudo-program:
25 int main(int argc, char **argv)
27 ir_graph *irg; /* this variable contains the irgraph */
28 type *owner; /* the class in which this method is defined */
29 type *proc_main; /* type information for the method main */
30 entity *ent; /* represents this method as entity of owner */
31 ir_node *x; /* to build control flow */
33 printf("\nCreating an IR graph: EMPTY...\n");
38 /** Build type information for the procedure. **/
40 /* FIRM was designed for oo languages where all methods belong to a class.
41 * For imperative languages like C we view a file as a large class containing
42 * all functions in this file as methods.
43 * This clas is generated automatically.
45 owner = get_glob_type();
47 #define METHODNAME "main"
50 /* The type of the method */
51 proc_main = new_type_method(id_from_str(METHODNAME, strlen(METHODNAME)),
53 /* An entity representing the method. Owner of the entity is the global class
54 type mentioned above. */
55 ent = new_entity ((type *)owner,
56 id_from_str (METHODNAME, strlen(METHODNAME)),
59 /** Build code for the procedure. **/
61 /* Generates the basic graph for the method represented by entity ent, that
62 * is, generates start and end blocks and nodes and a first, initial block.
63 * The constructor needs to know the number of local variables (including
64 * the arguments) in the method.
66 #define NUM_OF_LOCAL_VARS 0
67 irg = new_ir_graph (ent, NUM_OF_LOCAL_VARS);
69 /* The constructor new_ir_graph() generated a region to place nodes in.
70 * This region is accessible via the attribut current_block of irg and
72 * Generate the return node into this region. The Return node is needed to
73 * return at least the memory. */
75 ir_node *in[0]; /* this is the array containing the return parameters */
76 x = new_Return (get_store(), 0, in);
78 /* Now we generated all instructions for this block and all its predecessor
79 * blocks so we can mature it. (There are not too much.) */
80 mature_block (get_irg_current_block(irg));
82 /* This adds the in edge of the end block which originates at the return statement.
83 * The return node passes controlflow to the end block. */
84 add_in_edge (get_irg_end_block(irg), x);
85 /* Now we can mature the end block as all it's predecessors are known. */
86 mature_block (get_irg_end_block(irg));
88 /* Verify the graph. Finds some very bad errors in the graph. */
91 printf("Done building the graph. Dumping it.\n");
92 dump_ir_block_graph (irg);
94 printf("use xvcg to view this graph:\n");
95 printf("/ben/goetz/bin/xvcg GRAPHNAME\n\n");