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