quakeforge/tools/qfcc/include/flow.h
Bill Currie 554b2e4710 Add flow analysis to determin the type of .return.
It doesn't quite work yet, but...

It has proven necessary to know what type .return has at any point in the
function. The segfault in ctf is caused by the return statement added to
the end of the void function messing with the expr pointer stored in the
daglabel for .return. While this is actually by design (though the
statement really should have a valid expr pointer rather than), it actually
highlights a bigger problem: there's no stable knowledge of the current
type of .return. This is not a problem in expression statements as the
dagnodes for expression statements store the desired types of all operands.
However, when assigning from .return to attached variables in a leaf node,
the type of .return is not stored anywhere but the expression last
accessing .return.
2012-11-30 17:15:05 +09:00

123 lines
3.7 KiB
C

/*
flow.h
Flow graph analysis.
Copyright (C) 2012 Bill Currie <bill@taniwha.org>
Author: Bill Currie <bill@taniwha.org>
Date: 2012/10/30
This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License
as published by the Free Software Foundation; either version 2
of the License, or (at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
See the GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to:
Free Software Foundation, Inc.
59 Temple Place - Suite 330
Boston, MA 02111-1307, USA
*/
#ifndef flow_h
#define flow_h
/** \defgroup qfcc_flow Flow graph analysis
\ingroup qfcc
*/
//@{
struct function_s;
struct sblock_s;
struct statement_s;
struct operand_s;
typedef struct flowvar_s {
struct flowvar_s *next; ///< for ALLOC
struct set_s *use; ///< set of statements that use this var
struct set_s *define; ///< set of statements that define this var
struct operand_s *op; ///< an operand using this var
int number; ///< number of variable in func's ref list
} flowvar_t;
typedef struct flowloop_s {
struct flowloop_s *next;
unsigned head;
struct set_s *nodes;
} flowloop_t;
typedef struct flowedge_s {
unsigned tail;
unsigned head;
} flowedge_t;
/** Represent a node in a flow graph.
*/
typedef struct flownode_s {
struct flownode_s *next; ///< for ALLOC
unsigned id; ///< index of this node in the flow graph
unsigned dfn; ///< depth-first ordering of this node
struct set_s *predecessors; ///< predecessors of this node
struct set_s *successors; ///< successors of this node
struct set_s *edges; ///< edges leaving this node to successor nodes
struct set_s *dom; ///< dominating nodes
struct set_s *global_vars; ///< global vars used by function
struct {
struct set_s *use;
struct set_s *def;
struct set_s *in;
struct set_s *out;
} live_vars;
struct {
struct set_s *use;
struct set_s *def;
struct set_s *in;
struct set_s *out;
} init_vars;
struct {
etype_t in;
etype_t out; ///< if different from in, then block defines
} return_type; ///< type of .return for this node
struct sblock_s *sblock; ///< original statement block
struct dag_s *dag; ///< dag for this node
} flownode_t;
typedef struct flowgraph_s {
struct flowgraph_s *next; ///< for ALLOC
struct function_s *func; ///< function to which this graph is attached
flownode_t **nodes; ///< array of nodes in the graph
int num_nodes;
flowedge_t *edges; ///< array of all edges in the graph
int num_edges;
struct set_s *dfst; ///< edges in the depth-first search tree
unsigned *dfo; ///< depth-first order of nodes
flowloop_t *loops; ///< linked list of natural loops
} flowgraph_t;
flowvar_t *flow_get_var (struct operand_s *op);
void flow_analyze_statement (struct statement_s *s, struct set_s *use,
struct set_s *def, struct set_s *kill,
struct operand_s *operands[4]);
void flow_build_vars (struct function_s *func);
flowgraph_t *flow_build_graph (struct sblock_s *sblock,
struct function_s *func);
void flow_del_graph (flowgraph_t *graph);
void flow_data_flow (flowgraph_t *graph);
struct sblock_s *flow_generate (flowgraph_t *graph);
void dump_dot_flow (void *g, const char *filename);
void dump_dot_flow_dags (void *g, const char *filename);
void dump_dot_flow_live (void *g, const char *filename);
void dump_dot_flow_return (void *g, const char *filename);
//@}
#endif//flow_h