diff options
Diffstat (limited to 'miasm2/ir/analysis.py')
| -rw-r--r-- | miasm2/ir/analysis.py | 124 |
1 files changed, 16 insertions, 108 deletions
diff --git a/miasm2/ir/analysis.py b/miasm2/ir/analysis.py index 31f6294c..40a3bf64 100644 --- a/miasm2/ir/analysis.py +++ b/miasm2/ir/analysis.py @@ -4,7 +4,7 @@ import logging from miasm2.ir.symbexec import symbexec -from miasm2.core.graph import DiGraph +from miasm2.ir.ir import ir from miasm2.expression.expression \ import ExprAff, ExprCond, ExprId, ExprInt, ExprMem @@ -14,109 +14,21 @@ console_handler.setFormatter(logging.Formatter("%(levelname)-5s: %(message)s")) log.addHandler(console_handler) log.setLevel(logging.WARNING) -class ira: + +class ira(ir): + """IR Analysis + This class provides higher level manipulations on IR, such as dead + instruction removals. + + This class can be used as a common parent with `miasm2.ir.ir::ir` class. + For instance: + class ira_x86_16(ir_x86_16, ira) + """ def ira_regs_ids(self): """Returns ids of all registers used in the IR""" return self.arch.regs.all_regs_ids + [self.IRDst] - def sort_dst(self, todo, done): - out = set() - while todo: - dst = todo.pop() - if self.ExprIsLabel(dst): - done.add(dst) - elif isinstance(dst, ExprMem) or isinstance(dst, ExprInt): - done.add(dst) - elif isinstance(dst, ExprCond): - todo.add(dst.src1) - todo.add(dst.src2) - elif isinstance(dst, ExprId): - out.add(dst) - else: - done.add(dst) - return out - - def dst_trackback(self, b): - dst = b.dst - todo = set([dst]) - done = set() - - for irs in reversed(b.irs): - if len(todo) == 0: - break - out = self.sort_dst(todo, done) - found = set() - follow = set() - for i in irs: - if not out: - break - for o in out: - if i.dst == o: - follow.add(i.src) - found.add(o) - for o in found: - out.remove(o) - - for o in out: - if o not in found: - follow.add(o) - todo = follow - - return done - - def gen_graph(self, link_all = True): - """ - Gen irbloc digraph - @link_all: also gen edges to non present irblocs - """ - self.g = DiGraph() - for lbl, b in self.blocs.items(): - # print 'add', lbl - self.g.add_node(lbl) - # dst = self.get_bloc_dst(b) - dst = self.dst_trackback(b) - # print "\tdst", dst - for d in dst: - if isinstance(d, ExprInt): - d = ExprId( - self.symbol_pool.getby_offset_create(int(d.arg))) - if self.ExprIsLabel(d): - if d.name in self.blocs or link_all is True: - self.g.add_edge(lbl, d.name) - - def graph(self): - """Output the graphviz script""" - out = """ - digraph asm_graph { - size="80,50"; - node [ - fontsize = "16", - shape = "box" - ]; - """ - all_lbls = {} - for lbl in self.g.nodes(): - if lbl not in self.blocs: - continue - irb = self.blocs[lbl] - ir_txt = [str(lbl)] - for irs in irb.irs: - for l in irs: - ir_txt.append(str(l)) - ir_txt.append("") - ir_txt.append("") - all_lbls[hash(lbl)] = "\l\\\n".join(ir_txt) - for l, v in all_lbls.items(): - # print l, v - out += '%s [label="%s"];\n' % (l, v) - - for a, b in self.g.edges(): - # print 'edge', a, b, hash(a), hash(b) - out += '%s -> %s;\n' % (hash(a), hash(b)) - out += '}' - return out - def remove_dead_instr(self, irb, useful): """Remove dead affectations using previous reaches analysis @irb: irbloc instance @@ -149,12 +61,12 @@ class ira: useful = set() - for node in self.g.nodes(): + for node in self.graph.nodes(): if node not in self.blocs: continue block = self.blocs[node] - successors = self.g.successors(node) + successors = self.graph.successors(node) has_son = bool(successors) for p_son in successors: if p_son not in self.blocs: @@ -274,7 +186,7 @@ class ira: for key, value in irb.cur_reach[0].iteritems()} # Compute reach from predecessors - for n_pred in self.g.predecessors(irb.label): + for n_pred in self.graph.predecessors(irb.label): p_block = self.blocs[n_pred] # Handle each register definition @@ -313,7 +225,7 @@ class ira: analysis""" fixed = True - for node in self.g.nodes(): + for node in self.graph.nodes(): if node in self.blocs: irb = self.blocs[node] if (irb.cur_reach != irb.prev_reach or @@ -329,13 +241,11 @@ class ira: Source : Kennedy, K. (1979). A survey of data flow analysis techniques. IBM Thomas J. Watson Research Division, page 43 - - PRE: gen_graph() """ fixed_point = False log.debug('iteration...') while not fixed_point: - for node in self.g.nodes(): + for node in self.graph.nodes(): if node in self.blocs: self.compute_reach_block(self.blocs[node]) fixed_point = self._test_kill_reach_fix() @@ -347,8 +257,6 @@ class ira: Source : Kennedy, K. (1979). A survey of data flow analysis techniques. IBM Thomas J. Watson Research Division, page 43 - - PRE: gen_graph() """ # Update r/w variables for all irblocs self.get_rw(self.ira_regs_ids()) |