Add a benchmark comparing lldb vs. gdb with disassembly on a large function (lldb's Driver::MainLoop()).

Sample run on my OSX Lion (MacBook Pro):

1: test_run_gdb_then_lldb (TestDisassembly.DisassembleDriverMainLoop)
   Test disassembly on a large function with lldb vs. gdb. ... 
gdb benchmark: Avg: 0.201802 (Laps: 5, Total Elapsed Time: 1.009008)
lldb benchmark: Avg: 0.109569 (Laps: 5, Total Elapsed Time: 0.547843)
lldb_avg/gdb_avg: 0.542952
ok
2: test_run_lldb_then_gdb (TestDisassembly.DisassembleDriverMainLoop)
   Test disassembly on a large function with lldb vs. gdb. ... 
lldb benchmark: Avg: 0.109580 (Laps: 5, Total Elapsed Time: 0.547902)
gdb benchmark: Avg: 0.201587 (Laps: 5, Total Elapsed Time: 1.007936)
lldb_avg/gdb_avg: 0.543588
ok

llvm-svn: 136931

lldb/test/benchmarks/disassembly/TestDisassembly.py

@@ -0,0 +1,127 @@
+"""Disassemble lldb's Driver::MainLoop() functions comparing lldb against gdb."""
+
+import os, sys
+import unittest2
+import lldb
+import pexpect
+from lldbbench import *
+
+class DisassembleDriverMainLoop(BenchBase):
+
+    mydir = os.path.join("benchmarks", "example")
+
+    def setUp(self):
+        BenchBase.setUp(self)
+        self.exe = self.lldbExec
+        self.function = 'Driver::MainLoop()'
+        self.lldb_avg = None
+        self.gdb_avg = None
+
+    @benchmarks_test
+    def test_run_lldb_then_gdb(self):
+        """Test disassembly on a large function with lldb vs. gdb."""
+        print
+        self.run_lldb_disassembly(self.exe, self.function, 5)
+        print "lldb benchmark:", self.stopwatch
+        self.run_gdb_disassembly(self.exe, self.function, 5)
+        print "gdb benchmark:", self.stopwatch
+        print "lldb_avg/gdb_avg: %f" % (self.lldb_avg/self.gdb_avg)
+
+    @benchmarks_test
+    def test_run_gdb_then_lldb(self):
+        """Test disassembly on a large function with lldb vs. gdb."""
+        print
+        self.run_gdb_disassembly(self.exe, self.function, 5)
+        print "gdb benchmark:", self.stopwatch
+        self.run_lldb_disassembly(self.exe, self.function, 5)
+        print "lldb benchmark:", self.stopwatch
+        print "lldb_avg/gdb_avg: %f" % (self.lldb_avg/self.gdb_avg)
+
+    def run_lldb_disassembly(self, exe, function, count):
+        # Set self.child_prompt, which is "(lldb) ".
+        self.child_prompt = '(lldb) '
+        prompt = self.child_prompt
+
+        # So that the child gets torn down after the test.
+        self.child = pexpect.spawn('%s %s' % (self.lldbExec, exe))
+        child = self.child
+
+        # Turn on logging for what the child sends back.
+        if self.TraceOn():
+            child.logfile_read = sys.stdout
+
+        child.expect_exact(prompt)
+        child.sendline('breakpoint set -F %s' % function)
+        child.expect_exact(prompt)
+        child.sendline('run')
+        child.expect_exact(prompt)
+
+        # Reset the stopwatch now.
+        self.stopwatch.reset()
+        for i in range(count):
+            with self.stopwatch:
+                # Disassemble the function.
+                child.sendline('disassemble -f')
+                child.expect_exact(prompt)
+            child.sendline('next')
+            child.expect_exact(prompt)
+
+        child.sendline('quit')
+        try:
+            self.child.expect(pexpect.EOF)
+        except:
+            pass
+
+        self.lldb_avg = self.stopwatch.avg()
+        if self.TraceOn():
+            print "lldb disassembly benchmark:", str(self.stopwatch)
+        self.child = None
+
+    def run_gdb_disassembly(self, exe, function, count):
+        # Set self.child_prompt, which is "(gdb) ".
+        self.child_prompt = '(gdb) '
+        prompt = self.child_prompt
+
+        # So that the child gets torn down after the test.
+        self.child = pexpect.spawn('gdb %s' % exe)
+        child = self.child
+
+        # Turn on logging for what the child sends back.
+        if self.TraceOn():
+            child.logfile_read = sys.stdout
+
+        child.expect_exact(prompt)
+        child.sendline('break %s' % function)
+        child.expect_exact(prompt)
+        child.sendline('run')
+        child.expect_exact(prompt)
+
+        # Reset the stopwatch now.
+        self.stopwatch.reset()
+        for i in range(count):
+            with self.stopwatch:
+                # Disassemble the function.
+                child.sendline('disassemble')
+                child.expect_exact(prompt)
+            child.sendline('next')
+            child.expect_exact(prompt)
+
+        child.sendline('quit')
+        child.expect_exact('The program is running.  Exit anyway?')
+        child.sendline('y')
+        try:
+            self.child.expect(pexpect.EOF)
+        except:
+            pass
+
+        self.gdb_avg = self.stopwatch.avg()
+        if self.TraceOn():
+            print "gdb disassembly benchmark:", str(self.stopwatch)
+        self.child = None
+
+
+if __name__ == '__main__':
+    import atexit
+    lldb.SBDebugger.Initialize()
+    atexit.register(lambda: lldb.SBDebugger.Terminate())
+    unittest2.main()