Benchmark the turnaround time starting a debugger and run to the breakpoint with lldb vs. gdb.

An example (with /Developer/usr/bin/lldb vs. /usr/bin/gdb):

[13:05:04] johnny:/Volumes/data/lldb/svn/trunk/test $ ./dotest.py -v +b -n -p TestCompileRunToBreakpointTurnaround.py
1: test_run_lldb_then_gdb (TestCompileRunToBreakpointTurnaround.CompileRunToBreakpointBench)
   Benchmark turnaround time with lldb vs. gdb. ... 
lldb turnaround benchmark: Avg: 4.574600 (Laps: 3, Total Elapsed Time: 13.723799)
gdb turnaround benchmark: Avg: 7.966713 (Laps: 3, Total Elapsed Time: 23.900139)
lldb_avg/gdb_avg: 0.574214
ok

----------------------------------------------------------------------
Ran 1 test in 55.462s

OK

llvm-svn: 142949

lldb/test/benchmarks/turnaround/TestCompileRunToBreakpointTurnaround.py

@@ -0,0 +1,122 @@
+"""Benchmark the turnaround time starting a debugger and run to the breakpont with lldb vs. gdb."""
+
+import os, sys
+import unittest2
+import lldb
+import pexpect
+from lldbbench import *
+
+class CompileRunToBreakpointBench(BenchBase):
+
+    mydir = os.path.join("benchmarks", "turnaround")
+
+    def setUp(self):
+        BenchBase.setUp(self)
+        self.exe = self.lldbHere
+        self.function = 'Driver::MainLoop()'
+
+        self.count = lldb.bmIterationCount
+        if self.count <= 0:
+            self.count = 3
+
+        self.lldb_avg = None
+        self.gdb_avg = None
+
+    @benchmarks_test
+    def test_run_lldb_then_gdb(self):
+        """Benchmark turnaround time with lldb vs. gdb."""
+        print
+        self.run_lldb_turnaround(self.exe, self.function, self.count)
+        print "lldb turnaround benchmark:", self.stopwatch
+        self.run_gdb_turnaround(self.exe, self.function, self.count)
+        print "gdb turnaround benchmark:", self.stopwatch
+        print "lldb_avg/gdb_avg: %f" % (self.lldb_avg/self.gdb_avg)
+
+    def run_lldb_turnaround(self, exe, function, count):
+        def run_one_round():
+            prompt = self.child_prompt
+
+            # So that the child gets torn down after the test.
+            self.child = pexpect.spawn('%s %s %s' % (self.lldbExec, self.lldbOption, 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)
+
+        # Set self.child_prompt, which is "(lldb) ".
+        self.child_prompt = '(lldb) '
+        # Reset the stopwatch now.
+        self.stopwatch.reset()
+
+        for i in range(count + 1):
+            # Ignore the first invoke lldb and run to the breakpoint turnaround time.
+            if i == 0:
+                run_one_round()
+            else:
+                with self.stopwatch:
+                    run_one_round()
+
+            self.child.sendline('quit')
+            try:
+                self.child.expect(pexpect.EOF)
+            except:
+                pass
+
+        self.lldb_avg = self.stopwatch.avg()
+        self.child = None
+
+    def run_gdb_turnaround(self, exe, function, count):
+        def run_one_round():
+            prompt = self.child_prompt
+
+            # So that the child gets torn down after the test.
+            self.child = pexpect.spawn('gdb --nx %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)
+
+        # Set self.child_prompt, which is "(gdb) ".
+        self.child_prompt = '(gdb) '
+        # Reset the stopwatch now.
+        self.stopwatch.reset()
+
+        for i in range(count+1):
+            # Ignore the first invoke lldb and run to the breakpoint turnaround time.
+            if i == 0:
+                run_one_round()
+            else:
+                with self.stopwatch:
+                    run_one_round()
+
+            self.child.sendline('quit')
+            self.child.expect_exact('The program is running.  Exit anyway?')
+            self.child.sendline('y')
+            try:
+                self.child.expect(pexpect.EOF)
+            except:
+                pass
+
+        self.gdb_avg = self.stopwatch.avg()
+        self.child = None
+
+
+if __name__ == '__main__':
+    import atexit
+    lldb.SBDebugger.Initialize()
+    atexit.register(lambda: lldb.SBDebugger.Terminate())
+    unittest2.main()

lldb/test/dotest.py

@@ -666,18 +666,16 @@ def setupSysPath():
 
     if lldbHere:
         os.environ["LLDB_HERE"] = lldbHere
-        if not lldbExec:
-            lldbExec = lldbHere
-        os.environ["LLDB_BUILD_DIR"] = os.path.split(lldbExec)[0]
+        os.environ["LLDB_BUILD_DIR"] = os.path.split(lldbHere)[0]
         if not noHeaders:
             print "LLDB build dir:", os.environ["LLDB_BUILD_DIR"]
 
     # One last chance to locate the 'lldb' executable.
     if not lldbExec:
-        if lldbHere:
+        lldbExec = which('lldb')
+        if lldbHere and not lldbExec:
             lldbExec = lldbHere
-        else:
-            lldbExec = which('lldb')
+
 
     if not lldbExec:
         print "The 'lldb' executable cannot be located.  Some of the tests may not be run as a result."