[lldb] Introduce StackFrameRecognizer [take 3]

This patch introduces a concept of "frame recognizer" and "recognized frame". This should be an extensible mechanism that retrieves information about special frames based on ABI, arguments or other special properties of that frame, even without source code. A few examples where that could be useful could be 1) objc_exception_throw, where we'd like to get the current exception, 2) terminate_with_reason and extracting the current terminate string, 3) recognizing Objective-C frames and automatically extracting the receiver+selector, or perhaps all arguments (based on selector).

Differential Revision: https://reviews.llvm.org/D44603

llvm-svn: 345693

4 files changed, 161 insertions, 0 deletions

diff --git a/lldb/packages/Python/lldbsuite/test/functionalities/frame-recognizer/Makefile b/lldb/packages/Python/lldbsuite/test/functionalities/frame-recognizer/Makefile
new file mode 100644
index 00000000000..45f00b3e986
--- /dev/null
+++ b/lldb/packages/Python/lldbsuite/test/functionalities/frame-recognizer/Makefile
@@ -0,0 +1,10 @@
+LEVEL = ../../make
+
+OBJC_SOURCES := main.m
+
+CFLAGS_EXTRAS += -g0 # No debug info.
+MAKE_DSYM := NO
+
+include $(LEVEL)/Makefile.rules
+
+LDFLAGS += -framework Foundation
diff --git a/lldb/packages/Python/lldbsuite/test/functionalities/frame-recognizer/TestFrameRecognizer.py b/lldb/packages/Python/lldbsuite/test/functionalities/frame-recognizer/TestFrameRecognizer.py
new file mode 100644
index 00000000000..abd4ae8b382
--- /dev/null
+++ b/lldb/packages/Python/lldbsuite/test/functionalities/frame-recognizer/TestFrameRecognizer.py
@@ -0,0 +1,102 @@
+# encoding: utf-8
+"""
+Test lldb's frame recognizers.
+"""
+
+import lldb
+from lldbsuite.test.decorators import *
+from lldbsuite.test.lldbtest import *
+from lldbsuite.test import lldbutil
+
+import recognizer
+
+class FrameRecognizerTestCase(TestBase):
+
+    mydir = TestBase.compute_mydir(__file__)
+    NO_DEBUG_INFO_TESTCASE = True
+
+    @skipUnlessDarwin
+    def test_frame_recognizer_1(self):
+        self.build()
+
+        target = self.dbg.CreateTarget(self.getBuildArtifact("a.out"))
+        self.assertTrue(target, VALID_TARGET)
+
+        self.runCmd("command script import " + os.path.join(self.getSourceDir(), "recognizer.py"))
+
+        self.expect("frame recognizer list",
+                    substrs=['no matching results found.'])
+
+        self.runCmd("frame recognizer add -l recognizer.MyFrameRecognizer -s a.out -n foo")
+
+        self.expect("frame recognizer list",
+                    substrs=['0: recognizer.MyFrameRecognizer, module a.out, function foo'])
+
+        self.runCmd("frame recognizer add -l recognizer.MyOtherFrameRecognizer -s a.out -n bar -x")
+
+        self.expect("frame recognizer list",
+                    substrs=['0: recognizer.MyFrameRecognizer, module a.out, function foo',
+                             '1: recognizer.MyOtherFrameRecognizer, module a.out, function bar (regexp)'
+                    ])
+
+        self.runCmd("frame recognizer delete 0")
+
+        self.expect("frame recognizer list",
+                    substrs=['1: recognizer.MyOtherFrameRecognizer, module a.out, function bar (regexp)'])
+
+        self.runCmd("frame recognizer clear")
+
+        self.expect("frame recognizer list",
+                    substrs=['no matching results found.'])
+
+        self.runCmd("frame recognizer add -l recognizer.MyFrameRecognizer -s a.out -n foo")
+
+        lldbutil.run_break_set_by_symbol(self, "foo")
+        self.runCmd("r")
+
+        self.expect("thread list", STOPPED_DUE_TO_BREAKPOINT,
+                    substrs=['stopped', 'stop reason = breakpoint'])
+
+        process = target.GetProcess()
+        thread = process.GetSelectedThread()
+        frame = thread.GetSelectedFrame()
+
+        self.assertEqual(frame.GetSymbol().GetName(), "foo")
+        self.assertFalse(frame.GetLineEntry().IsValid())
+
+        self.expect("frame variable",
+                    substrs=['(int) a = 42', '(int) b = 56'])
+
+        opts = lldb.SBVariablesOptions();
+        opts.SetIncludeRecognizedArguments(True);
+        variables = frame.GetVariables(opts);
+
+        self.assertEqual(variables.GetSize(), 2)
+        self.assertEqual(variables.GetValueAtIndex(0).name, "a")
+        self.assertEqual(variables.GetValueAtIndex(0).signed, 42)
+        self.assertEqual(variables.GetValueAtIndex(1).name, "b")
+        self.assertEqual(variables.GetValueAtIndex(1).signed, 56)
+
+        self.expect("frame recognizer info 0",
+                    substrs=['frame 0 is recognized by recognizer.MyFrameRecognizer'])
+
+        self.expect("frame recognizer info 999", error=True,
+                    substrs=['no frame with index 999'])
+
+        self.expect("frame recognizer info 1",
+                    substrs=['frame 1 not recognized by any recognizer'])
+
+        # FIXME: The following doesn't work yet, but should be fixed.
+        """
+        lldbutil.run_break_set_by_symbol(self, "bar")
+        self.runCmd("c")
+
+        self.expect("thread list", STOPPED_DUE_TO_BREAKPOINT,
+                    substrs=['stopped', 'stop reason = breakpoint'])
+
+        self.expect("frame variable -t",
+                    substrs=['(int *) a = '])
+
+        self.expect("frame variable -t *a",
+                    substrs=['*a = 78'])
+        """
diff --git a/lldb/packages/Python/lldbsuite/test/functionalities/frame-recognizer/main.m b/lldb/packages/Python/lldbsuite/test/functionalities/frame-recognizer/main.m
new file mode 100644
index 00000000000..51103ae038a
--- /dev/null
+++ b/lldb/packages/Python/lldbsuite/test/functionalities/frame-recognizer/main.m
@@ -0,0 +1,28 @@
+//===-- main.m ------------------------------------------------*- ObjC -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#import <Foundation/Foundation.h>
+
+void foo(int a, int b)
+{
+    printf("%d %d\n", a, b);
+}
+
+void bar(int *ptr)
+{
+	printf("%d\n", *ptr);
+}
+
+int main (int argc, const char * argv[])
+{
+    foo(42, 56);
+    int i = 78;
+    bar(&i);
+    return 0;
+}
diff --git a/lldb/packages/Python/lldbsuite/test/functionalities/frame-recognizer/recognizer.py b/lldb/packages/Python/lldbsuite/test/functionalities/frame-recognizer/recognizer.py
new file mode 100644
index 00000000000..a8a50674511
--- /dev/null
+++ b/lldb/packages/Python/lldbsuite/test/functionalities/frame-recognizer/recognizer.py
@@ -0,0 +1,21 @@
+# encoding: utf-8
+
+import lldb
+
+class MyFrameRecognizer(object):
+    def get_recognized_arguments(self, frame):
+        if frame.name == "foo":
+            arg1 = frame.EvaluateExpression("$arg1").signed
+            arg2 = frame.EvaluateExpression("$arg2").signed
+            val1 = lldb.target.CreateValueFromExpression("a", "%d" % arg1)
+            val2 = lldb.target.CreateValueFromExpression("b", "%d" % arg2)
+            return [val1, val2]
+        elif frame.name == "bar":
+            arg1 = frame.EvaluateExpression("$arg1").signed
+            val1 = lldb.target.CreateValueFromExpression("a", "(int *)%d" % arg1)
+            return [val1]
+        return []
+
+class MyOtherFrameRecognizer(object):
+    def get_recognized_arguments(self, frame):
+        return []