Variable resolves

tests/inferior.c

@@ -2,6 +2,8 @@
 #include <stdio.h>
 #include <string.h>
 
+int global = 0xfeedface;
+
 void test_function()
 {
     printf("*** test_function()\n");

tests/lldb_api_tests.py

@@ -126,6 +126,21 @@ def test_command():
         assert 'rax' in output
         process.Destroy()
 
+    def test_resolve_variable():
+        process = target.LaunchSimple(None, None, os.getcwd())
+        output = adaptor.resolve_variable("global")
+        assert output.load_addr > 0
+        output = adaptor.resolve_variable("nonexistant")
+        assert output is None
+        process.Destroy()
+
+    def test_deref_variable():
+        process = target.LaunchSimple(None, None, os.getcwd())
+        output = adaptor.resolve_variable("global")
+        value = adaptor.read_pointer(output)
+        assert value == 0xfeedface
+        process.Destroy()
+
     def test_dereference_main():
         process = target.LaunchSimple(None, None, os.getcwd())
         regs = adaptor.registers()
@@ -162,4 +177,4 @@ def test_capabilities():
         assert adaptor.capabilities() == ['async']
 
 except:
-    print("No LLDB")
+    print("No LLDB")

voltron/plugins/debugger/dbg_lldb.py

@@ -265,6 +265,23 @@ def program_counter(self, target_id=0, thread_id=None):
 
             return (pc_name, pc)
 
+        @validate_busy
+        @validate_target
+        @lock_host
+        def resolve_variable(self, symbol, target_id=0):
+            """
+            Resolve a symbol, returning an SBValue if found, or None if not located.
+            """
+            target = self.host.GetTargetAtIndex(target_id)
+            # Send some absurd upper bound on matches
+            candidates = target.FindGlobalVariables(symbol, 256)
+            if len(candidates) == 0:
+                return None
+            elif len(candidates) != 1:
+                raise RuntimeError("Found more than 1 location for {}".format(symbol))
+            else:
+                return candidates[0]
+
         @validate_busy
         @validate_target
         @lock_host
@@ -330,6 +347,29 @@ def disassemble(self, target_id=0, address=None, count=None):
 
             return output
 
+        @validate_busy
+        @validate_target
+        @lock_host
+        def read_pointer(self, pointer, target_id=0):
+            """Read process memory at *pointer* returning the value pointed to.
+
+            if *pointer* is an SBValue it will automatically be lowered to an
+            address, otherwise pointer is assumed to be an *int* of pointer
+            width on the target platform
+            """
+            t = self.host.GetTargetAtIndex(target_id)
+            error = lldb.SBError()
+            if isinstance(pointer, lldb.SBValue):
+                # For convenience, do something reasonable if you hand in an
+                # SBValue, as retrieved by resolve_function, but default to
+                # doing the right thing when handed an address
+                pointer = pointer.load_addr
+            ptr = t.process.ReadPointerFromMemory(pointer, error)
+            if not error.Success():
+                raise Exception("Failed reading memory: {}".format(error.GetCString()))
+            return ptr
+
+
         @validate_busy
         @validate_target
         @lock_host