Add an accompanying option to the 'frame variable -w' command to, instead of watching the variable,

watch the location pointed to by the variable.  An example,

(lldb) frame variable -w write -x 1 -g g_char_ptr
(char *) g_char_ptr = 0x0000000100100860 ""...
Watchpoint created: WatchpointLocation 1: addr = 0x100100860 size = 1 state = enabled type = w
    declare @ '/Volumes/data/lldb/svn/trunk/test/functionalities/watchpoint/hello_watchlocation/main.cpp:21'

...

(lldb) c
Process 3936 resuming

...

rocess 3936 stopped
* thread #2: tid = 0x3403, 0x00000001000009b7 a.out`do_bad_thing_with_location(char*, char) + 23 at main.cpp:27, stop reason = watchpoint 1
    frame #0: 0x00000001000009b7 a.out`do_bad_thing_with_location(char*, char) + 23 at main.cpp:27
   24  	do_bad_thing_with_location(char *char_ptr, char new_val)
   25  	{
   26  	    *char_ptr = new_val;
-> 27  	}
   28  	
   29  	uint32_t access_pool (uint32_t flag = 0);
   30  	
(lldb) 

Also add TestWatchLocation.py test to exercise this functionality.

llvm-svn: 140836

1 files changed, 14 insertions, 6 deletions

diff --git a/lldb/source/Commands/CommandObjectFrame.cpp b/lldb/source/Commands/CommandObjectFrame.cpp
index 4790eef4cde..288a5ea1b7d 100644
--- a/lldb/source/Commands/CommandObjectFrame.cpp
+++ b/lldb/source/Commands/CommandObjectFrame.cpp
@@ -436,7 +436,7 @@ public:
                 }
 
                 // Things have checked out ok...
-                // m_option_watchpoint.watch_mode specifies the mode for watching.
+                // m_option_watchpoint.watch_type specifies the type of watching.
             }
             if (command.GetArgumentCount() > 0)
             {
@@ -532,12 +532,20 @@ public:
                             if (m_option_watchpoint.watch_variable)
                             {
                                 AddressType addr_type;
-                                lldb::addr_t addr = valobj_sp->GetAddressOf(false, &addr_type);
+                                lldb::addr_t addr = 0;
                                 size_t size = 0;
-                                if (addr_type == eAddressTypeLoad) {
-                                    // We're in business.
-                                    // Find out the size of this variable.
-                                    size = valobj_sp->GetByteSize();
+                                if (m_option_watchpoint.watch_size == 0) {
+                                    addr = valobj_sp->GetAddressOf(false, &addr_type);
+                                    if (addr_type == eAddressTypeLoad) {
+                                        // We're in business.
+                                        // Find out the size of this variable.
+                                        size = valobj_sp->GetByteSize();
+                                    }
+                                } else {
+                                    // The '-xsize'/'-x' option means to treat the value object as
+                                    // a pointer and to watch the pointee with the specified size.
+                                    addr = valobj_sp->GetValueAsUnsigned(0);
+                                    size = m_option_watchpoint.watch_size;
                                 }
                                 uint32_t watch_type = m_option_watchpoint.watch_type;
                                 WatchpointLocation *wp_loc = exe_ctx.GetTargetRef().CreateWatchpointLocation(addr, size, watch_type).get();