iterator when an optimization took place. This allows us to do more insane
things with the code than just remove an instruction or two.
llvm-svn: 113640
currently expect that to be useful for plugins, and this is important for
startup performance:
--
ddunbar@lordcrumb:tmp$ touch empty.c
ddunbar@lordcrumb:tmp$ runN 100 ~/llvm.obj.64/Release/bin/clang -c empty.c
name avg min med max SD total
user 0.0054 0.0052 0.0054 0.0055 0.0000 0.5350
sys 0.0084 0.0090 0.0078 0.0087 0.0008 0.8390
wall 0.0149 0.0149 0.0149 0.0149 0.0003 1.4943
ddunbar@lordcrumb:tmp$ runN 100 ~/llvm.obj.64/Release/bin/clang -c empty.c
name avg min med max SD total
user 0.0036 0.0036 0.0036 0.0038 0.0000 0.3646
sys 0.0072 0.0071 0.0068 0.0070 0.0006 0.7158
wall 0.0123 0.0123 0.0122 0.0136 0.0003 1.2262
--
llvm-svn: 113638
pointed out by Jim Ingham. The convenient one-liner specification should only
apply when there is only one breakpoint id being specified for the time being.
llvm-svn: 113609
up a seciton offset address (SBAddress) within a module that returns a
symbol context (SBSymbolContext). Also added a SBSymbolContextList in
preparation for adding find/lookup APIs that can return multiple results.
Added a lookup example code that shows how to do address lookups.
llvm-svn: 113599
command for a breakpoint, for example:
(lldb) breakpoint command add -p 1 "conditional_break.stop_if_called_from_a()"
The ScriptInterpreter interface has an extra method:
/// Set a one-liner as the callback for the breakpoint command.
virtual void
SetBreakpointCommandCallback (CommandInterpreter &interpreter,
BreakpointOptions *bp_options,
const char *oneliner);
to accomplish the above.
Also added a test case to demonstrate lldb's use of breakpoint callback command
to stop at function c() only when its immediate caller is function a(). The
following session shows the user entering the following commands:
1) command source .lldb (set up executable, breakpoint, and breakpoint command)
2) run (the callback mechanism will skip two breakpoints where c()'s immeidate caller is not a())
3) bt (to see that indeed c()'s immediate caller is a())
4) c (to continue and finish the program)
test/conditional_break $ ../../build/Debug/lldb
(lldb) command source .lldb
Executing commands in '.lldb'.
(lldb) file a.out
Current executable set to 'a.out' (x86_64).
(lldb) breakpoint set -n c
Breakpoint created: 1: name = 'c', locations = 1
(lldb) script import sys, os
(lldb) script sys.path.append(os.path.join(os.getcwd(), os.pardir))
(lldb) script import conditional_break
(lldb) breakpoint command add -p 1 "conditional_break.stop_if_called_from_a()"
(lldb) run
run
Launching '/Volumes/data/lldb/svn/trunk/test/conditional_break/a.out' (x86_64)
(lldb) Checking call frames...
Stack trace for thread id=0x2e03 name=None queue=com.apple.main-thread:
frame #0: a.out`c at main.c:39
frame #1: a.out`b at main.c:34
frame #2: a.out`a at main.c:25
frame #3: a.out`main at main.c:44
frame #4: a.out`start
c called from b
Continuing...
Checking call frames...
Stack trace for thread id=0x2e03 name=None queue=com.apple.main-thread:
frame #0: a.out`c at main.c:39
frame #1: a.out`b at main.c:34
frame #2: a.out`main at main.c:47
frame #3: a.out`start
c called from b
Continuing...
Checking call frames...
Stack trace for thread id=0x2e03 name=None queue=com.apple.main-thread:
frame #0: a.out`c at main.c:39
frame #1: a.out`a at main.c:27
frame #2: a.out`main at main.c:50
frame #3: a.out`start
c called from a
Stopped at c() with immediate caller as a().
a(1) returns 4
b(2) returns 5
Process 20420 Stopped
* thread #1: tid = 0x2e03, 0x0000000100000de8 a.out`c + 7 at main.c:39, stop reason = breakpoint 1.1, queue = com.apple.main-thread
36
37 int c(int val)
38 {
39 -> return val + 3;
40 }
41
42 int main (int argc, char const *argv[])
(lldb) bt
bt
thread #1: tid = 0x2e03, stop reason = breakpoint 1.1, queue = com.apple.main-thread
frame #0: 0x0000000100000de8 a.out`c + 7 at main.c:39
frame #1: 0x0000000100000dbc a.out`a + 44 at main.c:27
frame #2: 0x0000000100000e4b a.out`main + 91 at main.c:50
frame #3: 0x0000000100000d88 a.out`start + 52
(lldb) c
c
Resuming process 20420
Process 20420 Exited
a(3) returns 6
(lldb)
llvm-svn: 113596
The Unwind and RegisterContext subclasses still need
to be finished; none of this code is used by lldb at
this point (unless you call into it by hand).
The ObjectFile class now has an UnwindTable object.
The UnwindTable object has a series of FuncUnwinders
objects (Function Unwinders) -- one for each function
in that ObjectFile we've backtraced through during this
debug session.
The FuncUnwinders object has a few different UnwindPlans.
UnwindPlans are a generic way of describing how to find
the canonical address of a given function's stack frame
(the CFA idea from DWARF/eh_frame) and how to restore the
caller frame's register values, if they have been saved
by this function.
UnwindPlans are created from different sources. One source is the
eh_frame exception handling information generated by the compiler
for unwinding an exception throw. Another source is an assembly
language inspection class (UnwindAssemblyProfiler, uses the Plugin
architecture) which looks at the instructions in the funciton
prologue and describes the stack movements/register saves that are
done.
Two additional types of UnwindPlans that are worth noting are
the "fast" stack UnwindPlan which is useful for making a first
pass over a thread's stack, determining how many stack frames there
are and retrieving the pc and CFA values for each frame (enough
to create StackFrameIDs). Only a minimal set of registers is
recovered during a fast stack walk.
The final UnwindPlan is an architectural default unwind plan.
These are provided by the ArchDefaultUnwindPlan class (which uses
the plugin architecture). When no symbol/function address range can
be found for a given pc value -- when we have no eh_frame information
and when we don't have a start address so we can't examine the assembly
language instrucitons -- we have to make a best guess about how to
unwind. That's when we use the architectural default UnwindPlan.
On x86_64, this would be to assume that rbp is used as a stack pointer
and we can use that to find the caller's frame pointer and pc value.
It's a last-ditch best guess about how to unwind out of a frame.
There are heuristics about when to use one UnwindPlan versues the other --
this will all happen in the still-begin-written UnwindLLDB subclass of
Unwind which runs the UnwindPlans.
llvm-svn: 113581
Gabor Greif