[lldb] Define breakpoint location "." to mean the location(s) at which the current thread is stopped (#194272)

lldb/include/lldb/Breakpoint/BreakpointIDList.h

@@ -50,10 +50,9 @@ class BreakpointIDList {
   static std::pair<llvm::StringRef, llvm::StringRef>
   SplitIDRangeExpression(llvm::StringRef in_string);
 
-  static llvm::Error
-  FindAndReplaceIDRanges(Args &old_args, Target *target, bool allow_locations,
-                         BreakpointName::Permissions ::PermissionKinds purpose,
-                         Args &new_args);
+  static llvm::Error FindAndReplaceIDRanges(
+      Args &old_args, ExecutionContext &exe_ctx, bool allow_locations,
+      BreakpointName::Permissions ::PermissionKinds purpose, Args &new_args);
 
 private:
   BreakpointIDArray m_breakpoint_ids;

lldb/source/Breakpoint/BreakpointIDList.cpp

@@ -11,9 +11,13 @@
 
 #include "lldb/Breakpoint/Breakpoint.h"
 #include "lldb/Breakpoint/BreakpointLocation.h"
+#include "lldb/Target/ExecutionContext.h"
+#include "lldb/Target/StopInfo.h"
 #include "lldb/Target/Target.h"
+#include "lldb/Target/Thread.h"
 #include "lldb/Utility/Args.h"
 #include "lldb/Utility/StreamString.h"
+#include "lldb/lldb-forward.h"
 
 #include "llvm/ADT/STLExtras.h"
 #include "llvm/ADT/StringRef.h"
@@ -55,6 +59,16 @@ bool BreakpointIDList::Contains(BreakpointID bp_id) const {
   return llvm::is_contained(m_breakpoint_ids, bp_id);
 }
 
+static std::string LocationIDForStop(StopInfoSP stop_info_sp, uint32_t idx) {
+  assert(stop_info_sp->GetStopReason() == lldb::eStopReasonBreakpoint &&
+         "expected breakpoint stop");
+  break_id_t bp_id = stop_info_sp->GetStopReasonDataAtIndex(idx);
+  break_id_t loc_id = stop_info_sp->GetStopReasonDataAtIndex(idx + 1);
+  StreamString stream;
+  BreakpointID::GetCanonicalReference(&stream, bp_id, loc_id);
+  return stream.GetString().str();
+}
+
 //  This function takes OLD_ARGS, which is usually the result of breaking the
 //  command string arguments into
 //  an array of space-separated strings, and searches through the arguments for
@@ -69,8 +83,9 @@ bool BreakpointIDList::Contains(BreakpointID bp_id) const {
 //  by the members of the range.
 
 llvm::Error BreakpointIDList::FindAndReplaceIDRanges(
-    Args &old_args, Target *target, bool allow_locations,
+    Args &old_args, ExecutionContext &exe_ctx, bool allow_locations,
     BreakpointName::Permissions ::PermissionKinds purpose, Args &new_args) {
+  Target *target = exe_ctx.GetTargetPtr();
   llvm::StringRef range_from;
   llvm::StringRef range_to;
   llvm::StringRef current_arg;
@@ -80,6 +95,30 @@ llvm::Error BreakpointIDList::FindAndReplaceIDRanges(
     bool is_range = false;
 
     current_arg = old_args[i].ref();
+
+    if (allow_locations && current_arg == ".") {
+      Thread *thread = exe_ctx.GetThreadPtr();
+      if (!thread) {
+        new_args.Clear();
+        return llvm::createStringError("no current thread");
+      }
+      StopInfoSP stop_info_sp = thread->GetStopInfo();
+      if (!stop_info_sp ||
+          stop_info_sp->GetStopReason() != eStopReasonBreakpoint) {
+        new_args.Clear();
+        return llvm::createStringError(
+            "current thread is not stopped at a breakpoint");
+      }
+
+      uint32_t data_count = stop_info_sp->GetStopReasonDataCount();
+      for (uint32_t j = 0; j < data_count; j += 2) {
+        std::string location_id = LocationIDForStop(stop_info_sp, j);
+        new_args.AppendArgument(location_id);
+      }
+
+      continue;
+    }
+
     if (!allow_locations && current_arg.contains('.')) {
       new_args.Clear();
       return llvm::createStringError(

lldb/source/Commands/CommandObjectBreakpoint.cpp

@@ -2075,7 +2075,7 @@ class CommandObjectBreakpointModify : public CommandObjectParsed {
     BreakpointIDList valid_bp_ids;
 
     CommandObjectMultiwordBreakpoint::VerifyBreakpointOrLocationIDs(
-        command, target, result, &valid_bp_ids,
+        command, m_exe_ctx, result, &valid_bp_ids,
         BreakpointName::Permissions::PermissionKinds::disablePerm);
 
     if (result.Succeeded()) {
@@ -2156,7 +2156,7 @@ class CommandObjectBreakpointEnable : public CommandObjectParsed {
       // Particular breakpoint selected; enable that breakpoint.
       BreakpointIDList valid_bp_ids;
       CommandObjectMultiwordBreakpoint::VerifyBreakpointOrLocationIDs(
-          command, target, result, &valid_bp_ids,
+          command, m_exe_ctx, result, &valid_bp_ids,
           BreakpointName::Permissions::PermissionKinds::disablePerm);
 
       if (result.Succeeded()) {
@@ -2265,7 +2265,7 @@ the second re-enables the first location.");
       BreakpointIDList valid_bp_ids;
 
       CommandObjectMultiwordBreakpoint::VerifyBreakpointOrLocationIDs(
-          command, target, result, &valid_bp_ids,
+          command, m_exe_ctx, result, &valid_bp_ids,
           BreakpointName::Permissions::PermissionKinds::disablePerm);
 
       if (result.Succeeded()) {
@@ -2412,7 +2412,7 @@ class CommandObjectBreakpointList : public CommandObjectParsed {
       // Particular breakpoints selected; show info about that breakpoint.
       BreakpointIDList valid_bp_ids;
       CommandObjectMultiwordBreakpoint::VerifyBreakpointOrLocationIDs(
-          command, target, result, &valid_bp_ids,
+          command, m_exe_ctx, result, &valid_bp_ids,
           BreakpointName::Permissions::PermissionKinds::listPerm);
 
       if (result.Succeeded()) {
@@ -2691,7 +2691,7 @@ class CommandObjectBreakpointDelete : public CommandObjectParsed {
 
       if (!command.empty()) {
         CommandObjectMultiwordBreakpoint::VerifyBreakpointOrLocationIDs(
-            command, target, result, &excluded_bp_ids,
+            command, m_exe_ctx, result, &excluded_bp_ids,
             BreakpointName::Permissions::PermissionKinds::deletePerm);
         if (!result.Succeeded())
           return;
@@ -2710,7 +2710,7 @@ class CommandObjectBreakpointDelete : public CommandObjectParsed {
       }
     } else {
       CommandObjectMultiwordBreakpoint::VerifyBreakpointOrLocationIDs(
-          command, target, result, &valid_bp_ids,
+          command, m_exe_ctx, result, &valid_bp_ids,
           BreakpointName::Permissions::PermissionKinds::deletePerm);
       if (!result.Succeeded())
         return;
@@ -3021,7 +3021,7 @@ class CommandObjectBreakpointNameAdd : public CommandObjectParsed {
     // Particular breakpoint selected; disable that breakpoint.
     BreakpointIDList valid_bp_ids;
     CommandObjectMultiwordBreakpoint::VerifyBreakpointIDs(
-        command, target, result, &valid_bp_ids,
+        command, m_exe_ctx, result, &valid_bp_ids,
         BreakpointName::Permissions::PermissionKinds::listPerm);
 
     if (result.Succeeded()) {
@@ -3095,7 +3095,7 @@ class CommandObjectBreakpointNameDelete : public CommandObjectParsed {
     // Particular breakpoint selected; disable that breakpoint.
     BreakpointIDList valid_bp_ids;
     CommandObjectMultiwordBreakpoint::VerifyBreakpointIDs(
-        command, target, result, &valid_bp_ids,
+        command, m_exe_ctx, result, &valid_bp_ids,
         BreakpointName::Permissions::PermissionKinds::deletePerm);
 
     if (result.Succeeded()) {
@@ -3568,7 +3568,7 @@ class CommandObjectBreakpointWrite : public CommandObjectParsed {
     BreakpointIDList valid_bp_ids;
     if (!command.empty()) {
       CommandObjectMultiwordBreakpoint::VerifyBreakpointIDs(
-          command, target, result, &valid_bp_ids,
+          command, m_exe_ctx, result, &valid_bp_ids,
           BreakpointName::Permissions::PermissionKinds::listPerm);
 
       if (!result.Succeeded()) {
@@ -3654,7 +3654,7 @@ CommandObjectMultiwordBreakpoint::CommandObjectMultiwordBreakpoint(
 CommandObjectMultiwordBreakpoint::~CommandObjectMultiwordBreakpoint() = default;
 
 void CommandObjectMultiwordBreakpoint::VerifyIDs(
-    Args &args, Target &target, bool allow_locations,
+    Args &args, ExecutionContext &exe_ctx, bool allow_locations,
     CommandReturnObject &result, BreakpointIDList *valid_ids,
     BreakpointName::Permissions ::PermissionKinds purpose) {
   // args can be strings representing 1). integers (for breakpoint ids)
@@ -3668,6 +3668,7 @@ void CommandObjectMultiwordBreakpoint::VerifyIDs(
   // If args is empty, we will use the last created breakpoint (if there is
   // one.)
 
+  Target &target = exe_ctx.GetTargetRef();
   Args temp_args;
 
   if (args.empty()) {
@@ -3689,7 +3690,7 @@ void CommandObjectMultiwordBreakpoint::VerifyIDs(
   // into TEMP_ARGS.
 
   if (llvm::Error err = BreakpointIDList::FindAndReplaceIDRanges(
-          args, &target, allow_locations, purpose, temp_args)) {
+          args, exe_ctx, allow_locations, purpose, temp_args)) {
     result.SetError(std::move(err));
     return;
   }

lldb/source/Commands/CommandObjectBreakpoint.h

@@ -23,22 +23,22 @@ class CommandObjectMultiwordBreakpoint : public CommandObjectMultiword {
   ~CommandObjectMultiwordBreakpoint() override;
 
   static void VerifyBreakpointOrLocationIDs(
-      Args &args, Target &target, CommandReturnObject &result,
+      Args &args, ExecutionContext &exe_ctx, CommandReturnObject &result,
       BreakpointIDList *valid_ids,
       BreakpointName::Permissions ::PermissionKinds purpose) {
-    VerifyIDs(args, target, true, result, valid_ids, purpose);
+    VerifyIDs(args, exe_ctx, true, result, valid_ids, purpose);
   }
 
   static void
-  VerifyBreakpointIDs(Args &args, Target &target, CommandReturnObject &result,
-                      BreakpointIDList *valid_ids,
+  VerifyBreakpointIDs(Args &args, ExecutionContext &exe_ctx,
+                      CommandReturnObject &result, BreakpointIDList *valid_ids,
                       BreakpointName::Permissions::PermissionKinds purpose) {
-    VerifyIDs(args, target, false, result, valid_ids, purpose);
+    VerifyIDs(args, exe_ctx, false, result, valid_ids, purpose);
   }
 
 private:
-  static void VerifyIDs(Args &args, Target &target, bool allow_locations,
-                        CommandReturnObject &result,
+  static void VerifyIDs(Args &args, ExecutionContext &exe_ctx,
+                        bool allow_locations, CommandReturnObject &result,
                         BreakpointIDList *valid_ids,
                         BreakpointName::Permissions::PermissionKinds purpose);
 };

lldb/source/Commands/CommandObjectBreakpointCommand.cpp

@@ -344,7 +344,7 @@ are no syntax errors may indicate that a function was declared but never called.
 
     BreakpointIDList valid_bp_ids;
     CommandObjectMultiwordBreakpoint::VerifyBreakpointOrLocationIDs(
-        command, target, result, &valid_bp_ids,
+        command, m_exe_ctx, result, &valid_bp_ids,
         BreakpointName::Permissions::PermissionKinds::listPerm);
 
     m_bp_options_vec.clear();
@@ -500,7 +500,7 @@ class CommandObjectBreakpointCommandDelete : public CommandObjectParsed {
 
     BreakpointIDList valid_bp_ids;
     CommandObjectMultiwordBreakpoint::VerifyBreakpointOrLocationIDs(
-        command, target, result, &valid_bp_ids,
+        command, m_exe_ctx, result, &valid_bp_ids,
         BreakpointName::Permissions::PermissionKinds::listPerm);
 
     if (result.Succeeded()) {
@@ -567,7 +567,7 @@ class CommandObjectBreakpointCommandList : public CommandObjectParsed {
 
     BreakpointIDList valid_bp_ids;
     CommandObjectMultiwordBreakpoint::VerifyBreakpointOrLocationIDs(
-        command, target, result, &valid_bp_ids,
+        command, m_exe_ctx, result, &valid_bp_ids,
         BreakpointName::Permissions::PermissionKinds::listPerm);
 
     if (result.Succeeded()) {

lldb/source/Commands/CommandObjectProcess.cpp

@@ -534,7 +534,7 @@ class CommandObjectProcessContinue : public CommandObjectParsed {
       // default breakpoint.
       if (m_options.m_run_to_bkpt_args.GetArgumentCount() > 0)
         CommandObjectMultiwordBreakpoint::VerifyBreakpointOrLocationIDs(
-            m_options.m_run_to_bkpt_args, target, result, &run_to_bkpt_ids,
+            m_options.m_run_to_bkpt_args, m_exe_ctx, result, &run_to_bkpt_ids,
             BreakpointName::Permissions::disablePerm);
       if (!result.Succeeded()) {
         return;

lldb/source/Commands/CommandOptionArgumentTable.cpp

@@ -49,7 +49,10 @@ llvm::StringRef BreakpointIDHelpTextCallback() {
          "major "
          "number, or the major number followed by a dot and the location "
          "number (e.g. "
-         "3 or 3.2 could both be valid breakpoint IDs.)";
+         "3 or 3.2 could both be valid breakpoint IDs.)\n"
+         "\n"
+         "You can use . to refer to the breakpoint location(s) at which the "
+         "current thread is stopped.";
 }
 
 llvm::StringRef BreakpointIDRangeHelpTextCallback() {

lldb/test/API/commands/breakpoint/location-dot/Makefile

@@ -0,0 +1,3 @@
+C_SOURCES := main.c
+
+include Makefile.rules

lldb/test/API/commands/breakpoint/location-dot/TestBreakpointLocationDot.py

@@ -0,0 +1,51 @@
+import lldb
+from lldbsuite.test.lldbtest import TestBase
+from lldbsuite.test import lldbutil
+
+
+class TestCase(TestBase):
+    def test_disable_enable(self):
+        self.build()
+        _, _, _, bp = lldbutil.run_to_source_breakpoint(
+            self, "break here", lldb.SBFileSpec("main.c")
+        )
+
+        self.assertTrue(bp.FindLocationByID(1).IsEnabled())
+        self.expect("breakpoint disable .", startstr="1 breakpoints disabled.")
+        self.assertFalse(bp.FindLocationByID(1).IsEnabled())
+        self.expect("breakpoint enable .", startstr="1 breakpoints enabled.")
+        self.assertTrue(bp.FindLocationByID(1).IsEnabled())
+
+    def test_delete(self):
+        self.build()
+        _, _, _, bp = lldbutil.run_to_source_breakpoint(
+            self, "break here", lldb.SBFileSpec("main.c")
+        )
+
+        self.expect(
+            "breakpoint delete .",
+            startstr="0 breakpoints deleted; 1 breakpoint locations disabled",
+        )
+        self.assertFalse(bp.FindLocationByID(1).IsEnabled())
+
+    def test_error_not_breakpoint_stop(self):
+        self.build()
+        _, _, thread, bp = lldbutil.run_to_source_breakpoint(
+            self, "break here", lldb.SBFileSpec("main.c")
+        )
+
+        self.assertTrue(bp.FindLocationByID(1).IsEnabled())
+        thread.StepOver()
+        self.assertNotEqual(thread.stop_reason, lldb.eStopReasonBreakpoint)
+        self.expect(
+            "breakpoint disable .",
+            error=True,
+            startstr="error: current thread is not stopped at a breakpoint",
+        )
+        self.assertTrue(bp.FindLocationByID(1).IsEnabled())
+
+    def test_error_no_process(self):
+        self.build()
+        target = self.createTestTarget()
+        target.BreakpointCreateByLocation("main.c", 2)
+        self.expect("breakpoint disable .", error=True, substrs=["no current thread"])

lldb/test/API/commands/breakpoint/location-dot/main.c

@@ -0,0 +1,5 @@
+int main() {
+  int x = 1; // break here
+  int y = 2;
+  return x + y;
+}