Change Target::FindBreakpointsByName to return Expected<vector>

Summary:
Using a BreakpointList corrupts the breakpoints' IDs because
BreakpointList::Add sets the ID, so use a vector instead, and
update the signature to return the vector wrapped in an
llvm::Expected which can propagate any error from the inner
call to StringIsBreakpointName.

Note that, despite the similar name, SBTarget::FindBreakpointsByName
doesn't suffer the same problem, because it uses a SBBreakpointList,
which is more like a BreakpointIDList than a BreakpointList under the
covers.

Add a check to TestBreakpointNames that, without this fix, notices the
ID getting mutated and fails.

Reviewers: jingham, JDevlieghere

Reviewed By: JDevlieghere

Subscribers: lldb-commits

Tags: #lldb

Differential Revision: https://reviews.llvm.org/D70907

1 files changed, 11 insertions, 7 deletions

diff --git a/lldb/source/Breakpoint/BreakpointList.cpp b/lldb/source/Breakpoint/BreakpointList.cpp
index c80fb917b49..5b23c633d14 100644
--- a/lldb/source/Breakpoint/BreakpointList.cpp
+++ b/lldb/source/Breakpoint/BreakpointList.cpp
@@ -10,6 +10,8 @@
 
 #include "lldb/Target/Target.h"
 
+#include "llvm/Support/Errc.h"
+
 using namespace lldb;
 using namespace lldb_private;
 
@@ -128,22 +130,24 @@ BreakpointSP BreakpointList::FindBreakpointByID(break_id_t break_id) const {
   return {};
 }
 
-bool BreakpointList::FindBreakpointsByName(const char *name,
-                                           BreakpointList &matching_bps) {
-  Status error;
+llvm::Expected<std::vector<lldb::BreakpointSP>>
+BreakpointList::FindBreakpointsByName(const char *name) {
   if (!name)
-    return false;
+    return llvm::createStringError(llvm::errc::invalid_argument,
+                                   "FindBreakpointsByName requires a name");
 
+  Status error;
   if (!BreakpointID::StringIsBreakpointName(llvm::StringRef(name), error))
-    return false;
+    return error.ToError();
 
+  std::vector<lldb::BreakpointSP> matching_bps;
   for (BreakpointSP bkpt_sp : Breakpoints()) {
     if (bkpt_sp->MatchesName(name)) {
-      matching_bps.Add(bkpt_sp, false);
+      matching_bps.push_back(bkpt_sp);
     }
   }
 
-  return true;
+  return matching_bps;
 }
 
 void BreakpointList::Dump(Stream *s) const {