MIEngine: Fix multi-breakpoint gdb/mi information parsing (#1435)

This PR fixes gdb/mi breakpoint information parsing for breakpoints
that bind to multiple locations, which have a '<MULTIPLE>' in the addr field.
According to https://sourceware.org/gdb/onlinedocs/gdb/GDB_002fMI-Breakpoint-Information.html#GDB_002fMI-Breakpoint-Information
the locations field contains the list of locations for this breakpoint type.
This list of locations is used then to create the bound breakpoints for the specific breakpoint.

Signed-off-by: Andria Pazarloglou <[email protected]>

src/MIDebugEngine/Engine.Impl/BreakpointManager.cs

@@ -58,20 +58,13 @@ public async Task BreakpointModified(object sender, EventArgs args)
             string bkptId = null;
             //
             // =breakpoint-modified,
-            //    bkpt ={number="2",type="breakpoint",disp="keep",enabled="y",addr="<MULTIPLE>",times="0",original-location="main.cpp:220"},
+            //    bkpt ={number="2",type="breakpoint",disp="keep",enabled="y",addr="<MULTIPLE>",times="0",original-location="main.cpp:220"},locations=[
             //          { number="2.1",enabled="y",addr="0x9c2149a9",func="Foo::bar<int>(int)",file="main.cpp",fullname="C:\\\\...\\\\main.cpp",line="220",thread-groups=["i1"]},
-            //          { number="2.2",enabled="y",addr="0x9c2149f2",func="Foo::bar<float>(float)",file="main.cpp",fullname="C:\\\\...\\\\main.cpp",line="220",thread-groups=["i1"]}
+            //          { number="2.2",enabled="y",addr="0x9c2149f2",func="Foo::bar<float>(float)",file="main.cpp",fullname="C:\\\\...\\\\main.cpp",line="220",thread-groups=["i1"]}]}
             // note: the ".x" part of the breakpoint number never appears in stopping events, that is, when executing at one of these addresses 
             //       the stopping event delivered contains bkptno="2"
-            if (bkpt is MICore.ValueListValue)
-            {
-                MICore.ValueListValue list = bkpt as MICore.ValueListValue;
-                bkptId = list.Content[0].FindString("number"); // 0 is the "<MULTIPLE>" entry
-            }
-            else
-            {
-                bkptId = bkpt.FindString("number");
-            }
+            bkptId = bkpt.FindString("number");
+
             AD7PendingBreakpoint pending = CodeBreakpoints.FirstOrDefault((p) => { return p.BreakpointId == bkptId; });
             if (pending == null)
             {

src/MIDebugEngine/Engine.Impl/Breakpoints.cs

@@ -146,12 +146,11 @@ private static async Task<BindResult> EvalBindResult(Results bindResult, AD7Pend
                 if (b is TupleValue)
                 {
                     bkpt = b as TupleValue;
-                }
-                else if (b is ValueListValue)
-                {
-                    // "<MULTIPLE>" sometimes includes a list of bound breakpoints
-                    list = b as ValueListValue;
-                    bkpt = list.Content[0] as TupleValue;
+                    // The locations field is present if the breakpoint has multiple locations.
+                    if (b.TryFind("locations", out var locations) && locations is ValueListValue)
+                    {
+                        list = (ValueListValue) locations;
+                    }
                 }
             }
             else
@@ -189,9 +188,9 @@ private static async Task<BindResult> EvalBindResult(Results bindResult, AD7Pend
             else   // <MULTIPLE> with list of addresses
             {
                 BindResult res = new BindResult(bp);
-                for (int i = 1; i < list.Content.Length; ++i)
+                foreach (var t in list.Content)
                 {
-                    BoundBreakpoint bbp = await bp.GetBoundBreakpoint(list.Content[i] as TupleValue);
+                    BoundBreakpoint bbp = await bp.GetBoundBreakpoint(t as TupleValue);
                     res.BoundBreakpoints.Add(bbp);
                 }
                 return res;
@@ -290,12 +289,13 @@ internal async Task<List<BoundBreakpoint>> BindAddresses(ResultValue bkpt)
                 return resultList;
             }
             BoundBreakpoint bbp = null;
-            if (bkpt is ValueListValue)
+
+            // The locations field is present if the breakpoint has multiple locations.
+            if (bkpt.TryFind("locations", out var locations) && locations is ValueListValue list)
             {
-                var list = (ValueListValue)bkpt;
-                for (int i = 1; i < list.Content.Length; ++i)
+                foreach (var t in list.Content)
                 {
-                    bbp = await GetBoundBreakpoint(list.Content[i] as TupleValue);
+                    bbp = await GetBoundBreakpoint(t as TupleValue);
                     if (bbp != null)
                         resultList.Add(bbp);
                 }

test/CppTests/Tests/BreakpointTests.cs

@@ -125,7 +125,7 @@ public void FunctionBreakpointsBasic(ITestSettings settings)
                 runner.Launch(settings.DebuggerSettings, debuggee, "-fCalling");
 
                 this.Comment("Set initial function breakpoints");
-                FunctionBreakpoints functionBreakpoints = new FunctionBreakpoints("Arguments::CoreRun", "Calling::CoreRun", "a()");
+                FunctionBreakpoints functionBreakpoints = new FunctionBreakpoints("Arguments::CoreRun", "Calling::CoreRun", "a");
                 runner.SetFunctionBreakpoints(functionBreakpoints);
 
                 this.Comment("Launch and run until first initial breakpoint");
@@ -137,7 +137,7 @@ public void FunctionBreakpointsBasic(ITestSettings settings)
                               .AfterContinue();
 
                 this.Comment("Remove and replace third initial function breakpoint while in break mode");
-                functionBreakpoints.Remove("a()");
+                functionBreakpoints.Remove("a");
                 functionBreakpoints.Add("b()");
                 runner.SetFunctionBreakpoints(functionBreakpoints);
 

test/CppTests/debuggees/kitchensink/src/calling.cpp

@@ -52,4 +52,10 @@ void Calling::CoreRun()
     this->Log("Calling variable arg function.");
     double ave = average(10, 1.0, 3.0, 4.5, 11.0, -30.0, 17.4, 2.1, -4.0, 0.0, 12.1);
     this->Log("Average ", ave);
+}
+
+int a(int count)
+{
+    b();
+    return count - 1;
 }