Feature: allow user to specify search areas (#1259)

src/Decompiler/Scanning/StringFinder.cs

@@ -43,14 +43,8 @@ public StringFinder(Program program)
 
         public IEnumerable<AddressSearchHit> FindStrings(StringFinderCriteria criteria)
         {
-            foreach (var segment in program.SegmentMap.Segments.Values)
+            foreach (var rdr in GenerateReaders(program, criteria))
             {
-                if (segment.MemoryArea is not ByteMemoryArea mem)
-                    continue; //$TODO: what to do with odd archs?
-                Address segEnd = Address.Min(
-                    segment.Address + segment.Size,
-                    segment.MemoryArea.BaseAddress + mem.Bytes.Length);
-                var rdr = criteria.CreateReader(mem, segment.Address, segEnd);
                 Address? addrStartRun = null;
                 int cValid = 0;
                 var charType = (PrimitiveType)criteria.StringType.ElementType;
@@ -76,6 +70,36 @@ public IEnumerable<AddressSearchHit> FindStrings(StringFinderCriteria criteria)
             }
         }
 
+        private IEnumerable<EndianImageReader> GenerateReaders(Program program, StringFinderCriteria criteria)
+        {
+            if (criteria.Areas is null || criteria.Areas.Count == 0)
+            {
+                foreach (var segment in program.SegmentMap.Segments.Values)
+                {
+                    if (segment.MemoryArea is not ByteMemoryArea mem)
+                        continue; //$TODO: what to do with odd archs?
+                    Address segEnd = Address.Min(
+                        segment.Address + segment.Size,
+                        segment.MemoryArea.BaseAddress + mem.Bytes.Length);
+                    var rdr = criteria.CreateReader(mem, segment.Address, segment.Size);
+                    yield return rdr;
+                }
+            }
+            else
+            {
+                foreach (var area in criteria.Areas)
+                {
+                    if (area.Program.SegmentMap.TryFindSegment(area.Address, out var segment) &&
+                        segment.MemoryArea is ByteMemoryArea mem)
+                    {
+                        var rdr = criteria.CreateReader(mem, area.Address, area.Length);
+                        yield return rdr;
+                    }
+                }
+            }
+        }
+
+
         //$TODO: This assumes only ASCII values are valid.
         // How to deal with Swedish? Cyrillic? Chinese?
         // Added common escaped characters for C strings.
@@ -89,5 +113,6 @@ public record StringFinderCriteria(
         StringType StringType,
         Encoding Encoding,
         int MinimumLength,
-        Func<ByteMemoryArea, Address, Address, EndianImageReader> CreateReader);
+        List<ProgramAddressRange>? Areas, // Optional search areas; null means search entire program image.
+        Func<ByteMemoryArea, Address, long, EndianImageReader> CreateReader);
 }

src/Gui/AddressSearchResult.cs

@@ -206,6 +206,7 @@ public async virtual ValueTask<bool> ExecuteAsync(CommandID cmdID)
                 StringType.NullTerminated(PrimitiveType.Char),
                 Encoding.ASCII,
                 0,
+                null,
                 default!));
                 View.Invalidate(); break;
             case CmdIds.ViewAsData: details = new DataSearchDetails(); View.Invalidate(); break;

src/Gui/Forms/MainFormInteractor.cs

@@ -333,6 +333,12 @@ private void SelectProgram(Program? program = null)
             svc.SelectedProgram = program;
         }
 
+        private Program? SelectedProgram()
+        {
+            var svc = Services.RequireService<ISelectedAddressService>();
+            return svc.SelectedProgram;
+        }
+
         /// <summary>
         /// Prompts the user for a metadata file and adds to the project.
         /// </summary>
@@ -721,17 +727,17 @@ public void FindProcedures(ISearchResultService svc)
 
         public async ValueTask FindStrings(ISearchResultService srSvc)
         {
-            using (var dlgStrings = dlgFactory.CreateFindStringDialog())
+            var program = SelectedProgram();
+            if (program is null)
+                return;
+            using var dlgStrings = dlgFactory.CreateFindStringDialog(program);
+            var criteria = await uiSvc.ShowModalDialog(dlgStrings);
+            if (criteria is not null)
             {
-                var criteria = await uiSvc.ShowModalDialog(dlgStrings);
-                if (criteria is not null)
-                {
-                    var hits = this.decompilerSvc.Decompiler!.Project.Programs
-                        .SelectMany(p => new StringFinder(p).FindStrings(criteria));
-                    srSvc.ShowAddressSearchResults(
-                       hits,
-                       new StringSearchDetails(criteria));
-                }
+                var hits = new StringFinder(program).FindStrings(criteria);
+                srSvc.ShowAddressSearchResults(
+                   hits,
+                   new StringSearchDetails(criteria));
             }
         }
 

src/Gui/IDialogFactory.cs

@@ -42,7 +42,7 @@ public interface IDialogFactory
         IAssumedRegisterValuesDialog CreateAssumedRegisterValuesDialog(IProcessorArchitecture arch);
         IAddressPromptDialog CreateAddressPromptDialog();
         ICallSiteDialog CreateCallSiteDialog(Program program, UserCallData ucd);
-        IDialog<StringFinderCriteria?> CreateFindStringDialog();
+        IDialog<StringFinderCriteria?> CreateFindStringDialog(Program program);
         IKeyBindingsDialog CreateKeyBindingsDialog(Dictionary<string, Dictionary<int, CommandID>> keyBindings);
         IDialog<LoadDetails?> CreateOpenAsDialog(string initialFilename);
         IDialog<UserProcedure?> CreateProcedureDialog(Program program, UserProcedure proc);

src/Gui/Services/FileSystemSettingsService.cs

@@ -56,7 +56,8 @@ public override void Delete(string name)
 
         public override object? Get(string settingName, object? defaultValue)
         {
-            if (!this.settings.TryGetValue(settingName, out var value))
+            if (string.IsNullOrEmpty(settingName) ||
+                !this.settings.TryGetValue(settingName, out var value))
                 return defaultValue;
             if (value is JsonElement je)
             {
@@ -67,6 +68,18 @@ public override void Delete(string name)
 
         public override string[] GetList(string settingName)
         {
+            if (string.IsNullOrEmpty(settingName) ||
+                !this.settings.TryGetValue(settingName, out var value))
+                return Array.Empty<string>();
+            if (value is JsonElement je && je.ValueKind == JsonValueKind.Array)
+            {
+                var result = new String[je.GetArrayLength()];
+                for (int i = 0; i < result.Length; ++i)
+                {
+                    result[i] = je[i].GetString()!;
+                }
+                return result;
+            }
             throw new NotImplementedException();
         }
 

src/Gui/ViewModels/Dialogs/FindStringsViewModel.cs

@@ -22,17 +22,36 @@
 using Reko.Core.Memory;
 using Reko.Core.Types;
 using Reko.Gui.Reactive;
+using Reko.Gui.Services;
 using Reko.Scanning;
 using System;
+using System.Collections.ObjectModel;
+using System.Linq;
 using System.Text;
+using System.Threading.Tasks;
 
 namespace Reko.Gui.ViewModels.Dialogs
 {
     public class FindStringsViewModel : ChangeNotifyingObject
     {
-        public FindStringsViewModel()
+        private Program program;
+        private IDecompilerShellUiService uiSvc;
+        private ISettingsService settingsSvc;
+        private IDialogFactory dialogFactory;
+
+        public FindStringsViewModel(
+            Program program,
+            IDecompilerShellUiService uiSvc,
+            ISettingsService settingsSvc,
+            IDialogFactory dialogFactory)
         {
+            this.program = program;
+            this.uiSvc = uiSvc;
+            this.settingsSvc = settingsSvc;
+            this.dialogFactory = dialogFactory;
             this.minLength = 5;
+            this.program = program;
+            this.SearchAreasMru = LoadMruFromSettings();
         }
 
         public int CharacterType
@@ -56,6 +75,15 @@ public int MinLength
         }
         private int minLength;
 
+        public ObservableCollection<ListOption> SearchAreasMru { get; }
+
+        public int SelectedMruIndex
+        {
+            get => selectedMruIndex;
+            set => base.RaiseAndSetIfChanged(ref selectedMruIndex, value);
+        }
+        private int selectedMruIndex;
+
         public StringFinderCriteria GetCriteria()
         {
             return GetCriteria(this.CharacterType, this.StringKind, this.MinLength);
@@ -65,7 +93,7 @@ public StringFinderCriteria GetCriteria(int characterType, int stringKind, int m
         {
             Encoding encoding;
             PrimitiveType charType;
-            Func<ByteMemoryArea, Address, Address, EndianImageReader> rdrCreator;
+            Func<ByteMemoryArea, Address, long, EndianImageReader> rdrCreator;
             switch (characterType)
             {
             default:
@@ -93,11 +121,97 @@ public StringFinderCriteria GetCriteria(int characterType, int stringKind, int m
             case 2: case 3: strType = StringType.LengthPrefixedStringType(charType, PrimitiveType.UInt16); break;
             }
 
+            var searchAreasListOption = this.SearchAreasMru[this.SelectedMruIndex];
+            var searchAreas = (searchAreasListOption.Value is SearchArea sa && sa.Areas.Count != 0)
+                ? sa.Areas
+                : null;
             return new StringFinderCriteria(
                 StringType: strType,
                 Encoding: encoding,
+                Areas: searchAreas,  
                 MinimumLength: minLength,
                 CreateReader: rdrCreator);
         }
+
+        public async ValueTask SelectSearchArea()
+        {
+            var dlg = this.dialogFactory.CreateSearchAreaDialog(program, new SearchArea());
+            var searchArea = await uiSvc.ShowModalDialog(dlg);
+            if (searchArea is null || searchArea.Areas.Count == 0)
+                return;
+            UpdateSearchAreaMru(searchArea);
+        }
+
+        public void UpdateSearchAreaMru(SearchArea? searchArea)
+        {
+            var iExisting = IndexOf(this.SearchAreasMru, e => object.Equals(e.Value, searchArea));
+            ListOption item;
+            if (iExisting != 0)
+            {
+                if (iExisting >= 1)
+                {
+                    item = this.SearchAreasMru[iExisting];
+                    this.SearchAreasMru.RemoveAt(iExisting);
+                }
+                else
+                {
+                    item = new ListOption(searchArea?.ToString() ?? "", searchArea);
+                }
+                this.SearchAreasMru.Insert(0, item);
+            }
+            this.selectedMruIndex = -1;  // Hack to force an event to be raised.
+            this.SelectedMruIndex = 0;
+        }
+
+        private static int IndexOf<T>(ObservableCollection<T> list, Predicate<T> predicate)
+        {
+            for (int i = 0; i < list.Count; ++i)
+            {
+                if (predicate(list[i]))
+                    return i;
+            }
+            return -1;
+        }
+
+
+        public ObservableCollection<ListOption> LoadMruFromSettings()
+        {
+            var items = settingsSvc.GetList("FindStringsDialog/AreasMru");
+            if (items is null || items.Length == 0)
+            {
+                return new ObservableCollection<ListOption>
+                {
+                    new ListOption("Entire program", null)
+                };
+            }
+            else
+            {
+                var list = new ObservableCollection<ListOption>();
+                foreach (string s in items)
+                {
+                    ListOption item;
+                    if (string.IsNullOrEmpty(s))
+                    {
+                        item = new ListOption("Entire program", null);
+                        list.Add(item);
+                    }
+                    else
+                    {
+                        if (SearchArea.TryParse(program, s, out var sa))
+                        {
+                            item = new ListOption(s, sa);
+                            list.Add(item);
+                        }
+                    }
+                }
+                return list;
+            }
+        }
+
+        public void SaveMruToSettings()
+        {
+            settingsSvc.SetList("FindStringsDialog/AreasMru", SearchAreasMru
+                .Select(a => a.Value is null ? "" : a.Text));
+        }
     }
 }