Support multiple matches of RegExpr pattern

Previously, RegExpr would only match the first occurrence of the
pattern. In case of more than one match, a virtual syntax tree node is
now added as root, with all top-level tokens added as child nodes.

Change-Id: Id034dcf38c0d87aa2e4fac0810e0b65d6d43c2b7
Reviewed-by: Karsten Heimrich <karsten.heimrich@qt.io>

3 files changed, 130 insertions, 20 deletions

diff --git a/QtVsTools.RegExpr/parser/Parser.cs b/QtVsTools.RegExpr/parser/Parser.cs
index 60c6a0f7..0ae7a36b 100644
--- a/QtVsTools.RegExpr/parser/Parser.cs
+++ b/QtVsTools.RegExpr/parser/Parser.cs
@@ -27,6 +27,7 @@
 ****************************************************************************/
 
 using System;
+using System.Collections.Generic;
 using System.Linq;
 using System.Text.RegularExpressions;
 
@@ -88,26 +89,36 @@ namespace QtVsTools.SyntaxAnalysis
             ParseTree GetParseTree(string text)
             {
                 // Match regex pattern
-                var match = Regex.Match(text);
-                if (!match.Success || match.Length == 0)
+                var nodes = new List<ParseTree.Node>();
+                var matches = Regex.Matches(text);
+                if (matches.Count == 0)
                     throw new ParseErrorException();
+                foreach (Match match in matches) {
+                    if (!match.Success || match.Length == 0) {
+                        if (nodes.Any())
+                            continue;
+                        else
+                            throw new ParseErrorException();
+                    }
 
-                // Flat list of parse-tree nodes, from Regex captures
-                var nodes = match.Groups.Cast<Group>()
-                    .SelectMany((group, groupIdx) => group.Captures.Cast<Capture>()
-                        .Where(capture => !string.IsNullOrEmpty(capture.Value))
-                        .Select((capture, captureIdx) => new ParseTree.Node
-                        {
-                            CaptureId = Regex.GroupNameFromNumber(groupIdx),
-                            Token = Pattern.Tokens[Regex.GroupNameFromNumber(groupIdx)],
-                            Value = capture.Value,
-                            Begin = capture.Index,
-                            End = capture.Index + capture.Length,
-                            GroupIdx = groupIdx,
-                            CaptureIdx = captureIdx,
-                        }))
-                    .OrderBy(c => c.Begin)
-                    .ToList();
+                    // Flat list of parse-tree nodes, from Regex captures
+                    var matchNodes = match.Groups.Cast<Group>()
+                        .SelectMany((group, groupIdx) => group.Captures.Cast<Capture>()
+                            .Where(capture => !string.IsNullOrEmpty(capture.Value))
+                            .Select((capture, captureIdx) => new ParseTree.Node
+                            {
+                                CaptureId = Regex.GroupNameFromNumber(groupIdx),
+                                Token = Pattern.Tokens[Regex.GroupNameFromNumber(groupIdx)],
+                                Value = capture.Value,
+                                Begin = capture.Index,
+                                End = capture.Index + capture.Length,
+                                GroupIdx = groupIdx,
+                                CaptureIdx = captureIdx,
+                            }))
+                        .OrderBy(c => c.Begin)
+                        .ToList();
+                    nodes.AddRange(matchNodes);
+                }
 
                 // Node list partitioned by token
                 var nodesByToken = nodes
@@ -131,8 +142,23 @@ namespace QtVsTools.SyntaxAnalysis
                     (node.Parent = parentNodes[idx]).ChildNodes.Add(node.Begin, node);
                 }
 
-                // Return parse tree root
-                return nodesByToken[Pattern.Root].FirstOrDefault();
+                var topNodes = nodesByToken[Pattern.Root];
+                if (topNodes.Length == 1)
+                    return topNodes[0];
+
+                var root = new ParseTree.Node()
+                {
+                    CaptureId = string.Empty,
+                    Token = null,
+                    Value = text,
+                    Begin = 0,
+                    End = text.Length,
+                    GroupIdx = -1,
+                    CaptureIdx = -1,
+                };
+                foreach (var node in nodesByToken[Pattern.Root])
+                    (node.Parent = root).ChildNodes.Add(node.Begin, node);
+                return root;
             }
         }
 
diff --git a/Tests/Test_QtVsTools.RegExpr/Test_Matches.cs b/Tests/Test_QtVsTools.RegExpr/Test_Matches.cs
new file mode 100644
index 00000000..df52316b
--- /dev/null
+++ b/Tests/Test_QtVsTools.RegExpr/Test_Matches.cs
@@ -0,0 +1,83 @@
+/****************************************************************************
+**
+** Copyright (C) 2022 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the Qt VS Tools.
+**
+** $QT_BEGIN_LICENSE:GPL-EXCEPT$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 3 as published by the Free Software
+** Foundation with exceptions as appearing in the file LICENSE.GPL3-EXCEPT
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+using System.Collections.Generic;
+using System.Linq;
+using Microsoft.VisualStudio.TestTools.UnitTesting;
+
+namespace QtVsTools.Test.RegExpr
+{
+    using SyntaxAnalysis;
+    using static SyntaxAnalysis.RegExpr;
+
+    using Property = KeyValuePair<string, string>;
+
+    [TestClass]
+    public class Test_Matches
+    {
+        Parser propertyParser;
+
+        [TestInitialize]
+        public void GenerateParser()
+        {
+            var namePattern = (~CharSet['=', '\r', '\n']).Repeat(atLeast: 1);
+            var nameToken = new Token("name", namePattern);
+
+            var valuePattern = (~CharSet['\r', '\n']).Repeat(atLeast: 1);
+            var valueToken = new Token("value", valuePattern);
+
+            var propertyPattern
+                = StartOfLine & nameToken & "=" & valueToken & (LineBreak | EndOfFile);
+
+            var propertyToken = new Token("property", propertyPattern)
+            {
+                new Rule<Property>
+                {
+                    Create("name", (string s) => new Property(s, string.Empty)),
+                    Transform("value", (Property p, string s) => new Property(p.Key, s))
+                }
+            };
+            propertyParser = propertyToken.Render();
+        }
+
+        [TestMethod]
+        public void MultipleMatches()
+        {
+            string propertiesText = @"
+VSCMD_ARG_app_plat=Desktop
+VSCMD_ARG_HOST_ARCH=x64
+VSCMD_ARG_TGT_ARCH=x64
+VSCMD_VER=16.11.17";
+
+            IEnumerable<Property> properties = propertyParser
+                .Parse(propertiesText)
+                .GetValues<Property>("property");
+            Assert.IsTrue(properties.Count() == 4);
+        }
+    }
+}
diff --git a/Tests/Test_QtVsTools.RegExpr/Test_QtVsTools.RegExpr.csproj b/Tests/Test_QtVsTools.RegExpr/Test_QtVsTools.RegExpr.csproj
index a066d042..0fd1da52 100644
--- a/Tests/Test_QtVsTools.RegExpr/Test_QtVsTools.RegExpr.csproj
+++ b/Tests/Test_QtVsTools.RegExpr/Test_QtVsTools.RegExpr.csproj
@@ -102,6 +102,7 @@
       <Link>MacroParser.cs</Link>
     </Compile>
     <Compile Include="Test_MacroParser.cs" />
+    <Compile Include="Test_Matches.cs" />
     <Compile Include="Test_XmlIntParser.cs" />
     <Compile Include="Properties\AssemblyInfo.cs" />
     <Compile Include="Test_SubTokens.cs" />