Add a source-build smoke test for native debug symbols (#16488)

src/SourceBuild/content/test/Microsoft.DotNet.SourceBuild.SmokeTests/DebugTests.cs

@@ -0,0 +1,122 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using System;
+using System.IO;
+using System.Linq;
+using System.Text;
+using System.Text.RegularExpressions;
+using Xunit;
+using Xunit.Abstractions;
+
+namespace Microsoft.DotNet.SourceBuild.SmokeTests;
+
+public class DebugTests : SmokeTests
+{
+    private record ScanResult(string FileName, bool HasDebugInfo, bool HasDebugAbbrevs, bool HasFileSymbols, bool HasGnuDebugLink);
+
+    public DebugTests(ITestOutputHelper outputHelper) : base(outputHelper) { }
+
+    /// <Summary>
+    /// Verifies that all generated native files include native debug symbols.
+    /// </Summary>
+    [Fact]
+    public void SourceBuiltSdkContainsNativeDebugSymbols()
+    {
+
+        var fileNames = Directory.EnumerateFiles(Config.DotNetDirectory, "*", SearchOption.AllDirectories);
+        var foundIssue = false;
+        StringBuilder issueDetails = new();
+        foreach (var fileName in fileNames)
+        {
+            if (!IsElfFile(fileName))
+            {
+                continue;
+            }
+
+            var result = ScanFile(fileName);
+
+            string newLine = Environment.NewLine;
+
+            if (!result.HasDebugInfo)
+            {
+                foundIssue = true;
+                issueDetails.Append($"missing .debug_info section in {fileName}{newLine}");
+            }
+            if (!result.HasDebugAbbrevs)
+            {
+                foundIssue = true;
+                issueDetails.Append($"missing .debug_abbrev section in {fileName}{newLine}");
+            }
+            if (!result.HasFileSymbols)
+            {
+                foundIssue = true;
+                issueDetails.Append($"missing FILE symbols in {fileName}{newLine}");
+            }
+            if (result.HasGnuDebugLink)
+            {
+                foundIssue = true;
+                issueDetails.Append($"unexpected .gnu_debuglink section in {fileName}{newLine}");
+            }
+        }
+
+        Assert.False(foundIssue, issueDetails.ToString());
+    }
+
+    private bool IsElfFile(string fileName)
+    {
+        string fileStdOut = ExecuteHelper.ExecuteProcessValidateExitCode("file", $"{fileName}", OutputHelper);
+        return Regex.IsMatch(fileStdOut, @"ELF 64-bit [LM]SB (?:pie )?(?:executable|shared object)");
+    }
+
+    private ScanResult ScanFile(string fileName)
+    {
+        string readelfSStdOut = ExecuteHelper.ExecuteProcessValidateExitCode("eu-readelf", $"-S {fileName}", OutputHelper);
+
+        // Test for .debug_* sections in the shared object. This is the  main test.
+        // Stripped objects will not contain these.
+
+        bool hasDebugInfo = readelfSStdOut
+            .Split("\n")
+            .Where(line => line.Contains("] .debug_info"))
+            .Any();
+
+        bool hasDebugAbbrev = readelfSStdOut.Split("\n")
+            .Where(line => line.Contains("] .debug_abbrev"))
+            .Any();
+
+        string readelfsStdOut = ExecuteHelper.ExecuteProcessValidateExitCode("eu-readelf", $"-s {fileName}", OutputHelper);
+
+        // Test FILE symbols. These will most likely be removed by anyting that
+        // manipulates symbol tables because it's generally useless. So a nice test
+        // that nothing has messed with symbols.
+        bool hasFileSymbols = readelfsStdOut.Split("\n").Where(ContainsFileSymbols).Any();
+
+        // Test that there are no .gnu_debuglink sections pointing to another
+        // debuginfo file. There shouldn't be any debuginfo files, so the link makes
+        // no sense either.
+        bool hasGnuDebuglink = readelfsStdOut.Split("\n").Where(line => line.Contains("] .gnu_debuglink")).Any();
+
+        return new ScanResult(fileName, hasDebugInfo, hasDebugAbbrev, hasFileSymbols, hasGnuDebuglink);
+    }
+
+    private bool ContainsFileSymbols(string line)
+    {
+        // Try matching against output like this:
+        //    10: 0000000000000000      0 FILE    LOCAL  DEFAULT      ABS coreclr_resolver.cpp
+        //   779: 0000000000000000      0 FILE    LOCAL  DEFAULT      ABS header.cpp
+
+        var parts = new Regex(@"[ \t\n\r]+").Split(line);
+        int expectedNumberOfParts = 9;
+
+        if (parts.Length < expectedNumberOfParts)
+        {
+            return false;
+        }
+
+        var fileNameRegex = new Regex(@"(.*/)?[-_a-zA-Z0-9]+\.(c|cc|cpp|cxx)");
+        return (parts[3] == "0") && (parts[4] == "FILE") && (parts[5] == "LOCAL") && (parts[6] == "DEFAULT") &&
+                        (parts[7] == "ABS") && (fileNameRegex.IsMatch(parts[8]));
+    }
+}

src/SourceBuild/content/test/Microsoft.DotNet.SourceBuild.SmokeTests/README.md

@@ -3,6 +3,15 @@
 * Run these tests via `build.sh --run-smoke-test`
 * Various configuration settings are stored in `Config.cs`
 
+## Dependencies
+
+Some tests need additional dependencies. These must be installed (manually and separately) on the system for the tests to pass.
+
+The following programs are used by some tests:
+
+- eu-readelf
+- file
+
 ## Prereq Packages
 
 Some prerelease scenarios, usually security updates, require non-source-built packages which are not publicly available.