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Use the system linker for linking symbols libraries outside Windows.
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Builtin lld is giving some weird linking errors when linking with the
new LLVM version. We probably need to set some custom options. Using the
system linker should be a better idea anyway, more robust and future
proof.
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@tritao
tritao committed Sep 29, 2023
1 parent 7c87f29 commit c045dfd
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Showing 3 changed files with 212 additions and 16 deletions.
3 changes: 1 addition & 2 deletions src/CppParser/Parser.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -4853,8 +4853,7 @@ ParserResult* Parser::Compile(const std::string& File)
const llvm::Triple Triple = c->getTarget().getTriple();
llvm::StringRef Dir(llvm::sys::path::parent_path(File));
llvm::SmallString<1024> Object(Dir);
llvm::sys::path::append(Object,
(Triple.isOSWindows() ? "" : "lib") + Stem + ".o");
llvm::sys::path::append(Object, Stem + ".o");
c->getFrontendOpts().OutputFile = std::string(Object);

llvm::LLVMContext context;
Expand Down
73 changes: 60 additions & 13 deletions src/Generator/Passes/GenerateSymbolsPass.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -63,26 +63,73 @@ private void GenerateSymbols()
new[] { module }).SelectMany(d => d.Libraries))
linkerOptions.AddLibraries(library);

using (var result = Parser.ClangParser.Build(
Context.ParserOptions, linkerOptions, path,
Last: remainingCompilationTasks == 1))
{
if (PrintDiagnostics(result))
{
compiledLibraries[module] = new CompiledLibrary
{
OutputDir = Options.OutputDir,
Library = module.SymbolsLibraryName
};
}
}
compiledLibraries[module] = Build(linkerOptions, path, module);
}
}

RemainingCompilationTasks--;
}
}

private CompiledLibrary Build(LinkerOptions linkerOptions, string path, Module module)
{
var useBuiltinToolchain = Platform.IsWindows;
if (useBuiltinToolchain)
{
using var result = Parser.ClangParser.Build(
Context.ParserOptions, linkerOptions, path,
Last: remainingCompilationTasks == 1);

if (!PrintDiagnostics(result))
return null;
}
else
{
using var result = Parser.ClangParser.Compile(Context.ParserOptions, path);
if (result != null)
{
if (!PrintDiagnostics(result))
return null;
}

var targetPlatform = Options.Compilation.Platform.GetValueOrDefault(Platform.Host);
var linker = LinkerOptions.GetLinkerExecutableName(targetPlatform);

linkerOptions.AddArguments("-L" + Path.GetDirectoryName(path));
linkerOptions.SetupLibraryArguments();

var objectFile = Path.ChangeExtension(path, "o");
linkerOptions.AddArguments(objectFile);

var sharedObjectFile = LinkerOptions.GetSharedObjectName(path, targetPlatform);
linkerOptions.AddArguments("-o " + sharedObjectFile);

var invocation = linkerOptions.GetLinkerInvocation();

Diagnostics.Message($"Linking library {Path.GetFileName(sharedObjectFile)}...");
if (Options.Verbose)
Diagnostics.Message($"Invoking the linker with: {linker} {invocation}");

var outMessage = ProcessHelper.Run(
linker, invocation, out var errorCode, out var errorMessage);

if (errorCode != 0)
{
Diagnostics.Error($"Linking failed with: {outMessage} {errorMessage}");
}
else
{
Diagnostics.Message($"Linking success.");
}
}

return new CompiledLibrary
{
OutputDir = Options.OutputDir,
Library = module.SymbolsLibraryName
};
}

public override bool VisitClassTemplateSpecializationDecl(ClassTemplateSpecialization specialization)
{
if (!specialization.IsGenerated ||
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152 changes: 151 additions & 1 deletion src/Parser/LinkerOptions.cs
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Original file line number Diff line number Diff line change
@@ -1,4 +1,8 @@
using System.Linq;
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Text;

namespace CppSharp.Parser
{
Expand Down Expand Up @@ -70,5 +74,151 @@ public void Setup(string triple, LanguageVersion? languageVersion)
break;
}
}

public void SetupLibraryArguments()
{
for (uint i = 0; i < LibraryDirsCount; i++)
{
var dir = GetLibraryDirs(i);
AddArguments("-L" + dir);
}

for (uint i = 0; i < LibrariesCount; i++)
{
var lib = GetLibraries(i);
AddArguments("-l" + lib);
}
}

public string GetLinkerInvocation()
{
var args = new List<string>();
for (uint i = 0; i < ArgumentsCount; i++)
{
var arg = GetArguments(i);
args.Add(arg);
}

return string.Join(" ", args);
}

public static string GetSharedObjectName(string path, TargetPlatform targetPlatform)
{
var prefix = GetPlatformSharedObjectPrefix(targetPlatform);
var extension = GetPlatformSharedObjectExtension(targetPlatform);
var name = $"{prefix}{Path.GetFileNameWithoutExtension(path)}.{extension}";
return Path.Join(Path.GetDirectoryName(path), name);
}

public static string GetLinkerExecutableName(TargetPlatform targetPlatform)
{
// If LLD exists on the PATH, then prefer it. If not, use the host linker.
var lldLinkerExe = GetLLDLinkerExecutableName(targetPlatform);
return ExistsOnPath(lldLinkerExe) ?
lldLinkerExe : GetPlatformLinkerExecutableName(targetPlatform);
}

public static string GetPlatformSharedObjectPrefix(TargetPlatform targetPlatform)
{
switch (targetPlatform)
{
case TargetPlatform.Windows:
return "";
case TargetPlatform.Linux:
case TargetPlatform.Android:
case TargetPlatform.MacOS:
case TargetPlatform.iOS:
case TargetPlatform.WatchOS:
case TargetPlatform.TVOS:
case TargetPlatform.Emscripten:
return "lib";
default:
throw new ArgumentOutOfRangeException(nameof(targetPlatform), targetPlatform, null);
}
}

public static string GetPlatformSharedObjectExtension(TargetPlatform targetPlatform)
{
switch (targetPlatform)
{
case TargetPlatform.Windows:
return "dll";
case TargetPlatform.Linux:
case TargetPlatform.Android:
case TargetPlatform.MacOS:
case TargetPlatform.iOS:
case TargetPlatform.WatchOS:
case TargetPlatform.TVOS:
case TargetPlatform.Emscripten:
return "so";
default:
throw new ArgumentOutOfRangeException(nameof(targetPlatform), targetPlatform, null);
}
}

public static string GetPlatformLinkerExecutableName(TargetPlatform targetPlatform)
{
switch (targetPlatform)
{
case TargetPlatform.Windows:
return "link.exe";
case TargetPlatform.Linux:
return "ld";
case TargetPlatform.Android:
case TargetPlatform.MacOS:
case TargetPlatform.iOS:
case TargetPlatform.WatchOS:
case TargetPlatform.TVOS:
case TargetPlatform.Emscripten:
return GetLLDLinkerExecutableName(targetPlatform);
default:
throw new ArgumentOutOfRangeException(nameof(targetPlatform), targetPlatform, null);
}
}

public static string GetLLDLinkerExecutableName(TargetPlatform targetPlatform)
{
switch (targetPlatform)
{
case TargetPlatform.Windows:
return "lld-link";
case TargetPlatform.Linux:
case TargetPlatform.Android:
return "ld.lld";
case TargetPlatform.MacOS:
case TargetPlatform.iOS:
case TargetPlatform.WatchOS:
case TargetPlatform.TVOS:
return "ld64.lld";
case TargetPlatform.Emscripten:
return "wasm-ld";
default:
throw new ArgumentOutOfRangeException(nameof(targetPlatform), targetPlatform, null);
}
}

private static bool ExistsOnPath(string fileName)
{
return GetFullPath(fileName) != null;
}

private static string GetFullPath(string fileName)
{
if (fileName == null) throw new ArgumentNullException(nameof(fileName));
if (File.Exists(fileName))
return Path.GetFullPath(fileName);

var environmentVariablePath = Environment.GetEnvironmentVariable("PATH");
if (environmentVariablePath == null)
throw new NullReferenceException(nameof(environmentVariablePath));

foreach (var path in environmentVariablePath.Split(Path.PathSeparator))
{
var fullPath = Path.Combine(path, fileName);
if (File.Exists(fullPath))
return fullPath;
}
return null;
}
}
}

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