compile hack

CMakeLists.txt

@@ -75,6 +75,7 @@ if(CLANG_LINK_CLANG_DYLIB)
   target_link_libraries(ccls PRIVATE clang-cpp)
 else()
   target_link_libraries(ccls PRIVATE
+    clangCodeGen
     clangIndex
     clangFormat
     clangTooling
@@ -94,7 +95,7 @@ endif()
 if(LLVM_LINK_LLVM_DYLIB)
   target_link_libraries(ccls PRIVATE LLVM)
 else()
-  target_link_libraries(ccls PRIVATE LLVMOption LLVMSupport)
+  target_link_libraries(ccls PRIVATE LLVMOption LLVMSupport LLVMTarget LLVMX86CodeGen LLVMX86Desc LLVMX86Info)
   if(LLVM_VERSION_MAJOR GREATER_EQUAL 16) # llvmorg-16-init-15123-gf09cf34d0062
     target_link_libraries(ccls PRIVATE LLVMTargetParser)
   endif()
@@ -201,6 +202,7 @@ target_sources(ccls PRIVATE
   src/filesystem.cc
   src/fuzzy_match.cc
   src/main.cc
+  src/compile.cc
   src/indexer.cc
   src/log.cc
   src/lsp.cc

src/compile.cc

@@ -0,0 +1,110 @@
+#include <sys/mman.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#include <clang/Driver/Compilation.h>
+#include <clang/Driver/Driver.h>
+#include <clang/Driver/Tool.h>
+#include <clang/Driver/Types.h>
+#include <clang/CodeGen/CodeGenAction.h>
+#include <clang/Frontend/CompilerInstance.h>
+#include <clang/Frontend/FrontendAction.h>
+#include <llvm/Support/VirtualFileSystem.h>
+#include <llvm-c/Target.h>
+
+using namespace clang;
+
+struct StoreDiags : DiagnosticConsumer {
+  const LangOptions *langOpts;
+  std::string message;
+
+  void BeginSourceFile(const LangOptions &opts, const Preprocessor *) override { langOpts = &opts; }
+  void HandleDiagnostic(DiagnosticsEngine::Level level, const clang::Diagnostic &info) override {
+    DiagnosticConsumer::HandleDiagnostic(level, info);
+    const char *prefix;
+    switch (level) {
+    default:
+      return;
+    case DiagnosticsEngine::Warning:
+      prefix = "warning";
+      break;
+    case DiagnosticsEngine::Error:
+      prefix = "error";
+      break;
+    case DiagnosticsEngine::Fatal:
+      prefix = "fatal error";
+      break;
+    }
+
+    llvm::SmallString<64> msg;
+    info.FormatDiagnostic(msg);
+    auto &sm = info.getSourceManager();
+    std::pair<FileID, unsigned> i = sm.getDecomposedLoc(sm.getFileLoc(info.getLocation()));
+    int l = (int)sm.getLineNumber(i.first, i.second), c = (int)sm.getColumnNumber(i.first, i.second);
+    llvm::raw_string_ostream(message) << l << ':' << c << ": " << prefix << ": " << msg << '\n';
+  }
+};
+
+std::pair<std::string, std::string> compile(llvm::StringRef source) {
+  int fd_in = memfd_create("a.cc", 0), fd_out = memfd_create("a.o", 0);
+  llvm::raw_fd_stream osIn(fd_in, true), osOut(fd_out, true);
+  if (fd_in < 0 || fd_out < 0)
+    return {"", "failed to open file"};
+  osIn << source;
+  osIn.seek(0);
+
+  auto fs = llvm::vfs::getRealFileSystem();
+  StoreDiags dc;
+  char file_in[64], file_out[64];
+  snprintf(file_in, sizeof(file_in), "/proc/self/fd/%d", fd_in);
+  snprintf(file_out, sizeof(file_out), "/proc/self/fd/%d", fd_out);
+  std::vector<const char *> args{
+      "clang", "-c", "-Wall", "-Wextra", "-xc++", file_in, "-o", file_out, "-fno-ident"};
+  llvm::IntrusiveRefCntPtr<DiagnosticsEngine> diags(CompilerInstance::createDiagnostics(
+#if LLVM_VERSION_MAJOR >= 20
+      *fs,
+#endif
+      new DiagnosticOptions, &dc, false));
+  driver::Driver d(args[0], "x86_64", *diags, "cc", fs);
+  d.setCheckInputsExist(false);
+  std::unique_ptr<driver::Compilation> comp(d.BuildCompilation(args));
+  const auto &jobs = comp->getJobs();
+  assert(jobs.size() == 1 && isa<driver::Command>(*jobs.begin()));
+  const llvm::opt::ArgStringList &cc_args = cast<driver::Command>(*jobs.begin()).getArguments();
+  auto ci = std::make_unique<CompilerInvocation>();
+  CompilerInvocation::CreateFromArgs(*ci, cc_args, *diags);
+  ci->getFrontendOpts().DisableFree = false;
+
+  auto clang = std::make_unique<CompilerInstance>(std::make_shared<PCHContainerOperations>());
+  clang->setInvocation(std::move(ci));
+  clang->createDiagnostics(
+#if LLVM_VERSION_MAJOR >= 20
+      *fs,
+#endif
+      &dc, false);
+  diags.reset();
+  clang->setTarget(TargetInfo::CreateTargetInfo(clang->getDiagnostics(), clang->getInvocation().TargetOpts));
+  if (!clang->hasTarget())
+    return {"", "unsupported target"};
+  clang->createFileManager(fs);
+  clang->setSourceManager(new SourceManager(clang->getDiagnostics(), clang->getFileManager(), true));
+
+  LLVMInitializeX86AsmPrinter();
+  LLVMInitializeX86Target();
+  LLVMInitializeX86TargetInfo();
+  LLVMInitializeX86TargetMC();
+
+  auto action = std::make_unique<EmitObjAction>();
+  action->BeginSourceFile(*clang, clang->getFrontendOpts().Inputs[0]);
+  llvm::Error e = action->Execute();
+  if (e)
+    return {"", llvm::toString(std::move(e))};
+  action->EndSourceFile();
+
+  auto size = (long)lseek(fd_out, 0, SEEK_END);
+  std::string ret(size, '\0');
+  osOut.seek(0);
+  osOut.read(ret.data(), size);
+  return {std::move(ret), std::move(dc.message)};
+}