[PATCH] D101479: [Driver] Support libc++ in MSVC

[Petr Hosek via Phabricator via cfe-commits]

phosek created this revision.
phosek added reviewers: hans, rnk, thakis.
phosek requested review of this revision.
Herald added a project: clang.
Herald added a subscriber: cfe-commits.

This implements support for using libc++ headers in MSVC toolchain.
We only support libc++ headers that are part of the toolchain, and
not headers installed elsewhere on the system.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D101479

Files:
  clang/lib/Driver/ToolChains/MSVC.cpp
  clang/test/Driver/msvc-libcxx.cpp


Index: clang/test/Driver/msvc-libcxx.cpp
===================================================================
--- /dev/null
+++ clang/test/Driver/msvc-libcxx.cpp
@@ -0,0 +1,3 @@
+// RUN: %clangxx -target x86_64-pc-windows-msvc --stdlib=libc++ -### %s 2>&1 | FileCheck %s -check-prefix MSVC-LIBCXX
+
+// MSVC-LIBCXX: "-internal-isystem" "{{.*[/\\]}}include{{/|\\\\}}c++{{/|\\\\}}v1"
Index: clang/lib/Driver/ToolChains/MSVC.cpp
===================================================================
--- clang/lib/Driver/ToolChains/MSVC.cpp
+++ clang/lib/Driver/ToolChains/MSVC.cpp
@@ -1323,7 +1323,34 @@
 
 void MSVCToolChain::AddClangCXXStdlibIncludeArgs(const ArgList &DriverArgs,
                                                  ArgStringList &CC1Args) const {
-  // FIXME: There should probably be logic here to find libc++ on Windows.
+  if (DriverArgs.hasArg(options::OPT_nostdlibinc) ||
+      DriverArgs.hasArg(options::OPT_nostdincxx))
+    return;
+
+  const Driver &D = getDriver();
+
+  auto AddLibcxxIncludePath = [&](StringRef Path) {
+    std::string Version = detectLibcxxVersion(Path);
+    if (Version.empty())
+      return;
+
+    SmallString<128> Dir(Path);
+    llvm::sys::path::append(Dir, "c++", Version);
+    addSystemInclude(DriverArgs, CC1Args, Dir);
+  };
+
+  switch (GetCXXStdlibType(DriverArgs)) {
+  case ToolChain::CST_Libcxx: {
+    SmallString<128> P(D.Dir);
+    llvm::sys::path::append(P, "..", "include");
+    AddLibcxxIncludePath(P);
+    break;
+  }
+
+  default:
+    // TODO: Shall we report an error for other C++ standard libraries?
+    break;
+  }
 }
 
 VersionTuple MSVCToolChain::computeMSVCVersion(const Driver *D,


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