[Driver] move Minix header search path management to the driver

[brad]

Summary

As has been done for other OS's. Move the header path management to the driver.

[MaskRay]

Thank you for driving the migration!

case llvm::Triple::Minix:
  AddGnuCPlusPlusIncludePaths("/usr/gnu/include/c++/4.4.3",
                              "", "", "", triple);

The GCC 4.4.3 thing is from 3e2ee147d0ddb23592b2ec8294381b5e1801cc62 (2010). https://github.com/Stichting-MINIX-Research-Foundation/minix and https://git.minix3.org/index.cgi?p=minix.git haven't had any commit since 2018.
We haven't seen any actual Minix driver changes for many years. I think it unlikely works and perhaps we should remove Minix driver support.

[brad]

In D158378#4602289, @MaskRay wrote:

Thank you for driving the migration!

case llvm::Triple::Minix:
  AddGnuCPlusPlusIncludePaths("/usr/gnu/include/c++/4.4.3",
                              "", "", "", triple);

The GCC 4.4.3 thing is from 3e2ee147d0ddb23592b2ec8294381b5e1801cc62 (2010). https://github.com/Stichting-MINIX-Research-Foundation/minix and https://git.minix3.org/index.cgi?p=minix.git haven't had any commit since 2018.
We haven't seen any actual Minix driver changes for many years. I think it unlikely works and perhaps we should remove Minix driver support.

Ya, I should have noticed that. I had heard years ago that Minix had switched to Clang. I installed the latest in a VM and it does come with Clang. Clang 3.6.

[MaskRay]

In D158378#4602375, @brad wrote:

In D158378#4602289, @MaskRay wrote:

Thank you for driving the migration!

case llvm::Triple::Minix:
  AddGnuCPlusPlusIncludePaths("/usr/gnu/include/c++/4.4.3",
                              "", "", "", triple);

The GCC 4.4.3 thing is from 3e2ee147d0ddb23592b2ec8294381b5e1801cc62 (2010). https://github.com/Stichting-MINIX-Research-Foundation/minix and https://git.minix3.org/index.cgi?p=minix.git haven't had any commit since 2018.
We haven't seen any actual Minix driver changes for many years. I think it unlikely works and perhaps we should remove Minix driver support.

Ya, I should have noticed that. I had heard years ago that Minix had switched to Clang. I installed the latest in a VM and it does come with Clang. Clang 3.6.

Thanks. 3.6 is so old. Given many things like CompilerRT-Generic that unlikely works, I think it's better to remove Minix.cpp.
If the Minix community makes efforts to add back llvm-project support, starting from scratch with proper testing is likely better than the current nearly-untested state...

[MaskRay]

Created https://reviews.llvm.org/D158461 to remove it.

clang/lib/Driver/ToolChains/Minix.h

 
 namespace toolchains {
 
 class LLVM_LIBRARY_VISIBILITY Minix : public Generic_ELF {
 public:
   Minix(const Driver &D, const llvm::Triple &Triple,
         const llvm::opt::ArgList &Args);
 
+  void
+  AddClangSystemIncludeArgs(const llvm::opt::ArgList &DriverArgs,
+                            llvm::opt::ArgStringList &CC1Args) const override;
+  void addLibStdCxxIncludePaths(
+      const llvm::opt::ArgList &DriverArgs,
+      llvm::opt::ArgStringList &CC1Args) const override;
+
 protected:
   Tool *buildAssembler() const override;
   Tool *buildLinker() const override;
 };
 
 } // end namespace toolchains
 } // end namespace driver
 } // end namespace clang
 
 #endif // LLVM_CLANG_LIB_DRIVER_TOOLCHAINS_MINIX_H

clang/lib/Driver/ToolChains/Minix.cpp

 //===--- Minix.cpp - Minix ToolChain Implementations ------------*- C++ -*-===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 #include "Minix.h"
 #include "CommonArgs.h"
+#include "clang/Config/config.h"
 #include "clang/Driver/Compilation.h"
 #include "clang/Driver/Driver.h"
 #include "clang/Driver/InputInfo.h"
 #include "clang/Driver/Options.h"
 #include "llvm/Option/ArgList.h"
+#include "llvm/Support/Path.h"
 #include "llvm/Support/VirtualFileSystem.h"
 
 using namespace clang::driver;
 using namespace clang;
 using namespace llvm::opt;
 
 void tools::minix::Assembler::ConstructJob(Compilation &C, const JobAction &JA,
                                            const InputInfo &Output,

 
 toolchains::Minix::Minix(const Driver &D, const llvm::Triple &Triple,
                          const ArgList &Args)
     : Generic_ELF(D, Triple, Args) {
   getFilePaths().push_back(getDriver().Dir + "/../lib");
   getFilePaths().push_back("/usr/lib");
 }
 
+void toolchains::Minix::AddClangSystemIncludeArgs(
+    const llvm::opt::ArgList &DriverArgs,
+    llvm::opt::ArgStringList &CC1Args) const {
+  const Driver &D = getDriver();
+
+  if (DriverArgs.hasArg(clang::driver::options::OPT_nostdinc))
+    return;
+
+  if (!DriverArgs.hasArg(options::OPT_nobuiltininc)) {
+    SmallString<128> Dir(D.ResourceDir);
+    llvm::sys::path::append(Dir, "include");
+    addSystemInclude(DriverArgs, CC1Args, Dir.str());
+  }
+
+  if (DriverArgs.hasArg(options::OPT_nostdlibinc))
+    return;
+
+  // Check for configure-time C include directories.
+  StringRef CIncludeDirs(C_INCLUDE_DIRS);
+  if (CIncludeDirs != "") {
+    SmallVector<StringRef, 5> dirs;
+    CIncludeDirs.split(dirs, ":");
+    for (StringRef dir : dirs) {
+      StringRef Prefix =
+          llvm::sys::path::is_absolute(dir) ? StringRef(D.SysRoot) : "";
+      addExternCSystemInclude(DriverArgs, CC1Args, Prefix + dir);
+    }
+    return;
+  }
+
+  addExternCSystemInclude(DriverArgs, CC1Args,
+                          concat(D.SysRoot, "/usr/include"));
+}
+
+void toolchains::Minix::addLibStdCxxIncludePaths(const llvm::opt::ArgList &DriverArgs,
+                                         llvm::opt::ArgStringList &CC1Args) const {
+  addLibStdCXXIncludePaths(concat(getDriver().SysRoot, "/usr/gnu/include/c++/4.4.3"), "", "",
+                           DriverArgs, CC1Args);
+}
+
 Tool *toolchains::Minix::buildAssembler() const {
   return new tools::minix::Assembler(*this);
 }
 
 Tool *toolchains::Minix::buildLinker() const {
   return new tools::minix::Linker(*this);
 }

clang/lib/Lex/InitHeaderSearch.cpp

       // g++-4 / Cygwin-1.5
       AddMinGWCPlusPlusIncludePaths("/usr/lib/gcc", "i686-pc-cygwin", "4.3.2");
       break;
     }
     break;
   case llvm::Triple::DragonFly:
     AddPath("/usr/include/c++/5.0", CXXSystem, false);
     break;
-  case llvm::Triple::Minix:
-    AddGnuCPlusPlusIncludePaths("/usr/gnu/include/c++/4.4.3",
-                                "", "", "", triple);
-    break;
   default:
     break;
   }
 }
 
 bool InitHeaderSearch::ShouldAddDefaultIncludePaths(
     const llvm::Triple &triple) {
   switch (triple.getOS()) {
   case llvm::Triple::AIX:
   case llvm::Triple::Emscripten:
   case llvm::Triple::FreeBSD:
   case llvm::Triple::NetBSD:
   case llvm::Triple::OpenBSD:
   case llvm::Triple::PS4:
   case llvm::Triple::PS5:
   case llvm::Triple::Fuchsia:
   case llvm::Triple::Haiku:
   case llvm::Triple::Hurd:
   case llvm::Triple::Linux:
+  case llvm::Triple::Minix:
   case llvm::Triple::Solaris:
   case llvm::Triple::WASI:
     return false;
 
   case llvm::Triple::Win32:
     if (triple.getEnvironment() != llvm::Triple::Cygnus ||
         triple.isOSBinFormatMachO())
       return false;