Use the Windows SDK arguments over the environment

If any of the Windows SDK (and MSVC)-related argument is passed in the
command line, they should take priority over the environment variables
like `INCLUDE` or `LIB` set by vcvarsall from the Visual Studio
Developer Environment on Windows.

These changes ensure that all of the arguments related to VC Tools and
the Windows SDK cause the driver to ignore the environment.

Author: Steelskin

clang/lib/Driver/ToolChains/MSVC.cpp

@@ -110,8 +110,9 @@ void visualstudio::Linker::ConstructJob(Compilation &C, const JobAction &JA,
     CmdArgs.push_back(Args.MakeArgString(Twine("-libpath:") + DIAPath));
   }
   if (!llvm::sys::Process::GetEnv("LIB") ||
-      Args.getLastArg(options::OPT__SLASH_vctoolsdir,
-                      options::OPT__SLASH_winsysroot)) {
+      Args.hasArg(options::OPT__SLASH_vctoolsdir,
+                  options::OPT__SLASH_vctoolsversion,
+                  options::OPT__SLASH_winsysroot)) {
     CmdArgs.push_back(Args.MakeArgString(
         Twine("-libpath:") +
         TC.getSubDirectoryPath(llvm::SubDirectoryType::Lib)));
@@ -120,8 +121,9 @@ void visualstudio::Linker::ConstructJob(Compilation &C, const JobAction &JA,
         TC.getSubDirectoryPath(llvm::SubDirectoryType::Lib, "atlmfc")));
   }
   if (!llvm::sys::Process::GetEnv("LIB") ||
-      Args.getLastArg(options::OPT__SLASH_winsdkdir,
-                      options::OPT__SLASH_winsysroot)) {
+      Args.hasArg(options::OPT__SLASH_winsdkdir,
+                  options::OPT__SLASH_winsdkversion,
+                  options::OPT__SLASH_winsysroot)) {
     if (TC.useUniversalCRT()) {
       std::string UniversalCRTLibPath;
       if (TC.getUniversalCRTLibraryPath(Args, UniversalCRTLibPath))
@@ -686,9 +688,12 @@ void MSVCToolChain::AddClangSystemIncludeArgs(const ArgList &DriverArgs,
     return;
 
   // Honor %INCLUDE% and %EXTERNAL_INCLUDE%. It should have essential search
-  // paths set by vcvarsall.bat. Skip if the user expressly set a vctoolsdir.
-  if (!DriverArgs.getLastArg(options::OPT__SLASH_vctoolsdir,
-                             options::OPT__SLASH_winsysroot)) {
+  // paths set by vcvarsall.bat. Skip if the user expressly set any of the
+  // Windows SDK or VC Tools options.
+  if (!DriverArgs.hasArg(
+          options::OPT__SLASH_vctoolsdir, options::OPT__SLASH_vctoolsversion,
+          options::OPT__SLASH_winsysroot, options::OPT__SLASH_winsdkdir,
+          options::OPT__SLASH_winsdkversion)) {
     bool Found = AddSystemIncludesFromEnv("INCLUDE");
     Found |= AddSystemIncludesFromEnv("EXTERNAL_INCLUDE");
     if (Found)

clang/test/Driver/cl-include.c

@@ -41,3 +41,8 @@
 // EXTERNAL_ENV: "-internal-isystem" "/dir1"
 // EXTERNAL_ENV: "-internal-isystem" "/dir2"
 // EXTERNAL_ENV: "-internal-isystem" "/dir3"
+
+// /winsdkversion suppresses %INCLUDE% and %EXTERNAL_INCLUDE%
+// RUN:env INCLUDE=/my/system/inc env EXTERNAL_INCLUDE=/my/system/inc2 %clang_cl /winsdkversion 99.99.9999.9 -### -- %s 2>&1 | FileCheck %s --check-prefix=SDKVERSION
+// SDKVERSION-NOT: "-internal-isystem" "/my/system/inc"
+// SDKVERSION-NOT: "-internal-isystem" "/my/system/inc2"

lld/COFF/Driver.cpp

@@ -597,11 +597,12 @@ void LinkerDriver::detectWinSysRoot(const opt::InputArgList &Args) {
     if (A->getOption().getID() == OPT_winsysroot)
       path::append(diaPath, "DIA SDK");
   }
-  useWinSysRootLibPath = Args.hasArg(OPT_lldignoreenv) ||
-                         !Process::GetEnv("LIB") ||
-                         Args.getLastArg(OPT_vctoolsdir, OPT_winsysroot);
-  if (Args.hasArg(OPT_lldignoreenv) || !Process::GetEnv("LIB") ||
-      Args.getLastArg(OPT_winsdkdir, OPT_winsysroot)) {
+  useWinSysRootLibPath = !Process::GetEnv("LIB") ||
+                         Args.hasArg(OPT_lldignoreenv, OPT_vctoolsdir,
+                                     OPT_vctoolsversion, OPT_winsysroot);
+  if (!Process::GetEnv("LIB") ||
+      Args.hasArg(OPT_lldignoreenv, OPT_winsdkdir, OPT_winsdkversion,
+                  OPT_winsysroot)) {
     std::optional<StringRef> WinSdkDir, WinSdkVersion;
     if (auto *A = Args.getLastArg(OPT_winsdkdir))
       WinSdkDir = A->getValue();
@@ -1551,7 +1552,8 @@ void LinkerDriver::linkerMain(ArrayRef<const char *> argsArr) {
       // installations when operating in mingw mode. (This also makes LLD ignore
       // winsysroot and vctoolsdir arguments.)
       detectWinSysRoot(args);
-      if (!args.hasArg(OPT_lldignoreenv) && !args.hasArg(OPT_winsysroot))
+      if (!args.hasArg(OPT_lldignoreenv, OPT_winsysroot, OPT_vctoolsdir,
+                       OPT_vctoolsversion, OPT_winsdkdir, OPT_winsdkversion))
         addLibSearchPaths();
     } else {
       if (args.hasArg(OPT_vctoolsdir, OPT_winsysroot))

lld/test/COFF/winsysroot.test

@@ -58,3 +58,7 @@ LIBIGNORED_MINGW: could not open 'libstd32.a'
 
 # RUN: not lld-link -lldmingw %t.obj /defaultlib:std32 /winsysroot:%t.dir/sysroot 2>&1 | FileCheck -check-prefix=IGNORED_ARG %s
 IGNORED_ARG: warning: ignoring /vctoolsdir or /winsysroot flags in MinGW mode
+
+Check that when /winsdkversion is specified, %LIB% is ignored.
+# RUN: env LIB=%t.dir/sysroot/VC/Tools/MSVC/1.1.1.1/lib/x86 not lld-link %t.obj /winsdkversion:99.99.9999.9 /defaultlib:std32 2>&1 | FileCheck -check-prefix=WINSDKVERSION %s
+WINSDKVERSION: could not open 'std32.lib'