[PATCH] Add -m16 option for using x86-*-*-code16 triple

[David Woodhouse]

This lets me build the 16-bit startup code of the Linux kernel with
clang. If I work around (unrelated) PR3997 it even works.

---
 include/clang/Driver/Options.td |  1 +
 lib/Driver/Driver.cpp           | 12 ++++++++++--
 2 files changed, 11 insertions(+), 2 deletions(-)

diff --git a/include/clang/Driver/Options.td b/include/clang/Driver/Options.td
index 6682039..5e8a3b8 100644
--- a/include/clang/Driver/Options.td
+++ b/include/clang/Driver/Options.td
@@ -951,6 +951,7 @@ def lazy__framework : Separate<["-"], "lazy_framework">, Flags<[LinkerInput]>;
 def lazy__library : Separate<["-"], "lazy_library">, Flags<[LinkerInput]>;
 def EL : Flag<["-"], "EL">, Flags<[DriverOption]>;
 def EB : Flag<["-"], "EB">, Flags<[DriverOption]>;
+def m16 : Flag<["-"], "m16">, Group<m_Group>, Flags<[DriverOption, CoreOption]>;
 def m32 : Flag<["-"], "m32">, Group<m_Group>, Flags<[DriverOption, CoreOption]>;
 def mqdsp6_compat : Flag<["-"], "mqdsp6-compat">, Group<m_Group>, Flags<[DriverOption,CC1Option]>,
   HelpText<"Enable hexagon-qdsp6 backward compatibility">;
diff --git a/lib/Driver/Driver.cpp b/lib/Driver/Driver.cpp
index ad938b8..b146666 100644
--- a/lib/Driver/Driver.cpp
+++ b/lib/Driver/Driver.cpp
@@ -1901,12 +1901,20 @@ static llvm::Triple computeTargetTriple(StringRef DefaultTargetTriple,
     return Target;
 
   // Handle pseudo-target flags '-m32' and '-m64'.
-  if (Arg *A = Args.getLastArg(options::OPT_m32, options::OPT_m64)) {
+  if (Arg *A = Args.getLastArg(options::OPT_m32, options::OPT_m64, options::OPT_m16)) {
     llvm::Triple::ArchType AT;
     if (A->getOption().matches(options::OPT_m32))
       AT = Target.get32BitArchVariant().getArch();
-    else
+    else if (A->getOption().matches(options::OPT_m64))
       AT = Target.get64BitArchVariant().getArch();
+    else if (A->getOption().matches(options::OPT_m16)) {
+      AT = Target.get32BitArchVariant().getArch();
+      if (AT == llvm::Triple::x86)
+        Target.setEnvironment(llvm::Triple::CODE16);
+      else
+        AT = llvm::Triple::UnknownArch;
+    }
+
     if (AT != llvm::Triple::UnknownArch)
       Target.setArch(AT);
   }
-- 
1.8.4.2


-- 
David Woodhouse                            Open Source Technology Centre
David.Woodhouse at intel.com                              Intel Corporation
-------------- next part --------------
A non-text attachment was scrubbed...
Name: smime.p7s
Type: application/x-pkcs7-signature
Size: 5745 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/cfe-commits/attachments/20140120/a70008f0/attachment.bin>