[mips] Pass the ABI to the integrated assembler and add tests the existing arguments.

Summary:
With this patch (and a corresponding LLVM patch), assembling an empty file with
GCC and Clang -fintegrated-as produce near identical objects. The remaining
differences are:
* GCC/GAS produce objects have a .pdr section
* GCC/GAS produce objects have a .gnu.attributes section
Other differences are insignificant such as precise file offsets and the order
of strings in the string table.

Differential Revision: http://reviews.llvm.org/D4531

llvm-svn: 213241

1 files changed, 11 insertions, 0 deletions

diff --git a/clang/lib/Driver/Tools.cpp b/clang/lib/Driver/Tools.cpp
index e47db33803a..8f0902d80df 100644
--- a/clang/lib/Driver/Tools.cpp
+++ b/clang/lib/Driver/Tools.cpp
@@ -1036,6 +1036,17 @@ static void getMIPSTargetFeatures(const Driver &D, const llvm::Triple &Triple,
   mips::getMipsCPUAndABI(Args, Triple, CPUName, ABIName);
   ABIName = getGnuCompatibleMipsABIName(ABIName);
 
+  // Always override the backend's default ABI.
+  StringRef ABIFeature = llvm::StringSwitch<StringRef>(ABIName)
+                              .Case("32", "+o32")
+                              .Case("n32", "+n32")
+                              .Case("64", "+n64")
+                              .Case("eabi", "+eabi")
+                              .Default(("+" + ABIName).str());
+  Features.push_back("-o32");
+  Features.push_back("-n64");
+  Features.push_back(Args.MakeArgString(ABIFeature));
+
   StringRef FloatABI = getMipsFloatABI(D, Args);
   if (FloatABI == "soft") {
     // FIXME: Note, this is a hack. We need to pass the selected float