[mips] Allow ABI names from MCTargetOptions::ABIName but only if they agree with the triple.

[sdardis]

Summary

This brings the last of the targets into the 'pass in both the triple and
MCTargetOptions' camp.

Depends on D21069. I had expected to need a corresponding clang patch but
this proved unnecessary.

Patch by: Daniel Sanders

[dsanders]

Refresh and ping.

[dsanders]

Refresh and ping

[dsanders]

One last ping since I need to either commit this series next week or hand over to a colleague to continue it.

[sdardis]

Taking over this patch series.

[sdardis]

Rebase + ping. I am aware that you're exploring your alternate solution Eric.

[sdardis]

Ping.

[sdardis]

Ping.

[sdardis]

Ping.

[sdardis]

Ping.

[sdardis]

Rebase and ping.

lib/Support/Triple.cpp

case Triple::mips64el: {
     // N64 that is required by the MIPS backend.
     if (ABI == "o32")
       T = T.get32BitArchVariant();
     else if (ABI == "n32" || ABI == "n64")
       T = T.get64BitArchVariant();
 
     if (NewEnv != T.getEnvironment())
       T.setEnvironment(NewEnv);
-    return std::make_pair(T, "");
+    return std::make_pair(T, ABI);
   }
   }
 }
 
 StringRef Triple::getARMCPUForArch(StringRef MArch) const {
   if (MArch.empty())
     MArch = getArchName();
   MArch = ARM::getCanonicalArchName(MArch);

lib/Target/Mips/MCTargetDesc/MipsABIInfo.cpp

if (IsO32())
     return CC != CallingConv::Fast ? 16 : 0;
   if (IsN32() || IsN64())
     return 0;
   llvm_unreachable("Unhandled ABI");
 }
 
 MipsABIInfo MipsABIInfo::computeTargetABI(const Triple &TT, StringRef CPU,
                                           const MCTargetOptions &Options) {
-  if (!Options.getABIName().empty())
-    llvm_unreachable(
-        "ABI name should be in triple. See Triple::getABIVariant()");
+  if (Options.getABIName().startswith("o32")) {
+    assert((TT.getEnvironment() == Triple::ABI32 ||
+            TT.getEnvironment() == Triple::AndroidABI32 ||
+            TT.getEnvironment() == Triple::GNUABI32) &&
+           "Selected ABI disagrees with triple");
+    return MipsABIInfo::O32();
+  } else if (Options.getABIName().startswith("n32")) {
+    assert((TT.getEnvironment() == Triple::ABIN32 ||
+            TT.getEnvironment() == Triple::GNUABIN32) &&
+           "Selected ABI disagrees with triple");
+    return MipsABIInfo::N32();
+  } else if (Options.getABIName().startswith("n64")) {
+    assert((TT.getEnvironment() == Triple::ABI64 ||
+            TT.getEnvironment() == Triple::AndroidABI64 ||
+            TT.getEnvironment() == Triple::GNUABI64) &&
+           "Selected ABI disagrees with triple");
+    return MipsABIInfo::N64();
+  } else if (!Options.getABIName().empty())
+    llvm_unreachable("Unknown ABI option for MIPS");
   else if (TT.getEnvironment() == Triple::ABI32 ||
            TT.getEnvironment() == Triple::AndroidABI32 ||
            TT.getEnvironment() == Triple::GNUABI32)
     return MipsABIInfo::O32();
   else if (TT.getEnvironment() == Triple::ABIN32 ||
            TT.getEnvironment() == Triple::GNUABIN32)
     return MipsABIInfo::N32();
   else if (TT.getEnvironment() == Triple::ABI64 ||

unittests/ADT/TripleTest.cpp

for (const auto &TripleStr :
     EXPECT_EQ((T.getArch() == Triple::mips64 || T.getArch() == Triple::mips64el)
                   ? Triple::GNUABI64
                   : Triple::GNUABI32,
               Default.first.getEnvironment());
     EXPECT_EQ(Triple::GNUABI32, O32.first.getEnvironment());
     EXPECT_EQ(Triple::GNUABIN32, N32.first.getEnvironment());
     EXPECT_EQ(Triple::GNUABI64, N64.first.getEnvironment());
 
-    EXPECT_EQ("", Default.second);
-    EXPECT_EQ("", O32.second);
-    EXPECT_EQ("", N32.second);
-    EXPECT_EQ("", N64.second);
+    EXPECT_EQ((T.getArch() == Triple::mips64 || T.getArch() == Triple::mips64el)
+                  ? "n64"
+                  : "o32",
+              Default.second);
+    EXPECT_EQ("o32", O32.second);
+    EXPECT_EQ("n32", N32.second);
+    EXPECT_EQ("n64", N64.second);
 
     // Try an unsupported ABI name. This should change the arch component of the
     // triple to UnknownArch. Other values are undefined.
     std::pair<Triple, StringRef> Foo = T.getABIVariant("foo");
     EXPECT_EQ(Triple::UnknownArch, Foo.first.getArch());
   }
 
   for (const auto &TripleStr :
for (const auto &TripleStr :
 
     EXPECT_EQ((T.getArch() == Triple::mips64 || T.getArch() == Triple::mips64el)
                   ? Triple::AndroidABI64
                   : Triple::AndroidABI32,
               Default.first.getEnvironment());
     EXPECT_EQ(Triple::AndroidABI32, O32.first.getEnvironment());
     EXPECT_EQ(Triple::AndroidABI64, N64.first.getEnvironment());
 
-    EXPECT_EQ("", Default.second);
-    EXPECT_EQ("", O32.second);
-    EXPECT_EQ("", N64.second);
+    EXPECT_EQ((T.getArch() == Triple::mips64 || T.getArch() == Triple::mips64el)
+                  ? "n64"
+                  : "o32",
+              Default.second);
+    EXPECT_EQ("o32", O32.second);
+    EXPECT_EQ("n64", N64.second);
 
     // Try an unsupported ABI name. This should change the arch component of the
     // triple to UnknownArch. Other values are undefined.
     std::pair<Triple, StringRef> Foo = T.getABIVariant("foo");
     EXPECT_EQ(Triple::UnknownArch, Foo.first.getArch());
 
     // N32 is known to LLVM but unsupported for Android.
     EXPECT_EQ(Triple::UnknownArch, N32.first.getArch());
for (const auto &TripleStr :
     EXPECT_EQ((T.getArch() == Triple::mips64 || T.getArch() == Triple::mips64el)
                   ? Triple::ABI64
                   : Triple::ABI32,
               Default.first.getEnvironment());
     EXPECT_EQ(Triple::ABI32, O32.first.getEnvironment());
     EXPECT_EQ(Triple::ABIN32, N32.first.getEnvironment());
     EXPECT_EQ(Triple::ABI64, N64.first.getEnvironment());
 
-    EXPECT_EQ("", Default.second);
-    EXPECT_EQ("", O32.second);
-    EXPECT_EQ("", N32.second);
-    EXPECT_EQ("", N64.second);
+    EXPECT_EQ((T.getArch() == Triple::mips64 || T.getArch() == Triple::mips64el)
+                  ? "n64"
+                  : "o32",
+              Default.second);
+    EXPECT_EQ("o32", O32.second);
+    EXPECT_EQ("n32", N32.second);
+    EXPECT_EQ("n64", N64.second);
     EXPECT_EQ("foo", Foo.second);
   }
 }
 
 TEST(TripleTest, getOSVersion) {
   Triple T;
   unsigned Major, Minor, Micro;