[llvm] Add triples for managarm (#87845)

This PR aims to add a target for
[managarm](https://github.com/managarm/managarm). The targets
`{x86_64,aarch64,riscv64}-pc-managarm-{kernel,mlibc}` will be supported.

Discourse RFC:
[discourse.llvm.org/t/rfc-new-proposed-managarm-support-for-llvm-and-clang-87845/85884](https://discourse.llvm.org/t/rfc-new-proposed-managarm-support-for-llvm-and-clang-87845/85884)

Author: no92

llvm/include/llvm/TargetParser/Triple.h

@@ -208,6 +208,7 @@ class Triple {
     Linux,
     Lv2, // PS3
     MacOSX,
+    Managarm,
     NetBSD,
     OpenBSD,
     Solaris,
@@ -299,6 +300,7 @@ class Triple {
     Amplification,
     OpenCL,
     OpenHOS,
+    Mlibc,
 
     PAuthTest,
 
@@ -846,6 +848,8 @@ class Triple {
 
   bool isVulkanOS() const { return getOS() == Triple::Vulkan; }
 
+  bool isOSManagarm() const { return getOS() == Triple::Managarm; }
+
   bool isShaderStageEnvironment() const {
     EnvironmentType Env = getEnvironment();
     return Env == Triple::Pixel || Env == Triple::Vertex ||

llvm/lib/TargetParser/Triple.cpp

@@ -299,6 +299,8 @@ StringRef Triple::getOSTypeName(OSType Kind) {
   case Linux: return "linux";
   case Lv2: return "lv2";
   case MacOSX: return "macosx";
+  case Managarm:
+    return "managarm";
   case Mesa3D: return "mesa3d";
   case NVCL: return "nvcl";
   case NaCl: return "nacl";
@@ -384,6 +386,8 @@ StringRef Triple::getEnvironmentTypeName(EnvironmentType Kind) {
     return "pauthtest";
   case LLVM:
     return "llvm";
+  case Mlibc:
+    return "mlibc";
   }
 
   llvm_unreachable("Invalid EnvironmentType!");
@@ -678,6 +682,7 @@ static Triple::OSType parseOS(StringRef OSName) {
     .StartsWith("linux", Triple::Linux)
     .StartsWith("lv2", Triple::Lv2)
     .StartsWith("macos", Triple::MacOSX)
+    .StartsWith("managarm", Triple::Managarm)
     .StartsWith("netbsd", Triple::NetBSD)
     .StartsWith("openbsd", Triple::OpenBSD)
     .StartsWith("solaris", Triple::Solaris)
@@ -766,6 +771,7 @@ static Triple::EnvironmentType parseEnvironment(StringRef EnvironmentName) {
       .StartsWith("ohos", Triple::OpenHOS)
       .StartsWith("pauthtest", Triple::PAuthTest)
       .StartsWith("llvm", Triple::LLVM)
+      .StartsWith("mlibc", Triple::Mlibc)
       .Default(Triple::UnknownEnvironment);
 }
 

llvm/unittests/TargetParser/TripleTest.cpp

@@ -1354,6 +1354,24 @@ TEST(TripleTest, ParsedIDs) {
   EXPECT_EQ(Triple::UnknownOS, T.getOS());
   EXPECT_EQ(Triple::UnknownEnvironment, T.getEnvironment());
 
+  T = Triple("aarch64-unknown-managarm-mlibc");
+  EXPECT_EQ(Triple::aarch64, T.getArch());
+  EXPECT_EQ(Triple::UnknownVendor, T.getVendor());
+  EXPECT_EQ(Triple::Managarm, T.getOS());
+  EXPECT_EQ(Triple::Mlibc, T.getEnvironment());
+
+  T = Triple("x86_64-unknown-managarm-mlibc");
+  EXPECT_EQ(Triple::x86_64, T.getArch());
+  EXPECT_EQ(Triple::UnknownVendor, T.getVendor());
+  EXPECT_EQ(Triple::Managarm, T.getOS());
+  EXPECT_EQ(Triple::Mlibc, T.getEnvironment());
+
+  T = Triple("riscv64-unknown-managarm-mlibc");
+  EXPECT_EQ(Triple::riscv64, T.getArch());
+  EXPECT_EQ(Triple::UnknownVendor, T.getVendor());
+  EXPECT_EQ(Triple::Managarm, T.getOS());
+  EXPECT_EQ(Triple::Mlibc, T.getEnvironment());
+
   T = Triple("huh");
   EXPECT_EQ(Triple::UnknownArch, T.getArch());
 }