[llvm] [Triple] Add target triple support for CheriotRTOS. (PR #155374)

[Owen Anderson via llvm-commits]

https://github.com/resistor created https://github.com/llvm/llvm-project/pull/155374

For context, CheriotRTOS is a custom RTOS co-designed for the CHERIoT
CHERI-enabled RISCV32E platform. It uses a custom ABI and linkage model,
necesitating representing it in the target triple.


>From f43e1573472897910198dbc2f59c169eeda8dca4 Mon Sep 17 00:00:00 2001
From: Owen Anderson <resistor at mac.com>
Date: Tue, 26 Aug 2025 16:50:08 +0800
Subject: [PATCH] [Triple] Add target triple support for CheriotRTOS.

For context, CheriotRTOS is a custom RTOS co-designed for the CHERIoT
CHERI-enabled RISCV32E platform. It uses a custom ABI and linkage model,
necesitating representing it in the target triple.
---
 llvm/include/llvm/TargetParser/Triple.h    | 3 ++-
 llvm/lib/TargetParser/Triple.cpp           | 2 ++
 llvm/unittests/TargetParser/TripleTest.cpp | 5 +++++
 3 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/llvm/include/llvm/TargetParser/Triple.h b/llvm/include/llvm/TargetParser/Triple.h
index ede9797ac7488..f85984ed4f328 100644
--- a/llvm/include/llvm/TargetParser/Triple.h
+++ b/llvm/include/llvm/TargetParser/Triple.h
@@ -245,7 +245,8 @@ class Triple {
     LiteOS,
     Serenity,
     Vulkan, // Vulkan SPIR-V
-    LastOSType = Vulkan
+    CheriotRTOS,
+    LastOSType = CheriotRTOS
   };
   enum EnvironmentType {
     UnknownEnvironment,
diff --git a/llvm/lib/TargetParser/Triple.cpp b/llvm/lib/TargetParser/Triple.cpp
index 6acb0bc49ecfe..8eb863aee02d9 100644
--- a/llvm/lib/TargetParser/Triple.cpp
+++ b/llvm/lib/TargetParser/Triple.cpp
@@ -329,6 +329,7 @@ StringRef Triple::getOSTypeName(OSType Kind) {
   case LiteOS: return "liteos";
   case XROS: return "xros";
   case Vulkan: return "vulkan";
+  case CheriotRTOS: return "cheriotrtos";
   }
 
   llvm_unreachable("Invalid OSType");
@@ -729,6 +730,7 @@ static Triple::OSType parseOS(StringRef OSName) {
     .StartsWith("liteos", Triple::LiteOS)
     .StartsWith("serenity", Triple::Serenity)
     .StartsWith("vulkan", Triple::Vulkan)
+    .StartsWith("cheriotrtos", Triple::CheriotRTOS)
     .Default(Triple::UnknownOS);
 }
 
diff --git a/llvm/unittests/TargetParser/TripleTest.cpp b/llvm/unittests/TargetParser/TripleTest.cpp
index 35927e340a257..7d07615d273d7 100644
--- a/llvm/unittests/TargetParser/TripleTest.cpp
+++ b/llvm/unittests/TargetParser/TripleTest.cpp
@@ -1381,6 +1381,11 @@ TEST(TripleTest, ParsedIDs) {
 
   T = Triple("huh");
   EXPECT_EQ(Triple::UnknownArch, T.getArch());
+
+  T = Triple("riscv32-unknown-cheriotrtos");
+  EXPECT_EQ(Triple::riscv32, T.getArch());
+  EXPECT_EQ(Triple::UnknownVendor, T.getVendor());
+  EXPECT_EQ(Triple::CheriotRTOS, T.getOS());
 }
 
 static std::string Join(StringRef A, StringRef B, StringRef C) {