[Lldb-commits] [lldb] [lldb] Add a unit test for Wasm architecture compatibility (PR #213070)

[Jonas Devlieghere via lldb-commits]

https://github.com/JDevlieghere created https://github.com/llvm/llvm-project/pull/213070

A Wasm module encodes neither a vendor nor an OS, so ObjectFileWasm reports a bare wasm32 or wasm64 architecture. That keeps an on-disk module compatible with the more specific triple a Wasm runtime reports at launch, which lets the dynamic loader reuse the module instead of reparsing it from process memory. An over-specified triple, including one that spells out an unknown vendor and OS, does not match, because an explicitly specified component still counts as specified.

>From fc8ed7656a044a01c0582964a18153253b2aafa4 Mon Sep 17 00:00:00 2001
From: Jonas Devlieghere <jonas at devlieghere.com>
Date: Thu, 30 Jul 2026 09:47:16 -0700
Subject: [PATCH] [lldb] Add a unit test for Wasm architecture compatibility

A Wasm module encodes neither a vendor nor an OS, so ObjectFileWasm
reports a bare wasm32 or wasm64 architecture. That keeps an on-disk
module compatible with the more specific triple a Wasm runtime reports
at launch, which lets the dynamic loader reuse the module instead of
reparsing it from process memory. An over-specified triple, including
one that spells out an unknown vendor and OS, does not match, because
an explicitly specified component still counts as specified.
---
 lldb/unittests/Utility/ArchSpecTest.cpp | 26 +++++++++++++++++++++++++
 1 file changed, 26 insertions(+)

diff --git a/lldb/unittests/Utility/ArchSpecTest.cpp b/lldb/unittests/Utility/ArchSpecTest.cpp
index 4d914315dd1a0..7027c7648a273 100644
--- a/lldb/unittests/Utility/ArchSpecTest.cpp
+++ b/lldb/unittests/Utility/ArchSpecTest.cpp
@@ -482,6 +482,32 @@ TEST(ArchSpecTest, Compatibility) {
   }
 }
 
+TEST(ArchSpecTest, WasmCompatibility) {
+  // A Wasm module encodes no vendor or OS: those are properties of the runtime
+  // executing it. A bare wasm32 or wasm64 architecture therefore has to stay
+  // compatible with the more specific triple a runtime reports at launch.
+  {
+    ArchSpec A("wasm32");
+    ArchSpec B("wasm32-wamr-wasi-wasm");
+    ASSERT_TRUE(A.IsCompatibleMatch(B));
+    ASSERT_TRUE(B.IsCompatibleMatch(A));
+  }
+  {
+    // An explicitly specified "unknown" OS is still a specified OS, and does
+    // not match a runtime that reports a different one.
+    ArchSpec A("wasm32-unknown-unknown-wasm");
+    ArchSpec B("wasm32-wamr-wasi-wasm");
+    ASSERT_FALSE(A.IsCompatibleMatch(B));
+    ASSERT_FALSE(B.IsCompatibleMatch(A));
+  }
+  {
+    ArchSpec A("wasm32");
+    ArchSpec B("wasm64-wamr-wasi-wasm");
+    ASSERT_FALSE(A.IsCompatibleMatch(B));
+    ASSERT_FALSE(B.IsCompatibleMatch(A));
+  }
+}
+
 TEST(ArchSpecTest, OperatorBool) {
   EXPECT_FALSE(ArchSpec());
   EXPECT_TRUE(ArchSpec("x86_64-pc-linux"));