[llvm] Export LLVM plugin entrypoint for windows shared library builds (PR #115431)

[Thomas Fransham via llvm-commits]

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@@ -107,7 +107,13 @@ class PassPlugin {
 ///   };
 /// }
 /// ```
+
+#if defined(_WIN32) && defined(LLVM_BUILD_LLVM_DYLIB)
+extern "C" ::llvm::PassPluginLibraryInfo __declspec(dllexport)
+llvmGetPassPluginInfo();
+#else
 extern "C" ::llvm::PassPluginLibraryInfo LLVM_ATTRIBUTE_WEAK
 llvmGetPassPluginInfo();
+#endif
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fsfod wrote:

That looks a really painful way to declare it.

https://github.com/llvm/llvm-project/pull/115431