[Analysis] Provide inlined AnalysisKey in AnalysisInfoMixin

[paperchalice]

The comment about it is 8 years ago, we have newer VS and C++17. Try to move analysis keys to AnalysisInfoMixin.
If this change is feasible on Windows, I will remove analysis keys in analysis passes later.

[llvmbot]

@llvm/pr-subscribers-llvm-ir

Author: None (paperchalice)

Changes

The comment about it is 8 years ago, we have newer VS and C++17. Try to move analysis keys to AnalysisInfoMixin.

---

Full diff: https://github.com/llvm/llvm-project/pull/116046.diff

1 Files Affected:

• (modified) llvm/include/llvm/IR/PassManager.h (+4-10)

diff --git a/llvm/include/llvm/IR/PassManager.h b/llvm/include/llvm/IR/PassManager.h
index d269221fac0701..69643d6cab8fc2 100644
--- a/llvm/include/llvm/IR/PassManager.h
+++ b/llvm/include/llvm/IR/PassManager.h
@@ -95,21 +95,15 @@ struct AnalysisInfoMixin : PassInfoMixin<DerivedT> {
   /// This ID is a pointer type that is guaranteed to be 8-byte aligned and thus
   /// suitable for use in sets, maps, and other data structures that use the low
   /// bits of pointers.
-  ///
-  /// Note that this requires the derived type provide a static \c AnalysisKey
-  /// member called \c Key.
-  ///
-  /// FIXME: The only reason the mixin type itself can't declare the Key value
-  /// is that some compilers cannot correctly unique a templated static variable
-  /// so it has the same addresses in each instantiation. The only currently
-  /// known platform with this limitation is Windows DLL builds, specifically
-  /// building each part of LLVM as a DLL. If we ever remove that build
-  /// configuration, this mixin can provide the static key as well.
   static AnalysisKey *ID() {
     static_assert(std::is_base_of<AnalysisInfoMixin, DerivedT>::value,
                   "Must pass the derived type as the template argument!");
     return &DerivedT::Key;
   }
+
+private:
+  /// Opaque, unique ID for this analysis type.
+  static constexpr AnalysisKey Key = {};
 };
 
 namespace detail {

[paperchalice]

CC @fsfod because you are working on dynamic library support on Windows.

[fsfod]

I remember I had to work around with a clang-cl bug that was fixed in v19 to get these to export correctly.

[compnerd]

A local build in DLL mode would definitely be good to run against the minimum supported VS (which I believe is 2019).

If that compiler is able to deal with this properly, addressing this makes sense. I do wonder if this is going to break any out-of-tree analysis passes though due to the redeclaration.

[paperchalice]

Should be fine if ID returns &AnalysisInfoMixin::Key. Looks like it's not time yet because we need a new enough clang-cl.

[aeubanks]

Should be fine if ID returns &AnalysisInfoMixin::Key. Looks like it's not time yet because we need a new enough clang-cl.

Can you post more details on which version of clang-cl is broken?

[fsfod]

I should said the issue with the my new DLL build setup not the old existing system that filters exports with a python script, The current changes from this PR doesn't make it any worse or regress the new DLL build setup at least.

The original issue i had was this field wasn't getting imported from a extern explicit template instantiation declaration annotated with dllimport.
The missing symbols were:

llvm\lld-link : error : undefined symbol: private: static struct llvm::AnalysisKey llvm::InnerAnalysisManagerProxy<class llvm::AnalysisManager<class llvm::Function>, class llvm::Module>::Key
  >>> referenced by unittests\Analysis\CMakeFiles\AnalysisTests.dir\CGSCCPassManagerTest.cpp.obj:(public: __cdecl `anonymous namespace'::CGSCCPassManagerTest::CGSCCPassManagerTest(void))
  >>> referenced by unittests\Analysis\CMakeFiles\AnalysisTests.dir\CGSCCPassManagerTest.cpp.obj:(public: virtual class std::unique_ptr<struct llvm::detail::AnalysisResultConcept<class llvm::Module, class llvm::AnalysisManager<class llvm::Module>::Invalidator>, struct std::default_delete<struct llvm::detail::AnalysisResultConcept<class llvm::Module, class llvm::AnalysisManager<class llvm::Module>::Invalidator>>> __cdecl llvm::detail::AnalysisPassModel<class llvm::Module, class llvm::LazyCallGraphAnalysis, class llvm::AnalysisManager<class llvm::Module>::Invalidator>::run(class llvm::Module &, class llvm::AnalysisManager<class llvm::Module> &))
  >>> referenced by unittests\Analysis\CMakeFiles\AnalysisTests.dir\CGSCCPassManagerTest.cpp.obj:(private: virtual class llvm::PreservedAnalyses __cdecl std::_Func_impl_no_alloc<class `private: virtual void __cdecl `anonymous namespace'::CGSCCPassManagerTest_TestModulePassInvalidatesSCCAnalysis_Test::TestBody(void)'::`1'::<lambda_18>, class llvm::PreservedAnalyses, class PreservedAnalyses::Module &, class PreservedAnalyses::AnalysisManager<class llvm::Module> &>::_Do_call(class llvm::Module &, class llvm::AnalysisManager<class llvm::Module> &))
  >>> referenced 4 more times
  
lld-link : error : undefined symbol: private: static struct llvm::AnalysisKey llvm::InnerAnalysisManagerProxy<class llvm::AnalysisManager<class llvm::LazyCallGraph::SCC, class llvm::LazyCallGraph &>, class llvm::Module>::Key
  >>> referenced by unittests\Analysis\CMakeFiles\AnalysisTests.dir\CGSCCPassManagerTest.cpp.obj:(public: __cdecl `anonymous namespace'::CGSCCPassManagerTest::CGSCCPassManagerTest(void))
  >>> referenced by unittests\Analysis\CMakeFiles\AnalysisTests.dir\CGSCCPassManagerTest.cpp.obj:(private: virtual class llvm::PreservedAnalyses __cdecl std::_Func_impl_no_alloc<class `private: virtual void __cdecl `anonymous namespace'::CGSCCPassManagerTest_TestModulePassInvalidatesSCCAnalysis_Test::TestBody(void)'::`1'::<lambda_18>, class llvm::PreservedAnalyses, class PreservedAnalyses::Module &, class PreservedAnalyses::AnalysisManager<class llvm::Module> &>::_Do_call(class llvm::Module &, class llvm::AnalysisManager<class llvm::Module> &))
  >>> referenced by unittests\Analysis\CMakeFiles\AnalysisTests.dir\CGSCCPassManagerTest.cpp.obj:(private: virtual class llvm::PreservedAnalyses __cdecl std::_Func_impl_no_alloc<class `private: virtual void __cdecl `anonymous namespace'::CGSCCPassManagerTest_TestModulePassCanPreserveSCCAnalysis_Test::TestBody(void)'::`1'::<lambda_20>, class llvm::PreservedAnalyses, class PreservedAnalyses::Module &,

I double checked building with clang-cl 19 and this wasn't fixed so idk if I got confused with some other dllexport bug.

[paperchalice]

Unfortunately the address is still not unique in pass plugin and I can't reproduce it locally.

[paperchalice]

There is still something like:

llvm-project/llvm/include/llvm/IR/PassManager.h

Lines 642 to 644 in 0ee5924

	template <typename AnalysisManagerT, typename IRUnitT, typename... ExtraArgTs>
	AnalysisKey
	InnerAnalysisManagerProxy<AnalysisManagerT, IRUnitT, ExtraArgTs...>::Key;

which would be an issue in future...