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| -rw-r--r-- | llvm/include/llvm/IR/PassManager.h | 40 |
1 files changed, 40 insertions, 0 deletions
diff --git a/llvm/include/llvm/IR/PassManager.h b/llvm/include/llvm/IR/PassManager.h index e117b707ce7..8eed3f84d41 100644 --- a/llvm/include/llvm/IR/PassManager.h +++ b/llvm/include/llvm/IR/PassManager.h @@ -153,8 +153,23 @@ private: SmallPtrSet<void *, 2> PreservedPassIDs; }; +// We define the pass managers prior to the analysis managers that they use. class ModuleAnalysisManager; +/// \brief Manages a sequence of passes over Modules of IR. +/// +/// A module pass manager contains a sequence of module passes. It is also +/// itself a module pass. When it is run over a module of LLVM IR, it will +/// sequentially run each pass it contains over that module. +/// +/// If it is run with a \c ModuleAnalysisManager argument, it will propagate +/// that analysis manager to each pass it runs, as well as calling the analysis +/// manager's invalidation routine with the PreservedAnalyses of each pass it +/// runs. +/// +/// Module passes can rely on having exclusive access to the module they are +/// run over. No other threads will access that module, and they can mutate it +/// freely. However, they must not mutate other LLVM IR modules. class ModulePassManager { public: // We have to explicitly define all the special member functions because MSVC @@ -197,8 +212,33 @@ private: std::vector<std::unique_ptr<ModulePassConcept>> Passes; }; +// We define the pass managers prior to the analysis managers that they use. class FunctionAnalysisManager; +/// \brief Manages a sequence of passes over a Function of IR. +/// +/// A function pass manager contains a sequence of function passes. It is also +/// itself a function pass. When it is run over a function of LLVM IR, it will +/// sequentially run each pass it contains over that function. +/// +/// If it is run with a \c FunctionAnalysisManager argument, it will propagate +/// that analysis manager to each pass it runs, as well as calling the analysis +/// manager's invalidation routine with the PreservedAnalyses of each pass it +/// runs. +/// +/// Function passes can rely on having exclusive access to the function they +/// are run over. They should not read or modify any other functions! Other +/// threads or systems may be manipulating other functions in the module, and +/// so their state should never be relied on. +/// FIXME: Make the above true for all of LLVM's actual passes, some still +/// violate this principle. +/// +/// Function passes can also read the module containing the function, but they +/// should not modify that module outside of the use lists of various globals. +/// For example, a function pass is not permitted to add functions to the +/// module. +/// FIXME: Make the above true for all of LLVM's actual passes, some still +/// violate this principle. class FunctionPassManager { public: // We have to explicitly define all the special member functions because MSVC |
