Update prebuilt Clang to r416183b from Android.

https://android.googlesource.com/platform/prebuilts/clang/host/
linux-x86/+/06a71ddac05c22edb2d10b590e1769b3f8619bef

clang 12.0.5 (based on r416183b) from build 7284624.

Change-Id: I277a316abcf47307562d8b748b84870f31a72866
Signed-off-by: Olivier Deprez <olivier.deprez@arm.com>
diff --git a/linux-x64/clang/include/llvm/IR/PassInstrumentation.h b/linux-x64/clang/include/llvm/IR/PassInstrumentation.h
index f8a1196..291f324 100644
--- a/linux-x64/clang/include/llvm/IR/PassInstrumentation.h
+++ b/linux-x64/clang/include/llvm/IR/PassInstrumentation.h
@@ -44,10 +44,6 @@
 ///      of a pass. For those callbacks returning false means pass will not be
 ///      executed.
 ///
-/// TODO: currently there is no way for a pass to opt-out of execution control
-/// (e.g. become unskippable). PassManager is the only entity that determines
-/// how pass instrumentation affects pass execution.
-///
 //===----------------------------------------------------------------------===//
 
 #ifndef LLVM_IR_PASSINSTRUMENTATION_H
@@ -56,12 +52,13 @@
 #include "llvm/ADT/Any.h"
 #include "llvm/ADT/FunctionExtras.h"
 #include "llvm/ADT/SmallVector.h"
-#include "llvm/Support/TypeName.h"
+#include "llvm/ADT/StringMap.h"
 #include <type_traits>
 
 namespace llvm {
 
 class PreservedAnalyses;
+class StringRef;
 
 /// This class manages callbacks registration, as well as provides a way for
 /// PassInstrumentation to pass control to the registered callbacks.
@@ -71,13 +68,17 @@
   // to take them as constant pointers, wrapped with llvm::Any.
   // For the case when IRUnit has been invalidated there is a different
   // callback to use - AfterPassInvalidated.
+  // We call all BeforePassFuncs to determine if a pass should run or not.
+  // BeforeNonSkippedPassFuncs are called only if the pass should run.
   // TODO: currently AfterPassInvalidated does not accept IRUnit, since passing
-  // already invalidated IRUnit is unsafe. There are ways to handle invalidated IRUnits
-  // in a safe way, and we might pursue that as soon as there is a useful instrumentation
-  // that needs it.
+  // already invalidated IRUnit is unsafe. There are ways to handle invalidated
+  // IRUnits in a safe way, and we might pursue that as soon as there is a
+  // useful instrumentation that needs it.
   using BeforePassFunc = bool(StringRef, Any);
-  using AfterPassFunc = void(StringRef, Any);
-  using AfterPassInvalidatedFunc = void(StringRef);
+  using BeforeSkippedPassFunc = void(StringRef, Any);
+  using BeforeNonSkippedPassFunc = void(StringRef, Any);
+  using AfterPassFunc = void(StringRef, Any, const PreservedAnalyses &);
+  using AfterPassInvalidatedFunc = void(StringRef, const PreservedAnalyses &);
   using BeforeAnalysisFunc = void(StringRef, Any);
   using AfterAnalysisFunc = void(StringRef, Any);
 
@@ -88,8 +89,19 @@
   PassInstrumentationCallbacks(const PassInstrumentationCallbacks &) = delete;
   void operator=(const PassInstrumentationCallbacks &) = delete;
 
-  template <typename CallableT> void registerBeforePassCallback(CallableT C) {
-    BeforePassCallbacks.emplace_back(std::move(C));
+  template <typename CallableT>
+  void registerShouldRunOptionalPassCallback(CallableT C) {
+    ShouldRunOptionalPassCallbacks.emplace_back(std::move(C));
+  }
+
+  template <typename CallableT>
+  void registerBeforeSkippedPassCallback(CallableT C) {
+    BeforeSkippedPassCallbacks.emplace_back(std::move(C));
+  }
+
+  template <typename CallableT>
+  void registerBeforeNonSkippedPassCallback(CallableT C) {
+    BeforeNonSkippedPassCallbacks.emplace_back(std::move(C));
   }
 
   template <typename CallableT> void registerAfterPassCallback(CallableT C) {
@@ -111,17 +123,37 @@
     AfterAnalysisCallbacks.emplace_back(std::move(C));
   }
 
+  /// Add a class name to pass name mapping for use by pass instrumentation.
+  void addClassToPassName(StringRef ClassName, StringRef PassName);
+  /// Get the pass name for a given pass class name.
+  StringRef getPassNameForClassName(StringRef ClassName);
+
 private:
   friend class PassInstrumentation;
 
-  SmallVector<llvm::unique_function<BeforePassFunc>, 4> BeforePassCallbacks;
+  /// These are only run on passes that are not required. They return false when
+  /// an optional pass should be skipped.
+  SmallVector<llvm::unique_function<BeforePassFunc>, 4>
+      ShouldRunOptionalPassCallbacks;
+  /// These are run on passes that are skipped.
+  SmallVector<llvm::unique_function<BeforeSkippedPassFunc>, 4>
+      BeforeSkippedPassCallbacks;
+  /// These are run on passes that are about to be run.
+  SmallVector<llvm::unique_function<BeforeNonSkippedPassFunc>, 4>
+      BeforeNonSkippedPassCallbacks;
+  /// These are run on passes that have just run.
   SmallVector<llvm::unique_function<AfterPassFunc>, 4> AfterPassCallbacks;
+  /// These are run passes that have just run on invalidated IR.
   SmallVector<llvm::unique_function<AfterPassInvalidatedFunc>, 4>
       AfterPassInvalidatedCallbacks;
+  /// These are run on analyses that are about to be run.
   SmallVector<llvm::unique_function<BeforeAnalysisFunc>, 4>
       BeforeAnalysisCallbacks;
+  /// These are run on analyses that have been run.
   SmallVector<llvm::unique_function<AfterAnalysisFunc>, 4>
       AfterAnalysisCallbacks;
+
+  StringMap<std::string> ClassToPassName;
 };
 
 /// This class provides instrumentation entry points for the Pass Manager,
@@ -129,6 +161,26 @@
 class PassInstrumentation {
   PassInstrumentationCallbacks *Callbacks;
 
+  // Template argument PassT of PassInstrumentation::runBeforePass could be two
+  // kinds: (1) a regular pass inherited from PassInfoMixin (happen when
+  // creating a adaptor pass for a regular pass); (2) a type-erased PassConcept
+  // created from (1). Here we want to make case (1) skippable unconditionally
+  // since they are regular passes. We call PassConcept::isRequired to decide
+  // for case (2).
+  template <typename PassT>
+  using has_required_t = decltype(std::declval<PassT &>().isRequired());
+
+  template <typename PassT>
+  static std::enable_if_t<is_detected<has_required_t, PassT>::value, bool>
+  isRequired(const PassT &Pass) {
+    return Pass.isRequired();
+  }
+  template <typename PassT>
+  static std::enable_if_t<!is_detected<has_required_t, PassT>::value, bool>
+  isRequired(const PassT &Pass) {
+    return false;
+  }
+
 public:
   /// Callbacks object is not owned by PassInstrumentation, its life-time
   /// should at least match the life-time of corresponding
@@ -139,15 +191,28 @@
 
   /// BeforePass instrumentation point - takes \p Pass instance to be executed
   /// and constant reference to IR it operates on. \Returns true if pass is
-  /// allowed to be executed.
+  /// allowed to be executed. These are only run on optional pass since required
+  /// passes must always be run. This allows these callbacks to print info when
+  /// they want to skip a pass.
   template <typename IRUnitT, typename PassT>
   bool runBeforePass(const PassT &Pass, const IRUnitT &IR) const {
     if (!Callbacks)
       return true;
 
     bool ShouldRun = true;
-    for (auto &C : Callbacks->BeforePassCallbacks)
-      ShouldRun &= C(Pass.name(), llvm::Any(&IR));
+    if (!isRequired(Pass)) {
+      for (auto &C : Callbacks->ShouldRunOptionalPassCallbacks)
+        ShouldRun &= C(Pass.name(), llvm::Any(&IR));
+    }
+
+    if (ShouldRun) {
+      for (auto &C : Callbacks->BeforeNonSkippedPassCallbacks)
+        C(Pass.name(), llvm::Any(&IR));
+    } else {
+      for (auto &C : Callbacks->BeforeSkippedPassCallbacks)
+        C(Pass.name(), llvm::Any(&IR));
+    }
+
     return ShouldRun;
   }
 
@@ -155,20 +220,22 @@
   /// just been executed and constant reference to \p IR it operates on.
   /// \p IR is guaranteed to be valid at this point.
   template <typename IRUnitT, typename PassT>
-  void runAfterPass(const PassT &Pass, const IRUnitT &IR) const {
+  void runAfterPass(const PassT &Pass, const IRUnitT &IR,
+                    const PreservedAnalyses &PA) const {
     if (Callbacks)
       for (auto &C : Callbacks->AfterPassCallbacks)
-        C(Pass.name(), llvm::Any(&IR));
+        C(Pass.name(), llvm::Any(&IR), PA);
   }
 
   /// AfterPassInvalidated instrumentation point - takes \p Pass instance
   /// that has just been executed. For use when IR has been invalidated
   /// by \p Pass execution.
   template <typename IRUnitT, typename PassT>
-  void runAfterPassInvalidated(const PassT &Pass) const {
+  void runAfterPassInvalidated(const PassT &Pass,
+                               const PreservedAnalyses &PA) const {
     if (Callbacks)
       for (auto &C : Callbacks->AfterPassInvalidatedCallbacks)
-        C(Pass.name());
+        C(Pass.name(), PA);
   }
 
   /// BeforeAnalysis instrumentation point - takes \p Analysis instance
@@ -199,8 +266,20 @@
                   ExtraArgsT...) {
     return false;
   }
+
+  template <typename CallableT>
+  void pushBeforeNonSkippedPassCallback(CallableT C) {
+    if (Callbacks)
+      Callbacks->BeforeNonSkippedPassCallbacks.emplace_back(std::move(C));
+  }
+  void popBeforeNonSkippedPassCallback() {
+    if (Callbacks)
+      Callbacks->BeforeNonSkippedPassCallbacks.pop_back();
+  }
 };
 
+bool isSpecialPass(StringRef PassID, const std::vector<StringRef> &Specials);
+
 } // namespace llvm
 
 #endif