[PM] Complete the cross-layer interfaces with a Module-to-Function

proxy. This lets a function pass query a module analysis manager.
However, the interface is const to indicate that only cached results can
be safely queried.

With this, I think the new pass manager is largely functionally complete
for modules and analyses. Still lots to test, and need to generalize to
SCCs and Loops, and need to build an adaptor layer to support the use of
existing Pass objects in the new managers.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@195538 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/IR/PassManager.h

@@ -733,6 +733,50 @@ private:
   FunctionAnalysisManager &FAM;
 };
 
+/// \brief A function analysis which acts as a proxy for a module analysis
+/// manager.
+///
+/// This primarily provides an accessor to a parent module analysis manager to
+/// function passes. Only the const interface of the module analysis manager is
+/// provided to indicate that once inside of a function analysis pass you
+/// cannot request a module analysis to actually run. Instead, the user must
+/// rely on the \c getCachedResult API.
+///
+/// This proxy *doesn't* manage the invalidation in any way. That is handled by
+/// the recursive return path of each layer of the pass manager and the
+/// returned PreservedAnalysis set.
+class ModuleAnalysisManagerFunctionProxy {
+public:
+  /// \brief Result proxy object for \c ModuleAnalysisManagerFunctionProxy.
+  class Result {
+  public:
+    Result(const ModuleAnalysisManager &MAM) : MAM(MAM) {}
+
+    const ModuleAnalysisManager &getManager() const { return MAM; }
+
+    /// \brief Handle invalidation by ignoring it, this pass is immutable.
+    bool invalidate(Function *) { return false; }
+
+  private:
+    const ModuleAnalysisManager &MAM;
+  };
+
+  static void *ID() { return (void *)&PassID; }
+
+  ModuleAnalysisManagerFunctionProxy(const ModuleAnalysisManager &MAM)
+      : MAM(MAM) {}
+
+  /// \brief Run the analysis pass and create our proxy result object.
+  /// Nothing to see here, it just forwards the \c MAM reference into the
+  /// result.
+  Result run(Function *) { return Result(MAM); }
+
+private:
+  static char PassID;
+
+  const ModuleAnalysisManager &MAM;
+};
+
 /// \brief Trivial adaptor that maps from a module to its functions.
 ///
 /// Designed to allow composition of a FunctionPass(Manager) and

lib/IR/PassManager.cpp

@@ -170,3 +170,5 @@ bool FunctionAnalysisManagerModuleProxy::Result::invalidate(
   // Return false to indicate that this result is still a valid proxy.
   return false;
 }
+
+char ModuleAnalysisManagerFunctionProxy::PassID;

unittests/IR/PassManagerTest.cpp

@@ -51,6 +51,33 @@ private:
 
 char TestFunctionAnalysis::PassID;
 
+class TestModuleAnalysis {
+public:
+  struct Result {
+    Result(int Count) : FunctionCount(Count) {}
+    int FunctionCount;
+  };
+
+  static void *ID() { return (void * )&PassID; }
+
+  TestModuleAnalysis(int &Runs) : Runs(Runs) {}
+
+  Result run(Module *M, ModuleAnalysisManager *AM) {
+    ++Runs;
+    int Count = 0;
+    for (Module::iterator I = M->begin(), E = M->end(); I != E; ++I)
+      ++Count;
+    return Result(Count);
+  }
+
+private:
+  static char PassID;
+
+  int &Runs;
+};
+
+char TestModuleAnalysis::PassID;
+
 struct TestModulePass {
   TestModulePass(int &RunCount) : RunCount(RunCount) {}
 
@@ -72,11 +99,8 @@ struct TestMinPreservingModulePass {
   PreservedAnalyses run(Module *M, ModuleAnalysisManager *AM) {
     PreservedAnalyses PA;
 
-    // Check that we can get cached result objects for modules.
-    const FunctionAnalysisManagerModuleProxy::Result *R =
-        AM->getCachedResult<FunctionAnalysisManagerModuleProxy>(M);
-    (void)R; // FIXME: We should test this better by querying an actual analysis
-             // pass in interesting ways.
+    // Force running an analysis.
+    (void)AM->getResult<TestModuleAnalysis>(M);
 
     PA.preserve<FunctionAnalysisManagerModuleProxy>();
     return PA;
@@ -85,13 +109,21 @@ struct TestMinPreservingModulePass {
 
 struct TestFunctionPass {
   TestFunctionPass(int &RunCount, int &AnalyzedInstrCount,
+                   int &AnalyzedFunctionCount,
                    bool OnlyUseCachedResults = false)
       : RunCount(RunCount), AnalyzedInstrCount(AnalyzedInstrCount),
+        AnalyzedFunctionCount(AnalyzedFunctionCount),
         OnlyUseCachedResults(OnlyUseCachedResults) {}
 
   PreservedAnalyses run(Function *F, FunctionAnalysisManager *AM) {
     ++RunCount;
 
+    const ModuleAnalysisManager &MAM =
+        AM->getResult<ModuleAnalysisManagerFunctionProxy>(F).getManager();
+    if (const TestModuleAnalysis::Result *TMA =
+            MAM.getCachedResult<TestModuleAnalysis>(F->getParent()))
+      AnalyzedFunctionCount += TMA->FunctionCount;
+
     if (OnlyUseCachedResults) {
       // Hack to force the use of the cached interface.
       if (const TestFunctionAnalysis::Result *AR =
@@ -108,6 +140,7 @@ struct TestFunctionPass {
 
   int &RunCount;
   int &AnalyzedInstrCount;
+  int &AnalyzedFunctionCount;
   bool OnlyUseCachedResults;
 };
 
@@ -152,11 +185,14 @@ public:
 
 TEST_F(PassManagerTest, Basic) {
   FunctionAnalysisManager FAM;
-  int AnalysisRuns = 0;
-  FAM.registerPass(TestFunctionAnalysis(AnalysisRuns));
+  int FunctionAnalysisRuns = 0;
+  FAM.registerPass(TestFunctionAnalysis(FunctionAnalysisRuns));
 
   ModuleAnalysisManager MAM;
+  int ModuleAnalysisRuns = 0;
+  MAM.registerPass(TestModuleAnalysis(ModuleAnalysisRuns));
   MAM.registerPass(FunctionAnalysisManagerModuleProxy(FAM));
+  FAM.registerPass(ModuleAnalysisManagerFunctionProxy(MAM));
 
   ModulePassManager MPM;
 
@@ -164,7 +200,9 @@ TEST_F(PassManagerTest, Basic) {
   FunctionPassManager FPM1;
   int FunctionPassRunCount1 = 0;
   int AnalyzedInstrCount1 = 0;
-  FPM1.addPass(TestFunctionPass(FunctionPassRunCount1, AnalyzedInstrCount1));
+  int AnalyzedFunctionCount1 = 0;
+  FPM1.addPass(TestFunctionPass(FunctionPassRunCount1, AnalyzedInstrCount1,
+                                AnalyzedFunctionCount1));
   MPM.addPass(createModuleToFunctionPassAdaptor(FPM1));
 
   // Count the runs over a module.
@@ -175,7 +213,9 @@ TEST_F(PassManagerTest, Basic) {
   FunctionPassManager FPM2;
   int FunctionPassRunCount2 = 0;
   int AnalyzedInstrCount2 = 0;
-  FPM2.addPass(TestFunctionPass(FunctionPassRunCount2, AnalyzedInstrCount2));
+  int AnalyzedFunctionCount2 = 0;
+  FPM2.addPass(TestFunctionPass(FunctionPassRunCount2, AnalyzedInstrCount2,
+                                AnalyzedFunctionCount2));
   MPM.addPass(createModuleToFunctionPassAdaptor(FPM2));
 
   // A third function pass manager but with only preserving intervening passes
@@ -184,7 +224,9 @@ TEST_F(PassManagerTest, Basic) {
   FunctionPassManager FPM3;
   int FunctionPassRunCount3 = 0;
   int AnalyzedInstrCount3 = 0;
-  FPM3.addPass(TestFunctionPass(FunctionPassRunCount3, AnalyzedInstrCount3));
+  int AnalyzedFunctionCount3 = 0;
+  FPM3.addPass(TestFunctionPass(FunctionPassRunCount3, AnalyzedInstrCount3,
+                                AnalyzedFunctionCount3));
   FPM3.addPass(TestInvalidationFunctionPass("f"));
   MPM.addPass(createModuleToFunctionPassAdaptor(FPM3));
 
@@ -193,15 +235,19 @@ TEST_F(PassManagerTest, Basic) {
   FunctionPassManager FPM4;
   int FunctionPassRunCount4 = 0;
   int AnalyzedInstrCount4 = 0;
-  FPM4.addPass(TestFunctionPass(FunctionPassRunCount4, AnalyzedInstrCount4));
+  int AnalyzedFunctionCount4 = 0;
+  FPM4.addPass(TestFunctionPass(FunctionPassRunCount4, AnalyzedInstrCount4,
+                                AnalyzedFunctionCount4));
   MPM.addPass(createModuleToFunctionPassAdaptor(FPM4));
 
   // A fifth function pass manager but which uses only cached results.
   FunctionPassManager FPM5;
   int FunctionPassRunCount5 = 0;
   int AnalyzedInstrCount5 = 0;
+  int AnalyzedFunctionCount5 = 0;
   FPM5.addPass(TestInvalidationFunctionPass("f"));
   FPM5.addPass(TestFunctionPass(FunctionPassRunCount5, AnalyzedInstrCount5,
+                                AnalyzedFunctionCount5,
                                 /*OnlyUseCachedResults=*/true));
   MPM.addPass(createModuleToFunctionPassAdaptor(FPM5));
 
@@ -213,20 +259,27 @@ TEST_F(PassManagerTest, Basic) {
   // Validate all function pass counter sets are the same.
   EXPECT_EQ(3, FunctionPassRunCount1);
   EXPECT_EQ(5, AnalyzedInstrCount1);
+  EXPECT_EQ(0, AnalyzedFunctionCount1);
   EXPECT_EQ(3, FunctionPassRunCount2);
   EXPECT_EQ(5, AnalyzedInstrCount2);
+  EXPECT_EQ(0, AnalyzedFunctionCount2);
   EXPECT_EQ(3, FunctionPassRunCount3);
   EXPECT_EQ(5, AnalyzedInstrCount3);
+  EXPECT_EQ(0, AnalyzedFunctionCount3);
   EXPECT_EQ(3, FunctionPassRunCount4);
   EXPECT_EQ(5, AnalyzedInstrCount4);
+  EXPECT_EQ(0, AnalyzedFunctionCount4);
   EXPECT_EQ(3, FunctionPassRunCount5);
   EXPECT_EQ(2, AnalyzedInstrCount5); // Only 'g' and 'h' were cached.
+  EXPECT_EQ(0, AnalyzedFunctionCount5);
 
   // Validate the analysis counters:
   //   first run over 3 functions, then module pass invalidates
   //   second run over 3 functions, nothing invalidates
   //   third run over 0 functions, but 1 function invalidated
   //   fourth run over 1 function
-  EXPECT_EQ(7, AnalysisRuns);
+  EXPECT_EQ(7, FunctionAnalysisRuns);
+
+  EXPECT_EQ(1, ModuleAnalysisRuns);
 }
 }