Merge pull request swiftlang#34387 from CodaFi/a-giraffe-on-a-beach

Add Compilation "Wave" Assertion in +Asserts Builds

Author: CodaFi

include/swift/AST/AbstractSourceFileDepGraphFactory.h

@@ -13,6 +13,7 @@
 #ifndef SWIFT_AST_SOURCE_FILE_DEP_GRAPH_CONSTRUCTOR_H
 #define SWIFT_AST_SOURCE_FILE_DEP_GRAPH_CONSTRUCTOR_H
 
+#include "swift/AST/Decl.h"
 #include "swift/AST/DeclContext.h"
 #include "swift/AST/FineGrainedDependencies.h"
 
@@ -72,6 +73,21 @@ class AbstractSourceFileDepGraphFactory {
                        Optional<StringRef> fingerprint);
 
   void addAUsedDecl(const DependencyKey &def, const DependencyKey &use);
+
+  static Optional<std::string> getFingerprintIfAny(
+      std::pair<const NominalTypeDecl *, const ValueDecl *>) {
+    return None;
+  }
+
+  static Optional<std::string> getFingerprintIfAny(const Decl *d) {
+    if (const auto *idc = dyn_cast<IterableDeclContext>(d)) {
+      auto result = idc->getBodyFingerprint();
+      assert((!result || !result->empty()) &&
+             "Fingerprint should never be empty");
+      return result;
+    }
+    return None;
+  }
 };
 
 } // namespace fine_grained_dependencies

include/swift/AST/Decl.h

@@ -950,9 +950,6 @@ class alignas(1 << DeclAlignInBits) Decl {
   /// If this returns true, the decl can be safely casted to ValueDecl.
   bool isPotentiallyOverridable() const;
 
-  /// Returns true if this Decl cannot be seen by any other source file
-  bool isPrivateToEnclosingFile() const;
-
   /// Retrieve the global actor attribute that applies to this declaration,
   /// if any.
   ///

include/swift/Driver/Job.h

@@ -308,6 +308,23 @@ class Job {
   /// The modification time of the main input file, if any.
   llvm::sys::TimePoint<> InputModTime = llvm::sys::TimePoint<>::max();
 
+#ifndef NDEBUG
+  /// The "wave" of incremental jobs that this \c Job was scheduled into.
+  ///
+  /// The first "wave" of jobs is computed by the driver from the set of inputs
+  /// and external files that have been mutated by the user. From there, as
+  /// jobs from the first wave finish executing, we reload their \c swiftdeps
+  /// files and re-integrate them into the dependency graph to discover
+  /// the jobs for the second "wave".
+  ///
+  /// In +asserts builds, we ensure that no more than two "waves" occur for
+  /// any given incremental compilation session. This is a consequence of
+  /// 1) transitivity in dependency arcs
+  /// 2) dependency tracing from uses that affect a def's interfaces to that
+  ///    def's uses.
+  mutable unsigned Wave = 1;
+#endif
+
 public:
   Job(const JobAction &Source, SmallVectorImpl<const Job *> &&Inputs,
       std::unique_ptr<CommandOutput> Output, const char *Executable,
@@ -399,6 +416,11 @@ class Job {
   /// Assumes that, if a compile job, has one primary swift input
   /// May return empty if none.
   StringRef getFirstSwiftPrimaryInput() const;
+
+#ifndef NDEBUG
+  unsigned getWave() const { return Wave; }
+  void setWave(unsigned WaveNum) const { Wave = WaveNum; }
+#endif
 };
 
 /// A BatchJob comprises a _set_ of jobs, each of which is sufficiently similar

lib/AST/FrontendSourceFileDepGraphFactory.cpp

@@ -229,6 +229,13 @@ std::string FrontendSourceFileDepGraphFactory::getFingerprint(SourceFile *SF) {
   return getInterfaceHash(SF);
 }
 
+std::string
+FrontendSourceFileDepGraphFactory::getInterfaceHash(SourceFile *SF) {
+  llvm::SmallString<32> interfaceHash;
+  SF->getInterfaceHash(interfaceHash);
+  return interfaceHash.str().str();
+}
+
 //==============================================================================
 // MARK: FrontendSourceFileDepGraphFactory - adding collections of defined Decls
 //==============================================================================
@@ -407,7 +414,8 @@ template <NodeKind kind, typename ContentsT>
 void FrontendSourceFileDepGraphFactory::addAllDefinedDeclsOfAGivenType(
     std::vector<ContentsT> &contentsVec) {
   for (const auto &declOrPair : contentsVec) {
-    Optional<std::string> fp = getFingerprintIfAny(declOrPair);
+    Optional<std::string> fp =
+        AbstractSourceFileDepGraphFactory::getFingerprintIfAny(declOrPair);
     addADefinedDecl(
         DependencyKey::createForProvidedEntityInterface<kind>(declOrPair),
         fp ? StringRef(fp.getValue()) : Optional<StringRef>());
@@ -519,33 +527,6 @@ void FrontendSourceFileDepGraphFactory::addAllUsedDecls() {
     .enumerateAllUses();
 }
 
-//==============================================================================
-// MARK: FrontendSourceFileDepGraphFactory - adding individual defined Decls
-//==============================================================================
-
-std::string
-FrontendSourceFileDepGraphFactory::getInterfaceHash(SourceFile *SF) {
-  llvm::SmallString<32> interfaceHash;
-  SF->getInterfaceHash(interfaceHash);
-  return interfaceHash.str().str();
-}
-
-/// At present, only \c NominalTypeDecls have (body) fingerprints
-Optional<std::string> FrontendSourceFileDepGraphFactory::getFingerprintIfAny(
-    std::pair<const NominalTypeDecl *, const ValueDecl *>) {
-  return None;
-}
-Optional<std::string>
-FrontendSourceFileDepGraphFactory::getFingerprintIfAny(const Decl *d) {
-  if (const auto *idc = dyn_cast<IterableDeclContext>(d)) {
-    auto result = idc->getBodyFingerprint();
-    assert((!result || !result->empty()) &&
-           "Fingerprint should never be empty");
-    return result;
-  }
-  return None;
-}
-
 //==============================================================================
 // MARK: ModuleDepGraphFactory
 //==============================================================================
@@ -591,29 +572,10 @@ template <NodeKind kind, typename ContentsT>
 void ModuleDepGraphFactory::addAllDefinedDeclsOfAGivenType(
     std::vector<ContentsT> &contentsVec) {
   for (const auto &declOrPair : contentsVec) {
-    Optional<std::string> fp = getFingerprintIfAny(declOrPair);
+    Optional<std::string> fp =
+        AbstractSourceFileDepGraphFactory::getFingerprintIfAny(declOrPair);
     addADefinedDecl(
         DependencyKey::createForProvidedEntityInterface<kind>(declOrPair),
         fp ? StringRef(fp.getValue()) : Optional<StringRef>());
   }
 }
-
-//==============================================================================
-// MARK: ModuleDepGraphFactory - adding individual defined Decls
-//==============================================================================
-
-/// At present, only \c NominalTypeDecls have (body) fingerprints
-Optional<std::string> ModuleDepGraphFactory::getFingerprintIfAny(
-    std::pair<const NominalTypeDecl *, const ValueDecl *>) {
-  return None;
-}
-Optional<std::string>
-ModuleDepGraphFactory::getFingerprintIfAny(const Decl *d) {
-  if (const auto *idc = dyn_cast<IterableDeclContext>(d)) {
-    auto result = idc->getBodyFingerprint();
-    assert((!result || !result->empty()) &&
-           "Fingerprint should never be empty");
-    return result;
-  }
-  return None;
-}

lib/AST/FrontendSourceFileDepGraphFactory.h

@@ -44,12 +44,6 @@ class FrontendSourceFileDepGraphFactory
   /// create node pairs for context and name
   template <NodeKind kind, typename ContentsT>
   void addAllDefinedDeclsOfAGivenType(std::vector<ContentsT> &contentsVec);
-
-  /// At present, only nominals, protocols, and extensions have (body)
-  /// fingerprints
-  static Optional<std::string>
-  getFingerprintIfAny(std::pair<const NominalTypeDecl *, const ValueDecl *>);
-  static Optional<std::string> getFingerprintIfAny(const Decl *d);
 };
 
 class ModuleDepGraphFactory : public AbstractSourceFileDepGraphFactory {
@@ -68,12 +62,6 @@ class ModuleDepGraphFactory : public AbstractSourceFileDepGraphFactory {
   /// create node pairs for context and name
   template <NodeKind kind, typename ContentsT>
   void addAllDefinedDeclsOfAGivenType(std::vector<ContentsT> &contentsVec);
-
-  /// At present, only nominals, protocols, and extensions have (body)
-  /// fingerprints
-  static Optional<std::string> getFingerprintIfAny(
-      std::pair<const NominalTypeDecl *, const ValueDecl *>);
-  static Optional<std::string> getFingerprintIfAny(const Decl *d);
 };
 
 } // namespace fine_grained_dependencies

lib/Driver/Compilation.cpp

@@ -323,6 +323,17 @@ namespace driver {
         return;
       }
 
+#ifndef NDEBUG
+      // If we can, assert that no compile jobs are scheduled beyond the second
+      // wave. If this assertion fails, it indicates one of:
+      // 1) A failure of the driver's job tracing machinery to follow a
+      // dependency arc.
+      // 2) A failure of the frontend to emit a dependency arc.
+      if (isa<CompileJobAction>(Cmd->getSource()) && Cmd->getWave() > 2) {
+        llvm_unreachable("Scheduled a command into a third wave!");
+      }
+#endif
+
       // Adding to scheduled means we've committed to its completion (not
       // distinguished from skipping). We never remove it once inserted.
       ScheduledCommands.insert(Cmd);
@@ -694,8 +705,16 @@ namespace driver {
                        "because of dependencies discovered later");
 
       scheduleCommandsInSortedOrder(DependentsInEffect);
-      for (const Job *Cmd : DependentsInEffect)
-        DeferredCommands.erase(Cmd);
+      for (const Job *Cmd : DependentsInEffect) {
+        if (DeferredCommands.erase(Cmd)) {
+#ifndef NDEBUG
+          if (isa<CompileJobAction>(FinishedCmd->getSource()))
+            Cmd->setWave(FinishedCmd->getWave() + 1);
+#else
+          continue;
+#endif
+        }
+      }
       return TaskFinishedResponse::ContinueExecution;
     }