From c441f65f9183a4d1d7f5ecc63b4e32a42e09367e Mon Sep 17 00:00:00 2001
From: Yitzhak Mandelbaum <yitzhakm@google.com>
Date: Fri, 13 Jan 2023 19:26:57 +0000
Subject: [PATCH] [clang][dataflow] Add (initial) debug printing for `Value`
 and `Environment`.

Also adds uses of the new printing in analysis inner loop.

Differential Revision: https://reviews.llvm.org/D141716
---
 .../FlowSensitive/DataflowEnvironment.h       |  1 +
 .../clang/Analysis/FlowSensitive/Value.h      |  3 +++
 .../FlowSensitive/DataflowEnvironment.cpp     | 22 ++++++++++++++++++-
 .../TypeErasedDataflowAnalysis.cpp            | 14 +++++++++++-
 clang/lib/Analysis/FlowSensitive/Value.cpp    | 17 ++++++++++++++
 5 files changed, 55 insertions(+), 2 deletions(-)

diff --git a/clang/include/clang/Analysis/FlowSensitive/DataflowEnvironment.h b/clang/include/clang/Analysis/FlowSensitive/DataflowEnvironment.h
index 694dd0ea67d794..e457430a5e6467 100644
--- a/clang/include/clang/Analysis/FlowSensitive/DataflowEnvironment.h
+++ b/clang/include/clang/Analysis/FlowSensitive/DataflowEnvironment.h
@@ -430,6 +430,7 @@ class Environment {
   }
 
   LLVM_DUMP_METHOD void dump() const;
+  LLVM_DUMP_METHOD void dump(raw_ostream &OS) const;
 
 private:
   /// Creates a value appropriate for `Type`, if `Type` is supported, otherwise
diff --git a/clang/include/clang/Analysis/FlowSensitive/Value.h b/clang/include/clang/Analysis/FlowSensitive/Value.h
index 9012d3b00060cd..32d10a3489483c 100644
--- a/clang/include/clang/Analysis/FlowSensitive/Value.h
+++ b/clang/include/clang/Analysis/FlowSensitive/Value.h
@@ -19,6 +19,7 @@
 #include "llvm/ADT/DenseMap.h"
 #include "llvm/ADT/StringMap.h"
 #include "llvm/ADT/StringRef.h"
+#include "llvm/Support/raw_ostream.h"
 #include <cassert>
 #include <utility>
 
@@ -310,6 +311,8 @@ class StructValue final : public Value {
   llvm::DenseMap<const ValueDecl *, Value *> Children;
 };
 
+raw_ostream &operator<<(raw_ostream &OS, const Value &Val);
+
 } // namespace dataflow
 } // namespace clang
 
diff --git a/clang/lib/Analysis/FlowSensitive/DataflowEnvironment.cpp b/clang/lib/Analysis/FlowSensitive/DataflowEnvironment.cpp
index 37d200509e8d23..064d0f92e71a4b 100644
--- a/clang/lib/Analysis/FlowSensitive/DataflowEnvironment.cpp
+++ b/clang/lib/Analysis/FlowSensitive/DataflowEnvironment.cpp
@@ -786,9 +786,29 @@ bool Environment::flowConditionImplies(BoolValue &Val) const {
   return DACtx->flowConditionImplies(*FlowConditionToken, Val);
 }
 
-void Environment::dump() const {
+void Environment::dump(raw_ostream &OS) const {
+  // FIXME: add printing for remaining fields and allow caller to decide what
+  // fields are printed.
+  OS << "DeclToLoc:\n";
+  for (auto [D, L] : DeclToLoc)
+    OS << "  [" << D->getName() << ", " << L << "]\n";
+
+  OS << "ExprToLoc:\n";
+  for (auto [E, L] : ExprToLoc)
+    OS << "  [" << E << ", " << L << "]\n";
+
+  OS << "LocToVal:\n";
+  for (auto [L, V] : LocToVal) {
+    OS << "  [" << L << ", " << V << ": " << *V << "]\n";
+  }
+
+  OS << "FlowConditionToken:\n";
   DACtx->dumpFlowCondition(*FlowConditionToken);
 }
 
+void Environment::dump() const {
+  dump(llvm::dbgs());
+}
+
 } // namespace dataflow
 } // namespace clang
diff --git a/clang/lib/Analysis/FlowSensitive/TypeErasedDataflowAnalysis.cpp b/clang/lib/Analysis/FlowSensitive/TypeErasedDataflowAnalysis.cpp
index dc923fe2419751..b125701212c966 100644
--- a/clang/lib/Analysis/FlowSensitive/TypeErasedDataflowAnalysis.cpp
+++ b/clang/lib/Analysis/FlowSensitive/TypeErasedDataflowAnalysis.cpp
@@ -32,8 +32,10 @@
 #include "llvm/ADT/ArrayRef.h"
 #include "llvm/ADT/DenseSet.h"
 #include "llvm/ADT/STLExtras.h"
+#include "llvm/Support/Debug.h"
 #include "llvm/Support/Error.h"
-#include "llvm/Support/ErrorHandling.h"
+
+#define DEBUG_TYPE "clang-dataflow"
 
 namespace clang {
 namespace dataflow {
@@ -431,6 +433,8 @@ runTypeErasedDataflowAnalysis(
       std::min(RelativeMaxIterations, AbsoluteMaxIterations);
   uint32_t Iterations = 0;
   while (const CFGBlock *Block = Worklist.dequeue()) {
+    LLVM_DEBUG(llvm::dbgs()
+               << "Processing Block " << Block->getBlockID() << "\n");
     if (++Iterations > MaxIterations) {
       return llvm::createStringError(std::errc::timed_out,
                                      "maximum number of iterations reached");
@@ -440,8 +444,16 @@ runTypeErasedDataflowAnalysis(
         BlockStates[Block->getBlockID()];
     TypeErasedDataflowAnalysisState NewBlockState =
         transferCFGBlock(*Block, AC);
+    LLVM_DEBUG({
+      llvm::errs() << "New Env:\n";
+      NewBlockState.Env.dump();
+    });
 
     if (OldBlockState) {
+      LLVM_DEBUG({
+        llvm::errs() << "Old Env:\n";
+        OldBlockState->Env.dump();
+      });
       if (isLoopHead(*Block)) {
         LatticeJoinEffect Effect1 = Analysis.widenTypeErased(
             NewBlockState.Lattice, OldBlockState->Lattice);
diff --git a/clang/lib/Analysis/FlowSensitive/Value.cpp b/clang/lib/Analysis/FlowSensitive/Value.cpp
index 84c1ea8ca4e97c..59affa80bdce99 100644
--- a/clang/lib/Analysis/FlowSensitive/Value.cpp
+++ b/clang/lib/Analysis/FlowSensitive/Value.cpp
@@ -11,6 +11,7 @@
 //===----------------------------------------------------------------------===//
 
 #include "clang/Analysis/FlowSensitive/Value.h"
+#include "clang/Analysis/FlowSensitive/DebugSupport.h"
 #include "llvm/Support/Casting.h"
 
 namespace clang {
@@ -35,5 +36,21 @@ bool areEquivalentValues(const Value &Val1, const Value &Val2) {
                              areEquivalentIndirectionValues(Val1, Val2)));
 }
 
+raw_ostream &operator<<(raw_ostream &OS, const Value &Val) {
+  switch (Val.getKind()) {
+  case Value::Kind::Reference: {
+    const auto *RV = cast<ReferenceValue>(&Val);
+    return OS << "Reference(" << &RV->getReferentLoc() << ")";
+  }
+  case Value::Kind::Pointer: {
+    const auto *PV = dyn_cast<PointerValue>(&Val);
+    return OS << "Pointer(" << &PV->getPointeeLoc() << ")";
+  }
+  // FIXME: support remaining cases.
+  default:
+    return OS << debugString(Val.getKind());
+  }
+}
+
 } // namespace dataflow
 } // namespace clang