[clang][dataflow] Extend debug output for Environment.

[martinboehme]

• Print ReturnLoc, ReturnVal, and ThisPointeeLoc if applicable.

• For entries in LocToVal that correspond to declarations, print the names
  of the declarations next to them.

I've removed the FIXME because all relevant fields are now being dumped. I'm
not sure we actually need the capability for the caller to specify which fields
to dump, so I've simply deleted this part of the comment.

Some examples of the output:

[llvmbot]

@llvm/pr-subscribers-clang-analysis

@llvm/pr-subscribers-clang

Author: None (martinboehme)

Changes

• Print ReturnLoc, ReturnVal, and ThisPointeeLoc if applicable.

• For entries in LocToVal that correspond to declarations, print the names
  of the declarations next to them.

I've removed the FIXME because all relevant fields are now being dumped. I'm
not sure we actually need the capability for the caller to specify which fields
to dump, so I've simply deleted this part of the comment.

---

Full diff: https://github.com/llvm/llvm-project/pull/79982.diff

1 Files Affected:

• (modified) clang/lib/Analysis/FlowSensitive/DataflowEnvironment.cpp (+30-6)

diff --git a/clang/lib/Analysis/FlowSensitive/DataflowEnvironment.cpp b/clang/lib/Analysis/FlowSensitive/DataflowEnvironment.cpp
index acb38e576474..01db65866d13 100644
--- a/clang/lib/Analysis/FlowSensitive/DataflowEnvironment.cpp
+++ b/clang/lib/Analysis/FlowSensitive/DataflowEnvironment.cpp
@@ -1009,12 +1009,15 @@ bool Environment::allows(const Formula &F) 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->getNameAsString() << ", " << L << "]\n";
+  llvm::DenseMap<const StorageLocation *, std::string> LocToName;
+  if (ThisPointeeLoc != nullptr)
+    LocToName[ThisPointeeLoc] = "this";
 
+  OS << "DeclToLoc:\n";
+  for (auto [D, L] : DeclToLoc) {
+    auto Iter = LocToName.insert({L, D->getNameAsString()}).first;
+    OS << "  [" << Iter->second << ", " << L << "]\n";
+  }
   OS << "ExprToLoc:\n";
   for (auto [E, L] : ExprToLoc)
     OS << "  [" << E << ", " << L << "]\n";
@@ -1025,7 +1028,28 @@ void Environment::dump(raw_ostream &OS) const {
 
   OS << "LocToVal:\n";
   for (auto [L, V] : LocToVal) {
-    OS << "  [" << L << ", " << V << ": " << *V << "]\n";
+    OS << "  [" << L;
+    if (auto Iter = LocToName.find(L); Iter != LocToName.end())
+      OS << " (" << Iter->second << ")";
+    OS << ", " << V << ": " << *V << "]\n";
+  }
+
+  if (const FunctionDecl *Func = getCurrentFunc()) {
+    if (Func->getReturnType()->isReferenceType()) {
+      OS << "ReturnLoc: " << ReturnLoc;
+      if (auto Iter = LocToName.find(ReturnLoc); Iter != LocToName.end())
+        OS << " (" << Iter->second << ")";
+      OS << "\n";
+    } else if (!Func->getReturnType()->isVoidType()) {
+      if (ReturnVal == nullptr)
+        OS << "ReturnVal: nullptr\n";
+      else
+        OS << "ReturnVal: " << *ReturnVal << "\n";
+    }
+
+    if (isa<CXXMethodDecl>(Func)) {
+      OS << "ThisPointeeLoc: " << ThisPointeeLoc << "\n";
+    }
   }
 
   OS << "\n";