[clang][dataflow] Debug string for value kinds.

Differential Revision: https://reviews.llvm.org/D131891

clang/include/clang/Analysis/FlowSensitive/DebugSupport.h

@@ -20,15 +20,19 @@
 #include "clang/Analysis/FlowSensitive/Solver.h"
 #include "clang/Analysis/FlowSensitive/Value.h"
 #include "llvm/ADT/DenseMap.h"
+#include "llvm/ADT/StringRef.h"
 
 namespace clang {
 namespace dataflow {
 
+/// Returns a string representation of a value kind.
+llvm::StringRef debugString(Value::Kind Kind);
+
 /// Returns a string representation of a boolean assignment to true or false.
-std::string debugString(Solver::Result::Assignment Assignment);
+llvm::StringRef debugString(Solver::Result::Assignment Assignment);
 
 /// Returns a string representation of the result status of a SAT check.
-std::string debugString(Solver::Result::Status Status);
+llvm::StringRef debugString(Solver::Result::Status Status);
 
 /// Returns a string representation for the boolean value `B`.
 ///

clang/lib/Analysis/FlowSensitive/DebugSupport.cpp

@@ -18,6 +18,7 @@
 #include "clang/Analysis/FlowSensitive/Value.h"
 #include "llvm/ADT/DenseMap.h"
 #include "llvm/ADT/STLExtras.h"
+#include "llvm/ADT/StringRef.h"
 #include "llvm/ADT/StringSet.h"
 #include "llvm/Support/ErrorHandling.h"
 #include "llvm/Support/FormatAdapters.h"
@@ -31,7 +32,33 @@ using llvm::AlignStyle;
 using llvm::fmt_pad;
 using llvm::formatv;
 
-std::string debugString(Solver::Result::Assignment Assignment) {
+llvm::StringRef debugString(Value::Kind Kind) {
+  switch (Kind) {
+  case Value::Kind::Integer:
+    return "Integer";
+  case Value::Kind::Reference:
+    return "Reference";
+  case Value::Kind::Pointer:
+    return "Pointer";
+  case Value::Kind::Struct:
+    return "Struct";
+  case Value::Kind::AtomicBool:
+    return "AtomicBool";
+  case Value::Kind::Conjunction:
+    return "Conjunction";
+  case Value::Kind::Disjunction:
+    return "Disjunction";
+  case Value::Kind::Negation:
+    return "Negation";
+  case Value::Kind::Implication:
+    return "Implication";
+  case Value::Kind::Biconditional:
+    return "Biconditional";
+  }
+  llvm_unreachable("Unhandled value kind");
+}
+
+llvm::StringRef debugString(Solver::Result::Assignment Assignment) {
   switch (Assignment) {
   case Solver::Result::Assignment::AssignedFalse:
     return "False";
@@ -41,7 +68,7 @@ std::string debugString(Solver::Result::Assignment Assignment) {
   llvm_unreachable("Booleans can only be assigned true/false");
 }
 
-std::string debugString(Solver::Result::Status Status) {
+llvm::StringRef debugString(Solver::Result::Status Status) {
   switch (Status) {
   case Solver::Result::Status::Satisfiable:
     return "Satisfiable";