diff --git a/clang/docs/tools/clang-formatted-files.txt b/clang/docs/tools/clang-formatted-files.txt
--- a/clang/docs/tools/clang-formatted-files.txt
+++ b/clang/docs/tools/clang-formatted-files.txt
@@ -129,6 +129,7 @@
 clang/include/clang/Analysis/FlowSensitive/DataflowEnvironment.h
 clang/include/clang/Analysis/FlowSensitive/DataflowLattice.h
 clang/include/clang/Analysis/FlowSensitive/DataflowWorklist.h
+clang/include/clang/Analysis/FlowSensitive/DebugSupport.h
 clang/include/clang/Analysis/FlowSensitive/MapLattice.h
 clang/include/clang/Analysis/FlowSensitive/MatchSwitch.h
 clang/include/clang/Analysis/FlowSensitive/NoopLattice.h
@@ -309,6 +310,7 @@
 clang/lib/Analysis/FlowSensitive/ControlFlowContext.cpp
 clang/lib/Analysis/FlowSensitive/DataflowAnalysisContext.cpp
 clang/lib/Analysis/FlowSensitive/DataflowEnvironment.cpp
+clang/lib/Analysis/FlowSensitive/DebugSupport.cpp
 clang/lib/Analysis/FlowSensitive/Transfer.cpp
 clang/lib/Analysis/FlowSensitive/TypeErasedDataflowAnalysis.cpp
 clang/lib/Analysis/FlowSensitive/WatchedLiteralsSolver.cpp
diff --git a/clang/include/clang/Analysis/FlowSensitive/DebugSupport.h b/clang/include/clang/Analysis/FlowSensitive/DebugSupport.h
new file mode 100644
--- /dev/null
+++ b/clang/include/clang/Analysis/FlowSensitive/DebugSupport.h
@@ -0,0 +1,39 @@
+//===-- DebugSupport.h ------------------------------------------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+//  This file defines functions which generate more readable forms of data
+//  structures used in the dataflow analyses, for debugging purposes.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_CLANG_ANALYSIS_FLOWSENSITIVE_DEBUGSUPPORT_H_
+#define LLVM_CLANG_ANALYSIS_FLOWSENSITIVE_DEBUGSUPPORT_H_
+
+#include <string>
+
+#include "clang/Analysis/FlowSensitive/Value.h"
+#include "llvm/ADT/DenseMap.h"
+
+namespace clang {
+namespace dataflow {
+/// Returns a string representation for the boolean value `B`.
+///
+/// Atomic booleans appearing in the boolean value `B` are assigned to labels
+/// either specified in `AtomNames` or created by default rules as B0, B1, ...
+///
+/// Requirements:
+///
+///   Names assigned to atoms should not be repeated in `AtomNames`.
+std::string
+debugString(BoolValue &B,
+            llvm::DenseMap<AtomicBoolValue *, std::string> AtomNames = {{}});
+
+} // namespace dataflow
+} // namespace clang
+
+#endif // LLVM_CLANG_ANALYSIS_FLOWSENSITIVE_DEBUGSUPPORT_H_
diff --git a/clang/lib/Analysis/FlowSensitive/CMakeLists.txt b/clang/lib/Analysis/FlowSensitive/CMakeLists.txt
--- a/clang/lib/Analysis/FlowSensitive/CMakeLists.txt
+++ b/clang/lib/Analysis/FlowSensitive/CMakeLists.txt
@@ -5,6 +5,7 @@
   Transfer.cpp
   TypeErasedDataflowAnalysis.cpp
   WatchedLiteralsSolver.cpp
+  DebugSupport.cpp
 
   LINK_LIBS
   clangAnalysis
diff --git a/clang/lib/Analysis/FlowSensitive/DebugSupport.cpp b/clang/lib/Analysis/FlowSensitive/DebugSupport.cpp
new file mode 100644
--- /dev/null
+++ b/clang/lib/Analysis/FlowSensitive/DebugSupport.cpp
@@ -0,0 +1,102 @@
+//===- DebugSupport.cpp -----------------------------------------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+//  This file defines functions which generate more readable forms of data
+//  structures used in the dataflow analyses, for debugging purposes.
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/Analysis/FlowSensitive/DebugSupport.h"
+#include "clang/Analysis/FlowSensitive/Value.h"
+#include "llvm/ADT/DenseMap.h"
+#include "llvm/ADT/StringSet.h"
+#include "llvm/Support/ErrorHandling.h"
+#include "llvm/Support/FormatAdapters.h"
+#include "llvm/Support/FormatVariadic.h"
+
+namespace clang {
+namespace dataflow {
+
+using llvm::fmt_pad;
+using llvm::formatv;
+
+class DebugStringGenerator {
+public:
+  explicit DebugStringGenerator(
+      llvm::DenseMap<AtomicBoolValue *, std::string> AtomNames)
+      : Counter(0), AtomNames(std::move(AtomNames)) {
+#ifndef NDEBUG
+    llvm::StringSet<> Names;
+    for (auto &N : AtomNames) {
+      assert(Names.insert(N.second).second &&
+             "The same name must not assigned to different atoms");
+    }
+#endif
+  }
+
+  /// Returns a string representation of a boolean value `B`.
+  std::string debugString(BoolValue &B, size_t Depth = 0) {
+    std::string S;
+    switch (B.getKind()) {
+    case Value::Kind::AtomicBool: {
+      S = getAtomName(&cast<AtomicBoolValue>(B));
+      break;
+    }
+    case Value::Kind::Conjunction: {
+      auto &C = cast<ConjunctionValue>(B);
+      auto L = debugString(C.getLeftSubValue(), Depth + 1);
+      auto R = debugString(C.getRightSubValue(), Depth + 1);
+      S = formatv("(and\n{0}\n{1})", L, R);
+      break;
+    }
+    case Value::Kind::Disjunction: {
+      auto &D = cast<DisjunctionValue>(B);
+      auto L = debugString(D.getLeftSubValue(), Depth + 1);
+      auto R = debugString(D.getRightSubValue(), Depth + 1);
+      S = formatv("(or\n{0}\n{1})", L, R);
+      break;
+    }
+    case Value::Kind::Negation: {
+      auto &N = cast<NegationValue>(B);
+      S = formatv("(not\n{0})", debugString(N.getSubVal(), Depth + 1));
+      break;
+    }
+    default:
+      llvm_unreachable("Unhandled value kind");
+    }
+    auto Indent = Depth * 4;
+    return formatv("{0}", fmt_pad(S, Indent, 0));
+  }
+
+private:
+  /// Returns the name assigned to `Atom`, either user-specified or created by
+  /// default rules (B0, B1, ...).
+  std::string getAtomName(AtomicBoolValue *Atom) {
+    auto Entry = AtomNames.try_emplace(Atom, formatv("B{0}", Counter));
+    if (Entry.second) {
+      Counter++;
+    }
+    return Entry.first->second;
+  }
+
+  // Keep track of number of atoms without a user-specified name, used to assign
+  // non-repeating default names to such atoms.
+  size_t Counter;
+
+  // Keep track of names assigned to atoms.
+  llvm::DenseMap<AtomicBoolValue *, std::string> AtomNames;
+};
+
+std::string
+debugString(BoolValue &B,
+            llvm::DenseMap<AtomicBoolValue *, std::string> AtomNames) {
+  return DebugStringGenerator(AtomNames).debugString(B);
+}
+
+} // namespace dataflow
+} // namespace clang
diff --git a/clang/unittests/Analysis/FlowSensitive/CMakeLists.txt b/clang/unittests/Analysis/FlowSensitive/CMakeLists.txt
--- a/clang/unittests/Analysis/FlowSensitive/CMakeLists.txt
+++ b/clang/unittests/Analysis/FlowSensitive/CMakeLists.txt
@@ -7,6 +7,7 @@
   ChromiumCheckModelTest.cpp
   DataflowAnalysisContextTest.cpp
   DataflowEnvironmentTest.cpp
+  DebugSupportTest.cpp
   MapLatticeTest.cpp
   MatchSwitchTest.cpp
   MultiVarConstantPropagationTest.cpp
diff --git a/clang/unittests/Analysis/FlowSensitive/DebugSupportTest.cpp b/clang/unittests/Analysis/FlowSensitive/DebugSupportTest.cpp
new file mode 100644
--- /dev/null
+++ b/clang/unittests/Analysis/FlowSensitive/DebugSupportTest.cpp
@@ -0,0 +1,190 @@
+//===- unittests/Analysis/FlowSensitive/DebugSupportTest.cpp --------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/Analysis/FlowSensitive/DebugSupport.h"
+#include "TestingSupport.h"
+#include "clang/Analysis/FlowSensitive/Value.h"
+#include "gmock/gmock.h"
+#include "gtest/gtest.h"
+
+namespace {
+
+using namespace clang;
+using namespace dataflow;
+
+using test::ConstraintContext;
+using testing::StrEq;
+
+TEST(BoolValueDebugStringTest, AtomicBoolean) {
+  // B0
+  ConstraintContext Ctx;
+  auto B = Ctx.atom();
+
+  auto Expected = R"(B0)";
+  debugString(*B);
+  EXPECT_THAT(debugString(*B), StrEq(Expected));
+}
+
+TEST(BoolValueDebugStringTest, Negation) {
+  // !B0
+  ConstraintContext Ctx;
+  auto B = Ctx.neg(Ctx.atom());
+
+  auto Expected = R"((not
+    B0))";
+  EXPECT_THAT(debugString(*B), StrEq(Expected));
+}
+
+TEST(BoolValueDebugStringTest, Conjunction) {
+  // B0 ^ B1
+  ConstraintContext Ctx;
+  auto B = Ctx.conj(Ctx.atom(), Ctx.atom());
+
+  auto Expected = R"((and
+    B0
+    B1))";
+  EXPECT_THAT(debugString(*B), StrEq(Expected));
+}
+
+TEST(BoolValueDebugStringTest, Disjunction) {
+  // B0 v B1
+  ConstraintContext Ctx;
+  auto B = Ctx.disj(Ctx.atom(), Ctx.atom());
+
+  auto Expected = R"((or
+    B0
+    B1))";
+  EXPECT_THAT(debugString(*B), StrEq(Expected));
+}
+
+TEST(BoolValueDebugStringTest, Implication) {
+  // B0 => B1, implemented as !B0 v B1
+  ConstraintContext Ctx;
+  auto B = Ctx.disj(Ctx.neg(Ctx.atom()), Ctx.atom());
+
+  auto Expected = R"((or
+    (not
+        B0)
+    B1))";
+  EXPECT_THAT(debugString(*B), StrEq(Expected));
+}
+
+TEST(BoolValueDebugStringTest, Iff) {
+  // B0 <=> B1, implemented as (!B0 v B1) ^ (B0 v !B1)
+  ConstraintContext Ctx;
+  auto B0 = Ctx.atom();
+  auto B1 = Ctx.atom();
+  auto B = Ctx.conj(Ctx.disj(Ctx.neg(B0), B1), Ctx.disj(B0, Ctx.neg(B1)));
+
+  auto Expected = R"((and
+    (or
+        (not
+            B0)
+        B1)
+    (or
+        B0
+        (not
+            B1))))";
+  EXPECT_THAT(debugString(*B), StrEq(Expected));
+}
+
+TEST(BoolValueDebugStringTest, Xor) {
+  // (B0 ^ !B1) V (!B0 ^ B1)
+  ConstraintContext Ctx;
+  auto B0 = Ctx.atom();
+  auto B1 = Ctx.atom();
+  auto B = Ctx.disj(Ctx.conj(B0, Ctx.neg(B1)), Ctx.conj(Ctx.neg(B0), B1));
+
+  auto Expected = R"((or
+    (and
+        B0
+        (not
+            B1))
+    (and
+        (not
+            B0)
+        B1)))";
+  EXPECT_THAT(debugString(*B), StrEq(Expected));
+}
+
+TEST(BoolValueDebugStringTest, NestedBoolean) {
+  // B0 ^ (B1 v (B2 ^ (B3 v B4)))
+  ConstraintContext Ctx;
+  auto B = Ctx.conj(
+      Ctx.atom(),
+      Ctx.disj(Ctx.atom(),
+               Ctx.conj(Ctx.atom(), Ctx.disj(Ctx.atom(), Ctx.atom()))));
+
+  auto Expected = R"((and
+    B0
+    (or
+        B1
+        (and
+            B2
+            (or
+                B3
+                B4)))))";
+  EXPECT_THAT(debugString(*B), StrEq(Expected));
+}
+
+TEST(BoolValueDebugStringTest, AtomicBooleanWithName) {
+  // True
+  ConstraintContext Ctx;
+  auto True = cast<AtomicBoolValue>(Ctx.atom());
+  auto B = True;
+
+  auto Expected = R"(True)";
+  EXPECT_THAT(debugString(*B, {{True, "True"}}), StrEq(Expected));
+}
+
+TEST(BoolValueDebugStringTest, ComplexBooleanWithNames) {
+  // (Cond ^ Then ^ !Else) v (!Cond ^ !Then ^ Else)
+  ConstraintContext Ctx;
+  auto Cond = cast<AtomicBoolValue>(Ctx.atom());
+  auto Then = cast<AtomicBoolValue>(Ctx.atom());
+  auto Else = cast<AtomicBoolValue>(Ctx.atom());
+  auto B = Ctx.disj(Ctx.conj(Cond, Ctx.conj(Then, Ctx.neg(Else))),
+                    Ctx.conj(Ctx.neg(Cond), Ctx.conj(Ctx.neg(Then), Else)));
+
+  auto Expected = R"((or
+    (and
+        Cond
+        (and
+            Then
+            (not
+                Else)))
+    (and
+        (not
+            Cond)
+        (and
+            (not
+                Then)
+            Else))))";
+  EXPECT_THAT(debugString(*B, {{Cond, "Cond"}, {Then, "Then"}, {Else, "Else"}}),
+              StrEq(Expected));
+}
+
+TEST(BoolValueDebugStringTest, ComplexBooleanWithSomeNames) {
+  // (False && B0) v (True v B1)
+  ConstraintContext Ctx;
+  auto True = cast<AtomicBoolValue>(Ctx.atom());
+  auto False = cast<AtomicBoolValue>(Ctx.atom());
+  auto B = Ctx.disj(Ctx.conj(False, Ctx.atom()), Ctx.disj(True, Ctx.atom()));
+
+  auto Expected = R"((or
+    (and
+        False
+        B0)
+    (or
+        True
+        B1)))";
+  EXPECT_THAT(debugString(*B, {{True, "True"}, {False, "False"}}),
+              StrEq(Expected));
+}
+
+} // namespace
diff --git a/llvm/utils/gn/secondary/clang/lib/Analysis/FlowSensitive/BUILD.gn b/llvm/utils/gn/secondary/clang/lib/Analysis/FlowSensitive/BUILD.gn
--- a/llvm/utils/gn/secondary/clang/lib/Analysis/FlowSensitive/BUILD.gn
+++ b/llvm/utils/gn/secondary/clang/lib/Analysis/FlowSensitive/BUILD.gn
@@ -12,5 +12,6 @@
     "Transfer.cpp",
     "TypeErasedDataflowAnalysis.cpp",
     "WatchedLiteralsSolver.cpp",
+    "DebugSupport.cpp",
   ]
 }