diff --git a/clang-tools-extra/clangd/CMakeLists.txt b/clang-tools-extra/clangd/CMakeLists.txt
--- a/clang-tools-extra/clangd/CMakeLists.txt
+++ b/clang-tools-extra/clangd/CMakeLists.txt
@@ -26,6 +26,9 @@
   AllTargetsInfos
   FrontendOpenMP
   )
+  
+include(${CMAKE_CURRENT_SOURCE_DIR}/quality/CompletionModel.cmake)
+gen_decision_forest(${CMAKE_CURRENT_SOURCE_DIR}/quality/model CompletionModel clang::clangd::Example)
 
 add_clang_library(clangDaemon
   AST.cpp
@@ -69,6 +72,7 @@
   TUScheduler.cpp
   URI.cpp
   XRefs.cpp
+  ${DECISION_FOREST_OUTPUT_DIR}/CompletionModel.cpp
 
   index/Background.cpp
   index/BackgroundIndexLoader.cpp
@@ -109,6 +113,10 @@
   omp_gen
   )
 
+target_include_directories(clangDaemon PUBLIC
+  $<BUILD_INTERFACE:${DECISION_FOREST_OUTPUT_DIR}>
+)
+
 clang_target_link_libraries(clangDaemon
   PRIVATE
   clangAST
diff --git a/clang-tools-extra/clangd/for-review-only/CompletionModel.h b/clang-tools-extra/clangd/for-review-only/CompletionModel.h
new file mode 100644
--- /dev/null
+++ b/clang-tools-extra/clangd/for-review-only/CompletionModel.h
@@ -0,0 +1,22 @@
+#ifndef GENERATED_DECISION_FOREST_MODEL_COMPLETIONMODEL_H
+# define GENERATED_DECISION_FOREST_MODEL_COMPLETIONMODEL_H
+# include <cstdint>
+
+namespace clang {
+namespace clangd {
+class Example {
+public:
+  void setContextKind(unsigned V) { ContextKind = 1 << V; }
+
+private:
+  uint32_t ContextKind = 0;
+
+  // Produces an integer that sorts in the same order as F.
+  // That is: a < b <==> orderEncode(a) < orderEncode(b).
+  static uint32_t OrderEncode(float F);
+  friend float Evaluate(const Example&);
+};
+float Evaluate(const Example&);
+} // namespace clangd
+} // namespace clang
+#endif // GENERATED_DECISION_FOREST_MODEL_COMPLETIONMODEL_H
\ No newline at end of file
diff --git a/clang-tools-extra/clangd/for-review-only/CompletionModel.cpp b/clang-tools-extra/clangd/for-review-only/CompletionModel.cpp
new file mode 100644
--- /dev/null
+++ b/clang-tools-extra/clangd/for-review-only/CompletionModel.cpp
@@ -0,0 +1,39 @@
+#include <cstring>
+#include <limits>
+
+#include "CompletionModel.h"
+#include "llvm/ADT/bit.h"
+#include "clang/Sema/CodeCompleteConsumer.h"
+
+#define BIT(X) (1 << X)
+
+namespace clang {
+namespace clangd {
+
+using ContextKind_type = clang::CodeCompletionContext::Kind;
+
+uint32_t Example::OrderEncode(float F) {
+  static_assert(std::numeric_limits<float>::is_iec559, "");
+  constexpr uint32_t TopBit = ~(~uint32_t{0} >> 1);
+
+  // Get the bits of the float. Endianness is the same as for integers.
+  uint32_t U = llvm::bit_cast<uint32_t>(F);
+  std::memcpy(&U, &F, sizeof(U));
+  // IEEE 754 floats compare like sign-magnitude integers.
+  if (U & TopBit)    // Negative float.
+    return 0 - U;    // Map onto the low half of integers, order reversed.
+  return U + TopBit; // Positive floats map onto the high half of integers.
+}
+
+float Evaluate(const Example& E) {
+  float Score = 0;
+  t0:
+  t0_n0: if(E.ContextKind & (BIT(ContextKind_type::CCC_DotMemberAccess)|BIT(ContextKind_type::CCC_ArrowMemberAccess))) goto t0_n2;
+  t0_n1: Score += 1.0; goto t1;
+  t0_n2: Score += 3.0; goto t1;
+  
+  t1: // No such tree.
+  return Score;
+}
+} // namespace clangd
+} // namespace clang
diff --git a/clang-tools-extra/clangd/for-review-only/DecisionForestRuntimeTest.h b/clang-tools-extra/clangd/for-review-only/DecisionForestRuntimeTest.h
new file mode 100644
--- /dev/null
+++ b/clang-tools-extra/clangd/for-review-only/DecisionForestRuntimeTest.h
@@ -0,0 +1,28 @@
+#ifndef GENERATED_DECISION_FOREST_MODEL_DECISIONFORESTRUNTIMETEST_H
+# define GENERATED_DECISION_FOREST_MODEL_DECISIONFORESTRUNTIMETEST_H
+# include <cstdint>
+
+namespace ns1 {
+namespace ns2 {
+namespace test {
+class Example {
+public:
+  void setANumber(float V) { ANumber = OrderEncode(V); }
+  void setAFloat(float V) { AFloat = OrderEncode(V); }
+  void setACategorical(unsigned V) { ACategorical = 1 << V; }
+
+private:
+  uint32_t ANumber = 0;
+  uint32_t AFloat = 0;
+  uint32_t ACategorical = 0;
+
+  // Produces an integer that sorts in the same order as F.
+  // That is: a < b <==> orderEncode(a) < orderEncode(b).
+  static uint32_t OrderEncode(float F);
+  friend float Evaluate(const Example&);
+};
+float Evaluate(const Example&);
+} // namespace test
+} // namespace ns2
+} // namespace ns1
+#endif // GENERATED_DECISION_FOREST_MODEL_DECISIONFORESTRUNTIMETEST_H
\ No newline at end of file
diff --git a/clang-tools-extra/clangd/for-review-only/DecisionForestRuntimeTest.cpp b/clang-tools-extra/clangd/for-review-only/DecisionForestRuntimeTest.cpp
new file mode 100644
--- /dev/null
+++ b/clang-tools-extra/clangd/for-review-only/DecisionForestRuntimeTest.cpp
@@ -0,0 +1,50 @@
+#include <cstring>
+#include <limits>
+
+#include "llvm/ADT/bit.h"
+#include "model/CategoricalFeature.h"
+#include "DecisionForestRuntimeTest.h"
+
+#define BIT(X) (1 << X)
+
+namespace ns1 {
+namespace ns2 {
+namespace test {
+
+using ACategorical_type = ns1::ns2::TestEnum;
+
+uint32_t Example::OrderEncode(float F) {
+  static_assert(std::numeric_limits<float>::is_iec559, "");
+  constexpr uint32_t TopBit = ~(~uint32_t{0} >> 1);
+
+  // Get the bits of the float. Endianness is the same as for integers.
+  uint32_t U = llvm::bit_cast<uint32_t>(F);
+  std::memcpy(&U, &F, sizeof(U));
+  // IEEE 754 floats compare like sign-magnitude integers.
+  if (U & TopBit)    // Negative float.
+    return 0 - U;    // Map onto the low half of integers, order reversed.
+  return U + TopBit; // Positive floats map onto the high half of integers.
+}
+
+float Evaluate(const Example& E) {
+  float Score = 0;
+  t0:
+  t0_n0: if(E.ANumber >= 3276275712 /*200.0*/) goto t0_n4;
+  t0_n1: if(E.ACategorical & (BIT(ACategorical_type::A)|BIT(ACategorical_type::C))) goto t0_n3;
+  t0_n2: Score += -4.0; goto t1;
+  t0_n3: Score += 3.0; goto t1;
+  t0_n4: if(E.AFloat >= 1082130432 /*-1*/) goto t0_n6;
+  t0_n5: Score += -20.0; goto t1;
+  t0_n6: Score += 10.0; goto t1;
+  
+  t1:
+  t1_n0: if(E.ACategorical & (BIT(ACategorical_type::A)|BIT(ACategorical_type::B))) goto t1_n2;
+  t1_n1: Score += -6.0; goto t2;
+  t1_n2: Score += 5.0; goto t2;
+  
+  t2: // No such tree.
+  return Score;
+}
+} // namespace test
+} // namespace ns2
+} // namespace ns1
diff --git a/clang-tools-extra/clangd/quality/CompletionModel.cmake b/clang-tools-extra/clangd/quality/CompletionModel.cmake
new file mode 100644
--- /dev/null
+++ b/clang-tools-extra/clangd/quality/CompletionModel.cmake
@@ -0,0 +1,42 @@
+# Run the Completion Model Codegenerator on the model present in the 
+# ${model} directory.
+# Produces a pair of files called ${filename}.h and  ${filename}.cpp in the 
+# ${CMAKE_BINARY_DIR}/generated/decision_forest. The generated header
+# will define a C++ class called ${cpp_class} - which may be a
+# namespace-qualified class name.
+function(gen_decision_forest model filename cpp_class)
+  set(model_compiler ${CMAKE_SOURCE_DIR}/../clang-tools-extra/clangd/quality/CompletionModelCodegen.py)
+
+  set(model_json ${model}/forest.json)
+  set(model_features ${model}/features.json)
+  
+  set(output_dir ${CMAKE_BINARY_DIR}/generated/decision_forest)
+  set(header_file ${output_dir}/${filename}.h)
+  set(cpp_file ${output_dir}/${filename}.cpp)
+
+  add_custom_command(OUTPUT ${header_file} ${cpp_file}
+    COMMAND "${Python3_EXECUTABLE}" ${model_compiler}
+      --model ${model}
+      --output_dir ${output_dir}
+      --filename ${filename}
+      --cpp_class ${cpp_class}
+    COMMENT "Generating code completion model runtime..."
+    DEPENDS ${model_compiler} ${model_json} ${model_features}
+    VERBATIM )
+
+  set_source_files_properties(${header_file} PROPERTIES
+    GENERATED 1)
+  set_source_files_properties(${cpp_file} PROPERTIES
+    GENERATED 1)
+
+  # Disable unused label warning for generated files.
+  if (CMAKE_CXX_COMPILER_ID STREQUAL "MSVC")
+    set_source_files_properties(${cpp_file} PROPERTIES
+      COMPILE_FLAGS /wd4102)
+  else()
+    set_source_files_properties(${cpp_file} PROPERTIES
+      COMPILE_FLAGS -Wno-unused)
+  endif()
+
+  set(DECISION_FOREST_OUTPUT_DIR ${output_dir} PARENT_SCOPE)
+endfunction()
diff --git a/clang-tools-extra/clangd/quality/CompletionModelCodegen.py b/clang-tools-extra/clangd/quality/CompletionModelCodegen.py
new file mode 100644
--- /dev/null
+++ b/clang-tools-extra/clangd/quality/CompletionModelCodegen.py
@@ -0,0 +1,309 @@
+"""Code generator for Code Completion Model Inference.
+
+Tool runs on the Decision Forest model defined in {model} directory.
+It generates two files: {output_dir}/{filename}.h and {output_dir}/{filename}.cpp 
+The generated files defines the Example class named {cpp_class} having all the features as class members.
+The generated runtime provides an `Evaluate` function which can be used to score a code completion candidate.
+"""
+
+import argparse
+import json
+import struct
+from enum import Enum
+
+
+class CppClass:
+    """Holds class name and names of the enclosing namespaces."""
+
+    def __init__(self, cpp_class):
+        ns_and_class = cpp_class.split("::")
+        self.ns = [ns for ns in ns_and_class[0:-1] if len(ns) > 0]
+        self.name = ns_and_class[-1]
+        if len(self.name) == 0:
+            raise ValueError("Empty class name.")
+
+    def ns_begin(self):
+        """Returns snippet for opening namespace declarations."""
+        open_ns = ["namespace {ns} {{".format(ns=ns) for ns in self.ns]
+        return "\n".join(open_ns)
+
+    def ns_end(self):
+        """Returns snippet for closing namespace declarations."""
+        close_ns = [
+            "}} // namespace {ns}".format(ns=ns) for ns in reversed(self.ns)]
+        return "\n".join(close_ns)
+
+
+def header_guard(filename):
+    '''Returns the header guard for the generated header.'''
+    return "GENERATED_DECISION_FOREST_MODEL_{}_H".format(filename.upper())
+
+
+def boost_node(n, label, next_label):
+    """Returns code snippet for a leaf/boost node.
+    Adds value of leaf to the score and jumps to the root of the next tree."""
+    return "{label}: Score += {score}; goto {next_label};".format(
+        label=label,
+        score=n["score"],
+        next_label=next_label)
+
+
+def if_greater_node(n, label, next_label):
+    """Returns code snippet for a if_greater node.
+    Jumps to true_label if the Example feature (NUMBER) is greater than the threshold. 
+    Comparing integers is much faster than comparing floats. Assuming floating points 
+    are represented as IEEE 754, it order-encodes the floats to integers before comparing them.
+    Control falls through if condition is evaluated to false."""
+    return "{label}: if(E.{feature} >= {encoded} /*{threshold}*/) goto {true_label};".format(
+        label=label,
+        feature=n["feature"],
+        encoded=order_encode(n["threshold"]),
+        threshold=n["threshold"],
+        true_label=next_label)
+
+
+def if_member_node(n, label, next_label):
+    """Returns code snippet for a if_member node.
+    Jumps to true_label if the Example feature (ENUM) is present in the set of enum values 
+    described in the node.
+    Control falls through if condition is evaluated to false."""
+    members = '|'.join([
+        "BIT({feature}_type::{member})".format(
+            feature=n["feature"],
+            member=member)
+        for member in n["set"]
+    ])
+    return "{label}: if(E.{feature} & ({members})) goto {true_label};".format(
+        label=label,
+        feature=n["feature"],
+        members=members,
+        true_label=next_label)
+
+
+def node(n, label, next_label):
+    """Returns code snippet for the node."""
+    return {
+        'boost': boost_node,
+        'if_greater': if_greater_node,
+        'if_member': if_member_node,
+    }[n['operation']](n, label, next_label)
+
+
+def tree(t, tree_num: int, node_num: int):
+    """Returns code for inferencing a Decision Tree.
+
+    A tree starts with its label `t{tree#}`.
+    A node of the tree starts with label `t{tree#}_n{node#}`.
+
+    The tree contains two types of node: Conditional node and Leaf node.
+    -   Conditional node evaluates a condition. If true, it jumps to the true node/child.
+        Code is generated using pre-order traversal of the tree considering
+        false node as the first child. Therefore the false node is always the
+        immediately next label.
+    -   Leaf node adds the value to the score and jumps to the next tree.
+    """
+    label = "t{tree}_n{node}".format(tree=tree_num, node=node_num)
+    code = []
+    if node_num == 0:
+        code.append("t{0}:".format(tree_num))
+
+    if t["operation"] == "boost":
+        code.append(node(t, label=label, next_label="t{}".format(tree_num+1)))
+        return code, 1
+
+    false_code, false_size = tree(
+        t['else'], tree_num=tree_num, node_num=node_num+1)
+
+    true_node_num = node_num + false_size + 1
+    true_label = "t{tree_num}_n{true_node}".format(
+        tree_num=tree_num, true_node=true_node_num)
+
+    true_code, true_size = tree(
+        t['then'], tree_num=tree_num, node_num=true_node_num)
+
+    code.append(node(t, label=label, next_label=true_label))
+
+    return code + false_code + true_code, 1 + false_size+true_size
+
+
+def gen_header_code(features_json: list, cpp_class, filename: str):
+    """Returns code for header declaring the inference runtime.
+
+    Declares the Example class named {cpp_class} inside relevant namespaces.
+    The Example class contains all the features as class members. This 
+    class can be used to represent a code completion candidate.
+    Provides `float Evaluate()` function which can be used to score the Example.
+    """
+    # Header guard
+    code = """#ifndef {guard}
+# define {guard}
+# include <cstdint>
+
+""".format(guard=header_guard(filename))
+
+    # Namespace begin
+    code += cpp_class.ns_begin() + "\n"
+
+    setters = []
+    for f in features_json:
+        if f["type"] == "NUMBER":
+            # Floats are order-encoded to integers for faster comparison.
+            setters.append("void set{feature}(float V) {{ {feature} = OrderEncode(V); }}".format(
+                feature=f["name"]))
+        elif f["type"] == "ENUM":
+            setters.append("void set{feature}(unsigned V) {{ {feature} = 1 << V; }}".format(
+                feature=f["name"]))
+        else:
+            raise ValueError("Unhandled feature type.", f["type"])
+
+    # Class members represent all the features of the Example.
+    class_members = ["uint32_t {feature} = 0;".format(
+        feature=f["name"]) for f in features_json]
+
+    # Class definition.
+    code += "class {class_name} {{\n".format(class_name=cpp_class.name)
+    code += "public:\n"
+    code += "  " + "\n  ".join(setters) + "\n"
+    code += "\n"
+    code += "private:\n"
+    code += "  " + "\n  ".join(class_members) + "\n"
+
+    code += """
+  // Produces an integer that sorts in the same order as F.
+  // That is: a < b <==> orderEncode(a) < orderEncode(b).
+  static uint32_t OrderEncode(float F);
+""".format(class_name=cpp_class.name)
+
+    code += "  friend float Evaluate(const {}&);\n".format(cpp_class.name)
+    code += "};\n"
+    code += "float Evaluate(const {}&);".format(cpp_class.name) + "\n"
+
+    # Namespace end and Header guard.
+    code += cpp_class.ns_end() + "\n"
+    code += "#endif // {guard}".format(guard=header_guard(filename))
+    return code
+
+
+def order_encode(v: float):
+    i = struct.unpack('<I', struct.pack('<f', v))[0]
+    TopBit = 1 << 31
+    # IEEE 754 floats compare like sign-magnitude integers.
+    if (i & TopBit):  # Negative float
+        return (1 << 32) - i  # low half of integers, order reversed.
+    return TopBit + i  # top half of integers
+
+
+def evaluate_func(forest_json: list):
+    """Generates code for `float Evaluate(const Example&)` function.
+    The generated function can be used to score an Example."""
+    code = "float Evaluate(const Example& E) {\n"
+    lines = []
+    lines.append("float Score = 0;")
+    tree_num = 0
+    for tree_json in forest_json:
+        lines.extend(tree(tree_json, tree_num=tree_num, node_num=0)[0])
+        lines.append("")
+        tree_num += 1
+
+    lines.append("t{}: // No such tree.".format(len(forest_json)))
+    lines.append("return Score;")
+    code += "  " + "\n  ".join(lines)
+    code += "\n}"
+    return code
+
+
+def gen_cpp_code(forest_json: list, features_json: list, filename: str,
+                 cpp_class: CppClass):
+    """Generates code for the .cpp file."""
+    code = ""
+    # Headers
+    angled_include = [ # Required by OrderEncode(float F).
+        "cstring",
+        "limits",
+    ]
+    quoted_include = {
+        "{}.h".format(filename),  # Include generated header.
+        "llvm/ADT/bit.h",
+    }
+    # Headers required by ENUM features used by the model.
+    quoted_include |= {f["header"]
+                       for f in features_json if f["type"] == "ENUM"}
+    
+    code = "\n".join('#include <{h}>'.format(h=h)
+                     for h in angled_include) + "\n\n"
+    code += "\n".join('#include "{h}"'.format(h=h)
+                      for h in quoted_include) + "\n\n"
+    code += "#define BIT(X) (1 << X)\n\n"
+
+    # Namespaces Begin.
+    code += cpp_class.ns_begin() + "\n"
+
+    # using-decl for ENUM features.
+    code += "\n" + "\n".join("using {feature}_type = {enum};".format(
+        feature=feature["name"],
+        enum=feature["enum"]) for feature in features_json if feature["type"] == "ENUM") + "\n"
+
+    # Float order encoding.
+    code += """
+uint32_t {class_name}::OrderEncode(float F) {{
+  static_assert(std::numeric_limits<float>::is_iec559, "");
+  constexpr uint32_t TopBit = ~(~uint32_t{{0}} >> 1);
+
+  // Get the bits of the float. Endianness is the same as for integers.
+  uint32_t U = llvm::bit_cast<uint32_t>(F);
+  std::memcpy(&U, &F, sizeof(U));
+  // IEEE 754 floats compare like sign-magnitude integers.
+  if (U & TopBit)    // Negative float.
+    return 0 - U;    // Map onto the low half of integers, order reversed.
+  return U + TopBit; // Positive floats map onto the high half of integers.
+}}
+
+""".format(class_name=cpp_class.name)
+
+    code += evaluate_func(forest_json) + "\n"
+    # Namespaces End.
+    code += cpp_class.ns_end() + "\n"
+    return code
+
+
+def main():
+    parser = argparse.ArgumentParser('DecisionForestCodegen')
+    parser.add_argument('--filename', help='output file name.')
+    parser.add_argument('--output_dir', help='output directory')
+    parser.add_argument('--model', help='path to model directory')
+    parser.add_argument(
+        '--cpp_class',
+        help='The name of the class (which may be a namespace-qualified) created in generated header.'
+    )
+    ns = parser.parse_args()
+
+    output_dir = ns.output_dir
+    filename = ns.filename
+    header_file = "{dir}/{filename}.h".format(
+        dir=output_dir, filename=filename)
+    cpp_file = "{dir}/{filename}.cpp".format(dir=output_dir, filename=filename)
+    cpp_class = CppClass(cpp_class=ns.cpp_class)
+
+    model_file = "{dir}/forest.json".format(dir=ns.model)
+    features_file = "{dir}/features.json".format(dir=ns.model)
+
+    with open(features_file) as f:
+        features_json = json.load(f)
+
+    with open(model_file) as m:
+        forest_json = json.load(m)
+
+    with open(cpp_file, 'w+t') as output_cc:
+        output_cc.write(
+            gen_cpp_code(forest_json=forest_json,
+                         features_json=features_json,
+                         filename=filename,
+                         cpp_class=cpp_class))
+
+    with open(header_file, 'w+t') as output_h:
+        output_h.write(gen_header_code(
+            features_json=features_json, cpp_class=cpp_class, filename=filename))
+
+
+if __name__ == '__main__':
+    main()
diff --git a/clang-tools-extra/clangd/quality/README.md b/clang-tools-extra/clangd/quality/README.md
new file mode 100644
diff --git a/clang-tools-extra/clangd/quality/model/features.json b/clang-tools-extra/clangd/quality/model/features.json
new file mode 100644
--- /dev/null
+++ b/clang-tools-extra/clangd/quality/model/features.json
@@ -0,0 +1,8 @@
+[
+    {
+        "name": "ContextKind",
+        "type": "ENUM",
+        "enum": "clang::CodeCompletionContext::Kind",
+        "header": "clang/Sema/CodeCompleteConsumer.h"
+    }
+]
\ No newline at end of file
diff --git a/clang-tools-extra/clangd/quality/model/forest.json b/clang-tools-extra/clangd/quality/model/forest.json
new file mode 100644
--- /dev/null
+++ b/clang-tools-extra/clangd/quality/model/forest.json
@@ -0,0 +1,18 @@
+[
+    {
+        "operation": "if_member",
+        "feature": "ContextKind",
+        "set": [
+            "CCC_DotMemberAccess",
+            "CCC_ArrowMemberAccess"
+        ],
+        "then": {
+            "operation": "boost",
+            "score": 3.0
+        },
+        "else": {
+            "operation": "boost",
+            "score": 1.0
+        }
+    }
+]
\ No newline at end of file
diff --git a/clang-tools-extra/clangd/unittests/CMakeLists.txt b/clang-tools-extra/clangd/unittests/CMakeLists.txt
--- a/clang-tools-extra/clangd/unittests/CMakeLists.txt
+++ b/clang-tools-extra/clangd/unittests/CMakeLists.txt
@@ -28,6 +28,9 @@
   set(REMOTE_TEST_SOURCES remote/MarshallingTests.cpp)
 endif()
 
+include(${CMAKE_CURRENT_SOURCE_DIR}/../quality/CompletionModel.cmake)
+gen_decision_forest(${CMAKE_CURRENT_SOURCE_DIR}/model DecisionForestRuntimeTest ::ns1::ns2::test::Example)
+
 add_custom_target(ClangdUnitTests)
 add_unittest(ClangdUnitTests ClangdTests
   Annotations.cpp
@@ -44,6 +47,7 @@
   ConfigCompileTests.cpp
   ConfigProviderTests.cpp
   ConfigYAMLTests.cpp
+  DecisionForestTests.cpp
   DexTests.cpp
   DiagnosticsTests.cpp
   DraftStoreTests.cpp
@@ -87,6 +91,7 @@
   TweakTesting.cpp
   URITests.cpp
   XRefsTests.cpp
+  ${DECISION_FOREST_OUTPUT_DIR}/DecisionForestRuntimeTest.cpp
 
   support/CancellationTests.cpp
   support/ContextTests.cpp
@@ -101,6 +106,10 @@
   $<TARGET_OBJECTS:obj.clangDaemonTweaks>
   )
 
+target_include_directories(ClangdTests PUBLIC
+  $<BUILD_INTERFACE:${DECISION_FOREST_OUTPUT_DIR}>
+)
+
 clang_target_link_libraries(ClangdTests
   PRIVATE
   clangAST
diff --git a/clang-tools-extra/clangd/unittests/CodeCompleteTests.cpp b/clang-tools-extra/clangd/unittests/CodeCompleteTests.cpp
--- a/clang-tools-extra/clangd/unittests/CodeCompleteTests.cpp
+++ b/clang-tools-extra/clangd/unittests/CodeCompleteTests.cpp
@@ -10,6 +10,7 @@
 #include "ClangdServer.h"
 #include "CodeComplete.h"
 #include "Compiler.h"
+#include "CompletionModel.h"
 #include "Matchers.h"
 #include "Protocol.h"
 #include "Quality.h"
@@ -47,6 +48,7 @@
 using ::testing::IsEmpty;
 using ::testing::Not;
 using ::testing::UnorderedElementsAre;
+using ContextKind = CodeCompletionContext::Kind;
 
 // GMock helpers for matching completion items.
 MATCHER_P(Named, Name, "") { return arg.Name == Name; }
@@ -161,6 +163,16 @@
   return S;
 }
 
+TEST(DecisionForestRuntime, SanityTest) {
+  using Example = clangd::Example;
+  using clangd::Evaluate;
+  Example E1;
+  E1.setContextKind(ContextKind::CCC_ArrowMemberAccess);
+  Example E2;
+  E2.setContextKind(ContextKind::CCC_SymbolOrNewName);
+  EXPECT_GT(Evaluate(E1), Evaluate(E2));
+}
+
 TEST(CompletionTest, Limit) {
   clangd::CodeCompleteOptions Opts;
   Opts.Limit = 2;
diff --git a/clang-tools-extra/clangd/unittests/DecisionForestTests.cpp b/clang-tools-extra/clangd/unittests/DecisionForestTests.cpp
new file mode 100644
--- /dev/null
+++ b/clang-tools-extra/clangd/unittests/DecisionForestTests.cpp
@@ -0,0 +1,29 @@
+#include "DecisionForestRuntimeTest.h"
+#include "model/CategoricalFeature.h"
+#include "gtest/gtest.h"
+
+namespace clangd {
+namespace clangd {
+
+TEST(DecisionForestRuntime, Evaluate) {
+  using Example = ::ns1::ns2::test::Example;
+  using Cat = ::ns1::ns2::TestEnum;
+  using ::ns1::ns2::test::Evaluate;
+
+  Example E;
+  E.setANumber(200);         // True
+  E.setAFloat(0);            // True: +10.0
+  E.setACategorical(Cat::A); // True: +5.0
+  EXPECT_EQ(Evaluate(E), 15.0);
+
+  E.setANumber(200);         // True
+  E.setAFloat(-2.5);         // False: -20.0
+  E.setACategorical(Cat::B); // True: +5.0
+  EXPECT_EQ(Evaluate(E), -15.0);
+
+  E.setANumber(100);         // False
+  E.setACategorical(Cat::C); // True: +3.0, False: -6.0
+  EXPECT_EQ(Evaluate(E), -3.0);
+}
+} // namespace clangd
+} // namespace clangd
diff --git a/clang-tools-extra/clangd/unittests/model/CategoricalFeature.h b/clang-tools-extra/clangd/unittests/model/CategoricalFeature.h
new file mode 100644
--- /dev/null
+++ b/clang-tools-extra/clangd/unittests/model/CategoricalFeature.h
@@ -0,0 +1,5 @@
+namespace ns1 {
+namespace ns2 {
+enum TestEnum { A, B, C, D };
+} // namespace ns2
+} // namespace ns1
diff --git a/clang-tools-extra/clangd/unittests/model/features.json b/clang-tools-extra/clangd/unittests/model/features.json
new file mode 100644
--- /dev/null
+++ b/clang-tools-extra/clangd/unittests/model/features.json
@@ -0,0 +1,16 @@
+[
+    {
+        "name": "ANumber",
+        "type": "NUMBER"
+    },
+    {
+        "name": "AFloat",
+        "type": "NUMBER"
+    },
+    {
+        "name": "ACategorical",
+        "type": "ENUM",
+        "enum": "ns1::ns2::TestEnum",
+        "header": "model/CategoricalFeature.h"
+    }
+]
\ No newline at end of file
diff --git a/clang-tools-extra/clangd/unittests/model/forest.json b/clang-tools-extra/clangd/unittests/model/forest.json
new file mode 100644
--- /dev/null
+++ b/clang-tools-extra/clangd/unittests/model/forest.json
@@ -0,0 +1,52 @@
+[
+    {
+        "operation": "if_greater",
+        "feature": "ANumber",
+        "threshold": 200.0,
+        "then": {
+            "operation": "if_greater",
+            "feature": "AFloat",
+            "threshold": -1,
+            "then": {
+                "operation": "boost",
+                "score": 10.0
+            },
+            "else": {
+                "operation": "boost",
+                "score": -20.0
+            }
+        },
+        "else": {
+            "operation": "if_member",
+            "feature": "ACategorical",
+            "set": [
+                "A",
+                "C"
+            ],
+            "then": {
+                "operation": "boost",
+                "score": 3.0
+            },
+            "else": {
+                "operation": "boost",
+                "score": -4.0
+            }
+        }
+    },
+    {
+        "operation": "if_member",
+        "feature": "ACategorical",
+        "set": [
+            "A",
+            "B"
+        ],
+        "then": {
+            "operation": "boost",
+            "score": 5.0
+        },
+        "else": {
+            "operation": "boost",
+            "score": -6.0
+        }
+    }
+]
\ No newline at end of file