Add Support for LLC Metric for R Sources

Dependencies.cmake

@@ -53,6 +53,13 @@ dependency(
     DEPENDENCY_LINK_TARGETS tree-sitter-typescript
 )
 
+dependency(
+    DEPENDENCY_NAME         tree-sitter-r
+    DEPENDENCY_RESOURCE     kilo52/tree-sitter-r
+    DEPENDENCY_VERSION      v1.2.0-patch-cmakeliststxt
+    DEPENDENCY_LINK_TARGETS tree-sitter-r
+)
+
 dependency(
     DEPENDENCY_NAME         utf8proc
     DEPENDENCY_RESOURCE     JuliaStrings/utf8proc

Dependencies.cmake.sha256

@@ -1 +1 @@
-8648e7957901a3029837287b247ad68b2b2dce86ab816eaa4fc18505449f6701
+a2eff11c1a578a2fa505398b70101f4b92a544c7bb692daaf612f79204a9342f

cmake/ConfigTree-sitter-r.cmake

@@ -0,0 +1,6 @@
+# Configuration options for the Tree-Sitter-R dependency
+
+# Define the program variable to avoid errors when custom command
+# is executed since the CLI might not actually be available.
+set(TREE_SITTER_CLI "")
+set(BUILD_TESTING OFF)

src/lib/CMakeLists.txt

@@ -38,6 +38,7 @@ target_sources(
     "c/lang_python.c"
     "c/lang_javascript.c"
     "c/lang_typescript.c"
+    "c/lang_r.c"
     "c/lang_bash.c"
     "c/logical.c"
     "c/physical.c"

src/lib/c/factories.c

@@ -27,13 +27,15 @@ TSParser* createParserJava(void);
 TSParser* createParserPython(void);
 TSParser* createParserJavaScript(void);
 TSParser* createParserTypeScript(void);
+TSParser* createParserR(void);
 TSParser* createParserBash(void);
 
 void evaluateNodeC(TSNode node, NodeEvalTrace* trace);
 void evaluateNodeJava(TSNode node, NodeEvalTrace* trace);
 void evaluateNodePython(TSNode node, NodeEvalTrace* trace);
 void evaluateNodeJavaScript(TSNode node, NodeEvalTrace* trace);
 void evaluateNodeTypeScript(TSNode node, NodeEvalTrace* trace);
+void evaluateNodeR(TSNode node, NodeEvalTrace* trace);
 void evaluateNodeBash(TSNode node, NodeEvalTrace* trace);
 
 TSParser* createParser(RcnTextFormat language) {
@@ -48,6 +50,8 @@ TSParser* createParser(RcnTextFormat language) {
             return createParserJavaScript();
         case RCN_LANG_TYPESCRIPT:
             return createParserTypeScript();
+        case RCN_LANG_R:
+            return createParserR();
         case RCN_LANG_BASH:
             return createParserBash();
         default:
@@ -67,6 +71,8 @@ NodeVisitor createEvaluationFunction(RcnTextFormat language) {
             return evaluateNodeJavaScript;
         case RCN_LANG_TYPESCRIPT:
             return evaluateNodeTypeScript;
+        case RCN_LANG_R:
+            return evaluateNodeR;
         case RCN_LANG_BASH:
             return evaluateNodeBash;
         default:
@@ -77,6 +83,7 @@ NodeVisitor createEvaluationFunction(RcnTextFormat language) {
 const char* getInlineSourceCommentString(RcnTextFormat language) {
     switch (language) {
         case RCN_LANG_PYTHON:
+        case RCN_LANG_R:
         case RCN_LANG_BASH:
             return "#";
         case RCN_LANG_C:
@@ -158,9 +165,8 @@ SourceFormatDetection detectSourceFormat(const RcnSourceFile* file) {
         detection.format = RCN_TEXT_YAML;
     } else if (strcmp(extension, "R") == 0
         || strcmp(extension, "r") == 0) {
-        // isProgrammingLanguage is false for R format due to missing
-        // support for logical line counting in R files
         detection.isSupportedFormat = true;
+        detection.isProgrammingLanguage = true;
         detection.format = RCN_LANG_R;
     } else if (strcmp(extension, "txt") == 0) {
         detection.isSupportedFormat = true;

src/lib/c/lang_r.c

@@ -0,0 +1,105 @@
+/*
+ * Copyright (C) 2026 Raven Computing
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <stdbool.h>
+
+#include "tree_sitter/api.h"
+
+#include "reckon/reckon.h"
+#include "reckon_export.h"
+#include "evaluation.h"
+
+RECKON_NO_EXPORT const TSLanguage* tree_sitter_r(void);
+
+/**
+ * These are the symbol identifiers as defined by the R language parser
+ * of tree-sitter. We have only copied the symbol identifiers that we are
+ * interested in evaluating or counting. Others do not contribute to the weight
+ * of a node in the AST.
+ */
+enum SymbolIdentifiersR {
+    sym_return = 52,
+    sym_next = 53,
+    sym_break = 54,
+    sym_program = 81,
+    sym_function_definition = 82,
+    sym_if_statement = 88,
+    sym_for_statement = 89,
+    sym_while_statement = 90,
+    sym_repeat_statement = 91,
+    sym_braced_expression = 92,
+    sym_parenthesized_expression = 93,
+    sym_call = 94,
+    sym_unary_operator = 104,
+    sym_binary_operator = 105,
+};
+
+TSParser* createParserR(void) {
+    TSParser* parser = ts_parser_new();
+    if (parser) {
+        if (!ts_parser_set_language(parser, tree_sitter_r())) {
+            // LCOV_EXCL_START
+            ts_parser_delete(parser);
+            return NULL;
+            // LCOV_EXCL_STOP
+        }
+    }
+    return parser;
+}
+
+/**
+ * Checks whether the given node's immediate parent is the program node
+ * or a braced expression, i.e. the node is at statement level.
+ */
+static bool isAtStatementLevel(TSNode node) {
+    TSNode parent = ts_node_parent(node);
+    if (ts_node_is_null(parent)) {
+        return false;
+    }
+    TSSymbol sym = ts_node_grammar_symbol(parent);
+    return sym == sym_program || sym == sym_braced_expression;
+}
+
+static RcnCount evaluateNodeWeightRImpl(TSNode node, NodeEvalTrace* trace) {
+    RcnCount weight = 0;
+    TSSymbol sym = ts_node_grammar_symbol(node);
+    switch (sym) {
+        case sym_binary_operator:
+        case sym_call:
+        case sym_unary_operator:
+        case sym_function_definition:
+        case sym_parenthesized_expression:
+        case sym_if_statement:
+        case sym_for_statement:
+        case sym_while_statement:
+        case sym_repeat_statement:
+        case sym_next:
+        case sym_break:
+        case sym_return:
+            if (isAtStatementLevel(node)) {
+                weight += 1;
+            }
+            break;
+        default:
+            break;
+    }
+    return weight;
+}
+
+void evaluateNodeR(TSNode node, NodeEvalTrace* trace) {
+    trace->result->count += evaluateNodeWeightRImpl(node, trace);
+    trace->idx++;
+}

src/lib/tests/CMakeLists.txt

@@ -120,6 +120,13 @@ add_test_suite(
     TEST_SUITE_LINK        ${RECKON_TARGET_LIB_OBJ}
 )
 
+add_test_suite(
+    TEST_SUITE_NAME        RLanguageUnitTest
+    TEST_SUITE_TARGET      test_lang_r
+    TEST_SUITE_SOURCE      unit/c/test_lang_r.c
+    TEST_SUITE_LINK        ${RECKON_TARGET_LIB_OBJ}
+)
+
 add_compile_definitions(
     RECKON_TEST_PATH_RES_BASE="${CMAKE_CURRENT_SOURCE_DIR}/res"
 )

src/lib/tests/integration/c/test_fileio.c

@@ -239,8 +239,7 @@ void testDetectSourceFormatR(void) {
     TEST_ASSERT_NOT_NULL(file);
     SourceFormatDetection detection = detectSourceFormat(file);
     TEST_ASSERT_TRUE(detection.isSupportedFormat);
-    // Special case: Missing support for LLC metric.
-    TEST_ASSERT_FALSE(detection.isProgrammingLanguage);
+    TEST_ASSERT_TRUE(detection.isProgrammingLanguage);
     TEST_ASSERT_EQUAL_INT(RCN_LANG_R, detection.format);
     freeSourceFile(file);
 }