CppCheck: no need to write locations in unused preprocessor output / PreprocessorHelper: preserve locations for includes in getcode() (danmar#7846)

Author: firewave

lib/cppcheck.cpp

@@ -1055,7 +1055,7 @@ unsigned int CppCheck::checkInternal(const FileWithDetails& file, const std::str
 
         if (mSettings.checkConfiguration) {
             for (const std::string &config : configurations)
-                (void)preprocessor.getcode(tokens1, config, files, true);
+                (void)preprocessor.getcode(tokens1, config, files, false);
 
             if (analyzerInformation)
                 mLogger->setAnalyzerInfo(nullptr);

test/helpers.cpp

@@ -27,6 +27,7 @@
 
 #include <cerrno>
 #include <cstdio>
+#include <cstring>
 #include <iostream>
 #include <fstream>
 #include <list>
@@ -151,8 +152,8 @@ std::map<std::string, std::string> PreprocessorHelper::getcode(const Settings& s
         cfgs = preprocessor.getConfigs(tokens);
     for (const std::string & config : cfgs) {
         try {
-            // TODO: also preserve location information when #include exists - enabling that will fail since #line is treated like a regular token
-            cfgcode[config] = preprocessor.getcode(tokens, config, files, std::string(code).find("#file") != std::string::npos);
+            const bool writeLocations = (strstr(code, "#file") != nullptr) || (strstr(code, "#include") != nullptr);
+            cfgcode[config] = preprocessor.getcode(tokens, config, files, writeLocations);
         } catch (const simplecpp::Output &) {
             cfgcode[config] = "";
         }

test/testpreprocessor.cpp

@@ -298,6 +298,8 @@ class TestPreprocessor : public TestFixture {
         TEST_CASE(hashCalculation);
 
         TEST_CASE(standard);
+
+        TEST_CASE(writeLocations);
     }
 
     template<size_t size>
@@ -2655,6 +2657,25 @@ class TestPreprocessor : public TestFixture {
             ASSERT(!tokenlist.front()); // nothing is tokenized when an unknown standard is provided
         }
     }
+
+    void writeLocations()
+    {
+        const char inc[] = "class A {\n"
+                           "public:\n"
+                           "    void f() {}\n"
+                           "};";
+        const char code[] = R"(#include "test.h")";
+        ScopedFile header("test.h", inc);
+        const std::string processed = PreprocessorHelper::getcodeforcfg(settingsDefault, *this, code, "", "test.cpp");
+        ASSERT_EQUALS(
+            "\n"
+            "#line 1 \"test.h\"\n"
+            "class A {\n"
+            "public :\n"
+            "void f ( ) { }\n"
+            "} ;",
+            processed);
+    }
 };
 
 REGISTER_TEST(TestPreprocessor)

test/testunusedfunctions.cpp

@@ -79,7 +79,6 @@ class TestUnusedFunctions : public TestFixture {
         TEST_CASE(entrypointsWinU);
         TEST_CASE(entrypointsUnix);
 
-        TEST_CASE(includes);
         TEST_CASE(virtualFunc);
         TEST_CASE(parensInit);
         TEST_CASE(typeInCast);
@@ -732,21 +731,6 @@ class TestUnusedFunctions : public TestFixture {
         ASSERT_EQUALS("", errout_str());
     }
 
-    // TODO: fails because the location information is not be preserved by PreprocessorHelper::getcode()
-    void includes()
-    {
-        // #11483
-        const char inc[] = "class A {\n"
-                           "public:\n"
-                           "    void f() {}\n"
-                           "};";
-        const char code[] = R"(#include "test.h")";
-        ScopedFile header("test.h", inc);
-        const std::string processed = PreprocessorHelper::getcodeforcfg(settings, *this, code, "", "test.cpp");
-        check(processed);
-        TODO_ASSERT_EQUALS("[test.h:3:6]: (style) The function 'f' is never used. [unusedFunction]\n", "[test.cpp:3:6]: (style) The function 'f' is never used. [unusedFunction]\n", errout_str());
-    }
-
     void virtualFunc()
     {
         check("struct D : public B {\n" // #10660