Revert "Preprocessor: removed unreachable ConfigurationNotChecked finding (danmar#4790)" [skip ci]

This reverts commit 3813616.

Author: firewave

lib/preprocessor.cpp

@@ -912,6 +912,10 @@ simplecpp::TokenList Preprocessor::preprocess(const std::string &cfg, std::vecto
 
     tokens2.removeComments();
 
+    // ensure that guessed define macros without value are not used in the code
+    if (!validateCfg(cfg, macroUsage))
+        return simplecpp::TokenList(files);
+
     return tokens2;
 }
 
@@ -1059,6 +1063,44 @@ void Preprocessor::invalidSuppression(const simplecpp::Location& loc, const std:
     error(loc, msg, "invalidSuppression");
 }
 
+bool Preprocessor::validateCfg(const std::string &cfg, const std::list<simplecpp::MacroUsage> &macroUsageList)
+{
+    bool ret = true;
+    std::list<std::string> defines;
+    splitcfg(cfg, defines, emptyString);
+    for (const std::string &define : defines) {
+        if (define.find('=') != std::string::npos)
+            continue;
+        const std::string macroName(define.substr(0, define.find('(')));
+        for (const simplecpp::MacroUsage &mu : macroUsageList) {
+            if (mu.macroValueKnown)
+                continue;
+            if (mu.macroName != macroName)
+                continue;
+            const bool directiveLocation = std::any_of(mDirectives.cbegin(), mDirectives.cend(),
+                                                       [=](const Directive &dir) {
+                return mu.useLocation.file() == dir.file && mu.useLocation.line == dir.linenr;
+            });
+
+            if (!directiveLocation) {
+                if (mSettings.severity.isEnabled(Severity::information))
+                    validateCfgError(mu.useLocation.file(), mu.useLocation.line, cfg, macroName);
+                ret = false;
+            }
+        }
+    }
+
+    return ret;
+}
+
+void Preprocessor::validateCfgError(const std::string &file, const unsigned int line, const std::string &cfg, const std::string &macro)
+{
+    const std::string id = "ConfigurationNotChecked";
+    ErrorMessage::FileLocation loc(file, line, 0);
+    const ErrorMessage errmsg({std::move(loc)}, mFile0, Severity::information, "Skipping configuration '" + cfg + "' since the value of '" + macro + "' is unknown. Use -D if you want to check it. You can use -U to skip it explicitly.", id, Certainty::normal);
+    mErrorLogger->reportInfo(errmsg);
+}
+
 void Preprocessor::getErrorMessages(ErrorLogger &errorLogger, const Settings &settings)
 {
     std::vector<std::string> files;
@@ -1069,6 +1111,7 @@ void Preprocessor::getErrorMessages(ErrorLogger &errorLogger, const Settings &se
     loc.col = 2;
     preprocessor.missingInclude(loc, "", UserHeader);
     preprocessor.missingInclude(loc, "", SystemHeader);
+    preprocessor.validateCfgError("", 1, "X", "X");
     preprocessor.error(loc, "message", simplecpp::Output::ERROR);
     preprocessor.error(loc, "message", simplecpp::Output::SYNTAX_ERROR);
     preprocessor.error(loc, "message", simplecpp::Output::UNHANDLED_CHAR_ERROR);

lib/preprocessor.h

@@ -122,6 +122,15 @@ class CPPCHECKLIB WARN_UNUSED Preprocessor {
 
     std::string getcode(const std::string &cfg, std::vector<std::string> &files, bool writeLocations);
 
+    /**
+     * make sure empty configuration macros are not used in code. the given code must be a single configuration
+     * @param cfg configuration
+     * @param macroUsageList macro usage list
+     * @return true => configuration is valid
+     */
+    bool validateCfg(const std::string &cfg, const std::list<simplecpp::MacroUsage> &macroUsageList);
+    void validateCfgError(const std::string &file, const unsigned int line, const std::string &cfg, const std::string &macro);
+
     /**
      * Calculate HASH. Using toolinfo, tokens1, filedata.
      *

test/testpreprocessor.cpp

@@ -340,6 +340,9 @@ class TestPreprocessor : public TestFixture {
         TEST_CASE(getConfigsU6);
         TEST_CASE(getConfigsU7);
 
+        TEST_CASE(validateCfg1);
+        TEST_CASE(validateCfg2);
+
         TEST_CASE(getConfigsAndCodeIssue14317);
         TEST_CASE(getConfigsMostGeneralConfigIssue14317);
 
@@ -2668,6 +2671,36 @@ class TestPreprocessor : public TestFixture {
         ASSERT_EQUALS("\nY\n", getConfigsStr(code, "-DX"));
     }
 
+void validateCfg1() {
+        Preprocessor preprocessor(settings0, this);
+
+        std::vector<std::string> files(1, "test.c");
+        simplecpp::MacroUsage macroUsage(files, false);
+        macroUsage.useLocation.fileIndex = 0;
+        macroUsage.useLocation.line = 1;
+        macroUsage.macroName = "X";
+        std::list<simplecpp::MacroUsage> macroUsageList(1, macroUsage);
+
+        ASSERT_EQUALS(true, preprocessor.validateCfg("", macroUsageList));
+        ASSERT_EQUALS(false, preprocessor.validateCfg("X",macroUsageList));
+        ASSERT_EQUALS(false, preprocessor.validateCfg("A=42;X", macroUsageList));
+        ASSERT_EQUALS(true, preprocessor.validateCfg("X=1", macroUsageList));
+        ASSERT_EQUALS(true, preprocessor.validateCfg("Y", macroUsageList));
+
+        macroUsageList.front().macroValueKnown = true; // #8404
+        ASSERT_EQUALS(true, preprocessor.validateCfg("X", macroUsageList));
+    }
+
+    void validateCfg2() {
+        const char filedata[] = "#ifdef ABC\n"
+                                "#endif\n"
+                                "int i = ABC;";
+
+        std::map<std::string, std::string> actual;
+        preprocess(filedata, actual, "file.cpp");
+        ASSERT_EQUALS("[file.cpp:3]: (information) Skipping configuration 'ABC' since the value of 'ABC' is unknown. Use -D if you want to check it. You can use -U to skip it explicitly.\n", errout.str());
+    }
+
     void getConfigsAndCodeIssue14317() {
         const char filedata[] = "bool test() {\n"
                                 "return\n"