Add a --check-level option (#4942)

.github/workflows/CI-unixish.yml

@@ -446,7 +446,7 @@ jobs:
 
       - name: Self check
         run: |
-          selfcheck_options="-q -j$(nproc) --std=c++11 --template=selfcheck --showtime=top5 -D__CPPCHECK__ --error-exitcode=1 --inline-suppr --suppressions-list=.selfcheck_suppressions --library=cppcheck-lib -Ilib -Iexternals/simplecpp/ -Iexternals/tinyxml2/ --inconclusive --enable=style,performance,portability,warning,missingInclude,internal --exception-handling --debug-warnings"
+          selfcheck_options="-q -j$(nproc) --std=c++11 --template=selfcheck --showtime=top5 -D__CPPCHECK__ --error-exitcode=1 --inline-suppr --suppressions-list=.selfcheck_suppressions --library=cppcheck-lib -Ilib -Iexternals/simplecpp/ -Iexternals/tinyxml2/ --inconclusive --enable=style,performance,portability,warning,missingInclude,internal --exception-handling --debug-warnings --check-level=exhaustive"
           ec=0
           
           # early exit
@@ -464,4 +464,4 @@ jobs:
           ./cppcheck $selfcheck_options -Icli test/*.cpp tools/*.cpp || ec=1
           # triage
           ./cppcheck $selfcheck_options -DQ_MOC_OUTPUT_REVISION=67 -DQT_CHARTS_LIB --library=qt -Itools/triage/temp -Igui tools/triage/*.cpp tools/triage/temp/*.cpp || ec=1
-          exit $ec
+          exit $ec

.selfcheck_suppressions

@@ -24,5 +24,3 @@ autoNoType
 bailoutUninitVar
 
 *:externals/*/*
-
-performanceValueflowMaxIfCountExceeded

cli/cmdlineparser.cpp

@@ -254,6 +254,14 @@ bool CmdLineParser::parseFromArgs(int argc, const char* const argv[])
             else if (std::strcmp(argv[i], "--check-config") == 0)
                 mSettings.checkConfiguration = true;
 
+            // Check code exhaustively
+            else if (std::strcmp(argv[i], "--check-level=exhaustive") == 0)
+                mSettings.setCheckLevelExhaustive();
+
+            // Check code with normal analysis
+            else if (std::strcmp(argv[i], "--check-level=normal") == 0)
+                mSettings.setCheckLevelNormal();
+
             // Check library definitions
             else if (std::strcmp(argv[i], "--check-library") == 0) {
                 mSettings.checkLibrary = true;
@@ -1092,6 +1100,13 @@ void CmdLineParser::printHelp()
         "                            execute clang/clang-tidy/addons.\n"
         "    --check-config       Check cppcheck configuration. The normal code\n"
         "                         analysis is disabled by this flag.\n"
+        "    --check-level=<level>\n"
+        "                         Configure how much checking you want:\n"
+        "                          * normal: Cppcheck uses some compromises in the checking so\n"
+        "                            the checking will finish in reasonable time.\n"
+        "                          * exhaustive: deeper analysis that you choose when you can\n"
+        "                            wait.\n"
+        "                         The default choice is 'normal'.\n"
         "    --check-library      Show information messages when library files have\n"
         "                         incomplete info.\n"
         "    --clang=<path>       Experimental: Use Clang parser instead of the builtin Cppcheck\n"
@@ -1214,12 +1229,6 @@ void CmdLineParser::printHelp()
     "                         is 2. A larger value will mean more errors can be found\n"
     "                         but also means the analysis will be slower.\n"
     "    --output-file=<file> Write results to file, rather than standard error.\n"
-    "    --performance-valueflow-max-if-count=<limit>\n"
-    "                         If you have many conditional scopes in a function then\n"
-    "                         the number of possible control flow paths through that\n"
-    "                         function explodes and that can lead to very long analysis\n"
-    "                         time. Valueflow is limited in functions that have more\n"
-    "                         than <limit> conditional scopes.\n"
     "    --platform=<type>, --platform=<file>\n"
     "                         Specifies platform specific types and sizes. The\n"
     "                         available builtin platforms are:\n"

lib/settings.cpp

@@ -78,6 +78,7 @@ Settings::Settings()
 {
     severity.setEnabled(Severity::error, true);
     certainty.setEnabled(Certainty::normal, true);
+    setCheckLevelNormal();
 }
 
 void Settings::loadCppcheckCfg()
@@ -222,3 +223,16 @@ void Settings::loadSummaries()
 {
     Summaries::loadReturn(buildDir, summaryReturn);
 }
+
+
+void Settings::setCheckLevelExhaustive()
+{
+    // Checking can take a little while. ~ 10 times slower than normal analysis is OK.
+    performanceValueFlowMaxIfCount = -1;
+}
+
+void Settings::setCheckLevelNormal()
+{
+    // Checking should finish in reasonable time.
+    performanceValueFlowMaxIfCount = 100;
+}

lib/settings.h

@@ -250,7 +250,7 @@ public:
     int performanceValueFlowMaxTime;
 
     /** @brief --performance-valueflow-max-if-count=C */
-    int performanceValueFlowMaxIfCount = 100;
+    int performanceValueFlowMaxIfCount;
 
     /** @brief plist output (--plist-output=<dir>) */
     std::string plistOutput;
@@ -438,6 +438,9 @@ public:
         return jobs == 1;
     }
 
+    void setCheckLevelExhaustive();
+    void setCheckLevelNormal();
+
 private:
     static std::string parseEnabled(const std::string &str, std::tuple<SimpleEnableGroup<Severity::SeverityType>, SimpleEnableGroup<Checks>> &groups);
     std::string applyEnabled(const std::string &str, bool enable);

lib/valueflow.cpp

@@ -9106,11 +9106,8 @@ void ValueFlow::setValues(TokenList *tokenlist, SymbolDatabase* symboldatabase,
                     const std::string& functionName = functionScope->className;
                     const std::list<ErrorMessage::FileLocation> callstack(1, ErrorMessage::FileLocation(functionScope->bodyStart, tokenlist));
                     const ErrorMessage errmsg(callstack, tokenlist->getSourceFilePath(), Severity::information,
-                                              "ValueFlow analysis is limited in " + functionName + " because if-count in function " +
+                                              "ValueFlow analysis is limited in " + functionName + ". Use --check-level=exhaustive if full analysis is wanted.",
-                                              std::to_string(countIfScopes) + " exceeds limit " +
+                                              "checkLevelNormal", Certainty::normal);
-                                              std::to_string(settings->performanceValueFlowMaxIfCount) + ". The limit can be adjusted with "
-                                              "--performance-valueflow-max-if-count. Increasing the if-count limit will likely increase the "
-                                              "analysis time.", "performanceValueflowMaxIfCountExceeded", Certainty::normal);
                     errorLogger->reportErr(errmsg);
                 }
             }