Add --warn InfiniteGenerators

src/catch2/catch_config.cpp

@@ -197,6 +197,9 @@ namespace Catch {
     bool Config::warnAboutUnmatchedTestSpecs() const {
         return !!( m_data.warnings & WarnAbout::UnmatchedTestSpec );
     }
+    bool Config::warnAboutInfiniteGenerators() const {
+        return !!( m_data.warnings & WarnAbout::InfiniteGenerator );
+    }
     bool Config::zeroTestsCountAsSuccess() const       { return m_data.allowZeroTests; }
     ShowDurations Config::showDurations() const        { return m_data.showDurations; }
     double Config::minDuration() const                 { return m_data.minDuration; }

src/catch2/catch_config.hpp

@@ -124,6 +124,7 @@ namespace Catch {
         bool includeSuccessfulResults() const override;
         bool warnAboutMissingAssertions() const override;
         bool warnAboutUnmatchedTestSpecs() const override;
+        bool warnAboutInfiniteGenerators() const override;
         bool zeroTestsCountAsSuccess() const override;
         ShowDurations showDurations() const override;
         double minDuration() const override;

src/catch2/interfaces/catch_interfaces_config.hpp

@@ -29,6 +29,8 @@ namespace Catch {
         NoAssertions = 0x01,
         //! A command line test spec matched no test cases
         UnmatchedTestSpec = 0x02,
+        //! The resulting generator in GENERATE is infinite
+        InfiniteGenerator = 0x04,
     }; };
 
     enum class ShowDurations {
@@ -71,6 +73,7 @@ namespace Catch {
         virtual bool shouldDebugBreak() const = 0;
         virtual bool warnAboutMissingAssertions() const = 0;
         virtual bool warnAboutUnmatchedTestSpecs() const = 0;
+        virtual bool warnAboutInfiniteGenerators() const = 0;
         virtual bool zeroTestsCountAsSuccess() const = 0;
         virtual int abortAfter() const = 0;
         virtual bool showInvisibles() const = 0;

src/catch2/internal/catch_commandline.cpp

@@ -32,6 +32,9 @@ namespace Catch {
             } else if ( warning == "UnmatchedTestSpec" ) {
                 config.warnings = static_cast<WarnAbout::What>(config.warnings | WarnAbout::UnmatchedTestSpec);
                 return ParserResult::ok( ParseResultType::Matched );
+            } else if ( warning == "InfiniteGenerators" ) {
+                config.warnings = static_cast<WarnAbout::What>(config.warnings | WarnAbout::InfiniteGenerator);
+                return ParserResult::ok( ParseResultType::Matched );
             }
 
             return ParserResult ::runtimeError(

src/catch2/internal/catch_run_context.cpp

@@ -21,7 +21,9 @@
 #include <catch2/internal/catch_assertion_handler.hpp>
 #include <catch2/internal/catch_test_failure_exception.hpp>
 #include <catch2/internal/catch_thread_local.hpp>
+#include <catch2/internal/catch_unreachable.hpp>
 #include <catch2/internal/catch_result_type.hpp>
+#include <catch2/catch_test_macros.hpp>
 
 #include <cassert>
 #include <algorithm>
@@ -495,6 +497,11 @@ namespace Catch {
         currentTracker.addChild( CATCH_MOVE( newTracker ) );
 
         ret->setGenerator( CATCH_MOVE( generator ) );
+        if ( m_config->warnAboutInfiniteGenerators() &&
+             !ret->getGenerator()->isFinite() ) {
+            // TBD: Would it be better to expand this macro inline?
+            FAIL( "GENERATE() would run infinitely" );
+        }
         ret->open();
         return ret;
     }