issue #8023 Add option to exit with non-zero exit code on warnings even if WARN_AS_ERROR is OFF

In case we want for a Continuous integration system a non-zero exit status at the end of a doxygen we can now set `WARN_AS_ERRORS=FAIL_ON_WARNINGS`.
The behavior for `NO` and `YES` remains as it was.

4 files changed, 35 insertions, 7 deletions

diff --git a/src/config.xml b/src/config.xml
index 0ec4219..2880cbe 100644
--- a/src/config.xml
+++ b/src/config.xml
@@ -1335,13 +1335,19 @@ FILE_VERSION_FILTER = "cleartool desc -fmt \%Vn"
 ]]>
       </docs>
     </option>
-    <option type='bool' id='WARN_AS_ERROR' defval='0'>
+    <option type='enum' id='WARN_AS_ERROR' defval='NO'>
       <docs>
 <![CDATA[
  If the \c WARN_AS_ERROR tag is set to \c YES then doxygen will immediately stop
  when a warning is encountered.
+ If the \c WARN_AS_ERROR tag is set to \c FAIL_ON_WARNINGS then doxygen will continue
+ running as if \c WARN_AS_ERROR tag is set to \c NO, but at the end of the doxygen
+ process doxygen will return with a non-zero status.
 ]]>
       </docs>
+      <value name="NO"/>
+      <value name="YES" />
+      <value name="FAIL_ON_WARNINGS" />
     </option>
     <option type='string' id='WARN_FORMAT' format='string' defval='$file:$line: $text'>
       <docs>
diff --git a/src/doxygen.cpp b/src/doxygen.cpp
index 6c8c67a..2eec97e 100644
--- a/src/doxygen.cpp
+++ b/src/doxygen.cpp
@@ -11912,6 +11912,7 @@ void generateOutput()
   QDir thisDir;
   thisDir.remove(Doxygen::objDBFileName);
   thisDir.remove(Doxygen::filterDBFileName);
+  finishWarnExit();
   Config::deinit();
   QTextCodec::deleteAllCodecs();
   delete Doxygen::clangUsrMap;
diff --git a/src/message.cpp b/src/message.cpp
index e107139..95a7553 100644
--- a/src/message.cpp
+++ b/src/message.cpp
@@ -34,6 +34,14 @@ static const char *error_str = "error: ";
 
 static FILE *warnFile = stderr;
 
+enum warn_as_error
+{
+   WARN_NO,
+   WARN_YES,
+   FAIL_ON_WARNINGS,
+};
+static warn_as_error warnBehavior = WARN_NO;
+static bool warnStat = false;
 
 static std::mutex g_mutex;
 
@@ -99,7 +107,11 @@ void initWarningFormat()
     warnFile = stderr;
   }
 
-  if (Config_getBool(WARN_AS_ERROR))
+  QCString warnStr = Config_getEnum(WARN_AS_ERROR).upper();
+  if (warnStr =="NO") warnBehavior=WARN_NO;
+  else if (warnStr =="YES") warnBehavior=WARN_YES;
+  else if (warnStr =="FAIL_ON_WARNINGS") warnBehavior=FAIL_ON_WARNINGS;
+  if (warnBehavior == WARN_YES)
   {
     warning_str = error_str;
   }
@@ -129,7 +141,6 @@ static void format_warn(const char *file,int line,const char *text)
   QCString textSubst = text;
   QCString versionSubst;
   // substitute markers by actual values
-  bool warnAsError = Config_getBool(WARN_AS_ERROR);
   QCString msgText =
       substitute(
         substitute(
@@ -144,7 +155,7 @@ static void format_warn(const char *file,int line,const char *text)
         ),
         "$text",textSubst
       );
-  if (warnAsError)
+  if (warnBehavior == WARN_YES)
   {
     msgText += " (warning treated as error, aborting now)";
   }
@@ -155,22 +166,23 @@ static void format_warn(const char *file,int line,const char *text)
     // print resulting message
     fwrite(msgText.data(),1,msgText.length(),warnFile);
   }
-  if (warnAsError)
+  if (warnBehavior == WARN_YES)
   {
     exit(1);
   }
+  warnStat = true;
 }
 
 static void handle_warn_as_error()
 {
-  static bool warnAsError = Config_getBool(WARN_AS_ERROR);
-  if (warnAsError)
+  if (warnBehavior == WARN_YES)
   {
     std::unique_lock<std::mutex> lock(g_mutex);
     QCString msgText = " (warning treated as error, aborting now)\n";
     fwrite(msgText.data(),1,msgText.length(),warnFile);
     exit(1);
   }
+  warnStat = true;
 }
 
 static void do_warn(bool enabled, const char *file, int line, const char *prefix, const char *fmt, va_list args)
@@ -312,3 +324,11 @@ void printlex(int dbg, bool enter, const char *lexName, const char *fileName)
       Debug::print(Debug::Lex,0,"%s lexical analyzer: %s\n",enter_txt_uc, qPrint(lexName));
   }
 }
+
+extern void finishWarnExit()
+{
+  if (warnStat && warnBehavior == FAIL_ON_WARNINGS)
+  {
+    exit(1);
+  }
+}
diff --git a/src/message.h b/src/message.h
index dd9eeeb..af49632 100644
--- a/src/message.h
+++ b/src/message.h
@@ -36,6 +36,7 @@ extern void err_full(const char *file,int line,const char *fmt, ...) PRINTFLIKE(
 extern void term(const char *fmt, ...) PRINTFLIKE(1, 2);
 void initWarningFormat();
 void warn_flush();
+extern void finishWarnExit();
 
 extern void printlex(int dbg, bool enter, const char *lexName, const char *fileName);