Stateful ErrorSinks can now react to compilation ending. (#17051)

compiler/src/dmd/errors.d

@@ -784,6 +784,8 @@ extern (C++) void fatal()
     if (fatalErrorHandler && fatalErrorHandler())
         return;
 
+    global.plugErrorSinks();
+
     exit(EXIT_FAILURE);
 }
 

compiler/src/dmd/errorsink.d

@@ -34,6 +34,15 @@ abstract class ErrorSink
     void deprecation(const ref Loc loc, const(char)* format, ...);
 
     void deprecationSupplemental(const ref Loc loc, const(char)* format, ...);
+
+    /**
+     * This will be called to indicate compilation has either
+     * finished or terminated, no more errors are possible - it's
+     * now the time to print any stored errors.
+     *
+     * The default implementation does nothing since most error sinks have no state
+     */
+    void plugSink() {}
 }
 
 /*****************************************

compiler/src/dmd/frontend.h

@@ -8511,6 +8511,7 @@ struct Global final
     bool endGagging(uint32_t oldGagged);
     void increaseErrorCount();
     void _init();
+    void plugErrorSinks();
     uint32_t versionNumber();
     const char* const versionChars();
     Global() :

compiler/src/dmd/globals.d

@@ -467,6 +467,17 @@ extern (C++) struct Global
         return major * 1000 + minor;
     }
 
+    /**
+     * Indicate to stateful error sinks that no more errors can be produced.
+     * This is to support error sinks that collect information to produce a
+     * single (say) report.
+     */
+    extern(C++) void plugErrorSinks()
+    {
+        global.errorSink.plugSink();
+        global.errorSinkNull.plugSink();
+    }
+
     /**
     Returns: the version as the number that would be returned for __VERSION__
     */

compiler/src/dmd/globals.h

@@ -350,6 +350,13 @@ struct Global
 
     void _init();
 
+    /**
+     * Indicate to stateful error sinks that no more errors can be produced.
+     * This is to support error sinks that collect information to produce a
+     * single (say) report.
+     */
+    void plugErrorSinks();
+
     /**
     Returns: the version as the number that would be returned for __VERSION__
     */

compiler/src/dmd/main.d

@@ -166,6 +166,14 @@ private int tryMain(size_t argc, const(char)** argv, ref Param params)
     Strings files;
     Strings libmodules;
     global._init();
+
+    scope(exit)
+    {
+        // If we are here then compilation has ended
+        // gracefully as opposed to with `fatal`
+        global.plugErrorSinks();
+    }
+
     target.setTargetBuildDefaults();
 
     if (parseCommandlineAndConfig(argc, argv, params, files))