Limit the number of deprecation messages by default

changelog/dmd.deprecation-limit.dd

@@ -0,0 +1,26 @@
+Deprecation warnings are now also limited by `-verrors`
+
+By default, the compiler stops after 20 error messages, unless a different amount is specified by passing e.g. `-verrors=50` or `-verrors=0` for no limit.
+This error limit now also applies to deprecation messages, so the command line isn't flooded with hundreds of them when compiling a big project that hasn't fixed all deprecations yet.
+
+---
+deprecated void f()
+{
+}
+
+void main()
+{
+    f();
+    f();
+    f();
+    f();
+}
+---
+
+$(CONSOLE
+> dmd -verrors=3 app.d
+app.d(7): Deprecation: function `deprecationlimit.x` is deprecated
+app.d(8): Deprecation: function `deprecationlimit.x` is deprecated
+app.d(9): Deprecation: function `deprecationlimit.x` is deprecated
+1 deprecation warning omitted, use `-verrors=0` to show all
+)

compiler/src/dmd/cli.d

@@ -818,7 +818,7 @@ dmd -cov -unittest myprog.d
             "limit the number of supplemental messages for each error (0 means unlimited)"
         ),
         Option("verrors=<num>",
-            "limit the number of error messages (0 means unlimited)"
+            "limit the number of error/deprecation messages (0 means unlimited)"
         ),
         Option("verrors=context",
             "show error messages with the context of the erroring source line"

compiler/src/dmd/errors.d

@@ -478,8 +478,12 @@ extern (C++) void verrorReport(const ref Loc loc, const(char)* format, va_list a
         {
             if (!global.gag)
             {
-                info.headerColor = Classification.deprecation;
-                verrorPrint(format, ap, info);
+                global.deprecations++;
+                if (global.params.v.errorLimit == 0 || global.deprecations <= global.params.v.errorLimit)
+                {
+                    info.headerColor = Classification.deprecation;
+                    verrorPrint(format, ap, info);
+                }
             }
             else
             {

compiler/src/dmd/frontend.h

@@ -8294,6 +8294,7 @@ struct Global final
     CompileEnv compileEnv;
     Param params;
     uint32_t errors;
+    uint32_t deprecations;
     uint32_t warnings;
     uint32_t gag;
     uint32_t gaggedErrors;
@@ -8324,6 +8325,7 @@ struct Global final
         compileEnv(),
         params(),
         errors(),
+        deprecations(),
         warnings(),
         gag(),
         gaggedErrors(),
@@ -8339,7 +8341,7 @@ struct Global final
         preprocess()
     {
     }
-    Global(_d_dynamicArray< const char > inifilename, _d_dynamicArray< const char > copyright = { 73, "Copyright (C) 1999-2024 by The D Language Foundation, All Rights Reserved" }, _d_dynamicArray< const char > written = { 24, "written by Walter Bright" }, Array<const char* > path = Array<const char* >(), Array<const char* > filePath = Array<const char* >(), CompileEnv compileEnv = CompileEnv(), Param params = Param(), uint32_t errors = 0u, uint32_t warnings = 0u, uint32_t gag = 0u, uint32_t gaggedErrors = 0u, uint32_t gaggedWarnings = 0u, void* console = nullptr, Array<Identifier* > versionids = Array<Identifier* >(), Array<Identifier* > debugids = Array<Identifier* >(), bool hasMainFunction = false, uint32_t varSequenceNumber = 1u, FileManager* fileManager = nullptr, ErrorSink* errorSink = nullptr, ErrorSink* errorSinkNull = nullptr, DArray<uint8_t >(*preprocess)(FileName , const Loc& , OutBuffer& ) = nullptr) :
+    Global(_d_dynamicArray< const char > inifilename, _d_dynamicArray< const char > copyright = { 73, "Copyright (C) 1999-2024 by The D Language Foundation, All Rights Reserved" }, _d_dynamicArray< const char > written = { 24, "written by Walter Bright" }, Array<const char* > path = Array<const char* >(), Array<const char* > filePath = Array<const char* >(), CompileEnv compileEnv = CompileEnv(), Param params = Param(), uint32_t errors = 0u, uint32_t deprecations = 0u, uint32_t warnings = 0u, uint32_t gag = 0u, uint32_t gaggedErrors = 0u, uint32_t gaggedWarnings = 0u, void* console = nullptr, Array<Identifier* > versionids = Array<Identifier* >(), Array<Identifier* > debugids = Array<Identifier* >(), bool hasMainFunction = false, uint32_t varSequenceNumber = 1u, FileManager* fileManager = nullptr, ErrorSink* errorSink = nullptr, ErrorSink* errorSinkNull = nullptr, DArray<uint8_t >(*preprocess)(FileName , const Loc& , OutBuffer& ) = nullptr) :
         inifilename(inifilename),
         copyright(copyright),
         written(written),
@@ -8348,6 +8350,7 @@ struct Global final
         compileEnv(compileEnv),
         params(params),
         errors(errors),
+        deprecations(deprecations),
         warnings(warnings),
         gag(gag),
         gaggedErrors(gaggedErrors),

compiler/src/dmd/globals.d

@@ -284,6 +284,7 @@ extern (C++) struct Global
 
     Param params;           /// command line parameters
     uint errors;            /// number of errors reported so far
+    uint deprecations;      /// number of deprecations reported so far
     uint warnings;          /// number of warnings reported so far
     uint gag;               /// !=0 means gag reporting of errors & warnings
     uint gaggedErrors;      /// number of errors reported while gagged

compiler/src/dmd/globals.h

@@ -307,6 +307,7 @@ struct Global
 
     Param params;
     unsigned errors;         // number of errors reported so far
+    unsigned deprecations;   // number of deprecations reported so far
     unsigned warnings;       // number of warnings reported so far
     unsigned gag;            // !=0 means gag reporting of errors & warnings
     unsigned gaggedErrors;   // number of errors reported while gagged

compiler/src/dmd/main.d

@@ -250,6 +250,18 @@ private int tryMain(size_t argc, const(char)** argv, ref Param params)
         errorSupplemental(Loc.initial, "Use -wi if you wish to treat warnings only as informational.");
     }
 
+    // In case deprecation messages were omitted, inform the user about it
+    static void mentionOmittedDeprecations()
+    {
+        if (global.params.v.errorLimit != 0 &&
+            global.deprecations > global.params.v.errorLimit)
+        {
+            const omitted = global.deprecations - global.params.v.errorLimit;
+            message(Loc.initial, "%d deprecation warning%s omitted, use `-verrors=0` to show all",
+                omitted, omitted == 1 ? "".ptr : "s".ptr);
+        }
+    }
+
     /*
     Generates code to check for all `params` whether any usage page
     has been requested.
@@ -582,6 +594,9 @@ private int tryMain(size_t argc, const(char)** argv, ref Param params)
     if (global.warnings)
         errorOnWarning();
 
+    if (global.params.useDeprecated == DiagnosticReporting.inform)
+        mentionOmittedDeprecations();
+
     // Do not attempt to generate output files if errors or warnings occurred
     if (global.errors || global.warnings)
         removeHdrFilesAndFail(params, modules);

compiler/test/compilable/deprecationlimit.d

@@ -0,0 +1,22 @@
+/*
+REQUIRED_ARGS: -verrors=3
+TEST_OUTPUT:
+---
+compilable/deprecationlimit.d(18): Deprecation: function `deprecationlimit.f` is deprecated
+compilable/deprecationlimit.d(19): Deprecation: function `deprecationlimit.f` is deprecated
+compilable/deprecationlimit.d(20): Deprecation: function `deprecationlimit.f` is deprecated
+1 deprecation warning omitted, use `-verrors=0` to show all
+---
+*/
+
+deprecated void f()
+{
+}
+
+void main()
+{
+    f();
+    f();
+    f();
+    f();
+}

compiler/test/compilable/sw_transition_complex.d

@@ -1,5 +1,5 @@
 // PERMUTE_ARGS:
-// REQUIRED_ARGS: -unittest
+// REQUIRED_ARGS: -unittest -verrors=0
 
 /*
 TEST_OUTPUT:

compiler/test/runnable/template10.d

@@ -1,4 +1,5 @@
 // PERMUTE_ARGS: -inline
+// REQUIRED_ARGS: -verrors=0
 /* TEST_OUTPUT:
 ---
 runnable/template10.d(89): Deprecation: function `template10.test1b.f0.f!(a).f` function requires a dual-context, which is deprecated
@@ -58,7 +59,6 @@ runnable/template10.d(741):        instantiated from here: `fun!(n)`
 */
 
 /********************************************/
-
 void test1a()
 {
     int a = 1;