From 7fb4d613afb95a97f19cfab995e3d2ba920d9f2e Mon Sep 17 00:00:00 2001
From: Dennis <dkorpel@users.noreply.github.com>
Date: Sat, 22 Mar 2025 23:03:20 +0100
Subject: [PATCH] Use errorSupplemental for long errors with 2 sentences
 (#21060)

---
 compiler/src/dmd/dinterpret.d                  |  3 ++-
 compiler/src/dmd/initsem.d                     |  5 ++++-
 compiler/src/dmd/optimize.d                    |  3 ++-
 compiler/src/dmd/parse.d                       |  6 ++++--
 compiler/src/dmd/semantic2.d                   | 16 +++++++++++++---
 compiler/src/dmd/todt.d                        |  3 ++-
 compiler/src/dmd/toobj.d                       |  6 ++++--
 compiler/test/fail_compilation/fail11714.d     |  6 ++++--
 compiler/test/fail_compilation/fail15361.d     |  3 ++-
 compiler/test/fail_compilation/fail16.d        |  5 +++--
 compiler/test/fail_compilation/fail23439.d     |  3 ++-
 compiler/test/fail_compilation/failcontracts.d | 17 +++++++++--------
 compiler/test/fail_compilation/ice11153.d      |  5 +++--
 compiler/test/fail_compilation/test15989.d     |  8 +++++---
 compiler/test/fail_compilation/test19661.d     |  3 ++-
 15 files changed, 61 insertions(+), 31 deletions(-)

diff --git a/compiler/src/dmd/dinterpret.d b/compiler/src/dmd/dinterpret.d
index 641e8a0420..b223975f38 100644
--- a/compiler/src/dmd/dinterpret.d
+++ b/compiler/src/dmd/dinterpret.d
@@ -3183,7 +3183,8 @@ public:
             if (cmp == -1)
             {
                 char dir = (e.op == EXP.greaterThan || e.op == EXP.greaterOrEqual) ? '<' : '>';
-                error(e.loc, "the ordering of pointers to unrelated memory blocks is indeterminate in CTFE. To check if they point to the same memory block, use both `>` and `<` inside `&&` or `||`, eg `%s && %s %c= %s + 1`", e.toChars(), e.e1.toChars(), dir, e.e2.toChars());
+                error(e.loc, "the ordering of pointers to unrelated memory blocks is indeterminate in CTFE.");
+                errorSupplemental(e.loc, "to check if they point to the same memory block, use both `>` and `<` inside `&&` or `||`, eg `%s && %s %c= %s + 1`", e.toChars(), e.e1.toChars(), dir, e.e2.toChars());
                 result = CTFEExp.cantexp;
                 return;
             }
diff --git a/compiler/src/dmd/initsem.d b/compiler/src/dmd/initsem.d
index d37c85ad46..8737e0f646 100644
--- a/compiler/src/dmd/initsem.d
+++ b/compiler/src/dmd/initsem.d
@@ -394,7 +394,10 @@ Initializer initializerSemantic(Initializer init, Scope* sc, ref Type tx, NeedIn
             if (needInterpret)
                 i.exp = i.exp.ctfeInterpret();
             if (i.exp.op == EXP.voidExpression)
-                error(i.loc, "variables cannot be initialized with an expression of type `void`. Use `void` initialization instead.");
+            {
+                error(i.loc, "variables cannot be initialized with an expression of type `void`");
+                errorSupplemental(i.loc, "only `= void;` is allowed, which prevents default initialization");
+            }
         }
         else
         {
diff --git a/compiler/src/dmd/optimize.d b/compiler/src/dmd/optimize.d
index 7f2b030e5b..2e40f1826c 100644
--- a/compiler/src/dmd/optimize.d
+++ b/compiler/src/dmd/optimize.d
@@ -1072,7 +1072,8 @@ Expression optimize(Expression e, int result, bool keepLvalue = false)
         // All negative integral powers are illegal.
         if (e.e1.type.isIntegral() && (e.e2.op == EXP.int64) && cast(sinteger_t)e.e2.toInteger() < 0)
         {
-            error(e.loc, "cannot raise `%s` to a negative integer power. Did you mean `(cast(real)%s)^^%s` ?", e.e1.type.toBasetype().toChars(), e.e1.toChars(), e.e2.toChars());
+            error(e.loc, "cannot raise `%s` to a negative integer power.", e.e1.type.toBasetype().toChars());
+            errorSupplemental(e.loc, "did you mean `(cast(real)%s)^^%s` ?", e.e1.toChars(), e.e2.toChars());
             return errorReturn();
         }
         // If e2 *could* have been an integer, make it one.
diff --git a/compiler/src/dmd/parse.d b/compiler/src/dmd/parse.d
index 33f2a1e116..f031777238 100644
--- a/compiler/src/dmd/parse.d
+++ b/compiler/src/dmd/parse.d
@@ -4081,7 +4081,8 @@ class Parser(AST, Lexer = dmd.lexer.Lexer) : Lexer
                  */
                 if (isParameters(&peekt))
                 {
-                    error("function declaration without return type. (Note that constructors are always named `this`)");
+                    error("function declaration without return type");
+                    errorSupplemental("Note that constructors are always named `this`");
                 }
                 else
                     error("unexpected `(` in declarator");
@@ -8468,7 +8469,8 @@ class Parser(AST, Lexer = dmd.lexer.Lexer) : Lexer
                     nextToken();
                     if (token.value == TOK.identifier && peekNext() == TOK.leftParenthesis)
                     {
-                        error(loc, "unexpected `(` after `%s`, inside `is` expression. Try enclosing the contents of `is` with a `typeof` expression", token.toChars());
+                        error(loc, "unexpected `(` after `%s`, inside `is` expression", token.toChars());
+                        errorSupplemental("try enclosing the contents of `is` with a `typeof` expression");
                         nextToken();
                         Token* tempTok = peekPastParen(&token);
                         memcpy(&token, tempTok, Token.sizeof);
diff --git a/compiler/src/dmd/semantic2.d b/compiler/src/dmd/semantic2.d
index 4b410a17ca..a1bb7e895b 100644
--- a/compiler/src/dmd/semantic2.d
+++ b/compiler/src/dmd/semantic2.d
@@ -287,7 +287,10 @@ private extern(C++) final class Semantic2Visitor : Visitor
                 }
 
                 if (hasInvalidEnumInitializer(ei.exp))
-                    .error(vd.loc, "%s `%s` : Unable to initialize enum with class or pointer to struct. Use static const variable instead.", vd.kind, vd.toPrettyChars);
+                {
+                    .error(vd.loc, "%s `%s` : Unable to initialize enum with class or pointer to struct", vd.kind, vd.toPrettyChars);
+                    .errorSupplemental(vd.loc, "use static const variable instead");
+                }
             }
         }
         else if (vd._init && vd.isThreadlocal())
@@ -298,13 +301,20 @@ private extern(C++) final class Semantic2Visitor : Visitor
             {
                 ExpInitializer ei = vd._init.isExpInitializer();
                 if (ei && ei.exp.op == EXP.classReference)
-                    .error(vd.loc, "%s `%s` is a thread-local class and cannot have a static initializer. Use `static this()` to initialize instead.", vd.kind, vd.toPrettyChars);
+                {
+                    .error(vd.loc, "%s `%s` is a thread-local class and cannot have a static initializer", vd.kind, vd.toPrettyChars);
+                    .errorSupplemental(vd.loc, "use `static this()` to initialize instead");
+                }
             }
             else if (vd.type.ty == Tpointer && vd.type.nextOf().ty == Tstruct && vd.type.nextOf().isMutable() && !vd.type.nextOf().isShared())
             {
                 ExpInitializer ei = vd._init.isExpInitializer();
                 if (ei && ei.exp.op == EXP.address && (cast(AddrExp)ei.exp).e1.op == EXP.structLiteral)
-                    .error(vd.loc, "%s `%s` is a thread-local pointer to struct and cannot have a static initializer. Use `static this()` to initialize instead.", vd.kind, vd.toPrettyChars);
+                {
+                    .error(vd.loc, "%s `%s` is a thread-local pointer to struct and cannot have a static initializer", vd.kind, vd.toPrettyChars);
+                    .errorSupplemental(vd.loc, "use `static this()` to initialize instead");
+                }
+
             }
         }
         vd.semanticRun = PASS.semantic2done;
diff --git a/compiler/src/dmd/todt.d b/compiler/src/dmd/todt.d
index beab5f4e92..94453eface 100644
--- a/compiler/src/dmd/todt.d
+++ b/compiler/src/dmd/todt.d
@@ -1152,8 +1152,9 @@ private extern (C++) class TypeInfoDtVisitor : Visitor
                 printf("expected = x%x, %s.structsize = x%x\n", cast(uint)expected,
                     typeclass.toChars(), cast(uint)typeclass.structsize);
             }
-            error(typeclass.loc, "`%s`: mismatch between compiler (%d bytes) and object.d or object.di (%d bytes) found. Check installation and import paths with -v compiler switch.",
+            error(typeclass.loc, "`%s`: mismatch between compiler (%d bytes) and object.d or object.di (%d bytes) found",
                 typeclass.toChars(), cast(uint)expected, cast(uint)typeclass.structsize);
+            errorSupplemental(typeclass.loc, "check installation and import paths with `-v` compiler switch");
             fatal();
         }
     }
diff --git a/compiler/src/dmd/toobj.d b/compiler/src/dmd/toobj.d
index e27ce3ceda..943f3ed012 100644
--- a/compiler/src/dmd/toobj.d
+++ b/compiler/src/dmd/toobj.d
@@ -1217,8 +1217,9 @@ private void genClassInfoForClass(ClassDeclaration cd, Symbol* sinit)
         if (Type.typeinfoclass.structsize != target.classinfosize)
         {
             debug printf("target.classinfosize = x%x, Type.typeinfoclass.structsize = x%x\n", target.classinfosize, Type.typeinfoclass.structsize);
-            .error(cd.loc, "%s `%s` mismatch between compiler (%d bytes) and object.d or object.di (%d bytes) found. Check installation and import paths with -v compiler switch.",
+            .error(cd.loc, "%s `%s` mismatch between compiler (%d bytes) and object.d or object.di (%d bytes) found",
                    cd.kind, cd.toPrettyChars, cast(uint)target.classinfosize, cast(uint)Type.typeinfoclass.structsize);
+            .errorSupplemental(cd.loc, "check installation and import paths with `-v` compiler switch");
             fatal();
         }
     }
@@ -1554,8 +1555,9 @@ private void InterfaceInfoToDt(ref DtBuilder dtb, InterfaceDeclaration id)
         {
             if (Type.typeinfoclass.structsize != offset)
             {
-                .error(id.loc, "%s `%s` mismatch between compiler (%d bytes) and object.d or object.di (%d bytes) found. Check installation and import paths with -v compiler switch.",
+                .error(id.loc, "%s `%s` mismatch between compiler (%d bytes) and object.d or object.di (%d bytes) found",
                        id.kind, id.toPrettyChars, cast(uint)offset, cast(uint)Type.typeinfoclass.structsize);
+                .errorSupplemental(id.loc, "check installation and import paths with `-v` compiler switch");
                 fatal();
             }
         }
diff --git a/compiler/test/fail_compilation/fail11714.d b/compiler/test/fail_compilation/fail11714.d
index abc47087ff..f36f3e5831 100644
--- a/compiler/test/fail_compilation/fail11714.d
+++ b/compiler/test/fail_compilation/fail11714.d
@@ -1,8 +1,10 @@
 /*
 TEST_OUTPUT:
 ---
-fail_compilation/fail11714.d(14): Error: variable `fail11714.c` is a thread-local class and cannot have a static initializer. Use `static this()` to initialize instead.
-fail_compilation/fail11714.d(21): Error: variable `fail11714.s` is a thread-local pointer to struct and cannot have a static initializer. Use `static this()` to initialize instead.
+fail_compilation/fail11714.d(16): Error: variable `fail11714.c` is a thread-local class and cannot have a static initializer
+fail_compilation/fail11714.d(16):        use `static this()` to initialize instead
+fail_compilation/fail11714.d(23): Error: variable `fail11714.s` is a thread-local pointer to struct and cannot have a static initializer
+fail_compilation/fail11714.d(23):        use `static this()` to initialize instead
 ---
 */
 
diff --git a/compiler/test/fail_compilation/fail15361.d b/compiler/test/fail_compilation/fail15361.d
index 8e5f9800a8..aec716556a 100644
--- a/compiler/test/fail_compilation/fail15361.d
+++ b/compiler/test/fail_compilation/fail15361.d
@@ -1,7 +1,8 @@
 /*
 TEST_OUTPUT:
 ---
-fail_compilation/fail15361.d(8): Error: unexpected `(` after `errorize`, inside `is` expression. Try enclosing the contents of `is` with a `typeof` expression
+fail_compilation/fail15361.d(9): Error: unexpected `(` after `errorize`, inside `is` expression
+fail_compilation/fail15361.d(9):        try enclosing the contents of `is` with a `typeof` expression
 ---
 */
 
diff --git a/compiler/test/fail_compilation/fail16.d b/compiler/test/fail_compilation/fail16.d
index 4602d3de3b..ce021a95b8 100644
--- a/compiler/test/fail_compilation/fail16.d
+++ b/compiler/test/fail_compilation/fail16.d
@@ -2,8 +2,9 @@
 /*
 TEST_OUTPUT:
 ---
-fail_compilation/fail16.d(19): Error: function declaration without return type. (Note that constructors are always named `this`)
-fail_compilation/fail16.d(19): Error: variable name expected after type `bar!(typeof(X))(X)`, not `;`
+fail_compilation/fail16.d(20): Error: function declaration without return type
+fail_compilation/fail16.d(20):        Note that constructors are always named `this`
+fail_compilation/fail16.d(20): Error: variable name expected after type `bar!(typeof(X))(X)`, not `;`
 ---
 */
 
diff --git a/compiler/test/fail_compilation/fail23439.d b/compiler/test/fail_compilation/fail23439.d
index b070e581a4..6f16bc1343 100644
--- a/compiler/test/fail_compilation/fail23439.d
+++ b/compiler/test/fail_compilation/fail23439.d
@@ -2,7 +2,8 @@
 // PERMUTE_ARGS: -lowmem
 /* TEST_OUTPUT:
 ---
-fail_compilation/fail23439.d(13): Error: variable `fail23439.ice23439` is a thread-local class and cannot have a static initializer. Use `static this()` to initialize instead.
+fail_compilation/fail23439.d(14): Error: variable `fail23439.ice23439` is a thread-local class and cannot have a static initializer
+fail_compilation/fail23439.d(14):        use `static this()` to initialize instead
 ---
 */
 class C23439
diff --git a/compiler/test/fail_compilation/failcontracts.d b/compiler/test/fail_compilation/failcontracts.d
index b6c3bc906a..749d98f9bd 100644
--- a/compiler/test/fail_compilation/failcontracts.d
+++ b/compiler/test/fail_compilation/failcontracts.d
@@ -1,14 +1,15 @@
 /* TEST_OUTPUT:
 ---
-fail_compilation/failcontracts.d(17): Error: missing `{ ... }` for function literal
-fail_compilation/failcontracts.d(17): Error: semicolon expected following auto declaration, not `bode`
-fail_compilation/failcontracts.d(18): Error: function declaration without return type. (Note that constructors are always named `this`)
-fail_compilation/failcontracts.d(18): Error: variable name expected after type `test1()`, not `bode`
-fail_compilation/failcontracts.d(18): Error: semicolon expected following function declaration, not `bode`
+fail_compilation/failcontracts.d(18): Error: missing `{ ... }` for function literal
+fail_compilation/failcontracts.d(18): Error: semicolon expected following auto declaration, not `bode`
+fail_compilation/failcontracts.d(19): Error: function declaration without return type
+fail_compilation/failcontracts.d(19):        Note that constructors are always named `this`
+fail_compilation/failcontracts.d(19): Error: variable name expected after type `test1()`, not `bode`
 fail_compilation/failcontracts.d(19): Error: semicolon expected following function declaration, not `bode`
-fail_compilation/failcontracts.d(21): Error: unexpected `(` in declarator
-fail_compilation/failcontracts.d(21): Error: found `T` when expecting `)`
-fail_compilation/failcontracts.d(21): Error: expected `{`, not `;` for enum declaration
+fail_compilation/failcontracts.d(20): Error: semicolon expected following function declaration, not `bode`
+fail_compilation/failcontracts.d(22): Error: unexpected `(` in declarator
+fail_compilation/failcontracts.d(22): Error: found `T` when expecting `)`
+fail_compilation/failcontracts.d(22): Error: expected `{`, not `;` for enum declaration
 ---
 */
 
diff --git a/compiler/test/fail_compilation/ice11153.d b/compiler/test/fail_compilation/ice11153.d
index 826bd8cd7e..936d987c15 100644
--- a/compiler/test/fail_compilation/ice11153.d
+++ b/compiler/test/fail_compilation/ice11153.d
@@ -1,8 +1,9 @@
 /*
 TEST_OUTPUT:
 ---
-fail_compilation/ice11153.d(11): Error: function declaration without return type. (Note that constructors are always named `this`)
-fail_compilation/ice11153.d(11): Error: variable name expected after type `foo()`, not `{`
+fail_compilation/ice11153.d(12): Error: function declaration without return type
+fail_compilation/ice11153.d(12):        Note that constructors are always named `this`
+fail_compilation/ice11153.d(12): Error: variable name expected after type `foo()`, not `{`
 ---
 */
 
diff --git a/compiler/test/fail_compilation/test15989.d b/compiler/test/fail_compilation/test15989.d
index 38ca331267..85b74bfad5 100644
--- a/compiler/test/fail_compilation/test15989.d
+++ b/compiler/test/fail_compilation/test15989.d
@@ -1,9 +1,11 @@
 /*
 TEST_OUTPUT:
 ---
-fail_compilation/test15989.d(39): Error: variable `test15989.main.ctRegex` : Unable to initialize enum with class or pointer to struct. Use static const variable instead.
-fail_compilation/test15989.d(48): Error: variable `test15989.test.c` : Unable to initialize enum with class or pointer to struct. Use static const variable instead.
-fail_compilation/test15989.d(49): Error: cannot use non-constant CTFE pointer in an initializer `new int(3)`
+fail_compilation/test15989.d(41): Error: variable `test15989.main.ctRegex` : Unable to initialize enum with class or pointer to struct
+fail_compilation/test15989.d(41):        use static const variable instead
+fail_compilation/test15989.d(50): Error: variable `test15989.test.c` : Unable to initialize enum with class or pointer to struct
+fail_compilation/test15989.d(50):        use static const variable instead
+fail_compilation/test15989.d(51): Error: cannot use non-constant CTFE pointer in an initializer `new int(3)`
 ---
 */
 
diff --git a/compiler/test/fail_compilation/test19661.d b/compiler/test/fail_compilation/test19661.d
index 369c0a8624..712721487c 100644
--- a/compiler/test/fail_compilation/test19661.d
+++ b/compiler/test/fail_compilation/test19661.d
@@ -2,7 +2,8 @@
 EXTRA_FILES: imports/imp19661.d
 TEST_OUTPUT:
 ---
-fail_compilation/test19661.d(11): Error: variables cannot be initialized with an expression of type `void`. Use `void` initialization instead.
+fail_compilation/test19661.d(12): Error: variables cannot be initialized with an expression of type `void`
+fail_compilation/test19661.d(12):        only `= void;` is allowed, which prevents default initialization
 ---
 */