Fix Bugzilla 24599 - Wrongly elided TypeInfo emission (dlang#15868)

Reverting dlang#14844, which caused such missing TypeInfos, *and* making
sure the special TypeInfo members are fully analyzed and ready for
codegen (otherwise hitting an assertion for the real-world project).

compiler/src/dmd/expressionsem.d

@@ -7194,17 +7194,7 @@ private extern (C++) final class ExpressionSemanticVisitor : Visitor
         // Handle this in the glue layer
         Expression e = new TypeidExp(exp.loc, ta);
 
-        bool genObjCode = true;
-
-        // https://issues.dlang.org/show_bug.cgi?id=23650
-        // We generate object code for typeinfo, required
-        // by typeid, only if in non-speculative context
-        if (sc.traitsCompiles)
-        {
-            genObjCode = false;
-        }
-
-        e.type = getTypeInfoType(exp.loc, ta, sc, genObjCode);
+        e.type = getTypeInfoType(exp.loc, ta, sc);
         semanticTypeInfo(sc, ta);
 
         if (ea)

compiler/src/dmd/frontend.h

@@ -7596,7 +7596,7 @@ struct Target final
 
 extern Target target;
 
-extern Type* getTypeInfoType(const Loc& loc, Type* t, Scope* sc, bool genObjCode = true);
+extern Type* getTypeInfoType(const Loc& loc, Type* t, Scope* sc);
 
 class SemanticTimeTransitiveVisitor : public SemanticTimePermissiveVisitor
 {

compiler/src/dmd/todt.d

@@ -1441,6 +1441,13 @@ private extern (C++) class TypeInfoDtVisitor : Visitor
                 /* ti.toObjFile() won't get called. So, store these
                  * member functions into object file in here.
                  */
+
+                if (sd.semanticRun < PASS.semantic3done)
+                {
+                    import dmd.semantic3 : semanticTypeInfoMembers;
+                    semanticTypeInfoMembers(sd);
+                }
+
                 if (sd.xeq && sd.xeq != StructDeclaration.xerreq)
                     toObjFile(sd.xeq, global.params.multiobj);
                 if (sd.xcmp && sd.xcmp != StructDeclaration.xerrcmp)

compiler/src/dmd/typinf.d

@@ -100,14 +100,13 @@ bool genTypeInfo(Expression e, const ref Loc loc, Type torig, Scope* sc)
  *      loc = the location for reporting line nunbers in errors
  *      t   = the type to get the type of the `TypeInfo` object for
  *      sc  = the scope
- *      genObjCode = if true, object code will be generated for the obtained TypeInfo
  * Returns:
  *      The type of the `TypeInfo` object associated with `t`
  */
-extern (C++) Type getTypeInfoType(const ref Loc loc, Type t, Scope* sc, bool genObjCode = true)
+extern (C++) Type getTypeInfoType(const ref Loc loc, Type t, Scope* sc)
 {
     assert(t.ty != Terror);
-    if (genTypeInfo(null, loc, t, sc) && genObjCode)
+    if (genTypeInfo(null, loc, t, sc))
     {
         // Find module that will go all the way to an object file
         Module m = sc._module.importedFrom;

compiler/src/dmd/typinf.h

@@ -22,4 +22,4 @@ namespace dmd
     bool isSpeculativeType(Type *t);
     bool builtinTypeInfo(Type *t);
 }
-Type *getTypeInfoType(const Loc &loc, Type *t, Scope *sc, bool genObjCode = true);
+Type *getTypeInfoType(const Loc &loc, Type *t, Scope *sc);

compiler/src/tests/cxxfrontend.cc

@@ -1865,7 +1865,7 @@ void template_h(TemplateParameter *tp, Scope *sc, TemplateParameters *tps,
 void typinf_h(Expression *e, const Loc &loc, Type *t, Scope *sc)
 {
     dmd::genTypeInfo(e, loc, t, sc);
-    ::getTypeInfoType(loc, t, sc, false);
+    ::getTypeInfoType(loc, t, sc);
     dmd::isSpeculativeType(t);
     dmd::builtinTypeInfo(t);
 }

compiler/test/runnable/test24599.d

@@ -0,0 +1,24 @@
+module mod;
+
+struct Variable
+{
+    size_t toHash() const { return 0; }
+}
+
+enum hasInoutConstruction(T) = __traits(compiles, { struct S { T a; } });
+
+struct Algebraic(T)
+{
+    static if (hasInoutConstruction!T)
+    {
+    }
+}
+
+Algebraic!Variable foo();
+
+struct S
+{
+    Variable[] symbols;
+}
+
+void main() {}