Fix Issue 13738 - RTInfo generation on deprecated struct causes deprecation message

src/aggregate.h

@@ -73,6 +73,7 @@ class AggregateDeclaration : public ScopeDsymbol
     Sizeok sizeok;         // set when structsize contains valid data
     Dsymbol *deferred;          // any deferred semantic2() or semantic3() symbol
     bool isdeprecated;          // true if deprecated
+    bool mutedeprecation;       // true while analysing RTInfo to avoid deprecation message
 
     Dsymbol *enclosing;         /* !=NULL if is nested
                                  * pointing to the dsymbol that directly enclosing it.
@@ -112,6 +113,7 @@ class AggregateDeclaration : public ScopeDsymbol
     int firstFieldInUnion(int indx); // first field in union that includes indx
     int numFieldsInUnion(int firstIndex); // #fields in union starting at index
     bool isDeprecated();         // is aggregate deprecated?
+    bool muteDeprecationMessage(); // disable deprecation message on Dsymbol?
     bool isNested();
     void makeNested();
     bool isExport();

src/dsymbol.c

@@ -567,6 +567,11 @@ bool Dsymbol::isDeprecated()
     return false;
 }
 
+bool Dsymbol::muteDeprecationMessage()
+{
+    return false;
+}
+
 bool Dsymbol::isOverloadable()
 {
     return false;
@@ -665,7 +670,7 @@ void Dsymbol::deprecation(const char *format, ...)
 
 void Dsymbol::checkDeprecated(Loc loc, Scope *sc)
 {
-    if (global.params.useDeprecated != 1 && isDeprecated())
+    if (global.params.useDeprecated != 1 && isDeprecated() && !muteDeprecationMessage())
     {
         // Don't complain if we're inside a deprecated symbol's scope
         for (Dsymbol *sp = sc->parent; sp; sp = sp->parent)

src/dsymbol.h

@@ -215,6 +215,7 @@ class Dsymbol : public RootObject
     virtual bool isExport();                    // is Dsymbol exported?
     virtual bool isImportedSymbol();            // is Dsymbol imported?
     virtual bool isDeprecated();                // is Dsymbol deprecated?
+    virtual bool muteDeprecationMessage();      // disable deprecation message on Dsymbol?
     virtual bool isOverloadable();
     virtual bool hasOverloads();
     virtual LabelDsymbol *isLabel();            // is this a LabelDsymbol?

src/struct.c

@@ -137,6 +137,7 @@ AggregateDeclaration::AggregateDeclaration(Loc loc, Identifier *id)
     sizeok = SIZEOKnone;        // size not determined yet
     deferred = NULL;
     isdeprecated = false;
+    mutedeprecation = false;
     inv = NULL;
     aggNew = NULL;
     aggDelete = NULL;
@@ -238,6 +239,16 @@ void AggregateDeclaration::semantic3(Scope *sc)
         (!isDeprecated() || global.params.useDeprecated) &&
         (type && type->ty != Terror))
     {
+        // we do not want to report deprecated uses of this type during RTInfo
+        //  generation, so we disable reporting deprecation temporarily
+        // WARNING: Muting messages during analysis of RTInfo might silently instantiate
+        //  templates that use (other) deprecated types. If these template instances
+        //  are used in other parts of the program later, they will be reused without
+        //  ever producing the deprecation message. The implementation here restricts
+        //  muting to the types that RTInfo is currently generated for.
+        bool wasmuted = mutedeprecation;
+        mutedeprecation = true;
+
         // Evaluate: RTinfo!type
         Objects *tiargs = new Objects();
         tiargs->push(type);
@@ -255,6 +266,8 @@ void AggregateDeclaration::semantic3(Scope *sc)
 
         e = e->ctfeInterpret();
         getRTInfo = e;
+
+        mutedeprecation = wasmuted;
     }
 
     if (sd)
@@ -384,6 +397,11 @@ bool AggregateDeclaration::isDeprecated()
     return isdeprecated;
 }
 
+bool AggregateDeclaration::muteDeprecationMessage()
+{
+    return mutedeprecation;
+}
+
 bool AggregateDeclaration::isExport()
 {
     return protection.kind == PROTexport;