Structs or arrays may not contain structs with a flexible array member.

We previously ignored this, but it is a constraint violation under the C standards, so it should be reported as an error.

GCC and Clang allow this as an extension, as we were effectively doing previously. We will follow the standards for now, but if there was demand for such an extension in ORCA/C, it could be re-introduced subject to a #pragma ignore flag.

CCommon.pas

@@ -310,6 +310,7 @@ type
         unionType   : (fieldList: identPtr;	{field list}
 		       sName: stringPtr;	{struct name; for forward refs}
 		       constMember: boolean;    {does it have a const member?}
+		       flexibleArrayMember: boolean; {does it have a FAM?}
                       );
      end;
 

Header.pas

@@ -18,7 +18,7 @@ uses CCommon, MM, Scanner, Symbol, CGI;
 {$segment 'SCANNER'}
 
 const
-   symFileVersion = 17;                 {version number of .sym file format}
+   symFileVersion = 18;                 {version number of .sym file format}
 
 var
    inhibitHeader: boolean;		{should .sym includes be blocked?}
@@ -1063,6 +1063,7 @@ procedure EndInclude {chPtr: ptr};
                 	end; {while}
         	     WriteByte(0);
         	     WriteByte(ord(tp^.constMember));
+        	     WriteByte(ord(tp^.flexibleArrayMember));
         	     end;
 
 		  otherwise: ;
@@ -1700,6 +1701,7 @@ var
         		ep := ip;
         		end; {while}
         	     tp^.constMember := boolean(ReadByte);
+        	     tp^.flexibleArrayMember := boolean(ReadByte);
         	     end;
 
         	  enumType: ;

Parser.pas

@@ -2847,8 +2847,10 @@ var
                   maxDisp := disp;
                if variable^.itype^.size = 0 then
                   if (variable^.itype^.kind = arrayType) 
-                     and (disp > 0) then {handle flexible array member}
+                     and (disp > 0) then begin {handle flexible array member}
-                     didFlexibleArray := true
+                     didFlexibleArray := true;
+                     tp^.flexibleArrayMember := true;
+                     end {if}
                   else
                      Error(117);
                end {if}
@@ -2868,10 +2870,16 @@ var
                   tPtr := tPtr^.aType;
                end; {while}
             if tqConst in tPtr^.qualifiers then
-               tp^.constMember := true
+               tp^.constMember := true;
-            else if tPtr^.kind in [structType,unionType] then
+            if tPtr^.kind in [structType,unionType] then begin
                if tPtr^.constMember then
                   tp^.constMember := true;
+               if tPtr^.flexibleArrayMember then
+                  if kind = structType then
+                     Error(169)
+                  else {if kind = unionType then}
+                     tp^.flexibleArrayMember := true;
+               end; {if}
 
             if token.kind = commach then {allow repeated declarations}
                begin
@@ -3220,6 +3228,7 @@ while token.kind in allowedTokens do begin
                  {structTypePtr^.fieldList := nil;}
                  {structTypePtr^.sName := nil;}
                  {structTypePtr^.constMember := false;}
+                 {structTypePtr^.flexibleArrayMember := false;}
                   structPtr := NewSymbol(ttoken.name, structTypePtr, ident,
                      tagSpace, defined);
                   structTypePtr^.sName := structPtr^.name;
@@ -3253,6 +3262,7 @@ while token.kind in allowedTokens do begin
               {structTypePtr^.fieldList := nil;}
               {structTypePtr^.sName := nil;}
               {structTypePtr^.constMember := false;}
+              {structTypePtr^.flexibleArrayMember := false;}
                end; {if}
             if structPtr <> nil then
                structPtr^.itype := structTypePtr;
@@ -3389,6 +3399,9 @@ var
                Error(123);
                goto 1;
                end; {if}
+            if tp^.aType^.kind in [structType,unionType] then
+               if tp^.aType^.flexibleArrayMember then
+                  Error(169);
             end; {if}
          firstVariable := false;        {unspecified sizes are only allowed in }
                                         { the first subscript                  }

Scanner.pas

@@ -740,6 +740,7 @@ if list or (numErr <> 0) then begin
         166: msg := @'string literals with these prefixes may not be merged';
         167: msg := @'''L''-prefixed character or string constants are not supported by ORCA/C';
         168: msg := @'malformed hexadecimal floating constant';
+        169: msg := @'struct or array may not contain a struct with a flexible array member';
          otherwise: Error(57);
          end; {case}
        writeln(msg^);

Symbol.pas

@@ -1612,6 +1612,8 @@ with defaultStruct^ do begin            {(for structures with errors)}
    qualifiers := [];
    kind := structType;
    sName := nil;
+   constMember := false;
+   flexibleArrayMember := false;
    new(fieldList);
    with fieldlist^ do begin
       next := nil;