Implement basic support for Objective-C methods.

Basic support for classes, interfaces and instance methods.
This is implemented by adding a new linkage attribute, `Objective-C`,
and a compiler recognized UDA, `@selector`. The linkage attribute is
to be used on a class or interface. The UDA is attached to a method.

The linkage attribute tells the compiler that the class should use the
name mangling that matches the one used by Objective-C
(same as C, no mangling) and that all methods in the class
should use the Objective-C way of calling methods, see below.
The calling convention for Objective-C methods and functions is the
same as for C.

The selector UDA tells the compiler what Objective-C selector the
method should have. The selector is used in the Objective-C runtime
to find the implementation of a given method.

An Objective-C method call is implemented by making a regular C call
to the `objc_msgSend` function in the Objective-C runtime.
The signature of `objc_msgSend` looks something like this:

`id objc_msgSend(id self, SEL op, ...);`

* The first parameter is the object (this/self pointer)
* The second parameter is the selector attached to the method
* The last parameter is for all the arguments that the
implementation expects

The call to `objc_msgSend` should not be performed as a variadic
call but instead as if it had the same signature as the method
that should be called but with the two additional parameter,
`self` and `op`, added first. The implementation of `objc_msgSend`
will jump to the method instead of calling it.

Because of the above, multiple versions exist of `objc_msgSend`.
Depending on the return type of the method that is called the correct
version need to be used. This depends on the ABI. This is a list of
functions and for which types they're used on OS X 64bit:

* objc_msgSend_stret - Used for structs too large to be returned in
registries
* objc_msgSend_fpret - Used for `long double`
* objc_msgSend_fp2ret - Used for `_Complex long double`
* objc_msgSend - Used for everything else

src/aggregate.h

@@ -20,6 +20,7 @@
 
 #include "dsymbol.h"
 #include "declaration.h"
+#include "objc.h"
 
 class Identifier;
 class Type;
@@ -266,6 +267,7 @@ class ClassDeclaration : public AggregateDeclaration
     bool isabstract;                    // true if abstract class
     int inuse;                          // to prevent recursive attempts
     Baseok baseok;                      // set the progress of base classes resolving
+    Objc_ClassDeclaration objc;
 
     ClassDeclaration(Loc loc, Identifier *id, BaseClasses *baseclasses, bool inObject = false);
     Dsymbol *syntaxCopy(Dsymbol *s);

src/attrib.c

@@ -1358,7 +1358,7 @@ void UserAttributeDeclaration::semantic2(Scope *sc)
         if (atts && atts->dim && scope)
         {
             scope = NULL;
-            arrayExpressionSemantic(atts, sc);  // run semantic
+            arrayExpressionSemantic(atts, sc, true);  // run semantic
         }
     }
 

src/class.c

@@ -30,6 +30,7 @@
 #include "expression.h"
 #include "statement.h"
 #include "template.h"
+#include "objc.h"
 
 /********************************* ClassDeclaration ****************************/
 
@@ -233,6 +234,7 @@ ClassDeclaration::ClassDeclaration(Loc loc, Identifier *id, BaseClasses *basecla
     isabstract = false;
     inuse = 0;
     baseok = BASEOKnone;
+    objc.objc = false;
 }
 
 Dsymbol *ClassDeclaration::syntaxCopy(Dsymbol *s)
@@ -320,6 +322,8 @@ void ClassDeclaration::semantic(Scope *sc)
 
         if (sc->linkage == LINKcpp)
             cpp = true;
+        if (sc->linkage == LINKobjc)
+            objc_ClassDeclaration_semantic_PASSinit_LINKobjc(this);
     }
     else if (symtab && !scx)
     {
@@ -1383,6 +1387,7 @@ void InterfaceDeclaration::semantic(Scope *sc)
 
         if (!baseclasses->dim && sc->linkage == LINKcpp)
             cpp = true;
+        objc_InterfaceDeclaration_semantic_objcExtern(this, sc);
 
         // Check for errors, handle forward references
         for (size_t i = 0; i < baseclasses->dim; )
@@ -1551,6 +1556,8 @@ void InterfaceDeclaration::semantic(Scope *sc)
         sc2->linkage = LINKwindows;
     else if (cpp)
         sc2->linkage = LINKcpp;
+    else if (this->objc.isInterface())
+        sc->linkage = LINKobjc;
     sc2->protection = Prot(PROTpublic);
     sc2->explicitProtection = 0;
     sc2->structalign = STRUCTALIGN_DEFAULT;

src/declaration.h

@@ -18,6 +18,7 @@
 
 #include "dsymbol.h"
 #include "mtype.h"
+#include "objc.h"
 
 class Expression;
 class Statement;
@@ -526,6 +527,7 @@ class FuncDeclaration : public Declaration
                                         // scopes from having the same name
     VarDeclaration *vthis;              // 'this' parameter (member and nested)
     VarDeclaration *v_arguments;        // '_arguments' parameter
+    Objc_FuncDeclaration objc;
 #ifdef IN_GCC
     VarDeclaration *v_argptr;           // '_argptr' variable
 #endif

src/e2ir.c

@@ -71,6 +71,10 @@ void genTypeInfo(Type *t, Scope *sc);
 int callSideEffectLevel(FuncDeclaration *f);
 int callSideEffectLevel(Type *t);
 
+void objc_callfunc_setupMethodSelector(Type *tret, FuncDeclaration *fd, Type *t, elem *ehidden, elem **esel);
+void objc_callfunc_setupMethodCall(elem **ec, elem *ehidden, elem *ethis, TypeFunction *tf);
+void objc_callfunc_setupEp(elem *esel, elem **ep, int reverse);
+
 #define el_setLoc(e,loc)        ((e)->Esrcpos.Sfilename = (char *)(loc).filename, \
                                  (e)->Esrcpos.Slinnum = (loc).linnum, \
                                  (e)->Esrcpos.Scharnum = (loc).charnum)
@@ -121,7 +125,8 @@ elem *callfunc(Loc loc,
         FuncDeclaration *fd,    // if !=NULL, this is the function being called
         Type *t,                // TypeDelegate or TypeFunction for this function
         elem *ehidden,          // if !=NULL, this is the 'hidden' argument
-        Expressions *arguments)
+        Expressions *arguments,
+        elem *esel = NULL)      // selector for Objective-C methods (when not provided by fd)
 {
     elem *ep;
     elem *e;
@@ -235,6 +240,9 @@ elem *callfunc(Loc loc,
         }
     }
 
+    objc_callfunc_setupMethodSelector(tret, fd, t, ehidden, &esel);
+    objc_callfunc_setupEp(esel, &ep, reverse);
+
     if (retmethod == RETstack)
     {
         if (!ehidden)
@@ -294,7 +302,11 @@ elem *callfunc(Loc loc,
         }
         Symbol *sfunc = toSymbol(fd);
 
-        if (!fd->isVirtual() ||
+        if (esel)
+        {
+            objc_callfunc_setupMethodCall(&ec, ehidden, ethis, tf);
+        }
+        else if (!fd->isVirtual() ||
             directcall ||               // BUG: fix
             fd->isFinalFunc()
            /* Future optimization: || (whole program analysis && not overridden)

src/expression.c

@@ -936,7 +936,7 @@ Expression *resolveUFCSProperties(Scope *sc, Expression *e1, Expression *e2 = NU
  * Perform semantic() on an array of Expressions.
  */
 
-bool arrayExpressionSemantic(Expressions *exps, Scope *sc)
+bool arrayExpressionSemantic(Expressions *exps, Scope *sc, bool preserveErrors)
 {
     bool err = false;
     if (exps)
@@ -949,7 +949,7 @@ bool arrayExpressionSemantic(Expressions *exps, Scope *sc)
                 e = e->semantic(sc);
                 if (e->op == TOKerror)
                     err = true;
-                else
+                if (preserveErrors || e->op != TOKerror)
                     (*exps)[i] = e;
             }
         }

src/expression.h

@@ -61,7 +61,7 @@ TupleDeclaration *isAliasThisTuple(Expression *e);
 int expandAliasThisTuples(Expressions *exps, size_t starti = 0);
 FuncDeclaration *hasThis(Scope *sc);
 Expression *fromConstInitializer(int result, Expression *e);
-bool arrayExpressionSemantic(Expressions *exps, Scope *sc);
+bool arrayExpressionSemantic(Expressions *exps, Scope *sc, bool preserveErrors = false);
 TemplateDeclaration *getFuncTemplateDecl(Dsymbol *s);
 Expression *valueNoDtor(Expression *e);
 int modifyFieldVar(Loc loc, Scope *sc, VarDeclaration *var, Expression *e1);

src/func.c

@@ -30,6 +30,7 @@
 #include "parse.h"
 #include "rmem.h"
 #include "visitor.h"
+#include "objc.h"
 
 Expression *addInvariant(Loc loc, Scope *sc, AggregateDeclaration *ad, VarDeclaration *vthis, bool direct);
 
@@ -273,6 +274,7 @@ class NrvoWalker : public StatementRewriteWalker
 FuncDeclaration::FuncDeclaration(Loc loc, Loc endloc, Identifier *id, StorageClass storage_class, Type *type)
     : Declaration(id)
 {
+    objc = Objc_FuncDeclaration(this);
     //printf("FuncDeclaration(id = '%s', type = %p)\n", id->toChars(), type);
     //printf("storage_class = x%x\n", storage_class);
     this->storage_class = storage_class;
@@ -1218,6 +1220,18 @@ void FuncDeclaration::semantic(Scope *sc)
 
 void FuncDeclaration::semantic2(Scope *sc)
 {
+    if (semanticRun >= PASSsemantic2done)
+        return;
+    assert(semanticRun <= PASSsemantic2);
+    semanticRun = PASSsemantic2;
+
+    objc_FuncDeclaration_semantic_setSelector(this, sc);
+    objc_FuncDeclaration_semantic_validateSelector(this);
+
+    if (ClassDeclaration *cd = parent->isClassDeclaration())
+    {
+        objc_FuncDeclaration_semantic_checkLinkage(this);
+    }
 }
 
 // Do the semantic analysis on the internals of the function.

src/globals.h

@@ -271,6 +271,7 @@ enum LINK
     LINKcpp,
     LINKwindows,
     LINKpascal,
+    LINKobjc,
 };
 
 enum DYNCAST

src/glue.c

@@ -1463,6 +1463,7 @@ unsigned totym(Type *tx)
 
                 case LINKc:
                 case LINKcpp:
+                case LINKobjc:
                 Lc:
                     t = TYnfunc;
 #if TARGET_LINUX || TARGET_OSX || TARGET_FREEBSD || TARGET_OPENBSD || TARGET_SOLARIS

src/hdrgen.c

@@ -1223,6 +1223,7 @@ class PrettyPrintVisitor : public Visitor
             case LINKcpp:           p = "C++";              break;
             case LINKwindows:       p = "Windows";          break;
             case LINKpascal:        p = "Pascal";           break;
+            case LINKobjc:          p = "Objective-C";      break;
             default:
                 assert(0);
                 break;
@@ -3177,6 +3178,7 @@ const char *linkageToChars(LINK linkage)
         case LINKcpp:       return "C++";
         case LINKwindows:   return "Windows";
         case LINKpascal:    return "Pascal";
+        case LINKobjc:      return "Objective-C";
         default:            assert(0);
     }
     return NULL;    // never reached

src/idgen.d

@@ -144,6 +144,7 @@ Msgtable[] msgtable =
     { "Windows" },
     { "Pascal" },
     { "System" },
+    { "Objective" },
 
     { "exit" },
     { "success" },
@@ -294,6 +295,7 @@ Msgtable[] msgtable =
     // Builtin functions
     { "std" },
     { "core" },
+    { "attribute" },
     { "math" },
     { "sin" },
     { "cos" },
@@ -362,6 +364,9 @@ Msgtable[] msgtable =
     { "basic_ostream" },
     { "basic_iostream" },
     { "char_traits" },
+
+    // Compiler recognized UDA's
+    { "udaSelector", "selector" },
 ];
 
 

src/magicport.json

@@ -21,6 +21,7 @@
         "tokens.c", "tokens.h",
         "globals.c", "globals.h",
         "escape.c",
+        "objc.c", "objc.h",
         "root/aav.h", "root/aav.c",
         "root/filename.h", "root/filename.c",
         "root/file.h", "root/file.c",
@@ -109,6 +110,43 @@
                 "function setValue"
             ]
         },
+        {
+          "module" : "objc",
+          "package" : "",
+          "imports" : [
+            "arraytypes",
+            "cond",
+            "dclass",
+            "dmangle",
+            "dmodule",
+            "dscope",
+            "dstruct",
+            "expression",
+            "func",
+            "globals",
+            "id",
+            "identifier",
+            "mtype",
+            "root.outbuffer",
+            "root.stringtable"
+          ],
+          "members" : [
+            "struct ObjcSelector",
+            "struct Objc_ClassDeclaration",
+            "struct Objc_FuncDeclaration",
+            "function objc_ClassDeclaration_semantic_PASSinit_LINKobjc",
+            "function objc_InterfaceDeclaration_semantic_objcExtern",
+            "function objc_FuncDeclaration_semantic_setSelector",
+            "function objc_isUdaSelector",
+            "function objc_FuncDeclaration_semantic_validateSelector",
+            "function objc_FuncDeclaration_semantic_checkLinkage",
+            "function objc_tryMain_dObjc",
+            "function objc_tryMain_init"
+          ],
+          "extra" : [
+            "extern(C++) void objc_initSymbols();"
+          ]
+        },
         {
             "module" : "dclass",
             "package" : "",
@@ -132,6 +170,7 @@
                 "identifier",
                 "globals",
                 "mtype",
+                "objc",
                 "root.outbuffer",
                 "root.rmem",
                 "root.rootobject",
@@ -1443,6 +1482,7 @@
                 "globals",
                 "mtype",
                 "nogc",
+                "objc",
                 "opover",
                 "root.filename",
                 "root.outbuffer",
@@ -2519,6 +2559,7 @@
                 "lib",
                 "link",
                 "mtype",
+                "objc",
                 "parse",
                 "root.file",
                 "root.filename",

src/magicport/typenames.d

@@ -13,4 +13,4 @@ bool lookup(bool[string] aa, string n)
     return p !is null;
 }
 
-auto dropdefaultctor = ["Loc", "Token", "HdrGenState", "CtfeStack", "InterState", "BaseClass", "Mem", "StringValue", "OutBuffer", "Scope", "DocComment", "PrefixAttributes", "Prot", "UnionExp"];
+auto dropdefaultctor = ["Loc", "Token", "HdrGenState", "CtfeStack", "InterState", "BaseClass", "Mem", "StringValue", "OutBuffer", "Scope", "DocComment", "PrefixAttributes", "Prot", "UnionExp", "Objc_FuncDeclaration"];

src/mangle.c

@@ -227,6 +227,7 @@ class Mangler : public Visitor
             case LINKwindows:       mc = 'W';       break;
             case LINKpascal:        mc = 'V';       break;
             case LINKcpp:           mc = 'R';       break;
+            case LINKobjc:          mc = 'Y';       break;
             default:
                 assert(0);
         }
@@ -414,6 +415,7 @@ class Mangler : public Visitor
                 case LINKc:
                 case LINKwindows:
                 case LINKpascal:
+                case LINKobjc:
                     buf->writestring(d->ident->toChars());
                     return;
 

src/mars.c

@@ -41,6 +41,7 @@
 #include "declaration.h"
 #include "hdrgen.h"
 #include "doc.h"
+#include "objc.h"
 
 bool response_expand(Strings *arguments);
 
@@ -1193,6 +1194,7 @@ Language changes listed by -transition=id:\n\
         VersionCondition::addPredefinedGlobalIdent("D_NoBoundsChecks");
 
     VersionCondition::addPredefinedGlobalIdent("D_HardFloat");
+    objc_tryMain_dObjc();
 
     // Initialization
     Lexer::initLexer();
@@ -1201,6 +1203,7 @@ Language changes listed by -transition=id:\n\
     Module::init();
     Target::init();
     Expression::init();
+    objc_tryMain_init();
     initPrecedence();
     builtin_init();
     initTraitsStringTable();

src/module.c

@@ -1025,6 +1025,11 @@ bool Module::rootImports()
     return rootimports == 2;
 }
 
+bool Module::isCoreModule(Identifier *ident)
+{
+    return this->ident == ident && parent && parent->ident == Id::core && !parent->parent;
+}
+
 /* =========================== ModuleDeclaration ===================== */
 
 ModuleDeclaration::ModuleDeclaration(Loc loc, Identifiers *packages, Identifier *id)

src/module.h

@@ -142,6 +142,7 @@ class Module : public Package
     bool isRoot() { return this->importedFrom == this; }
                                 // true if the module source file is directly
                                 // listed in command line.
+    bool isCoreModule(Identifier *ident);
 
     // Back end