/
func.d
5605 lines (4994 loc) · 188 KB
/
func.d
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/**
* Compiler implementation of the
* $(LINK2 http://www.dlang.org, D programming language).
*
* Copyright: Copyright (c) 1999-2017 by Digital Mars, All Rights Reserved
* Authors: $(LINK2 http://www.digitalmars.com, Walter Bright)
* License: $(LINK2 http://www.boost.org/LICENSE_1_0.txt, Boost License 1.0)
* Source: $(DMDSRC _func.d)
*/
module ddmd.func;
import core.stdc.stdio;
import core.stdc.string;
import ddmd.aggregate;
import ddmd.arraytypes;
import ddmd.blockexit;
import ddmd.gluelayer;
import ddmd.dclass;
import ddmd.declaration;
import ddmd.delegatize;
import ddmd.dinterpret;
import ddmd.dmodule;
import ddmd.dscope;
import ddmd.dstruct;
import ddmd.dsymbol;
import ddmd.dtemplate;
import ddmd.errors;
import ddmd.escape;
import ddmd.expression;
import ddmd.globals;
import ddmd.hdrgen;
import ddmd.id;
import ddmd.identifier;
import ddmd.init;
import ddmd.mars;
import ddmd.mtype;
import ddmd.nogc;
import ddmd.objc;
import ddmd.opover;
import ddmd.root.filename;
import ddmd.root.outbuffer;
import ddmd.root.rootobject;
import ddmd.statement_rewrite_walker;
import ddmd.statementsem;
import ddmd.statement;
import ddmd.target;
import ddmd.tokens;
import ddmd.visitor;
/// Inline Status
enum ILS : int
{
ILSuninitialized, /// not computed yet
ILSno, /// cannot inline
ILSyes, /// can inline
}
alias ILSuninitialized = ILS.ILSuninitialized;
alias ILSno = ILS.ILSno;
alias ILSyes = ILS.ILSyes;
enum BUILTIN : int
{
BUILTINunknown = -1, /// not known if this is a builtin
BUILTINno, /// this is not a builtin
BUILTINyes, /// this is a builtin
}
alias BUILTINunknown = BUILTIN.BUILTINunknown;
alias BUILTINno = BUILTIN.BUILTINno;
alias BUILTINyes = BUILTIN.BUILTINyes;
/* Tweak all return statements and dtor call for nrvo_var, for correct NRVO.
*/
extern (C++) final class NrvoWalker : StatementRewriteWalker
{
alias visit = super.visit;
public:
FuncDeclaration fd;
Scope* sc;
override void visit(ReturnStatement s)
{
// See if all returns are instead to be replaced with a goto returnLabel;
if (fd.returnLabel)
{
/* Rewrite:
* return exp;
* as:
* vresult = exp; goto Lresult;
*/
auto gs = new GotoStatement(s.loc, Id.returnLabel);
gs.label = fd.returnLabel;
Statement s1 = gs;
if (s.exp)
s1 = new CompoundStatement(s.loc, new ExpStatement(s.loc, s.exp), gs);
replaceCurrent(s1);
}
}
override void visit(TryFinallyStatement s)
{
DtorExpStatement des;
if (fd.nrvo_can && s.finalbody && (des = s.finalbody.isDtorExpStatement()) !is null && fd.nrvo_var == des.var)
{
/* Normally local variable dtors are called regardless exceptions.
* But for nrvo_var, its dtor should be called only when exception is thrown.
*
* Rewrite:
* try { s.body; } finally { nrvo_var.edtor; }
* // equivalent with:
* // s.body; scope(exit) nrvo_var.edtor;
* as:
* try { s.body; } catch(Throwable __o) { nrvo_var.edtor; throw __o; }
* // equivalent with:
* // s.body; scope(failure) nrvo_var.edtor;
*/
Statement sexception = new DtorExpStatement(Loc(), fd.nrvo_var.edtor, fd.nrvo_var);
Identifier id = Identifier.generateId("__o");
Statement handler = new PeelStatement(sexception);
if (sexception.blockExit(fd, false) & BEfallthru)
{
auto ts = new ThrowStatement(Loc(), new IdentifierExp(Loc(), id));
ts.internalThrow = true;
handler = new CompoundStatement(Loc(), handler, ts);
}
auto catches = new Catches();
auto ctch = new Catch(Loc(), getThrowable(), id, handler);
ctch.internalCatch = true;
ctch.semantic(sc); // Run semantic to resolve identifier '__o'
catches.push(ctch);
Statement s2 = new TryCatchStatement(Loc(), s._body, catches);
replaceCurrent(s2);
s2.accept(this);
}
else
StatementRewriteWalker.visit(s);
}
}
enum FUNCFLAGpurityInprocess = 1; /// working on determining purity
enum FUNCFLAGsafetyInprocess = 2; /// working on determining safety
enum FUNCFLAGnothrowInprocess = 4; /// working on determining nothrow
enum FUNCFLAGnogcInprocess = 8; /// working on determining @nogc
enum FUNCFLAGreturnInprocess = 0x10; /// working on inferring 'return' for parameters
enum FUNCFLAGinlineScanned = 0x20; /// function has been scanned for inline possibilities
enum FUNCFLAGinferScope = 0x40; /// infer 'scope' for parameters
/***********************************************************
*/
extern (C++) class FuncDeclaration : Declaration
{
Types* fthrows; /// Array of Type's of exceptions (not used)
Statement frequire; /// in contract body
Statement fensure; /// out contract body
Statement fbody; /// function body
FuncDeclarations foverrides; /// functions this function overrides
FuncDeclaration fdrequire; /// function that does the in contract
FuncDeclaration fdensure; /// function that does the out contract
const(char)* mangleString; /// mangled symbol created from mangleExact()
Identifier outId; /// identifier for out statement
VarDeclaration vresult; /// variable corresponding to outId
LabelDsymbol returnLabel; /// where the return goes
// used to prevent symbols in different
// scopes from having the same name
DsymbolTable localsymtab;
VarDeclaration vthis; /// 'this' parameter (member and nested)
VarDeclaration v_arguments; /// '_arguments' parameter
ObjcSelector* selector; /// Objective-C method selector (member function only)
VarDeclaration v_argptr; /// '_argptr' variable
VarDeclarations* parameters; /// Array of VarDeclaration's for parameters
DsymbolTable labtab; /// statement label symbol table
Dsymbol overnext; /// next in overload list
FuncDeclaration overnext0; /// next in overload list (only used during IFTI)
Loc endloc; /// location of closing curly bracket
int vtblIndex = -1; /// for member functions, index into vtbl[]
bool naked; /// true if naked
bool generated; /// true if function was generated by the compiler rather than
/// supplied by the user
ILS inlineStatusStmt = ILSuninitialized;
ILS inlineStatusExp = ILSuninitialized;
PINLINE inlining = PINLINEdefault;
CompiledCtfeFunction* ctfeCode; /// Compiled code for interpreter (not actually)
int inlineNest; /// !=0 if nested inline
bool isArrayOp; /// true if array operation
bool semantic3Errors; /// true if errors in semantic3 this function's frame ptr
ForeachStatement fes; /// if foreach body, this is the foreach
BaseClass* interfaceVirtual; /// if virtual, but only appears in base interface vtbl[]
bool introducing; /// true if 'introducing' function
/** if !=NULL, then this is the type
of the 'introducing' function
this one is overriding
*/
Type tintro;
bool inferRetType; /// true if return type is to be inferred
StorageClass storage_class2; /// storage class for template onemember's
// Things that should really go into Scope
/// 1 if there's a return exp; statement
/// 2 if there's a throw statement
/// 4 if there's an assert(0)
/// 8 if there's inline asm
int hasReturnExp;
// Support for NRVO (named return value optimization)
bool nrvo_can = true; /// true means we can do NRVO
VarDeclaration nrvo_var; /// variable to replace with shidden
Symbol* shidden; /// hidden pointer passed to function
ReturnStatements* returns;
GotoStatements* gotos; /// Gotos with forward references
/// set if this is a known, builtin function we can evaluate at compile time
BUILTIN builtin = BUILTINunknown;
/// set if someone took the address of this function
int tookAddressOf;
bool requiresClosure; // this function needs a closure
/// local variables in this function which are referenced by nested functions
VarDeclarations closureVars;
/// Sibling nested functions which called this one
FuncDeclarations siblingCallers;
FuncDeclarations *inlinedNestedCallees;
uint flags; /// FUNCFLAGxxxxx
final extern (D) this(Loc loc, Loc endloc, Identifier id, StorageClass storage_class, Type type)
{
super(id);
//printf("FuncDeclaration(id = '%s', type = %p)\n", id.toChars(), type);
//printf("storage_class = x%x\n", storage_class);
this.storage_class = storage_class;
this.type = type;
if (type)
{
// Normalize storage_class, because function-type related attributes
// are already set in the 'type' in parsing phase.
this.storage_class &= ~(STC_TYPECTOR | STC_FUNCATTR);
}
this.loc = loc;
this.endloc = endloc;
/* The type given for "infer the return type" is a TypeFunction with
* NULL for the return type.
*/
inferRetType = (type && type.nextOf() is null);
}
override Dsymbol syntaxCopy(Dsymbol s)
{
//printf("FuncDeclaration::syntaxCopy('%s')\n", toChars());
FuncDeclaration f = s ? cast(FuncDeclaration)s : new FuncDeclaration(loc, endloc, ident, storage_class, type.syntaxCopy());
f.outId = outId;
f.frequire = frequire ? frequire.syntaxCopy() : null;
f.fensure = fensure ? fensure.syntaxCopy() : null;
f.fbody = fbody ? fbody.syntaxCopy() : null;
assert(!fthrows); // deprecated
return f;
}
/// Do the semantic analysis on the external interface to the function.
override void semantic(Scope* sc)
{
TypeFunction f;
AggregateDeclaration ad;
InterfaceDeclaration id;
version (none)
{
printf("FuncDeclaration::semantic(sc = %p, this = %p, '%s', linkage = %d)\n", sc, this, toPrettyChars(), sc.linkage);
if (isFuncLiteralDeclaration())
printf("\tFuncLiteralDeclaration()\n");
printf("sc.parent = %s, parent = %s\n", sc.parent.toChars(), parent ? parent.toChars() : "");
printf("type: %p, %s\n", type, type.toChars());
}
if (semanticRun != PASSinit && isFuncLiteralDeclaration())
{
/* Member functions that have return types that are
* forward references can have semantic() run more than
* once on them.
* See test\interface2.d, test20
*/
return;
}
if (semanticRun >= PASSsemanticdone)
return;
assert(semanticRun <= PASSsemantic);
semanticRun = PASSsemantic;
if (_scope)
{
sc = _scope;
_scope = null;
}
if (!sc || errors)
return;
parent = sc.parent;
Dsymbol parent = toParent();
foverrides.setDim(0); // reset in case semantic() is being retried for this function
storage_class |= sc.stc & ~STCref;
ad = isThis();
// Don't nest structs b/c of generated methods which should not access the outer scopes.
// https://issues.dlang.org/show_bug.cgi?id=16627
if (ad && !generated)
{
storage_class |= ad.storage_class & (STC_TYPECTOR | STCsynchronized);
ad.makeNested();
}
if (sc.func)
storage_class |= sc.func.storage_class & STCdisable;
// Remove prefix storage classes silently.
if ((storage_class & STC_TYPECTOR) && !(ad || isNested()))
storage_class &= ~STC_TYPECTOR;
//printf("function storage_class = x%llx, sc.stc = x%llx, %x\n", storage_class, sc.stc, Declaration::isFinal());
FuncLiteralDeclaration fld = isFuncLiteralDeclaration();
if (fld && fld.treq)
{
Type treq = fld.treq;
assert(treq.nextOf().ty == Tfunction);
if (treq.ty == Tdelegate)
fld.tok = TOKdelegate;
else if (treq.ty == Tpointer && treq.nextOf().ty == Tfunction)
fld.tok = TOKfunction;
else
assert(0);
linkage = treq.nextOf().toTypeFunction().linkage;
}
else
linkage = sc.linkage;
inlining = sc.inlining;
protection = sc.protection;
userAttribDecl = sc.userAttribDecl;
if (!originalType)
originalType = type.syntaxCopy();
if (type.ty != Tfunction)
{
if (type.ty != Terror)
{
error("%s must be a function instead of %s", toChars(), type.toChars());
type = Type.terror;
}
errors = true;
return;
}
if (!type.deco)
{
sc = sc.push();
sc.stc |= storage_class & (STCdisable | STCdeprecated); // forward to function type
TypeFunction tf = type.toTypeFunction();
if (sc.func)
{
/* If the nesting parent is pure without inference,
* then this function defaults to pure too.
*
* auto foo() pure {
* auto bar() {} // become a weak purity function
* class C { // nested class
* auto baz() {} // become a weak purity function
* }
*
* static auto boo() {} // typed as impure
* // Even though, boo cannot call any impure functions.
* // See also Expression::checkPurity().
* }
*/
if (tf.purity == PUREimpure && (isNested() || isThis()))
{
FuncDeclaration fd = null;
for (Dsymbol p = toParent2(); p; p = p.toParent2())
{
if (AggregateDeclaration adx = p.isAggregateDeclaration())
{
if (adx.isNested())
continue;
break;
}
if ((fd = p.isFuncDeclaration()) !is null)
break;
}
/* If the parent's purity is inferred, then this function's purity needs
* to be inferred first.
*/
if (fd && fd.isPureBypassingInference() >= PUREweak && !isInstantiated())
{
tf.purity = PUREfwdref; // default to pure
}
}
}
if (tf.isref)
sc.stc |= STCref;
if (tf.isscope)
sc.stc |= STCscope;
if (tf.isnothrow)
sc.stc |= STCnothrow;
if (tf.isnogc)
sc.stc |= STCnogc;
if (tf.isproperty)
sc.stc |= STCproperty;
if (tf.purity == PUREfwdref)
sc.stc |= STCpure;
if (tf.trust != TRUSTdefault)
sc.stc &= ~(STCsafe | STCsystem | STCtrusted);
if (tf.trust == TRUSTsafe)
sc.stc |= STCsafe;
if (tf.trust == TRUSTsystem)
sc.stc |= STCsystem;
if (tf.trust == TRUSTtrusted)
sc.stc |= STCtrusted;
if (isCtorDeclaration())
{
sc.flags |= SCOPEctor;
Type tret = ad.handleType();
assert(tret);
tret = tret.addStorageClass(storage_class | sc.stc);
tret = tret.addMod(type.mod);
tf.next = tret;
if (ad.isStructDeclaration())
sc.stc |= STCref;
}
// 'return' on a non-static class member function implies 'scope' as well
if (ad && ad.isClassDeclaration() && (tf.isreturn || sc.stc & STCreturn) && !(sc.stc & STCstatic))
sc.stc |= STCscope;
// If 'this' has no pointers, remove 'scope' as it has no meaning
if (sc.stc & STCscope && ad && ad.isStructDeclaration() && !ad.type.hasPointers())
{
sc.stc &= ~STCscope;
tf.isscope = false;
}
sc.linkage = linkage;
if (!tf.isNaked() && !(isThis() || isNested()))
{
OutBuffer buf;
MODtoBuffer(&buf, tf.mod);
error("without 'this' cannot be %s", buf.peekString());
tf.mod = 0; // remove qualifiers
}
/* Apply const, immutable, wild and shared storage class
* to the function type. Do this before type semantic.
*/
auto stc = storage_class;
if (type.isImmutable())
stc |= STCimmutable;
if (type.isConst())
stc |= STCconst;
if (type.isShared() || storage_class & STCsynchronized)
stc |= STCshared;
if (type.isWild())
stc |= STCwild;
type = type.addSTC(stc);
type = type.semantic(loc, sc);
sc = sc.pop();
}
if (type.ty != Tfunction)
{
if (type.ty != Terror)
{
error("%s must be a function instead of %s", toChars(), type.toChars());
type = Type.terror;
}
errors = true;
return;
}
else
{
// Merge back function attributes into 'originalType'.
// It's used for mangling, ddoc, and json output.
TypeFunction tfo = originalType.toTypeFunction();
TypeFunction tfx = type.toTypeFunction();
tfo.mod = tfx.mod;
tfo.isscope = tfx.isscope;
tfo.isscopeinferred = tfx.isscopeinferred;
tfo.isref = tfx.isref;
tfo.isnothrow = tfx.isnothrow;
tfo.isnogc = tfx.isnogc;
tfo.isproperty = tfx.isproperty;
tfo.purity = tfx.purity;
tfo.trust = tfx.trust;
storage_class &= ~(STC_TYPECTOR | STC_FUNCATTR);
}
f = cast(TypeFunction)type;
size_t nparams = Parameter.dim(f.parameters);
if ((storage_class & STCauto) && !f.isref && !inferRetType)
error("storage class 'auto' has no effect if return type is not inferred");
/* Functions can only be 'scope' if they have a 'this'
*/
if (f.isscope && !isNested() && !ad)
{
error("functions cannot be scope");
}
if (f.isreturn && !needThis() && !isNested())
{
/* Non-static nested functions have a hidden 'this' pointer to which
* the 'return' applies
*/
error("static member has no 'this' to which 'return' can apply");
}
if (isAbstract() && !isVirtual())
{
const(char)* sfunc;
if (isStatic())
sfunc = "static";
else if (protection.kind == PROTprivate || protection.kind == PROTpackage)
sfunc = protectionToChars(protection.kind);
else
sfunc = "non-virtual";
error("%s functions cannot be abstract", sfunc);
}
if (isOverride() && !isVirtual())
{
PROTKIND kind = prot().kind;
if ((kind == PROTprivate || kind == PROTpackage) && isMember())
error("%s method is not virtual and cannot override", protectionToChars(kind));
else
error("cannot override a non-virtual function");
}
if (isAbstract() && isFinalFunc())
error("cannot be both final and abstract");
version (none)
{
if (isAbstract() && fbody)
error("abstract functions cannot have bodies");
}
version (none)
{
if (isStaticConstructor() || isStaticDestructor())
{
if (!isStatic() || type.nextOf().ty != Tvoid)
error("static constructors / destructors must be static void");
if (f.arguments && f.arguments.dim)
error("static constructors / destructors must have empty parameter list");
// BUG: check for invalid storage classes
}
}
id = parent.isInterfaceDeclaration();
if (id)
{
storage_class |= STCabstract;
if (isCtorDeclaration() || isPostBlitDeclaration() || isDtorDeclaration() || isInvariantDeclaration() || isNewDeclaration() || isDelete())
error("constructors, destructors, postblits, invariants, new and delete functions are not allowed in interface %s", id.toChars());
if (fbody && isVirtual())
error("function body only allowed in final functions in interface %s", id.toChars());
}
if (UnionDeclaration ud = parent.isUnionDeclaration())
{
if (isPostBlitDeclaration() || isDtorDeclaration() || isInvariantDeclaration())
error("destructors, postblits and invariants are not allowed in union %s", ud.toChars());
}
/* Contracts can only appear without a body when they are virtual interface functions
*/
if (!fbody && (fensure || frequire) && !(id && isVirtual()))
error("in and out contracts require function body");
if (StructDeclaration sd = parent.isStructDeclaration())
{
if (isCtorDeclaration())
{
goto Ldone;
}
}
if (ClassDeclaration cd = parent.isClassDeclaration())
{
if (isCtorDeclaration())
{
goto Ldone;
}
if (storage_class & STCabstract)
cd.isabstract = ABSyes;
// if static function, do not put in vtbl[]
if (!isVirtual())
{
//printf("\tnot virtual\n");
goto Ldone;
}
// Suppress further errors if the return type is an error
if (type.nextOf() == Type.terror)
goto Ldone;
bool may_override = false;
for (size_t i = 0; i < cd.baseclasses.dim; i++)
{
BaseClass* b = (*cd.baseclasses)[i];
ClassDeclaration cbd = b.type.toBasetype().isClassHandle();
if (!cbd)
continue;
for (size_t j = 0; j < cbd.vtbl.dim; j++)
{
FuncDeclaration f2 = cbd.vtbl[j].isFuncDeclaration();
if (!f2 || f2.ident != ident)
continue;
if (cbd.parent && cbd.parent.isTemplateInstance())
{
if (!f2.functionSemantic())
goto Ldone;
}
may_override = true;
}
}
if (may_override && type.nextOf() is null)
{
/* If same name function exists in base class but 'this' is auto return,
* cannot find index of base class's vtbl[] to override.
*/
error("return type inference is not supported if may override base class function");
}
/* Find index of existing function in base class's vtbl[] to override
* (the index will be the same as in cd's current vtbl[])
*/
int vi = cd.baseClass ? findVtblIndex(&cd.baseClass.vtbl, cast(int)cd.baseClass.vtbl.dim) : -1;
bool doesoverride = false;
switch (vi)
{
case -1:
Lintro:
/* Didn't find one, so
* This is an 'introducing' function which gets a new
* slot in the vtbl[].
*/
// Verify this doesn't override previous final function
if (cd.baseClass)
{
Dsymbol s = cd.baseClass.search(loc, ident);
if (s)
{
FuncDeclaration f2 = s.isFuncDeclaration();
if (f2)
{
f2 = f2.overloadExactMatch(type);
if (f2 && f2.isFinalFunc() && f2.prot().kind != PROTprivate)
error("cannot override final function %s", f2.toPrettyChars());
}
}
}
/* These quirky conditions mimic what VC++ appears to do
*/
if (global.params.mscoff && cd.cpp &&
cd.baseClass && cd.baseClass.vtbl.dim)
{
/* if overriding an interface function, then this is not
* introducing and don't put it in the class vtbl[]
*/
interfaceVirtual = overrideInterface();
if (interfaceVirtual)
{
//printf("\tinterface function %s\n", toChars());
cd.vtblFinal.push(this);
goto Linterfaces;
}
}
if (isFinalFunc())
{
// Don't check here, as it may override an interface function
//if (isOverride())
// error("is marked as override, but does not override any function");
cd.vtblFinal.push(this);
}
else
{
//printf("\tintroducing function %s\n", toChars());
introducing = 1;
if (cd.cpp && Target.reverseCppOverloads)
{
// with dmc, overloaded functions are grouped and in reverse order
vtblIndex = cast(int)cd.vtbl.dim;
for (size_t i = 0; i < cd.vtbl.dim; i++)
{
if (cd.vtbl[i].ident == ident && cd.vtbl[i].parent == parent)
{
vtblIndex = cast(int)i;
break;
}
}
// shift all existing functions back
for (size_t i = cd.vtbl.dim; i > vtblIndex; i--)
{
FuncDeclaration fd = cd.vtbl[i - 1].isFuncDeclaration();
assert(fd);
fd.vtblIndex++;
}
cd.vtbl.insert(vtblIndex, this);
}
else
{
// Append to end of vtbl[]
vi = cast(int)cd.vtbl.dim;
cd.vtbl.push(this);
vtblIndex = vi;
}
}
break;
case -2:
// can't determine because of forward references
errors = true;
return;
default:
{
FuncDeclaration fdv = cd.baseClass.vtbl[vi].isFuncDeclaration();
FuncDeclaration fdc = cd.vtbl[vi].isFuncDeclaration();
// This function is covariant with fdv
if (fdc == this)
{
doesoverride = true;
break;
}
if (fdc.toParent() == parent)
{
//printf("vi = %d,\tthis = %p %s %s @ [%s]\n\tfdc = %p %s %s @ [%s]\n\tfdv = %p %s %s @ [%s]\n",
// vi, this, this.toChars(), this.type.toChars(), this.loc.toChars(),
// fdc, fdc .toChars(), fdc .type.toChars(), fdc .loc.toChars(),
// fdv, fdv .toChars(), fdv .type.toChars(), fdv .loc.toChars());
// fdc overrides fdv exactly, then this introduces new function.
if (fdc.type.mod == fdv.type.mod && this.type.mod != fdv.type.mod)
goto Lintro;
}
// This function overrides fdv
if (fdv.isFinalFunc())
error("cannot override final function %s", fdv.toPrettyChars());
if (!isOverride())
{
int vi2 = findVtblIndex(&cd.baseClass.vtbl, cast(int)cd.baseClass.vtbl.dim, false);
if (vi2 < 0)
// https://issues.dlang.org/show_bug.cgi?id=17349
.deprecation(loc, "cannot implicitly override base class method `%s` with `%s`; add `override` attribute", fdv.toPrettyChars(), toPrettyChars());
else
.error(loc, "cannot implicitly override base class method %s with %s; add 'override' attribute", fdv.toPrettyChars(), toPrettyChars());
}
doesoverride = true;
if (fdc.toParent() == parent)
{
// If both are mixins, or both are not, then error.
// If either is not, the one that is not overrides the other.
bool thismixin = this.parent.isClassDeclaration() !is null;
bool fdcmixin = fdc.parent.isClassDeclaration() !is null;
if (thismixin == fdcmixin)
{
error("multiple overrides of same function");
}
else if (!thismixin) // fdc overrides fdv
{
// this doesn't override any function
break;
}
}
cd.vtbl[vi] = this;
vtblIndex = vi;
/* Remember which functions this overrides
*/
foverrides.push(fdv);
/* This works by whenever this function is called,
* it actually returns tintro, which gets dynamically
* cast to type. But we know that tintro is a base
* of type, so we could optimize it by not doing a
* dynamic cast, but just subtracting the isBaseOf()
* offset if the value is != null.
*/
if (fdv.tintro)
tintro = fdv.tintro;
else if (!type.equals(fdv.type))
{
/* Only need to have a tintro if the vptr
* offsets differ
*/
int offset;
if (fdv.type.nextOf().isBaseOf(type.nextOf(), &offset))
{
tintro = fdv.type;
}
}
break;
}
}
/* Go through all the interface bases.
* If this function is covariant with any members of those interface
* functions, set the tintro.
*/
Linterfaces:
foreach (b; cd.interfaces)
{
vi = findVtblIndex(&b.sym.vtbl, cast(int)b.sym.vtbl.dim);
switch (vi)
{
case -1:
break;
case -2:
// can't determine because of forward references
errors = true;
return;
default:
{
auto fdv = cast(FuncDeclaration)b.sym.vtbl[vi];
Type ti = null;
/* Remember which functions this overrides
*/
foverrides.push(fdv);
/* Should we really require 'override' when implementing
* an interface function?
*/
//if (!isOverride())
// warning(loc, "overrides base class function %s, but is not marked with 'override'", fdv.toPrettyChars());
if (fdv.tintro)
ti = fdv.tintro;
else if (!type.equals(fdv.type))
{
/* Only need to have a tintro if the vptr
* offsets differ
*/
int offset;
if (fdv.type.nextOf().isBaseOf(type.nextOf(), &offset))
{
ti = fdv.type;
}
}
if (ti)
{
if (tintro)
{
if (!tintro.nextOf().equals(ti.nextOf()) && !tintro.nextOf().isBaseOf(ti.nextOf(), null) && !ti.nextOf().isBaseOf(tintro.nextOf(), null))
{
error("incompatible covariant types %s and %s", tintro.toChars(), ti.toChars());
}
}
tintro = ti;
}
goto L2;
}
}
}
if (!doesoverride && isOverride() && (type.nextOf() || !may_override))
{
BaseClass* bc = null;
Dsymbol s = null;
for (size_t i = 0; i < cd.baseclasses.dim; i++)
{
bc = (*cd.baseclasses)[i];
s = bc.sym.search_correct(ident);
if (s)
break;
}
if (s)
error("does not override any function, did you mean to override '%s%s'?",
bc.sym.isCPPclass() ? "extern (C++) ".ptr : "".ptr, s.toPrettyChars());
else
error("does not override any function");
}
L2:
/* Go through all the interface bases.
* Disallow overriding any final functions in the interface(s).
*/
foreach (b; cd.interfaces)
{
if (b.sym)
{
Dsymbol s = search_function(b.sym, ident);
if (s)
{
FuncDeclaration f2 = s.isFuncDeclaration();
if (f2)
{
f2 = f2.overloadExactMatch(type);
if (f2 && f2.isFinalFunc() && f2.prot().kind != PROTprivate)
error("cannot override final function %s.%s", b.sym.toChars(), f2.toPrettyChars());
}
}
}
}
if (isOverride)
{
if (storage_class & STCdisable)
deprecation("overridden functions cannot be annotated @disable");
if (isDeprecated)
deprecation("deprecated functions cannot be annotated @disable");
}
}
else if (isOverride() && !parent.isTemplateInstance())
error("override only applies to class member functions");
// Reflect this.type to f because it could be changed by findVtblIndex
f = type.toTypeFunction();
/* Do not allow template instances to add virtual functions
* to a class.
*/
if (isVirtual())
{
TemplateInstance ti = parent.isTemplateInstance();
if (ti)
{
// Take care of nested templates
while (1)
{
TemplateInstance ti2 = ti.tempdecl.parent.isTemplateInstance();
if (!ti2)
break;
ti = ti2;
}
// If it's a member template
ClassDeclaration cd = ti.tempdecl.isClassMember();
if (cd)
{
error("cannot use template to add virtual function to class '%s'", cd.toChars());
}
}
}
if (isMain())
checkDmain(); // Check main() parameters and return type
if (isVirtual() && semanticRun != PASSsemanticdone)
{
/* Rewrite contracts as nested functions, then call them.
* Doing it as nested functions means that overriding functions
* can call them.
*/
if (frequire)
{
/* in { ... }
* becomes:
* void __require() { ... }
* __require();
*/