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func.d
3949 lines (3501 loc) · 125 KB
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func.d
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/***
* Compiler implementation of the
* $(LINK2 http://www.dlang.org, D programming language).
*
* Copyright: Copyright (C) 1999-2019 by The D Language Foundation, 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: $(LINK2 https://github.com/dlang/dmd/blob/master/src/dmd/func.d, _func.d)
* Documentation: https://dlang.org/phobos/dmd_func.html
* Coverage: https://codecov.io/gh/dlang/dmd/src/master/src/dmd/func.d
*/
module dmd.func;
import core.stdc.stdio;
import core.stdc.string;
import dmd.aggregate;
import dmd.arraytypes;
import dmd.blockexit;
import dmd.gluelayer;
import dmd.dclass;
import dmd.declaration;
import dmd.delegatize;
import dmd.dinterpret;
import dmd.dmodule;
import dmd.dscope;
import dmd.dstruct;
import dmd.dsymbol;
import dmd.dsymbolsem;
import dmd.dtemplate;
import dmd.errors;
import dmd.escape;
import dmd.expression;
import dmd.globals;
import dmd.hdrgen;
import dmd.id;
import dmd.identifier;
import dmd.init;
import dmd.mtype;
import dmd.objc;
import dmd.root.outbuffer;
import dmd.root.rootobject;
import dmd.semantic2;
import dmd.semantic3;
import dmd.statement_rewrite_walker;
import dmd.statement;
import dmd.statementsem;
import dmd.tokens;
import dmd.visitor;
/// Inline Status
enum ILS : int
{
uninitialized, /// not computed yet
no, /// cannot inline
yes, /// can inline
}
enum BUILTIN : int
{
unknown = -1, /// not known if this is a builtin
no, /// this is not a builtin
yes, /// this is a builtin
}
/* Tweak all return statements and dtor call for nrvo_var, for correct NRVO.
*/
extern (C++) final class NrvoWalker : StatementRewriteWalker
{
alias visit = typeof(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)
{
if (!(global.params.useExceptions && ClassDeclaration.throwable))
{
/* Don't need to call destructor at all, since it is nrvo
*/
replaceCurrent(s._body);
s._body.accept(this);
return;
}
/* 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.initial, fd.nrvo_var.edtor, fd.nrvo_var);
Identifier id = Identifier.generateId("__o");
Statement handler = new PeelStatement(sexception);
if (sexception.blockExit(fd, false) & BE.fallthru)
{
auto ts = new ThrowStatement(Loc.initial, new IdentifierExp(Loc.initial, id));
ts.internalThrow = true;
handler = new CompoundStatement(Loc.initial, handler, ts);
}
auto catches = new Catches();
auto ctch = new Catch(Loc.initial, getThrowable(), id, handler);
ctch.internalCatch = true;
ctch.catchSemantic(sc); // Run semantic to resolve identifier '__o'
catches.push(ctch);
Statement s2 = new TryCatchStatement(Loc.initial, s._body, catches);
fd.eh_none = false;
replaceCurrent(s2);
s2.accept(this);
}
else
StatementRewriteWalker.visit(s);
}
}
enum FUNCFLAG : uint
{
purityInprocess = 1, /// working on determining purity
safetyInprocess = 2, /// working on determining safety
nothrowInprocess = 4, /// working on determining nothrow
nogcInprocess = 8, /// working on determining @nogc
returnInprocess = 0x10, /// working on inferring 'return' for parameters
inlineScanned = 0x20, /// function has been scanned for inline possibilities
inferScope = 0x40, /// infer 'scope' for parameters
hasCatches = 0x80, /// function has try-catch statements
compileTimeOnly = 0x100, /// is a compile time only function; no code will be generated for it
}
/***********************************************************
* Tuple of result identifier (possibly null) and statement.
* This is used to store out contracts: out(id){ ensure }
*/
extern (C++) struct Ensure
{
Identifier id;
Statement ensure;
Ensure syntaxCopy()
{
return Ensure(id, ensure.syntaxCopy());
}
/*****************************************
* Do syntax copy of an array of Ensure's.
*/
static Ensures* arraySyntaxCopy(Ensures* a)
{
Ensures* b = null;
if (a)
{
b = a.copy();
foreach (i, e; *a)
{
(*b)[i] = e.syntaxCopy();
}
}
return b;
}
}
/***********************************************************
*/
extern (C++) class FuncDeclaration : Declaration
{
/// All hidden parameters bundled.
static struct HiddenParameters
{
/**
* The `this` parameter for methods or nested functions.
*
* For methods, it would be the class object or struct value the
* method is called on. For nested functions it would be the enclosing
* function's stack frame.
*/
VarDeclaration vthis;
/**
* Is 'this' a pointer to a static array holding two contexts.
*/
bool isThis2;
/// The selector parameter for Objective-C methods.
VarDeclaration selectorParameter;
}
Statements* frequires; /// in contracts
Ensures* fensures; /// out contracts
Statement frequire; /// lowered in contract
Statement fensure; /// lowered out contract
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
Expressions* fdrequireParams; /// argument list for __require
Expressions* fdensureParams; /// argument list for __ensure
const(char)* mangleString; /// mangled symbol created from mangleExact()
VarDeclaration vresult; /// result variable for out contracts
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)
bool isThis2; /// has a dual-context 'this' parameter
VarDeclaration v_arguments; /// '_arguments' parameter
ObjcSelector* selector; /// Objective-C method selector (member function only)
VarDeclaration selectorParameter; /// Objective-C implicit selector parameter
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
ubyte isCrtCtorDtor; /// has attribute pragma(crt_constructor(1)/crt_destructor(2))
/// not set before the glue layer
ILS inlineStatusStmt = ILS.uninitialized;
ILS inlineStatusExp = ILS.uninitialized;
PINLINE inlining = PINLINE.default_;
int inlineNest; /// !=0 if nested inline
bool isArrayOp; /// true if array operation
bool eh_none; /// true if no exception unwinding is needed
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
/// 16 if there are multiple return statements
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 = BUILTIN.unknown;
/// 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; /// FUNCFLAG.xxxxx
extern (D) this(const ref Loc loc, const ref Loc endloc, Identifier ident, StorageClass storage_class, Type type)
{
super(loc, ident);
//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.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);
}
static FuncDeclaration create(const ref Loc loc, const ref Loc endloc, Identifier id, StorageClass storage_class, Type type)
{
return new FuncDeclaration(loc, endloc, id, storage_class, type);
}
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.frequires = frequires ? Statement.arraySyntaxCopy(frequires) : null;
f.fensures = fensures ? Ensure.arraySyntaxCopy(fensures) : null;
f.fbody = fbody ? fbody.syntaxCopy() : null;
return f;
}
/****************************************************
* Resolve forward reference of function signature -
* parameter types, return type, and attributes.
* Returns false if any errors exist in the signature.
*/
final bool functionSemantic()
{
if (!_scope)
return !errors;
if (!originalType) // semantic not yet run
{
TemplateInstance spec = isSpeculative();
uint olderrs = global.errors;
uint oldgag = global.gag;
if (global.gag && !spec)
global.gag = 0;
dsymbolSemantic(this, _scope);
global.gag = oldgag;
if (spec && global.errors != olderrs)
spec.errors = (global.errors - olderrs != 0);
if (olderrs != global.errors) // if errors compiling this function
return false;
}
this.cppnamespace = _scope.namespace;
// if inferring return type, sematic3 needs to be run
// - When the function body contains any errors, we cannot assume
// the inferred return type is valid.
// So, the body errors should become the function signature error.
if (inferRetType && type && !type.nextOf())
return functionSemantic3();
TemplateInstance ti;
if (isInstantiated() && !isVirtualMethod() &&
((ti = parent.isTemplateInstance()) is null || ti.isTemplateMixin() || ti.tempdecl.ident == ident))
{
AggregateDeclaration ad = isMemberLocal();
if (ad && ad.sizeok != Sizeok.done)
{
/* Currently dmd cannot resolve forward references per methods,
* then setting SIZOKfwd is too conservative and would break existing code.
* So, just stop method attributes inference until ad.dsymbolSemantic() done.
*/
//ad.sizeok = Sizeok.fwd;
}
else
return functionSemantic3() || !errors;
}
if (storage_class & STC.inference)
return functionSemantic3() || !errors;
return !errors;
}
/****************************************************
* Resolve forward reference of function body.
* Returns false if any errors exist in the body.
*/
final bool functionSemantic3()
{
if (semanticRun < PASS.semantic3 && _scope)
{
/* Forward reference - we need to run semantic3 on this function.
* If errors are gagged, and it's not part of a template instance,
* we need to temporarily ungag errors.
*/
TemplateInstance spec = isSpeculative();
uint olderrs = global.errors;
uint oldgag = global.gag;
if (global.gag && !spec)
global.gag = 0;
semantic3(this, _scope);
global.gag = oldgag;
// If it is a speculatively-instantiated template, and errors occur,
// we need to mark the template as having errors.
if (spec && global.errors != olderrs)
spec.errors = (global.errors - olderrs != 0);
if (olderrs != global.errors) // if errors compiling this function
return false;
}
return !errors && !semantic3Errors;
}
/****************************************************
* Check that this function type is properly resolved.
* If not, report "forward reference error" and return true.
*/
extern (D) final bool checkForwardRef(const ref Loc loc)
{
if (!functionSemantic())
return true;
/* No deco means the functionSemantic() call could not resolve
* forward referenes in the type of this function.
*/
if (!type.deco)
{
bool inSemantic3 = (inferRetType && semanticRun >= PASS.semantic3);
.error(loc, "forward reference to %s`%s`",
(inSemantic3 ? "inferred return type of function " : "").ptr,
toChars());
return true;
}
return false;
}
// called from semantic3
/**
* Creates and returns the hidden parameters for this function declaration.
*
* Hidden parameters include the `this` parameter of a class, struct or
* nested function and the selector parameter for Objective-C methods.
*/
extern (D) final HiddenParameters declareThis(Scope* sc, AggregateDeclaration ad)
{
if (toParent2() != toParentLocal())
{
Type tthis2 = Type.tvoidptr.sarrayOf(2).pointerTo();
tthis2 = tthis2.addMod(type.mod)
.addStorageClass(storage_class);
VarDeclaration v2 = new VarDeclaration(loc, tthis2, Id.this2, null);
v2.storage_class |= STC.parameter | STC.nodtor;
if (type.ty == Tfunction)
{
TypeFunction tf = cast(TypeFunction)type;
if (tf.isreturn)
v2.storage_class |= STC.return_;
if (tf.isscope)
v2.storage_class |= STC.scope_;
// if member function is marked 'inout', then this is 'return ref'
if (tf.iswild & 2)
v2.storage_class |= STC.return_;
}
if (flags & FUNCFLAG.inferScope && !(v2.storage_class & STC.scope_))
v2.storage_class |= STC.maybescope;
v2.dsymbolSemantic(sc);
if (!sc.insert(v2))
assert(0);
v2.parent = this;
return HiddenParameters(v2, true);
}
if (ad)
{
//printf("declareThis() %s\n", toChars());
Type thandle = ad.handleType();
assert(thandle);
thandle = thandle.addMod(type.mod);
thandle = thandle.addStorageClass(storage_class);
VarDeclaration v = new ThisDeclaration(loc, thandle);
v.storage_class |= STC.parameter;
if (thandle.ty == Tstruct)
{
v.storage_class |= STC.ref_;
// if member function is marked 'inout', then 'this' is 'return ref'
if (type.ty == Tfunction && (cast(TypeFunction)type).iswild & 2)
v.storage_class |= STC.return_;
}
if (type.ty == Tfunction)
{
TypeFunction tf = cast(TypeFunction)type;
if (tf.isreturn)
v.storage_class |= STC.return_;
if (tf.isscope)
v.storage_class |= STC.scope_;
}
if (flags & FUNCFLAG.inferScope && !(v.storage_class & STC.scope_))
v.storage_class |= STC.maybescope;
v.dsymbolSemantic(sc);
if (!sc.insert(v))
assert(0);
v.parent = this;
return HiddenParameters(v, false, objc.createSelectorParameter(this, sc));
}
if (isNested())
{
/* The 'this' for a nested function is the link to the
* enclosing function's stack frame.
* Note that nested functions and member functions are disjoint.
*/
VarDeclaration v = new VarDeclaration(loc, Type.tvoid.pointerTo(), Id.capture, null);
v.storage_class |= STC.parameter | STC.nodtor;
if (type.ty == Tfunction)
{
TypeFunction tf = cast(TypeFunction)type;
if (tf.isreturn)
v.storage_class |= STC.return_;
if (tf.isscope)
v.storage_class |= STC.scope_;
}
if (flags & FUNCFLAG.inferScope && !(v.storage_class & STC.scope_))
v.storage_class |= STC.maybescope;
v.dsymbolSemantic(sc);
if (!sc.insert(v))
assert(0);
v.parent = this;
return HiddenParameters(v);
}
return HiddenParameters.init;
}
override final bool equals(const RootObject o) const
{
if (this == o)
return true;
if (auto s = isDsymbol(o))
{
auto fd1 = this;
auto fd2 = s.isFuncDeclaration();
if (!fd2)
return false;
auto fa1 = fd1.isFuncAliasDeclaration();
auto faf1 = fa1 ? fa1.toAliasFunc() : fd1;
auto fa2 = fd2.isFuncAliasDeclaration();
auto faf2 = fa2 ? fa2.toAliasFunc() : fd2;
if (fa1 && fa2)
{
return faf1.equals(faf2) && fa1.hasOverloads == fa2.hasOverloads;
}
bool b1 = fa1 !is null;
if (b1 && faf1.isUnique() && !fa1.hasOverloads)
b1 = false;
bool b2 = fa2 !is null;
if (b2 && faf2.isUnique() && !fa2.hasOverloads)
b2 = false;
if (b1 != b2)
return false;
return faf1.toParent().equals(faf2.toParent()) &&
faf1.ident.equals(faf2.ident) &&
faf1.type.equals(faf2.type);
}
return false;
}
/****************************************************
* Determine if 'this' overrides fd.
* Return !=0 if it does.
*/
final int overrides(FuncDeclaration fd)
{
int result = 0;
if (fd.ident == ident)
{
int cov = type.covariant(fd.type);
if (cov)
{
ClassDeclaration cd1 = toParent().isClassDeclaration();
ClassDeclaration cd2 = fd.toParent().isClassDeclaration();
if (cd1 && cd2 && cd2.isBaseOf(cd1, null))
result = 1;
}
}
return result;
}
/*************************************************
* Find index of function in vtbl[0..dim] that
* this function overrides.
* Prefer an exact match to a covariant one.
* Params:
* vtbl = vtable to use
* dim = maximal vtable dimension
* fix17349 = enable fix https://issues.dlang.org/show_bug.cgi?id=17349
* Returns:
* -1 didn't find one
* -2 can't determine because of forward references
*/
final int findVtblIndex(Dsymbols* vtbl, int dim, bool fix17349 = true)
{
//printf("findVtblIndex() %s\n", toChars());
FuncDeclaration mismatch = null;
StorageClass mismatchstc = 0;
int mismatchvi = -1;
int exactvi = -1;
int bestvi = -1;
for (int vi = 0; vi < dim; vi++)
{
FuncDeclaration fdv = (*vtbl)[vi].isFuncDeclaration();
if (fdv && fdv.ident == ident)
{
if (type.equals(fdv.type)) // if exact match
{
if (fdv.parent.isClassDeclaration())
{
if (fdv.isFuture())
{
bestvi = vi;
continue; // keep looking
}
return vi; // no need to look further
}
if (exactvi >= 0)
{
error("cannot determine overridden function");
return exactvi;
}
exactvi = vi;
bestvi = vi;
continue;
}
StorageClass stc = 0;
int cov = type.covariant(fdv.type, &stc, fix17349);
//printf("\tbaseclass cov = %d\n", cov);
switch (cov)
{
case 0:
// types are distinct
break;
case 1:
bestvi = vi; // covariant, but not identical
break;
// keep looking for an exact match
case 2:
mismatchvi = vi;
mismatchstc = stc;
mismatch = fdv; // overrides, but is not covariant
break;
// keep looking for an exact match
case 3:
return -2; // forward references
default:
assert(0);
}
}
}
if (bestvi == -1 && mismatch)
{
//type.print();
//mismatch.type.print();
//printf("%s %s\n", type.deco, mismatch.type.deco);
//printf("stc = %llx\n", mismatchstc);
if (mismatchstc)
{
// Fix it by modifying the type to add the storage classes
type = type.addStorageClass(mismatchstc);
bestvi = mismatchvi;
}
}
return bestvi;
}
/*********************************
* If function a function in a base class,
* return that base class.
* Returns:
* base class if overriding, null if not
*/
final BaseClass* overrideInterface()
{
if (ClassDeclaration cd = toParent2().isClassDeclaration())
{
foreach (b; cd.interfaces)
{
auto v = findVtblIndex(&b.sym.vtbl, cast(int)b.sym.vtbl.dim);
if (v >= 0)
return b;
}
}
return null;
}
/****************************************************
* Overload this FuncDeclaration with the new one f.
* Return true if successful; i.e. no conflict.
*/
override bool overloadInsert(Dsymbol s)
{
//printf("FuncDeclaration::overloadInsert(s = %s) this = %s\n", s.toChars(), toChars());
assert(s != this);
AliasDeclaration ad = s.isAliasDeclaration();
if (ad)
{
if (overnext)
return overnext.overloadInsert(ad);
if (!ad.aliassym && ad.type.ty != Tident && ad.type.ty != Tinstance && ad.type.ty != Ttypeof)
{
//printf("\tad = '%s'\n", ad.type.toChars());
return false;
}
overnext = ad;
//printf("\ttrue: no conflict\n");
return true;
}
TemplateDeclaration td = s.isTemplateDeclaration();
if (td)
{
if (!td.funcroot)
td.funcroot = this;
if (overnext)
return overnext.overloadInsert(td);
overnext = td;
return true;
}
FuncDeclaration fd = s.isFuncDeclaration();
if (!fd)
return false;
version (none)
{
/* Disable this check because:
* const void foo();
* semantic() isn't run yet on foo(), so the const hasn't been
* applied yet.
*/
if (type)
{
printf("type = %s\n", type.toChars());
printf("fd.type = %s\n", fd.type.toChars());
}
// fd.type can be NULL for overloaded constructors
if (type && fd.type && fd.type.covariant(type) && fd.type.mod == type.mod && !isFuncAliasDeclaration())
{
//printf("\tfalse: conflict %s\n", kind());
return false;
}
}
if (overnext)
{
td = overnext.isTemplateDeclaration();
if (td)
fd.overloadInsert(td);
else
return overnext.overloadInsert(fd);
}
overnext = fd;
//printf("\ttrue: no conflict\n");
return true;
}
/********************************************
* Find function in overload list that exactly matches t.
*/
extern (D) final FuncDeclaration overloadExactMatch(Type t)
{
FuncDeclaration fd;
overloadApply(this, (Dsymbol s)
{
auto f = s.isFuncDeclaration();
if (!f)
return 0;
if (t.equals(f.type))
{
fd = f;
return 1;
}
/* Allow covariant matches, as long as the return type
* is just a const conversion.
* This allows things like pure functions to match with an impure function type.
*/
if (t.ty == Tfunction)
{
auto tf = cast(TypeFunction)f.type;
if (tf.covariant(t) == 1 &&
tf.nextOf().implicitConvTo(t.nextOf()) >= MATCH.constant)
{
fd = f;
return 1;
}
}
return 0;
});
return fd;
}
/********************************************
* Find function in overload list that matches to the 'this' modifier.
* There's four result types.
*
* 1. If the 'tthis' matches only one candidate, it's an "exact match".
* Returns the function and 'hasOverloads' is set to false.
* eg. If 'tthis" is mutable and there's only one mutable method.
* 2. If there's two or more match candidates, but a candidate function will be
* a "better match".
* Returns the better match function but 'hasOverloads' is set to true.
* eg. If 'tthis' is mutable, and there's both mutable and const methods,
* the mutable method will be a better match.
* 3. If there's two or more match candidates, but there's no better match,
* Returns null and 'hasOverloads' is set to true to represent "ambiguous match".
* eg. If 'tthis' is mutable, and there's two or more mutable methods.
* 4. If there's no candidates, it's "no match" and returns null with error report.
* e.g. If 'tthis' is const but there's no const methods.
*/
extern (D) final FuncDeclaration overloadModMatch(const ref Loc loc, Type tthis, ref bool hasOverloads)
{
//printf("FuncDeclaration::overloadModMatch('%s')\n", toChars());
MatchAccumulator m;
overloadApply(this, (Dsymbol s)
{
auto f = s.isFuncDeclaration();
if (!f || f == m.lastf) // skip duplicates
return 0;
auto tf = f.type.toTypeFunction();
//printf("tf = %s\n", tf.toChars());
MATCH match;
if (tthis) // non-static functions are preferred than static ones
{
if (f.needThis())
match = f.isCtorDeclaration() ? MATCH.exact : MODmethodConv(tthis.mod, tf.mod);
else
match = MATCH.constant; // keep static function in overload candidates
}
else // static functions are preferred than non-static ones
{
if (f.needThis())
match = MATCH.convert;
else
match = MATCH.exact;
}
if (match == MATCH.nomatch)
return 0;
if (match > m.last) goto LcurrIsBetter;
if (match < m.last) goto LlastIsBetter;
// See if one of the matches overrides the other.
if (m.lastf.overrides(f)) goto LlastIsBetter;
if (f.overrides(m.lastf)) goto LcurrIsBetter;
//printf("\tambiguous\n");
m.nextf = f;
m.count++;
return 0;
LlastIsBetter:
//printf("\tlastbetter\n");
m.count++; // count up
return 0;
LcurrIsBetter:
//printf("\tisbetter\n");
if (m.last <= MATCH.convert)
{
// clear last secondary matching
m.nextf = null;
m.count = 0;
}
m.last = match;
m.lastf = f;
m.count++; // count up
return 0;
});
if (m.count == 1) // exact match
{
hasOverloads = false;
}
else if (m.count > 1) // better or ambiguous match
{
hasOverloads = true;
}
else // no match
{
hasOverloads = true;
auto tf = this.type.toTypeFunction();
assert(tthis);
assert(!MODimplicitConv(tthis.mod, tf.mod)); // modifier mismatch
{
OutBuffer thisBuf, funcBuf;
MODMatchToBuffer(&thisBuf, tthis.mod, tf.mod);
MODMatchToBuffer(&funcBuf, tf.mod, tthis.mod);
.error(loc, "%smethod %s is not callable using a %sobject",
funcBuf.peekChars(), this.toPrettyChars(), thisBuf.peekChars());
}
}
return m.lastf;
}
/********************************************
* find function template root in overload list
*/
extern (D) final TemplateDeclaration findTemplateDeclRoot()
{
FuncDeclaration f = this;
while (f && f.overnext)
{
//printf("f.overnext = %p %s\n", f.overnext, f.overnext.toChars());
TemplateDeclaration td = f.overnext.isTemplateDeclaration();
if (td)
return td;
f = f.overnext.isFuncDeclaration();
}
return null;
}
/********************************************
* Returns true if function was declared
* directly or indirectly in a unittest block
*/
final bool inUnittest()
{
Dsymbol f = this;
do
{
if (f.isUnitTestDeclaration())
return true;
f = f.toParent();
}
while (f);
return false;
}
/*************************************
* Determine partial specialization order of 'this' vs g.
* This is very similar to TemplateDeclaration::leastAsSpecialized().
* Returns:
* match 'this' is at least as specialized as g
* 0 g is more specialized than 'this'
*/
final MATCH leastAsSpecialized(FuncDeclaration g)
{
enum LOG_LEASTAS = 0;
static if (LOG_LEASTAS)
{
printf("%s.leastAsSpecialized(%s)\n", toChars(), g.toChars());
printf("%s, %s\n", type.toChars(), g.type.toChars());
}
/* This works by calling g() with f()'s parameters, and
* if that is possible, then f() is at least as specialized
* as g() is.
*/
TypeFunction tf = type.toTypeFunction();
TypeFunction tg = g.type.toTypeFunction();