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dsymbolsem.d
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dsymbolsem.d
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/**
* Does the semantic 1 pass on the AST, which looks at symbol declarations but not initializers
* or function bodies.
*
* Copyright: Copyright (C) 1999-2020 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/dsymbolsem.d, _dsymbolsem.d)
* Documentation: https://dlang.org/phobos/dmd_dsymbolsem.html
* Coverage: https://codecov.io/gh/dlang/dmd/src/master/src/dmd/dsymbolsem.d
*/
module dmd.dsymbolsem;
import core.stdc.stdio;
import core.stdc.string;
import dmd.aggregate;
import dmd.aliasthis;
import dmd.arraytypes;
import dmd.astcodegen;
import dmd.attrib;
import dmd.blockexit;
import dmd.clone;
import dmd.compiler;
import dmd.dcast;
import dmd.dclass;
import dmd.declaration;
import dmd.denum;
import dmd.dimport;
import dmd.dinterpret;
import dmd.dmangle;
import dmd.dmodule;
import dmd.dscope;
import dmd.dstruct;
import dmd.dsymbol;
import dmd.dtemplate;
import dmd.dversion;
import dmd.errors;
import dmd.escape;
import dmd.expression;
import dmd.expressionsem;
import dmd.func;
import dmd.globals;
import dmd.id;
import dmd.identifier;
import dmd.init;
import dmd.initsem;
import dmd.hdrgen;
import dmd.mtype;
import dmd.nogc;
import dmd.nspace;
import dmd.objc;
import dmd.opover;
import dmd.parse;
import dmd.root.filename;
import dmd.root.outbuffer;
import dmd.root.rmem;
import dmd.root.rootobject;
import dmd.semantic2;
import dmd.semantic3;
import dmd.sideeffect;
import dmd.statementsem;
import dmd.staticassert;
import dmd.tokens;
import dmd.utf;
import dmd.utils;
import dmd.statement;
import dmd.target;
import dmd.templateparamsem;
import dmd.typesem;
import dmd.visitor;
enum LOG = false;
/*****************************************
* Create inclusive postblit for struct by aggregating
* all the postblits in postblits[] with the postblits for
* all the members.
* Note the close similarity with AggregateDeclaration::buildDtor(),
* and the ordering changes (runs forward instead of backwards).
*/
private FuncDeclaration buildPostBlit(StructDeclaration sd, Scope* sc)
{
//printf("StructDeclaration::buildPostBlit() %s\n", sd.toChars());
if (sd.isUnionDeclaration())
return null;
// by default, the storage class of the created postblit
StorageClass stc = STC.safe | STC.nothrow_ | STC.pure_ | STC.nogc;
Loc declLoc = sd.postblits.dim ? sd.postblits[0].loc : sd.loc;
Loc loc; // internal code should have no loc to prevent coverage
// if any of the postblits are disabled, then the generated postblit
// will be disabled
for (size_t i = 0; i < sd.postblits.dim; i++)
{
stc |= sd.postblits[i].storage_class & STC.disable;
}
VarDeclaration[] fieldsToDestroy;
auto postblitCalls = new Statements();
// iterate through all the struct fields that are not disabled
for (size_t i = 0; i < sd.fields.dim && !(stc & STC.disable); i++)
{
auto structField = sd.fields[i];
if (structField.storage_class & STC.ref_)
continue;
if (structField.overlapped)
continue;
// if it's a struct declaration or an array of structs
Type tv = structField.type.baseElemOf();
if (tv.ty != Tstruct)
continue;
auto sdv = (cast(TypeStruct)tv).sym;
// which has a postblit declaration
if (!sdv.postblit)
continue;
assert(!sdv.isUnionDeclaration());
// if this field's postblit is not `nothrow`, add a `scope(failure)`
// block to destroy any prior successfully postblitted fields should
// this field's postblit fail
if (fieldsToDestroy.length > 0 && !(cast(TypeFunction)sdv.postblit.type).isnothrow)
{
// create a list of destructors that need to be called
Expression[] dtorCalls;
foreach(sf; fieldsToDestroy)
{
Expression ex;
tv = sf.type.toBasetype();
if (tv.ty == Tstruct)
{
// this.v.__xdtor()
ex = new ThisExp(loc);
ex = new DotVarExp(loc, ex, sf);
// This is a hack so we can call destructors on const/immutable objects.
ex = new AddrExp(loc, ex);
ex = new CastExp(loc, ex, sf.type.mutableOf().pointerTo());
ex = new PtrExp(loc, ex);
if (stc & STC.safe)
stc = (stc & ~STC.safe) | STC.trusted;
auto sfv = (cast(TypeStruct)sf.type.baseElemOf()).sym;
ex = new DotVarExp(loc, ex, sfv.dtor, false);
ex = new CallExp(loc, ex);
dtorCalls ~= ex;
}
else
{
// _ArrayDtor((cast(S*)this.v.ptr)[0 .. n])
const length = tv.numberOfElems(loc);
ex = new ThisExp(loc);
ex = new DotVarExp(loc, ex, sf);
// This is a hack so we can call destructors on const/immutable objects.
ex = new DotIdExp(loc, ex, Id.ptr);
ex = new CastExp(loc, ex, sdv.type.pointerTo());
if (stc & STC.safe)
stc = (stc & ~STC.safe) | STC.trusted;
auto se = new SliceExp(loc, ex, new IntegerExp(loc, 0, Type.tsize_t),
new IntegerExp(loc, length, Type.tsize_t));
// Prevent redundant bounds check
se.upperIsInBounds = true;
se.lowerIsLessThanUpper = true;
ex = new CallExp(loc, new IdentifierExp(loc, Id.__ArrayDtor), se);
dtorCalls ~= ex;
}
}
fieldsToDestroy = [];
// aggregate the destructor calls
auto dtors = new Statements();
foreach_reverse(dc; dtorCalls)
{
dtors.push(new ExpStatement(loc, dc));
}
// put destructor calls in a `scope(failure)` block
postblitCalls.push(new ScopeGuardStatement(loc, TOK.onScopeFailure, new CompoundStatement(loc, dtors)));
}
// perform semantic on the member postblit in order to
// be able to aggregate it later on with the rest of the
// postblits
sdv.postblit.functionSemantic();
stc = mergeFuncAttrs(stc, sdv.postblit);
stc = mergeFuncAttrs(stc, sdv.dtor);
// if any of the struct member fields has disabled
// its postblit, then `sd` is not copyable, so no
// postblit is generated
if (stc & STC.disable)
{
postblitCalls.setDim(0);
break;
}
Expression ex;
tv = structField.type.toBasetype();
if (tv.ty == Tstruct)
{
// this.v.__xpostblit()
ex = new ThisExp(loc);
ex = new DotVarExp(loc, ex, structField);
// This is a hack so we can call postblits on const/immutable objects.
ex = new AddrExp(loc, ex);
ex = new CastExp(loc, ex, structField.type.mutableOf().pointerTo());
ex = new PtrExp(loc, ex);
if (stc & STC.safe)
stc = (stc & ~STC.safe) | STC.trusted;
ex = new DotVarExp(loc, ex, sdv.postblit, false);
ex = new CallExp(loc, ex);
}
else
{
// _ArrayPostblit((cast(S*)this.v.ptr)[0 .. n])
const length = tv.numberOfElems(loc);
if (length == 0)
continue;
ex = new ThisExp(loc);
ex = new DotVarExp(loc, ex, structField);
// This is a hack so we can call postblits on const/immutable objects.
ex = new DotIdExp(loc, ex, Id.ptr);
ex = new CastExp(loc, ex, sdv.type.pointerTo());
if (stc & STC.safe)
stc = (stc & ~STC.safe) | STC.trusted;
auto se = new SliceExp(loc, ex, new IntegerExp(loc, 0, Type.tsize_t),
new IntegerExp(loc, length, Type.tsize_t));
// Prevent redundant bounds check
se.upperIsInBounds = true;
se.lowerIsLessThanUpper = true;
ex = new CallExp(loc, new IdentifierExp(loc, Id.__ArrayPostblit), se);
}
postblitCalls.push(new ExpStatement(loc, ex)); // combine in forward order
/* https://issues.dlang.org/show_bug.cgi?id=10972
* When subsequent field postblit calls fail,
* this field should be destructed for Exception Safety.
*/
if (sdv.dtor)
{
sdv.dtor.functionSemantic();
// keep a list of fields that need to be destroyed in case
// of a future postblit failure
fieldsToDestroy ~= structField;
}
}
void checkShared()
{
if (sd.type.isShared())
stc |= STC.shared_;
}
// Build our own "postblit" which executes a, but only if needed.
if (postblitCalls.dim || (stc & STC.disable))
{
//printf("Building __fieldPostBlit()\n");
checkShared();
auto dd = new PostBlitDeclaration(declLoc, Loc.initial, stc, Id.__fieldPostblit);
dd.generated = true;
dd.storage_class |= STC.inference;
dd.fbody = (stc & STC.disable) ? null : new CompoundStatement(loc, postblitCalls);
sd.postblits.shift(dd);
sd.members.push(dd);
dd.dsymbolSemantic(sc);
}
// create __xpostblit, which is the generated postblit
FuncDeclaration xpostblit = null;
switch (sd.postblits.dim)
{
case 0:
break;
case 1:
xpostblit = sd.postblits[0];
break;
default:
Expression e = null;
stc = STC.safe | STC.nothrow_ | STC.pure_ | STC.nogc;
for (size_t i = 0; i < sd.postblits.dim; i++)
{
auto fd = sd.postblits[i];
stc = mergeFuncAttrs(stc, fd);
if (stc & STC.disable)
{
e = null;
break;
}
Expression ex = new ThisExp(loc);
ex = new DotVarExp(loc, ex, fd, false);
ex = new CallExp(loc, ex);
e = Expression.combine(e, ex);
}
checkShared();
auto dd = new PostBlitDeclaration(declLoc, Loc.initial, stc, Id.__aggrPostblit);
dd.generated = true;
dd.storage_class |= STC.inference;
dd.fbody = new ExpStatement(loc, e);
sd.members.push(dd);
dd.dsymbolSemantic(sc);
xpostblit = dd;
break;
}
// Add an __xpostblit alias to make the inclusive postblit accessible
if (xpostblit)
{
auto _alias = new AliasDeclaration(Loc.initial, Id.__xpostblit, xpostblit);
_alias.dsymbolSemantic(sc);
sd.members.push(_alias);
_alias.addMember(sc, sd); // add to symbol table
}
return xpostblit;
}
/**
* Generates a copy constructor declaration with the specified storage
* class for the parameter and the function.
*
* Params:
* sd = the `struct` that contains the copy constructor
* paramStc = the storage class of the copy constructor parameter
* funcStc = the storage class for the copy constructor declaration
*
* Returns:
* The copy constructor declaration for struct `sd`.
*/
private CtorDeclaration generateCopyCtorDeclaration(StructDeclaration sd, const StorageClass paramStc, const StorageClass funcStc)
{
auto fparams = new Parameters();
auto structType = sd.type;
fparams.push(new Parameter(paramStc | STC.ref_ | STC.return_ | STC.scope_, structType, Id.p, null, null));
ParameterList pList = ParameterList(fparams);
auto tf = new TypeFunction(pList, structType, LINK.d, STC.ref_);
auto ccd = new CtorDeclaration(sd.loc, Loc.initial, STC.ref_, tf, true);
ccd.storage_class |= funcStc;
ccd.storage_class |= STC.inference;
ccd.generated = true;
return ccd;
}
/**
* Generates a trivial copy constructor body that simply does memberwise
* initialization:
*
* this.field1 = rhs.field1;
* this.field2 = rhs.field2;
* ...
*
* Params:
* sd = the `struct` declaration that contains the copy constructor
*
* Returns:
* A `CompoundStatement` containing the body of the copy constructor.
*/
private Statement generateCopyCtorBody(StructDeclaration sd)
{
Loc loc;
Expression e;
foreach (v; sd.fields)
{
auto ec = new AssignExp(loc,
new DotVarExp(loc, new ThisExp(loc), v),
new DotVarExp(loc, new IdentifierExp(loc, Id.p), v));
e = Expression.combine(e, ec);
//printf("e.toChars = %s\n", e.toChars());
}
Statement s1 = new ExpStatement(loc, e);
return new CompoundStatement(loc, s1);
}
/**
* Generates a copy constructor for a specified `struct` sd if
* the following conditions are met:
*
* 1. sd does not define a copy constructor
* 2. at least one field of sd defines a copy constructor
*
* If the above conditions are met, the following copy constructor
* is generated:
*
* this(ref return scope inout(S) rhs) inout
* {
* this.field1 = rhs.field1;
* this.field2 = rhs.field2;
* ...
* }
*
* Params:
* sd = the `struct` for which the copy constructor is generated
* sc = the scope where the copy constructor is generated
*
* Returns:
* `true` if `struct` sd defines a copy constructor (explicitly or generated),
* `false` otherwise.
*/
private bool buildCopyCtor(StructDeclaration sd, Scope* sc)
{
if (global.errors)
return false;
bool hasPostblit;
if (sd.postblit && !sd.postblit.isDisabled())
hasPostblit = true;
auto ctor = sd.search(sd.loc, Id.ctor);
CtorDeclaration cpCtor;
CtorDeclaration rvalueCtor;
if (ctor)
{
if (ctor.isOverloadSet())
return false;
if (auto td = ctor.isTemplateDeclaration())
ctor = td.funcroot;
}
if (!ctor)
goto LcheckFields;
overloadApply(ctor, (Dsymbol s)
{
if (s.isTemplateDeclaration())
return 0;
auto ctorDecl = s.isCtorDeclaration();
assert(ctorDecl);
if (ctorDecl.isCpCtor)
{
if (!cpCtor)
cpCtor = ctorDecl;
return 0;
}
auto tf = ctorDecl.type.toTypeFunction();
auto dim = Parameter.dim(tf.parameterList);
if (dim == 1)
{
auto param = Parameter.getNth(tf.parameterList, 0);
if (param.type.mutableOf().unSharedOf() == sd.type.mutableOf().unSharedOf())
{
rvalueCtor = ctorDecl;
}
}
return 0;
});
if (cpCtor && rvalueCtor)
{
.error(sd.loc, "`struct %s` may not define both a rvalue constructor and a copy constructor", sd.toChars());
errorSupplemental(rvalueCtor.loc,"rvalue constructor defined here");
errorSupplemental(cpCtor.loc, "copy constructor defined here");
return true;
}
else if (cpCtor)
{
return !hasPostblit;
}
LcheckFields:
VarDeclaration fieldWithCpCtor;
// see if any struct members define a copy constructor
foreach (v; sd.fields)
{
if (v.storage_class & STC.ref_)
continue;
if (v.overlapped)
continue;
auto ts = v.type.baseElemOf().isTypeStruct();
if (!ts)
continue;
if (ts.sym.hasCopyCtor)
{
fieldWithCpCtor = v;
break;
}
}
if (fieldWithCpCtor && rvalueCtor)
{
.error(sd.loc, "`struct %s` may not define a rvalue constructor and have fields with copy constructors", sd.toChars());
errorSupplemental(rvalueCtor.loc,"rvalue constructor defined here");
errorSupplemental(fieldWithCpCtor.loc, "field with copy constructor defined here");
return false;
}
else if (!fieldWithCpCtor)
return false;
if (hasPostblit)
return false;
//printf("generating copy constructor for %s\n", sd.toChars());
const MOD paramMod = MODFlags.wild;
const MOD funcMod = MODFlags.wild;
auto ccd = generateCopyCtorDeclaration(sd, ModToStc(paramMod), ModToStc(funcMod));
auto copyCtorBody = generateCopyCtorBody(sd);
ccd.fbody = copyCtorBody;
sd.members.push(ccd);
ccd.addMember(sc, sd);
const errors = global.startGagging();
Scope* sc2 = sc.push();
sc2.stc = 0;
sc2.linkage = LINK.d;
ccd.dsymbolSemantic(sc2);
ccd.semantic2(sc2);
ccd.semantic3(sc2);
//printf("ccd semantic: %s\n", ccd.type.toChars());
sc2.pop();
if (global.endGagging(errors))
{
ccd.storage_class |= STC.disable;
ccd.fbody = null;
}
return true;
}
private uint setMangleOverride(Dsymbol s, const(char)[] sym)
{
if (s.isFuncDeclaration() || s.isVarDeclaration())
{
s.isDeclaration().mangleOverride = sym;
return 1;
}
if (auto ad = s.isAttribDeclaration())
{
uint nestedCount = 0;
ad.include(null).foreachDsymbol( (s) { nestedCount += setMangleOverride(s, sym); } );
return nestedCount;
}
return 0;
}
/*************************************
* Does semantic analysis on the public face of declarations.
*/
extern(C++) void dsymbolSemantic(Dsymbol dsym, Scope* sc)
{
scope v = new DsymbolSemanticVisitor(sc);
dsym.accept(v);
}
structalign_t getAlignment(AlignDeclaration ad, Scope* sc)
{
if (ad.salign != ad.UNKNOWN)
return ad.salign;
if (!ad.ealign)
return ad.salign = STRUCTALIGN_DEFAULT;
sc = sc.startCTFE();
ad.ealign = ad.ealign.expressionSemantic(sc);
ad.ealign = resolveProperties(sc, ad.ealign);
sc = sc.endCTFE();
ad.ealign = ad.ealign.ctfeInterpret();
if (ad.ealign.op == TOK.error)
return ad.salign = STRUCTALIGN_DEFAULT;
Type tb = ad.ealign.type.toBasetype();
auto n = ad.ealign.toInteger();
if (n < 1 || n & (n - 1) || structalign_t.max < n || !tb.isintegral())
{
error(ad.loc, "alignment must be an integer positive power of 2, not %s", ad.ealign.toChars());
return ad.salign = STRUCTALIGN_DEFAULT;
}
return ad.salign = cast(structalign_t)n;
}
const(char)* getMessage(DeprecatedDeclaration dd)
{
if (auto sc = dd._scope)
{
dd._scope = null;
sc = sc.startCTFE();
dd.msg = dd.msg.expressionSemantic(sc);
dd.msg = resolveProperties(sc, dd.msg);
sc = sc.endCTFE();
dd.msg = dd.msg.ctfeInterpret();
if (auto se = dd.msg.toStringExp())
dd.msgstr = se.toStringz().ptr;
else
dd.msg.error("compile time constant expected, not `%s`", dd.msg.toChars());
}
return dd.msgstr;
}
// Returns true if a contract can appear without a function body.
package bool allowsContractWithoutBody(FuncDeclaration funcdecl)
{
assert(!funcdecl.fbody);
/* Contracts can only appear without a body when they are virtual
* interface functions or abstract.
*/
Dsymbol parent = funcdecl.toParent();
InterfaceDeclaration id = parent.isInterfaceDeclaration();
if (!funcdecl.isAbstract() &&
(funcdecl.fensures || funcdecl.frequires) &&
!(id && funcdecl.isVirtual()))
{
auto cd = parent.isClassDeclaration();
if (!(cd && cd.isAbstract()))
return false;
}
return true;
}
private extern(C++) final class DsymbolSemanticVisitor : Visitor
{
alias visit = Visitor.visit;
Scope* sc;
this(Scope* sc)
{
this.sc = sc;
}
override void visit(Dsymbol dsym)
{
dsym.error("%p has no semantic routine", dsym);
}
override void visit(ScopeDsymbol) { }
override void visit(Declaration) { }
override void visit(AliasThis dsym)
{
if (dsym.semanticRun != PASS.init)
return;
if (dsym._scope)
{
sc = dsym._scope;
dsym._scope = null;
}
if (!sc)
return;
dsym.semanticRun = PASS.semantic;
dsym.isDeprecated_ = !!(sc.stc & STC.deprecated_);
Dsymbol p = sc.parent.pastMixin();
AggregateDeclaration ad = p.isAggregateDeclaration();
if (!ad)
{
error(dsym.loc, "alias this can only be a member of aggregate, not %s `%s`", p.kind(), p.toChars());
return;
}
assert(ad.members);
Dsymbol s = ad.search(dsym.loc, dsym.ident);
if (!s)
{
s = sc.search(dsym.loc, dsym.ident, null);
if (s)
error(dsym.loc, "`%s` is not a member of `%s`", s.toChars(), ad.toChars());
else
error(dsym.loc, "undefined identifier `%s`", dsym.ident.toChars());
return;
}
if (ad.aliasthis && s != ad.aliasthis)
{
error(dsym.loc, "there can be only one alias this");
return;
}
/* disable the alias this conversion so the implicit conversion check
* doesn't use it.
*/
ad.aliasthis = null;
Dsymbol sx = s;
if (sx.isAliasDeclaration())
sx = sx.toAlias();
Declaration d = sx.isDeclaration();
if (d && !d.isTupleDeclaration())
{
/* https://issues.dlang.org/show_bug.cgi?id=18429
*
* If the identifier in the AliasThis declaration
* is defined later and is a voldemort type, we must
* perform semantic on the declaration to deduce the type.
*/
if (!d.type)
d.dsymbolSemantic(sc);
Type t = d.type;
assert(t);
if (ad.type.implicitConvTo(t) > MATCH.nomatch)
{
error(dsym.loc, "alias this is not reachable as `%s` already converts to `%s`", ad.toChars(), t.toChars());
}
}
dsym.sym = s;
// Restore alias this
ad.aliasthis = dsym;
dsym.semanticRun = PASS.semanticdone;
}
override void visit(AliasDeclaration dsym)
{
if (dsym.semanticRun >= PASS.semanticdone)
return;
assert(dsym.semanticRun <= PASS.semantic);
dsym.storage_class |= sc.stc & STC.deprecated_;
dsym.protection = sc.protection;
dsym.userAttribDecl = sc.userAttribDecl;
if (!sc.func && dsym.inNonRoot())
return;
aliasSemantic(dsym, sc);
}
override void visit(VarDeclaration dsym)
{
version (none)
{
printf("VarDeclaration::semantic('%s', parent = '%s') sem = %d\n",
dsym.toChars(), sc.parent ? sc.parent.toChars() : null, dsym.semanticRun);
printf(" type = %s\n", dsym.type ? dsym.type.toChars() : "null");
printf(" stc = x%x\n", dsym.storage_class.stc);
printf(" storage_class = x%llx\n", dsym.storage_class);
printf("linkage = %d\n", dsym.linkage);
//if (strcmp(toChars(), "mul") == 0) assert(0);
}
//if (semanticRun > PASS.init)
// return;
//semanticRun = PSSsemantic;
if (dsym.semanticRun >= PASS.semanticdone)
return;
if (sc && sc.inunion && sc.inunion.isAnonDeclaration())
dsym.overlapped = true;
Scope* scx = null;
if (dsym._scope)
{
sc = dsym._scope;
scx = sc;
dsym._scope = null;
}
if (!sc)
return;
dsym.semanticRun = PASS.semantic;
/* Pick up storage classes from context, but except synchronized,
* override, abstract, and final.
*/
dsym.storage_class |= (sc.stc & ~(STC.synchronized_ | STC.override_ | STC.abstract_ | STC.final_));
if (dsym.storage_class & STC.extern_ && dsym._init)
dsym.error("extern symbols cannot have initializers");
dsym.userAttribDecl = sc.userAttribDecl;
dsym.cppnamespace = sc.namespace;
AggregateDeclaration ad = dsym.isThis();
if (ad)
dsym.storage_class |= ad.storage_class & STC.TYPECTOR;
/* If auto type inference, do the inference
*/
int inferred = 0;
if (!dsym.type)
{
dsym.inuse++;
// Infering the type requires running semantic,
// so mark the scope as ctfe if required
bool needctfe = (dsym.storage_class & (STC.manifest | STC.static_)) != 0;
if (needctfe)
{
sc.flags |= SCOPE.condition;
sc = sc.startCTFE();
}
//printf("inferring type for %s with init %s\n", dsym.toChars(), dsym._init.toChars());
dsym._init = dsym._init.inferType(sc);
dsym.type = dsym._init.initializerToExpression().type;
if (needctfe)
sc = sc.endCTFE();
dsym.inuse--;
inferred = 1;
/* This is a kludge to support the existing syntax for RAII
* declarations.
*/
dsym.storage_class &= ~STC.auto_;
dsym.originalType = dsym.type.syntaxCopy();
}
else
{
if (!dsym.originalType)
dsym.originalType = dsym.type.syntaxCopy();
/* Prefix function attributes of variable declaration can affect
* its type:
* pure nothrow void function() fp;
* static assert(is(typeof(fp) == void function() pure nothrow));
*/
Scope* sc2 = sc.push();
sc2.stc |= (dsym.storage_class & STC.FUNCATTR);
dsym.inuse++;
dsym.type = dsym.type.typeSemantic(dsym.loc, sc2);
dsym.inuse--;
sc2.pop();
}
//printf(" semantic type = %s\n", dsym.type ? dsym.type.toChars() : "null");
if (dsym.type.ty == Terror)
dsym.errors = true;
dsym.type.checkDeprecated(dsym.loc, sc);
dsym.linkage = sc.linkage;
dsym.parent = sc.parent;
//printf("this = %p, parent = %p, '%s'\n", dsym, dsym.parent, dsym.parent.toChars());
dsym.protection = sc.protection;
/* If scope's alignment is the default, use the type's alignment,
* otherwise the scope overrrides.
*/
dsym.alignment = sc.alignment();
if (dsym.alignment == STRUCTALIGN_DEFAULT)
dsym.alignment = dsym.type.alignment(); // use type's alignment
//printf("sc.stc = %x\n", sc.stc);
//printf("storage_class = x%x\n", storage_class);
if (global.params.vcomplex)
dsym.type.checkComplexTransition(dsym.loc, sc);
// Calculate type size + safety checks
if (sc.func && !sc.intypeof)
{
if (dsym.storage_class & STC.gshared && !dsym.isMember())
{
if (sc.func.setUnsafe())
dsym.error("__gshared not allowed in safe functions; use shared");
}
}
Dsymbol parent = dsym.toParent();
Type tb = dsym.type.toBasetype();
Type tbn = tb.baseElemOf();
if (tb.ty == Tvoid && !(dsym.storage_class & STC.lazy_))
{
if (inferred)
{
dsym.error("type `%s` is inferred from initializer `%s`, and variables cannot be of type `void`", dsym.type.toChars(), dsym._init.toChars());
}
else
dsym.error("variables cannot be of type `void`");
dsym.type = Type.terror;
tb = dsym.type;
}
if (tb.ty == Tfunction)
{
dsym.error("cannot be declared to be a function");
dsym.type = Type.terror;
tb = dsym.type;
}
if (auto ts = tb.isTypeStruct())
{
if (!ts.sym.members)
{
dsym.error("no definition of struct `%s`", ts.toChars());
}
}
if ((dsym.storage_class & STC.auto_) && !inferred)
dsym.error("storage class `auto` has no effect if type is not inferred, did you mean `scope`?");
if (auto tt = tb.isTypeTuple())
{
/* Instead, declare variables for each of the tuple elements
* and add those.
*/
size_t nelems = Parameter.dim(tt.arguments);
Expression ie = (dsym._init && !dsym._init.isVoidInitializer()) ? dsym._init.initializerToExpression() : null;
if (ie)
ie = ie.expressionSemantic(sc);
if (nelems > 0 && ie)
{
auto iexps = new Expressions();
iexps.push(ie);
auto exps = new Expressions();
for (size_t pos = 0; pos < iexps.dim; pos++)
{
Lexpand1:
Expression e = (*iexps)[pos];
Parameter arg = Parameter.getNth(tt.arguments, pos);
arg.type = arg.type.typeSemantic(dsym.loc, sc);
//printf("[%d] iexps.dim = %d, ", pos, iexps.dim);
//printf("e = (%s %s, %s), ", Token::tochars[e.op], e.toChars(), e.type.toChars());
//printf("arg = (%s, %s)\n", arg.toChars(), arg.type.toChars());
if (e != ie)
{
if (iexps.dim > nelems)
goto Lnomatch;
if (e.type.implicitConvTo(arg.type))
continue;
}
if (e.op == TOK.tuple)
{
TupleExp te = cast(TupleExp)e;
if (iexps.dim - 1 + te.exps.dim > nelems)
goto Lnomatch;
iexps.remove(pos);
iexps.insert(pos, te.exps);
(*iexps)[pos] = Expression.combine(te.e0, (*iexps)[pos]);
goto Lexpand1;
}
else if (isAliasThisTuple(e))
{
auto v = copyToTemp(0, "__tup", e);
v.dsymbolSemantic(sc);
auto ve = new VarExp(dsym.loc, v);
ve.type = e.type;
exps.setDim(1);
(*exps)[0] = ve;
expandAliasThisTuples(exps, 0);
for (size_t u = 0; u < exps.dim; u++)
{
Lexpand2:
Expression ee = (*exps)[u];
arg = Parameter.getNth(tt.arguments, pos + u);
arg.type = arg.type.typeSemantic(dsym.loc, sc);
//printf("[%d+%d] exps.dim = %d, ", pos, u, exps.dim);
//printf("ee = (%s %s, %s), ", Token::tochars[ee.op], ee.toChars(), ee.type.toChars());
//printf("arg = (%s, %s)\n", arg.toChars(), arg.type.toChars());
size_t iexps_dim = iexps.dim - 1 + exps.dim;
if (iexps_dim > nelems)
goto Lnomatch;
if (ee.type.implicitConvTo(arg.type))
continue;
if (expandAliasThisTuples(exps, u) != -1)
goto Lexpand2;
}
if ((*exps)[0] != ve)
{
Expression e0 = (*exps)[0];
(*exps)[0] = new CommaExp(dsym.loc, new DeclarationExp(dsym.loc, v), e0);
(*exps)[0].type = e0.type;
iexps.remove(pos);
iexps.insert(pos, exps);
goto Lexpand1;
}
}
}
if (iexps.dim < nelems)
goto Lnomatch;
ie = new TupleExp(dsym._init.loc, iexps);
}
Lnomatch: