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view dmd2/scope.h @ 1117:4c20fcc4252b
Fun with parameter attributes: For several of the "synthetic" parameters added
to D functions, we can apply noalias and nocapture. They are sret parameters,
'nest' pointers passed to nested functions, and _argptr:
Nocapture:
- Sret and nest are nocapture because they don't represent D-level variables,
and thus the callee can't (validly) obtain a pointer to them, let alone keep
it around after it returns.
- _argptr is nocapture because although the callee has access to it as a
pointer, that pointer is invalidated when it returns.
All three are noalias because they're function-local variables
- Sret and _argptr are noalias because they're freshly alloca'd memory only
used for a single function call that's not allowed to keep an aliasing
pointer to it around (since the parameter is nocapture).
- 'Nest' is noalias because the callee only ever has access to one such pointer
per parent function, and every parent function has a different one.
This commit also ensures attributes set on sret, _arguments and _argptr are
propagated to calls to such functions.
It also adds one exception to the general rule that attributes on function types
should propagate to calls: the type of a delegate's function pointer has a
'nest' parameter, but this can either be a true 'nest' (for delegates to nested
functions) or a 'this' (for delegates to member functions). Since 'this' is
neither noalias nor nocapture, and there's generally no way to tell which one it
is, we remove these attributes at the call site if the callee is a delegate.
author | Frits van Bommel <fvbommel wxs.nl> |
---|---|
date | Sat, 14 Mar 2009 22:15:31 +0100 |
parents | 356e65836fb5 |
children | 638d16625da2 |
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// Copyright (c) 1999-2005 by Digital Mars // All Rights Reserved // written by Walter Bright // http://www.digitalmars.com // License for redistribution is by either the Artistic License // in artistic.txt, or the GNU General Public License in gnu.txt. // See the included readme.txt for details. #ifndef DMD_SCOPE_H #define DMD_SCOPE_H #ifdef __DMC__ #pragma once #endif /* __DMC__ */ struct Dsymbol; struct ScopeDsymbol; struct Array; struct Identifier; struct Module; struct Statement; struct SwitchStatement; struct TryFinallyStatement; struct LabelStatement; struct ForeachStatement; struct ClassDeclaration; struct AggregateDeclaration; struct AnonymousAggregateDeclaration; struct FuncDeclaration; struct DocComment; struct EnclosingHandler; struct AnonDeclaration; #if __GNUC__ #include "dsymbol.h" // PROT #include "mars.h" // LINK #else enum LINK; enum PROT; #endif struct Scope { Scope *enclosing; // enclosing Scope Module *module; // Root module ScopeDsymbol *scopesym; // current symbol ScopeDsymbol *sd; // if in static if, and declaring new symbols, // sd gets the addMember() FuncDeclaration *func; // function we are in Dsymbol *parent; // parent to use LabelStatement *slabel; // enclosing labelled statement SwitchStatement *sw; // enclosing switch statement TryFinallyStatement *tf; // enclosing try finally statement; set inside its finally block EnclosingHandler *tfOfTry; // enclosing try-finally, volatile or synchronized statement; set inside its try or body block TemplateInstance *tinst; // enclosing template instance Statement *sbreak; // enclosing statement that supports "break" Statement *scontinue; // enclosing statement that supports "continue" ForeachStatement *fes; // if nested function for ForeachStatement, this is it unsigned offset; // next offset to use in aggregate int inunion; // we're processing members of a union int incontract; // we're inside contract code int nofree; // set if shouldn't free it int noctor; // set if constructor calls aren't allowed int intypeof; // in typeof(exp) int parameterSpecialization; // if in template parameter specialization int noaccesscheck; // don't do access checks unsigned callSuper; // primitive flow analysis for constructors #define CSXthis_ctor 1 // called this() #define CSXsuper_ctor 2 // called super() #define CSXthis 4 // referenced this #define CSXsuper 8 // referenced super #define CSXlabel 0x10 // seen a label #define CSXreturn 0x20 // seen a return statement #define CSXany_ctor 0x40 // either this() or super() was called unsigned structalign; // alignment for struct members enum LINK linkage; // linkage for external functions enum PROT protection; // protection for class members int explicitProtection; // set if in an explicit protection attribute unsigned stc; // storage class unsigned flags; #define SCOPEctor 1 // constructor type #define SCOPEstaticif 2 // inside static if #define SCOPEfree 4 // is on free list AnonymousAggregateDeclaration *anonAgg; // for temporary analysis DocComment *lastdc; // documentation comment for last symbol at this scope unsigned lastoffset; // offset in docbuf of where to insert next dec OutBuffer *docbuf; // buffer for documentation output static Scope *freelist; static void *operator new(size_t sz); static Scope *createGlobal(Module *module); Scope(); Scope(Module *module); Scope(Scope *enclosing); Scope *push(); Scope *push(ScopeDsymbol *ss); Scope *pop(); void mergeCallSuper(Loc loc, unsigned cs); Dsymbol *search(Loc loc, Identifier *ident, Dsymbol **pscopesym); Dsymbol *insert(Dsymbol *s); ClassDeclaration *getClassScope(); AggregateDeclaration *getStructClassScope(); void setNoFree(); }; #endif /* DMD_SCOPE_H */