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view dmd2/mars.c @ 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 | 123812e02bc8 |
children | 638d16625da2 |
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// Compiler implementation of the D programming language // Copyright (c) 1999-2009 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. #include <stdio.h> #include <stdlib.h> #include <ctype.h> #include <assert.h> #include <limits.h> #include <string> #include <cstdarg> #if __DMC__ #include <dos.h> #endif #if POSIX #include <errno.h> #elif _WIN32 #include <windows.h> #endif #include "mem.h" #include "root.h" #include "mars.h" #include "module.h" #include "mtype.h" #include "id.h" #include "cond.h" #include "expression.h" #include "lexer.h" #include "revisions.h" Global global; Global::Global() { mars_ext = "d"; sym_ext = "d"; hdr_ext = "di"; doc_ext = "html"; ddoc_ext = "ddoc"; // LDC ll_ext = "ll"; bc_ext = "bc"; s_ext = "s"; obj_ext = "o"; #if _WIN32 obj_ext_alt = "obj"; #endif copyright = "Copyright (c) 1999-2009 by Digital Mars and Tomas Lindquist Olsen"; written = "written by Walter Bright and Tomas Lindquist Olsen"; version = "v2.021"; ldc_version = LDC_REV; llvm_version = LLVM_REV_STR; global.structalign = 8; // This should only be used as a global, so the other fields are // automatically initialized to zero when the program is loaded. // In particular, DO NOT zero-initialize .params here (like DMD // does) because command-line options initialize some of those // fields to non-zero defaults, and do so from constructors that // may run before this one. } char *Loc::toChars() const { OutBuffer buf; if (filename) { buf.printf("%s", filename); } if (linnum) buf.printf("(%d)", linnum); buf.writeByte(0); return (char *)buf.extractData(); } Loc::Loc(Module *mod, unsigned linnum) { this->linnum = linnum; this->filename = mod ? mod->srcfile->toChars() : NULL; } /************************************** * Print error message and exit. */ void error(Loc loc, const char *format, ...) { va_list ap; va_start(ap, format); verror(loc, format, ap); va_end( ap ); } void verror(Loc loc, const char *format, va_list ap) { if (!global.gag) { char *p = loc.toChars(); if (*p) fprintf(stdmsg, "%s: ", p); mem.free(p); fprintf(stdmsg, "Error: "); vfprintf(stdmsg, format, ap); fprintf(stdmsg, "\n"); fflush(stdmsg); } global.errors++; } /*************************************** * Call this after printing out fatal error messages to clean up and exit * the compiler. */ void fatal() { #if 0 halt(); #endif exit(EXIT_FAILURE); } /************************************** * Try to stop forgetting to remove the breakpoints from * release builds. */ void halt() { #ifdef DEBUG *(char*)0=0; #endif } /*********************************** * Parse and append contents of environment variable envvar * to argc and argv[]. * The string is separated into arguments, processing \ and ". */ void getenv_setargv(const char *envvar, int *pargc, char** *pargv) { char *env; char *p; Array *argv; int argc; int wildcard; // do wildcard expansion int instring; int slash; char c; int j; env = getenv(envvar); if (!env) return; env = mem.strdup(env); // create our own writable copy argc = *pargc; argv = new Array(); argv->setDim(argc); int argc_left = 0; for (int i = 0; i < argc; i++) { if (!strcmp((*pargv)[i], "-run") || !strcmp((*pargv)[i], "--run")) { // HACK: set flag to indicate we saw '-run' here global.params.run = true; // Don't eat -run yet so the program arguments don't get changed argc_left = argc - i; argc = i; *pargv = &(*pargv)[i]; argv->setDim(i); break; } else { argv->data[i] = (void *)(*pargv)[i]; } } // HACK to stop required values from command line being drawn from DFLAGS argv->push((char*)""); argc++; j = 1; // leave argv[0] alone while (1) { wildcard = 1; switch (*env) { case ' ': case '\t': env++; break; case 0: goto Ldone; case '"': wildcard = 0; default: argv->push(env); // append //argv->insert(j, env); // insert at position j j++; argc++; p = env; slash = 0; instring = 0; c = 0; while (1) { c = *env++; switch (c) { case '"': p -= (slash >> 1); if (slash & 1) { p--; goto Laddc; } instring ^= 1; slash = 0; continue; case ' ': case '\t': if (instring) goto Laddc; *p = 0; //if (wildcard) //wildcardexpand(); // not implemented break; case '\\': slash++; *p++ = c; continue; case 0: *p = 0; //if (wildcard) //wildcardexpand(); // not implemented goto Ldone; default: Laddc: slash = 0; *p++ = c; continue; } break; } } } Ldone: assert(argc == argv->dim); argv->reserve(argc_left); for (int i = 0; i < argc_left; i++) argv->data[argc++] = (void *)(*pargv)[i]; *pargc = argc; *pargv = (char **)argv->data; }