pet.cc

   1 /*
   2  * Copyright 2011 Leiden University. All rights reserved.
   3  *
   4  * Redistribution and use in source and binary forms, with or without
   5  * modification, are permitted provided that the following conditions
   6  * are met:
   7  *
   8  *    1. Redistributions of source code must retain the above copyright
   9  *       notice, this list of conditions and the following disclaimer.
  10  *
  11  *    2. Redistributions in binary form must reproduce the above
  12  *       copyright notice, this list of conditions and the following
  13  *       disclaimer in the documentation and/or other materials provided
  14  *       with the distribution.
  15  *
  16  * THIS SOFTWARE IS PROVIDED BY LEIDEN UNIVERSITY ''AS IS'' AND ANY
  17  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  19  * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL LEIDEN UNIVERSITY OR
  20  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  21  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  22  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA,
  23  * OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  24  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  26  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  27  *
  28  * The views and conclusions contained in the software and documentation
  29  * are those of the authors and should not be interpreted as
  30  * representing official policies, either expressed or implied, of
  31  * Leiden University.
  32  */
  33
  34 #include <stdlib.h>
  35 #include <map>
  36 #include <iostream>
  37 #include <llvm/Support/raw_ostream.h>
  38 #include <llvm/Support/ManagedStatic.h>
  39 #include <llvm/Support/Host.h>
  40 #include <clang/Basic/Version.h>
  41 #include <clang/Basic/FileSystemOptions.h>
  42 #include <clang/Basic/FileManager.h>
  43 #include <clang/Basic/TargetOptions.h>
  44 #include <clang/Basic/TargetInfo.h>
  45 #include <clang/Frontend/CompilerInstance.h>
  46 #include <clang/Frontend/CompilerInvocation.h>
  47 #include <clang/Frontend/DiagnosticOptions.h>
  48 #include <clang/Frontend/TextDiagnosticPrinter.h>
  49 #include <clang/Frontend/HeaderSearchOptions.h>
  50 #include <clang/Frontend/LangStandard.h>
  51 #include <clang/Frontend/PreprocessorOptions.h>
  52 #include <clang/Frontend/FrontendOptions.h>
  53 #include <clang/Frontend/Utils.h>
  54 #include <clang/Lex/HeaderSearch.h>
  55 #include <clang/Lex/Preprocessor.h>
  56 #include <clang/Lex/Pragma.h>
  57 #include <clang/AST/ASTContext.h>
  58 #include <clang/AST/ASTConsumer.h>
  59 #include <clang/Sema/Sema.h>
  60 #include <clang/Sema/SemaDiagnostic.h>
  61 #include <clang/Parse/Parser.h>
  62 #include <clang/Parse/ParseAST.h>
  63
  64 #include <isl/ctx.h>
  65 #include <isl/constraint.h>
  66
  67 #include "scan.h"
  68
  69 #include "config.h"
  70
  71 #define ARRAY_SIZE(array) (sizeof(array)/sizeof(*array))
  72
  73 using namespace std;
  74 using namespace clang;
  75
  76 /* Called if we found something we didn't expect in one of the pragmas.
  77  * We'll provide more informative warnings later.
  78  */
  79 static void unsupported(Preprocessor &PP, SourceLocation loc)
  80 {
  81         Diagnostic &diag = PP.getDiagnostics();
  82         unsigned id = diag.getCustomDiagID(Diagnostic::Warning, "unsupported");
  83         DiagnosticBuilder B = diag.Report(loc, id);
  84 }
  85
  86 /* Set the lower and upper bounds on the given dimension of "set"
  87  * to "lb" and "ub".
  88  */
  89 static __isl_give isl_set *set_bounds(__isl_take isl_set *set,
  90         enum isl_dim_type type, int pos, int lb, int ub)
  91 {
  92         isl_constraint *c;
  93         isl_local_space *ls;
  94
  95         ls = isl_local_space_from_space(isl_set_get_space(set));
  96
  97         c = isl_inequality_alloc(isl_local_space_copy(ls));
  98         c = isl_constraint_set_coefficient_si(c, type, pos, 1);
  99         c = isl_constraint_set_constant_si(c, -lb);
 100         set = isl_set_add_constraint(set, c);
 101
 102         c = isl_inequality_alloc(ls);
 103         c = isl_constraint_set_coefficient_si(c, type, pos, -1);
 104         c = isl_constraint_set_constant_si(c, ub);
 105         set = isl_set_add_constraint(set, c);
 106
 107         return set;
 108 }
 109
 110 static int get_int(const char *s)
 111 {
 112         return s[0] == '"' ? atoi(s + 1) : atoi(s);
 113 }
 114
 115 static ValueDecl *get_value_decl(Sema &sema, Token &token)
 116 {
 117         IdentifierInfo *name;
 118         Decl *decl;
 119
 120         if (token.isNot(tok::identifier))
 121                 return NULL;
 122
 123         name = token.getIdentifierInfo();
 124         decl = sema.LookupSingleName(sema.TUScope, name,
 125                                 token.getLocation(), Sema::LookupOrdinaryName);
 126         return decl ? cast_or_null<ValueDecl>(decl) : NULL;
 127 }
 128
 129 /* Handle pragmas of the form
 130  *
 131  *      #pragma value_bounds identifier lower_bound upper_bound
 132  *
 133  * For each such pragma, add a mapping from the ValueDecl corresponding
 134  * to "identifier" to a set { [i] : lower_bound <= i <= upper_bound }
 135  * to the map value_bounds.
 136  */
 137 struct PragmaValueBoundsHandler : public PragmaHandler {
 138         Sema &sema;
 139         isl_ctx *ctx;
 140         map<ValueDecl *, isl_set *> &value_bounds;
 141
 142         PragmaValueBoundsHandler(isl_ctx *ctx, Sema &sema,
 143                                 map<ValueDecl *, isl_set *> &value_bounds) :
 144                 PragmaHandler("value_bounds"), ctx(ctx), sema(sema),
 145                 value_bounds(value_bounds) {}
 146
 147         virtual void HandlePragma(Preprocessor &PP,
 148                                   PragmaIntroducerKind Introducer,
 149                                   Token &ScopTok) {
 150                 isl_space *dim;
 151                 isl_set *set;
 152                 ValueDecl *vd;
 153                 Token token;
 154                 int lb;
 155                 int ub;
 156
 157                 PP.Lex(token);
 158                 vd = get_value_decl(sema, token);
 159                 if (!vd) {
 160                         unsupported(PP, token.getLocation());
 161                         return;
 162                 }
 163
 164                 PP.Lex(token);
 165                 if (!token.isLiteral()) {
 166                         unsupported(PP, token.getLocation());
 167                         return;
 168                 }
 169
 170                 lb = get_int(token.getLiteralData());
 171
 172                 PP.Lex(token);
 173                 if (!token.isLiteral()) {
 174                         unsupported(PP, token.getLocation());
 175                         return;
 176                 }
 177
 178                 ub = get_int(token.getLiteralData());
 179
 180                 dim = isl_space_set_alloc(ctx, 0, 1);
 181                 set = isl_set_universe(dim);
 182                 set = set_bounds(set, isl_dim_set, 0, lb, ub);
 183
 184                 value_bounds[vd] = set;
 185         }
 186 };
 187
 188 /* Handle pragmas of the form
 189  *
 190  *      #pragma parameter identifier lower_bound upper_bound
 191  *
 192  * For each such pragma, intersect the context with the set
 193  * [identifier] -> { [] : lower_bound <= identifier <= upper_bound }
 194  */
 195 struct PragmaParameterHandler : public PragmaHandler {
 196         Sema &sema;
 197         isl_set *&context;
 198
 199         PragmaParameterHandler(Sema &sema, isl_set *&context) :
 200                 PragmaHandler("parameter"), sema(sema), context(context) {}
 201
 202         virtual void HandlePragma(Preprocessor &PP,
 203                                   PragmaIntroducerKind Introducer,
 204                                   Token &ScopTok) {
 205                 isl_id *id;
 206                 isl_ctx *ctx = isl_set_get_ctx(context);
 207                 isl_space *dim;
 208                 isl_set *set;
 209                 ValueDecl *vd;
 210                 Token token;
 211                 int lb;
 212                 int ub;
 213
 214                 PP.Lex(token);
 215                 vd = get_value_decl(sema, token);
 216                 if (!vd) {
 217                         unsupported(PP, token.getLocation());
 218                         return;
 219                 }
 220
 221                 PP.Lex(token);
 222                 if (!token.isLiteral()) {
 223                         unsupported(PP, token.getLocation());
 224                         return;
 225                 }
 226
 227                 lb = get_int(token.getLiteralData());
 228
 229                 PP.Lex(token);
 230                 if (!token.isLiteral()) {
 231                         unsupported(PP, token.getLocation());
 232                         return;
 233                 }
 234
 235                 ub = get_int(token.getLiteralData());
 236
 237                 id = isl_id_alloc(ctx, vd->getName().str().c_str(), vd);
 238                 dim = isl_space_params_alloc(ctx, 1);
 239                 dim = isl_space_set_dim_id(dim, isl_dim_param, 0, id);
 240
 241                 set = isl_set_universe(dim);
 242
 243                 set = set_bounds(set, isl_dim_param, 0, lb, ub);
 244
 245                 context = isl_set_intersect(context, set);
 246         }
 247 };
 248
 249 /* Handle pragmas of the form
 250  *
 251  *      #pragma scop
 252  *
 253  * In particular, store the current location in loc.start.
 254  */
 255 struct PragmaScopHandler : public PragmaHandler {
 256         ScopLoc &loc;
 257
 258         PragmaScopHandler(ScopLoc &loc) : PragmaHandler("scop"), loc(loc) {}
 259
 260         virtual void HandlePragma(Preprocessor &PP,
 261                                   PragmaIntroducerKind Introducer,
 262                                   Token &ScopTok) {
 263                 SourceManager &SM = PP.getSourceManager();
 264                 loc.start = SM.getFileOffset(ScopTok.getLocation());
 265         }
 266 };
 267
 268 /* Handle pragmas of the form
 269  *
 270  *      #pragma endscop
 271  *
 272  * In particular, store the current location in loc.end.
 273  */
 274 struct PragmaEndScopHandler : public PragmaHandler {
 275         ScopLoc &loc;
 276
 277         PragmaEndScopHandler(ScopLoc &loc) :
 278                 PragmaHandler("endscop"), loc(loc) {}
 279
 280         virtual void HandlePragma(Preprocessor &PP,
 281                                   PragmaIntroducerKind Introducer,
 282                                   Token &EndScopTok) {
 283                 SourceManager &SM = PP.getSourceManager();
 284                 loc.end = SM.getFileOffset(EndScopTok.getLocation());
 285         }
 286 };
 287
 288 /* Handle pragmas of the form
 289  *
 290  *      #pragma live-out identifier, identifier, ...
 291  *
 292  * Each identifier on the line is stored in live_out.
 293  */
 294 struct PragmaLiveOutHandler : public PragmaHandler {
 295         Sema &sema;
 296         set<ValueDecl *> &live_out;
 297
 298         PragmaLiveOutHandler(Sema &sema, set<ValueDecl *> &live_out) :
 299                 PragmaHandler("live"), sema(sema), live_out(live_out) {}
 300
 301         virtual void HandlePragma(Preprocessor &PP,
 302                                   PragmaIntroducerKind Introducer,
 303                                   Token &ScopTok) {
 304                 Token token;
 305
 306                 PP.Lex(token);
 307                 if (token.isNot(tok::minus))
 308                         return;
 309                 PP.Lex(token);
 310                 if (token.isNot(tok::identifier) ||
 311                     !token.getIdentifierInfo()->isStr("out"))
 312                         return;
 313
 314                 PP.Lex(token);
 315                 while (token.isNot(tok::eod)) {
 316                         ValueDecl *vd;
 317
 318                         vd = get_value_decl(sema, token);
 319                         if (!vd) {
 320                                 unsupported(PP, token.getLocation());
 321                                 return;
 322                         }
 323                         live_out.insert(vd);
 324                         PP.Lex(token);
 325                         if (token.is(tok::comma))
 326                                 PP.Lex(token);
 327                 }
 328         }
 329 };
 330
 331 /* Extract a pet_scop from the appropriate function.
 332  * If "function" is not NULL, then we only extract a pet_scop if the
 333  * name of the function matches.
 334  * If "autodetect" is false, then we only extract if we have seen
 335  * scop and endscop pragmas and if these are situated inside the function
 336  * body.
 337  */
 338 struct PetASTConsumer : public ASTConsumer {
 339         Preprocessor &PP;
 340         ASTContext &ast_context;
 341         ScopLoc &loc;
 342         const char *function;
 343         bool autodetect;
 344         isl_ctx *ctx;
 345         struct pet_scop *scop;
 346
 347         PetASTConsumer(isl_ctx *ctx, Preprocessor &PP, ASTContext &ast_context,
 348                 ScopLoc &loc, const char *function, bool autodetect) :
 349                 ctx(ctx), PP(PP), ast_context(ast_context), loc(loc),
 350                 scop(NULL), function(function), autodetect(autodetect) { }
 351
 352         virtual void HandleTopLevelDecl(DeclGroupRef dg) {
 353                 DeclGroupRef::iterator it;
 354
 355                 if (scop)
 356                         return;
 357                 for (it = dg.begin(); it != dg.end(); ++it) {
 358                         FunctionDecl *fd = dyn_cast<clang::FunctionDecl>(*it);
 359                         if (!fd)
 360                                 continue;
 361                         if (!fd->hasBody())
 362                                 continue;
 363                         if (function &&
 364                             fd->getNameInfo().getAsString() != function)
 365                                 continue;
 366                         if (autodetect) {
 367                                 PetScan ps(ctx, PP, ast_context, loc, 1);
 368                                 scop = ps.scan(fd);
 369                                 if (scop)
 370                                         break;
 371                                 else
 372                                         continue;
 373                         }
 374                         if (!loc.end)
 375                                 continue;
 376                         SourceManager &SM = PP.getSourceManager();
 377                         if (SM.getFileOffset(fd->getLocStart()) > loc.end)
 378                                 continue;
 379                         if (SM.getFileOffset(fd->getLocEnd()) < loc.start)
 380                                 continue;
 381                         PetScan ps(ctx, PP, ast_context, loc, 0);
 382                         scop = ps.scan(fd);
 383                         break;
 384                 }
 385         }
 386 };
 387
 388 static const char *ResourceDir = CLANG_PREFIX"/lib/clang/"CLANG_VERSION_STRING;
 389
 390 static const char *implicit_functions[] = {
 391         "min", "max", "ceild", "floord"
 392 };
 393
 394 static bool is_implicit(const IdentifierInfo *ident)
 395 {
 396         const char *name = ident->getNameStart();
 397         for (int i = 0; i < ARRAY_SIZE(implicit_functions); ++i)
 398                 if (!strcmp(name, implicit_functions[i]))
 399                         return true;
 400         return false;
 401 }
 402
 403 /* Ignore implicit function declaration warnings on
 404  * "min", "max", "ceild" and "floord" as we detect and handle these
 405  * in PetScan.
 406  */
 407 struct MyDiagnosticPrinter : public TextDiagnosticPrinter {
 408         MyDiagnosticPrinter(const DiagnosticOptions &DO) :
 409                 TextDiagnosticPrinter(llvm::errs(), DO) {}
 410         virtual void HandleDiagnostic(Diagnostic::Level level,
 411                                         const DiagnosticInfo &info) {
 412                 if (info.getID() == diag::ext_implicit_function_decl &&
 413                     info.getNumArgs() == 1 &&
 414                     info.getArgKind(0) == Diagnostic::ak_identifierinfo &&
 415                     is_implicit(info.getArgIdentifier(0)))
 416                         /* ignore warning */;
 417                 else
 418                         TextDiagnosticPrinter::HandleDiagnostic(level, info);
 419         }
 420 };
 421
 422 static void update_arrays(struct pet_scop *scop,
 423         map<ValueDecl *, isl_set *> &value_bounds,
 424         set<ValueDecl *> &live_out)
 425 {
 426         map<ValueDecl *, isl_set *>::iterator vb_it;
 427         set<ValueDecl *>::iterator lo_it;
 428
 429         if (!scop)
 430                 return;
 431
 432         for (int i = 0; i < scop->n_array; ++i) {
 433                 isl_id *id;
 434                 ValueDecl *decl;
 435                 pet_array *array = scop->arrays[i];
 436
 437                 id = isl_set_get_tuple_id(array->extent);
 438                 decl = (ValueDecl *)isl_id_get_user(id);
 439                 isl_id_free(id);
 440
 441                 vb_it = value_bounds.find(decl);
 442                 if (vb_it != value_bounds.end())
 443                         array->value_bounds = isl_set_copy(vb_it->second);
 444
 445                 lo_it = live_out.find(decl);
 446                 if (lo_it != live_out.end())
 447                         array->live_out = 1;
 448         }
 449 }
 450
 451 /* Extract a pet_scop from the C source file called "filename".
 452  * If "function" is not NULL, extract the pet_scop from the function
 453  * with that name.
 454  * If "autodetect" is set, extract any pet_scop we can find.
 455  * Otherwise, extract the pet_scop from the region delimited
 456  * by "scop" and "endscop" pragmas.
 457  *
 458  * We first set up the clang parser and then try to extract the
 459  * pet_scop from the appropriate function in PetASTConsumer.
 460  * If we have found a pet_scop, we add the context and value_bounds
 461  * constraints specified through pragmas.
 462  */
 463 struct pet_scop *pet_scop_extract_from_C_source(isl_ctx *ctx,
 464         const char *filename, const char *function, int autodetect)
 465 {
 466         isl_space *dim;
 467         isl_set *context;
 468         set<ValueDecl *> live_out;
 469         map<ValueDecl *, isl_set *> value_bounds;
 470         map<ValueDecl *, isl_set *>::iterator vb_it;
 471
 472         CompilerInstance *Clang = new CompilerInstance();
 473         DiagnosticOptions DO;
 474         Clang->createDiagnostics(0, NULL, new MyDiagnosticPrinter(DO));
 475         Diagnostic &Diags = Clang->getDiagnostics();
 476         Diags.setSuppressSystemWarnings(true);
 477         Clang->createFileManager();
 478         Clang->createSourceManager(Clang->getFileManager());
 479         TargetOptions TO;
 480         TO.Triple = llvm::sys::getHostTriple();
 481         TargetInfo *target = TargetInfo::CreateTargetInfo(Diags, TO);
 482         Clang->setTarget(target);
 483         CompilerInvocation::setLangDefaults(Clang->getLangOpts(), IK_C,
 484                                             LangStandard::lang_unspecified);
 485         Clang->getHeaderSearchOpts().ResourceDir = ResourceDir;
 486         Clang->createPreprocessor();
 487         Preprocessor &PP = Clang->getPreprocessor();
 488
 489         ScopLoc loc;
 490
 491         const FileEntry *file = Clang->getFileManager().getFile(filename);
 492         if (!file)
 493                 isl_die(ctx, isl_error_unknown, "unable to open file",
 494                         return NULL);
 495         Clang->getSourceManager().createMainFileID(file);
 496
 497         Clang->createASTContext();
 498         PetASTConsumer consumer(ctx, PP, Clang->getASTContext(),
 499                                 loc, function, autodetect);
 500         Sema *sema = new Sema(PP, Clang->getASTContext(), consumer);
 501
 502         if (!autodetect) {
 503                 PP.AddPragmaHandler(new PragmaScopHandler(loc));
 504                 PP.AddPragmaHandler(new PragmaEndScopHandler(loc));
 505                 PP.AddPragmaHandler(new PragmaLiveOutHandler(*sema, live_out));
 506         }
 507
 508         dim = isl_space_params_alloc(ctx, 0);
 509         context = isl_set_universe(dim);
 510         PP.AddPragmaHandler(new PragmaParameterHandler(*sema, context));
 511         PP.AddPragmaHandler(new PragmaValueBoundsHandler(ctx, *sema, value_bounds));
 512
 513         Diags.getClient()->BeginSourceFile(Clang->getLangOpts(), &PP);
 514         ParseAST(*sema);
 515         Diags.getClient()->EndSourceFile();
 516
 517         delete sema;
 518         delete Clang;
 519         llvm::llvm_shutdown();
 520
 521         if (consumer.scop)
 522                 consumer.scop->context = isl_set_intersect(context,
 523                                                     consumer.scop->context);
 524         else
 525                 isl_set_free(context);
 526
 527         update_arrays(consumer.scop, value_bounds, live_out);
 528
 529         for (vb_it = value_bounds.begin(); vb_it != value_bounds.end(); vb_it++)
 530                 isl_set_free(vb_it->second);
 531
 532         return consumer.scop;
 533 }