1 //=- AnalysisBasedWarnings.cpp - Sema warnings based on libAnalysis -*- C++ -*-=//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file defines analysis_warnings::[Policy,Executor].
11 // Together they are used by Sema to issue warnings based on inexpensive
12 // static analysis algorithms in libAnalysis.
14 //===----------------------------------------------------------------------===//
16 #include "clang/Sema/AnalysisBasedWarnings.h"
17 #include "clang/Sema/SemaInternal.h"
18 #include "clang/Sema/ScopeInfo.h"
19 #include "clang/Basic/SourceManager.h"
20 #include "clang/Lex/Preprocessor.h"
21 #include "clang/AST/DeclObjC.h"
22 #include "clang/AST/DeclCXX.h"
23 #include "clang/AST/ExprObjC.h"
24 #include "clang/AST/ExprCXX.h"
25 #include "clang/AST/StmtObjC.h"
26 #include "clang/AST/StmtCXX.h"
27 #include "clang/AST/EvaluatedExprVisitor.h"
28 #include "clang/Analysis/AnalysisContext.h"
29 #include "clang/Analysis/CFG.h"
30 #include "clang/Analysis/Analyses/ReachableCode.h"
31 #include "clang/Analysis/Analyses/CFGReachabilityAnalysis.h"
32 #include "clang/Analysis/CFGStmtMap.h"
33 #include "clang/Analysis/Analyses/UninitializedValues.h"
34 #include "llvm/ADT/BitVector.h"
35 #include "llvm/Support/Casting.h"
37 using namespace clang;
39 //===----------------------------------------------------------------------===//
40 // Unreachable code analysis.
41 //===----------------------------------------------------------------------===//
44 class UnreachableCodeHandler : public reachable_code::Callback {
47 UnreachableCodeHandler(Sema &s) : S(s) {}
49 void HandleUnreachable(SourceLocation L, SourceRange R1, SourceRange R2) {
50 S.Diag(L, diag::warn_unreachable) << R1 << R2;
55 /// CheckUnreachable - Check for unreachable code.
56 static void CheckUnreachable(Sema &S, AnalysisContext &AC) {
57 UnreachableCodeHandler UC(S);
58 reachable_code::FindUnreachableCode(AC, UC);
61 //===----------------------------------------------------------------------===//
62 // Check for missing return value.
63 //===----------------------------------------------------------------------===//
65 enum ControlFlowKind {
70 NeverFallThroughOrReturn
73 /// CheckFallThrough - Check that we don't fall off the end of a
74 /// Statement that should return a value.
76 /// \returns AlwaysFallThrough iff we always fall off the end of the statement,
77 /// MaybeFallThrough iff we might or might not fall off the end,
78 /// NeverFallThroughOrReturn iff we never fall off the end of the statement or
79 /// return. We assume NeverFallThrough iff we never fall off the end of the
80 /// statement but we may return. We assume that functions not marked noreturn
82 static ControlFlowKind CheckFallThrough(AnalysisContext &AC) {
83 CFG *cfg = AC.getCFG();
84 if (cfg == 0) return UnknownFallThrough;
86 // The CFG leaves in dead things, and we don't want the dead code paths to
87 // confuse us, so we mark all live things first.
88 llvm::BitVector live(cfg->getNumBlockIDs());
89 unsigned count = reachable_code::ScanReachableFromBlock(cfg->getEntry(),
92 bool AddEHEdges = AC.getAddEHEdges();
93 if (!AddEHEdges && count != cfg->getNumBlockIDs())
94 // When there are things remaining dead, and we didn't add EH edges
95 // from CallExprs to the catch clauses, we have to go back and
97 for (CFG::iterator I = cfg->begin(), E = cfg->end(); I != E; ++I) {
99 if (!live[b.getBlockID()]) {
100 if (b.pred_begin() == b.pred_end()) {
101 if (b.getTerminator() && isa<CXXTryStmt>(b.getTerminator()))
102 // When not adding EH edges from calls, catch clauses
103 // can otherwise seem dead. Avoid noting them as dead.
104 count += reachable_code::ScanReachableFromBlock(b, live);
110 // Now we know what is live, we check the live precessors of the exit block
111 // and look for fall through paths, being careful to ignore normal returns,
112 // and exceptional paths.
113 bool HasLiveReturn = false;
114 bool HasFakeEdge = false;
115 bool HasPlainEdge = false;
116 bool HasAbnormalEdge = false;
118 // Ignore default cases that aren't likely to be reachable because all
119 // enums in a switch(X) have explicit case statements.
120 CFGBlock::FilterOptions FO;
121 FO.IgnoreDefaultsWithCoveredEnums = 1;
123 for (CFGBlock::filtered_pred_iterator
124 I = cfg->getExit().filtered_pred_start_end(FO); I.hasMore(); ++I) {
125 const CFGBlock& B = **I;
126 if (!live[B.getBlockID()])
129 // Destructors can appear after the 'return' in the CFG. This is
130 // normal. We need to look pass the destructors for the return
131 // statement (if it exists).
132 CFGBlock::const_reverse_iterator ri = B.rbegin(), re = B.rend();
133 bool hasNoReturnDtor = false;
135 for ( ; ri != re ; ++ri) {
138 // FIXME: The right solution is to just sever the edges in the
140 if (const CFGImplicitDtor *iDtor = ri->getAs<CFGImplicitDtor>())
141 if (iDtor->isNoReturn(AC.getASTContext())) {
142 hasNoReturnDtor = true;
147 if (isa<CFGStmt>(CE))
154 // No more CFGElements in the block?
156 if (B.getTerminator() && isa<CXXTryStmt>(B.getTerminator())) {
157 HasAbnormalEdge = true;
160 // A labeled empty statement, or the entry block...
165 CFGStmt CS = cast<CFGStmt>(*ri);
166 Stmt *S = CS.getStmt();
167 if (isa<ReturnStmt>(S)) {
168 HasLiveReturn = true;
171 if (isa<ObjCAtThrowStmt>(S)) {
175 if (isa<CXXThrowExpr>(S)) {
179 if (const AsmStmt *AS = dyn_cast<AsmStmt>(S)) {
182 HasLiveReturn = true;
186 if (isa<CXXTryStmt>(S)) {
187 HasAbnormalEdge = true;
191 bool NoReturnEdge = false;
192 if (CallExpr *C = dyn_cast<CallExpr>(S)) {
193 if (std::find(B.succ_begin(), B.succ_end(), &cfg->getExit())
195 HasAbnormalEdge = true;
198 Expr *CEE = C->getCallee()->IgnoreParenCasts();
199 QualType calleeType = CEE->getType();
200 if (calleeType == AC.getASTContext().BoundMemberTy) {
201 calleeType = Expr::findBoundMemberType(CEE);
202 assert(!calleeType.isNull() && "analyzing unresolved call?");
204 if (getFunctionExtInfo(calleeType).getNoReturn()) {
207 } else if (DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(CEE)) {
208 ValueDecl *VD = DRE->getDecl();
209 if (VD->hasAttr<NoReturnAttr>()) {
215 // FIXME: Add noreturn message sends.
216 if (NoReturnEdge == false)
221 return NeverFallThrough;
222 return NeverFallThroughOrReturn;
224 if (HasAbnormalEdge || HasFakeEdge || HasLiveReturn)
225 return MaybeFallThrough;
226 // This says AlwaysFallThrough for calls to functions that are not marked
227 // noreturn, that don't return. If people would like this warning to be more
228 // accurate, such functions should be marked as noreturn.
229 return AlwaysFallThrough;
234 struct CheckFallThroughDiagnostics {
235 unsigned diag_MaybeFallThrough_HasNoReturn;
236 unsigned diag_MaybeFallThrough_ReturnsNonVoid;
237 unsigned diag_AlwaysFallThrough_HasNoReturn;
238 unsigned diag_AlwaysFallThrough_ReturnsNonVoid;
239 unsigned diag_NeverFallThroughOrReturn;
241 SourceLocation FuncLoc;
243 static CheckFallThroughDiagnostics MakeForFunction(const Decl *Func) {
244 CheckFallThroughDiagnostics D;
245 D.FuncLoc = Func->getLocation();
246 D.diag_MaybeFallThrough_HasNoReturn =
247 diag::warn_falloff_noreturn_function;
248 D.diag_MaybeFallThrough_ReturnsNonVoid =
249 diag::warn_maybe_falloff_nonvoid_function;
250 D.diag_AlwaysFallThrough_HasNoReturn =
251 diag::warn_falloff_noreturn_function;
252 D.diag_AlwaysFallThrough_ReturnsNonVoid =
253 diag::warn_falloff_nonvoid_function;
255 // Don't suggest that virtual functions be marked "noreturn", since they
256 // might be overridden by non-noreturn functions.
257 bool isVirtualMethod = false;
258 if (const CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Func))
259 isVirtualMethod = Method->isVirtual();
261 if (!isVirtualMethod)
262 D.diag_NeverFallThroughOrReturn =
263 diag::warn_suggest_noreturn_function;
265 D.diag_NeverFallThroughOrReturn = 0;
271 static CheckFallThroughDiagnostics MakeForBlock() {
272 CheckFallThroughDiagnostics D;
273 D.diag_MaybeFallThrough_HasNoReturn =
274 diag::err_noreturn_block_has_return_expr;
275 D.diag_MaybeFallThrough_ReturnsNonVoid =
276 diag::err_maybe_falloff_nonvoid_block;
277 D.diag_AlwaysFallThrough_HasNoReturn =
278 diag::err_noreturn_block_has_return_expr;
279 D.diag_AlwaysFallThrough_ReturnsNonVoid =
280 diag::err_falloff_nonvoid_block;
281 D.diag_NeverFallThroughOrReturn =
282 diag::warn_suggest_noreturn_block;
287 bool checkDiagnostics(Diagnostic &D, bool ReturnsVoid,
288 bool HasNoReturn) const {
290 return (ReturnsVoid ||
291 D.getDiagnosticLevel(diag::warn_maybe_falloff_nonvoid_function,
292 FuncLoc) == Diagnostic::Ignored)
294 D.getDiagnosticLevel(diag::warn_noreturn_function_has_return_expr,
295 FuncLoc) == Diagnostic::Ignored)
297 D.getDiagnosticLevel(diag::warn_suggest_noreturn_block, FuncLoc)
298 == Diagnostic::Ignored);
302 return ReturnsVoid && !HasNoReturn
304 D.getDiagnosticLevel(diag::warn_suggest_noreturn_block, FuncLoc)
305 == Diagnostic::Ignored);
311 /// CheckFallThroughForFunctionDef - Check that we don't fall off the end of a
312 /// function that should return a value. Check that we don't fall off the end
313 /// of a noreturn function. We assume that functions and blocks not marked
314 /// noreturn will return.
315 static void CheckFallThroughForBody(Sema &S, const Decl *D, const Stmt *Body,
316 const BlockExpr *blkExpr,
317 const CheckFallThroughDiagnostics& CD,
318 AnalysisContext &AC) {
320 bool ReturnsVoid = false;
321 bool HasNoReturn = false;
323 if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) {
324 ReturnsVoid = FD->getResultType()->isVoidType();
325 HasNoReturn = FD->hasAttr<NoReturnAttr>() ||
326 FD->getType()->getAs<FunctionType>()->getNoReturnAttr();
328 else if (const ObjCMethodDecl *MD = dyn_cast<ObjCMethodDecl>(D)) {
329 ReturnsVoid = MD->getResultType()->isVoidType();
330 HasNoReturn = MD->hasAttr<NoReturnAttr>();
332 else if (isa<BlockDecl>(D)) {
333 QualType BlockTy = blkExpr->getType();
334 if (const FunctionType *FT =
335 BlockTy->getPointeeType()->getAs<FunctionType>()) {
336 if (FT->getResultType()->isVoidType())
338 if (FT->getNoReturnAttr())
343 Diagnostic &Diags = S.getDiagnostics();
345 // Short circuit for compilation speed.
346 if (CD.checkDiagnostics(Diags, ReturnsVoid, HasNoReturn))
349 // FIXME: Function try block
350 if (const CompoundStmt *Compound = dyn_cast<CompoundStmt>(Body)) {
351 switch (CheckFallThrough(AC)) {
352 case UnknownFallThrough:
355 case MaybeFallThrough:
357 S.Diag(Compound->getRBracLoc(),
358 CD.diag_MaybeFallThrough_HasNoReturn);
359 else if (!ReturnsVoid)
360 S.Diag(Compound->getRBracLoc(),
361 CD.diag_MaybeFallThrough_ReturnsNonVoid);
363 case AlwaysFallThrough:
365 S.Diag(Compound->getRBracLoc(),
366 CD.diag_AlwaysFallThrough_HasNoReturn);
367 else if (!ReturnsVoid)
368 S.Diag(Compound->getRBracLoc(),
369 CD.diag_AlwaysFallThrough_ReturnsNonVoid);
371 case NeverFallThroughOrReturn:
372 if (ReturnsVoid && !HasNoReturn && CD.diag_NeverFallThroughOrReturn)
373 S.Diag(Compound->getLBracLoc(),
374 CD.diag_NeverFallThroughOrReturn);
376 case NeverFallThrough:
382 //===----------------------------------------------------------------------===//
384 //===----------------------------------------------------------------------===//
387 /// ContainsReference - A visitor class to search for references to
388 /// a particular declaration (the needle) within any evaluated component of an
389 /// expression (recursively).
390 class ContainsReference : public EvaluatedExprVisitor<ContainsReference> {
392 const DeclRefExpr *Needle;
395 ContainsReference(ASTContext &Context, const DeclRefExpr *Needle)
396 : EvaluatedExprVisitor<ContainsReference>(Context),
397 FoundReference(false), Needle(Needle) {}
399 void VisitExpr(Expr *E) {
400 // Stop evaluating if we already have a reference.
404 EvaluatedExprVisitor<ContainsReference>::VisitExpr(E);
407 void VisitDeclRefExpr(DeclRefExpr *E) {
409 FoundReference = true;
411 EvaluatedExprVisitor<ContainsReference>::VisitDeclRefExpr(E);
414 bool doesContainReference() const { return FoundReference; }
418 /// DiagnoseUninitializedUse -- Helper function for diagnosing uses of an
419 /// uninitialized variable. This manages the different forms of diagnostic
420 /// emitted for particular types of uses. Returns true if the use was diagnosed
421 /// as a warning. If a pariticular use is one we omit warnings for, returns
423 static bool DiagnoseUninitializedUse(Sema &S, const VarDecl *VD,
424 const Expr *E, bool isAlwaysUninit) {
425 bool isSelfInit = false;
427 if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(E)) {
428 if (isAlwaysUninit) {
429 // Inspect the initializer of the variable declaration which is
430 // being referenced prior to its initialization. We emit
431 // specialized diagnostics for self-initialization, and we
432 // specifically avoid warning about self references which take the
437 // This is used to indicate to GCC that 'x' is intentionally left
438 // uninitialized. Proven code paths which access 'x' in
439 // an uninitialized state after this will still warn.
441 // TODO: Should we suppress maybe-uninitialized warnings for
442 // variables initialized in this way?
443 if (const Expr *Initializer = VD->getInit()) {
444 if (DRE == Initializer->IgnoreParenImpCasts())
447 ContainsReference CR(S.Context, DRE);
448 CR.Visit(const_cast<Expr*>(Initializer));
449 isSelfInit = CR.doesContainReference();
452 S.Diag(DRE->getLocStart(),
453 diag::warn_uninit_self_reference_in_init)
454 << VD->getDeclName() << VD->getLocation() << DRE->getSourceRange();
456 S.Diag(DRE->getLocStart(), diag::warn_uninit_var)
457 << VD->getDeclName() << DRE->getSourceRange();
460 S.Diag(DRE->getLocStart(), diag::warn_maybe_uninit_var)
461 << VD->getDeclName() << DRE->getSourceRange();
464 const BlockExpr *BE = cast<BlockExpr>(E);
465 S.Diag(BE->getLocStart(),
466 isAlwaysUninit ? diag::warn_uninit_var_captured_by_block
467 : diag::warn_maybe_uninit_var_captured_by_block)
468 << VD->getDeclName();
471 // Report where the variable was declared when the use wasn't within
472 // the initializer of that declaration.
474 S.Diag(VD->getLocStart(), diag::note_uninit_var_def)
475 << VD->getDeclName();
480 static void SuggestInitializationFixit(Sema &S, const VarDecl *VD) {
481 // Don't issue a fixit if there is already an initializer.
485 // Suggest possible initialization (if any).
486 const char *initialization = 0;
487 QualType VariableTy = VD->getType().getCanonicalType();
489 if (VariableTy->isObjCObjectPointerType() ||
490 VariableTy->isBlockPointerType()) {
491 // Check if 'nil' is defined.
492 if (S.PP.getMacroInfo(&S.getASTContext().Idents.get("nil")))
493 initialization = " = nil";
495 initialization = " = 0";
497 else if (VariableTy->isRealFloatingType())
498 initialization = " = 0.0";
499 else if (VariableTy->isBooleanType() && S.Context.getLangOptions().CPlusPlus)
500 initialization = " = false";
501 else if (VariableTy->isEnumeralType())
503 else if (VariableTy->isPointerType() || VariableTy->isMemberPointerType()) {
504 // Check if 'NULL' is defined.
505 if (S.PP.getMacroInfo(&S.getASTContext().Idents.get("NULL")))
506 initialization = " = NULL";
508 initialization = " = 0";
510 else if (VariableTy->isScalarType())
511 initialization = " = 0";
513 if (initialization) {
514 SourceLocation loc = S.PP.getLocForEndOfToken(VD->getLocEnd());
515 S.Diag(loc, diag::note_var_fixit_add_initialization)
516 << FixItHint::CreateInsertion(loc, initialization);
520 typedef std::pair<const Expr*, bool> UninitUse;
524 bool operator()(const UninitUse &a, const UninitUse &b) {
525 SourceLocation aLoc = a.first->getLocStart();
526 SourceLocation bLoc = b.first->getLocStart();
527 return aLoc.getRawEncoding() < bLoc.getRawEncoding();
531 class UninitValsDiagReporter : public UninitVariablesHandler {
533 typedef llvm::SmallVector<UninitUse, 2> UsesVec;
534 typedef llvm::DenseMap<const VarDecl *, UsesVec*> UsesMap;
538 UninitValsDiagReporter(Sema &S) : S(S), uses(0) {}
539 ~UninitValsDiagReporter() {
543 void handleUseOfUninitVariable(const Expr *ex, const VarDecl *vd,
544 bool isAlwaysUninit) {
546 uses = new UsesMap();
548 UsesVec *&vec = (*uses)[vd];
552 vec->push_back(std::make_pair(ex, isAlwaysUninit));
555 void flushDiagnostics() {
559 for (UsesMap::iterator i = uses->begin(), e = uses->end(); i != e; ++i) {
560 const VarDecl *vd = i->first;
561 UsesVec *vec = i->second;
563 bool fixitIssued = false;
565 // Sort the uses by their SourceLocations. While not strictly
566 // guaranteed to produce them in line/column order, this will provide
567 // a stable ordering.
568 std::sort(vec->begin(), vec->end(), SLocSort());
570 for (UsesVec::iterator vi = vec->begin(), ve = vec->end(); vi != ve;
572 if (!DiagnoseUninitializedUse(S, vd, vi->first,
573 /*isAlwaysUninit=*/vi->second))
576 // Suggest a fixit hint the first time we diagnose a use of a variable.
578 SuggestInitializationFixit(S, vd);
590 //===----------------------------------------------------------------------===//
591 // AnalysisBasedWarnings - Worker object used by Sema to execute analysis-based
592 // warnings on a function, method, or block.
593 //===----------------------------------------------------------------------===//
595 clang::sema::AnalysisBasedWarnings::Policy::Policy() {
596 enableCheckFallThrough = 1;
597 enableCheckUnreachable = 0;
600 clang::sema::AnalysisBasedWarnings::AnalysisBasedWarnings(Sema &s)
602 NumFunctionsAnalyzed(0),
603 NumFunctionsWithBadCFGs(0),
605 MaxCFGBlocksPerFunction(0),
606 NumUninitAnalysisFunctions(0),
607 NumUninitAnalysisVariables(0),
608 MaxUninitAnalysisVariablesPerFunction(0),
609 NumUninitAnalysisBlockVisits(0),
610 MaxUninitAnalysisBlockVisitsPerFunction(0) {
611 Diagnostic &D = S.getDiagnostics();
612 DefaultPolicy.enableCheckUnreachable = (unsigned)
613 (D.getDiagnosticLevel(diag::warn_unreachable, SourceLocation()) !=
614 Diagnostic::Ignored);
617 static void flushDiagnostics(Sema &S, sema::FunctionScopeInfo *fscope) {
618 for (llvm::SmallVectorImpl<sema::PossiblyUnreachableDiag>::iterator
619 i = fscope->PossiblyUnreachableDiags.begin(),
620 e = fscope->PossiblyUnreachableDiags.end();
622 const sema::PossiblyUnreachableDiag &D = *i;
628 AnalysisBasedWarnings::IssueWarnings(sema::AnalysisBasedWarnings::Policy P,
629 sema::FunctionScopeInfo *fscope,
630 const Decl *D, const BlockExpr *blkExpr) {
632 // We avoid doing analysis-based warnings when there are errors for
634 // (1) The CFGs often can't be constructed (if the body is invalid), so
635 // don't bother trying.
636 // (2) The code already has problems; running the analysis just takes more
638 Diagnostic &Diags = S.getDiagnostics();
640 // Do not do any analysis for declarations in system headers if we are
641 // going to just ignore them.
642 if (Diags.getSuppressSystemWarnings() &&
643 S.SourceMgr.isInSystemHeader(D->getLocation()))
646 // For code in dependent contexts, we'll do this at instantiation time.
647 if (cast<DeclContext>(D)->isDependentContext())
650 if (Diags.hasErrorOccurred() || Diags.hasFatalErrorOccurred()) {
651 // Flush out any possibly unreachable diagnostics.
652 flushDiagnostics(S, fscope);
656 const Stmt *Body = D->getBody();
659 // Don't generate EH edges for CallExprs as we'd like to avoid the n^2
660 // explosion for destrutors that can result and the compile time hit.
661 AnalysisContext AC(D, 0, /*useUnoptimizedCFG=*/false, /*addehedges=*/false,
662 /*addImplicitDtors=*/true, /*addInitializers=*/true);
664 // Emit delayed diagnostics.
665 if (!fscope->PossiblyUnreachableDiags.empty()) {
666 bool analyzed = false;
668 // Register the expressions with the CFGBuilder.
669 for (llvm::SmallVectorImpl<sema::PossiblyUnreachableDiag>::iterator
670 i = fscope->PossiblyUnreachableDiags.begin(),
671 e = fscope->PossiblyUnreachableDiags.end();
673 if (const Stmt *stmt = i->stmt)
674 AC.registerForcedBlockExpression(stmt);
679 for (llvm::SmallVectorImpl<sema::PossiblyUnreachableDiag>::iterator
680 i = fscope->PossiblyUnreachableDiags.begin(),
681 e = fscope->PossiblyUnreachableDiags.end();
684 const sema::PossiblyUnreachableDiag &D = *i;
685 bool processed = false;
686 if (const Stmt *stmt = i->stmt) {
687 const CFGBlock *block = AC.getBlockForRegisteredExpression(stmt);
689 if (CFGReverseBlockReachabilityAnalysis *cra = AC.getCFGReachablityAnalysis()) {
690 // Can this block be reached from the entrance?
691 if (cra->isReachable(&AC.getCFG()->getEntry(), block))
697 // Emit the warning anyway if we cannot map to a basic block.
704 flushDiagnostics(S, fscope);
708 // Warning: check missing 'return'
709 if (P.enableCheckFallThrough) {
710 const CheckFallThroughDiagnostics &CD =
711 (isa<BlockDecl>(D) ? CheckFallThroughDiagnostics::MakeForBlock()
712 : CheckFallThroughDiagnostics::MakeForFunction(D));
713 CheckFallThroughForBody(S, D, Body, blkExpr, CD, AC);
716 // Warning: check for unreachable code
717 if (P.enableCheckUnreachable)
718 CheckUnreachable(S, AC);
720 if (Diags.getDiagnosticLevel(diag::warn_uninit_var, D->getLocStart())
721 != Diagnostic::Ignored ||
722 Diags.getDiagnosticLevel(diag::warn_maybe_uninit_var, D->getLocStart())
723 != Diagnostic::Ignored) {
724 if (CFG *cfg = AC.getCFG()) {
725 UninitValsDiagReporter reporter(S);
726 UninitVariablesAnalysisStats stats;
727 std::memset(&stats, 0, sizeof(UninitVariablesAnalysisStats));
728 runUninitializedVariablesAnalysis(*cast<DeclContext>(D), *cfg, AC,
731 if (S.CollectStats && stats.NumVariablesAnalyzed > 0) {
732 ++NumUninitAnalysisFunctions;
733 NumUninitAnalysisVariables += stats.NumVariablesAnalyzed;
734 NumUninitAnalysisBlockVisits += stats.NumBlockVisits;
735 MaxUninitAnalysisVariablesPerFunction =
736 std::max(MaxUninitAnalysisVariablesPerFunction,
737 stats.NumVariablesAnalyzed);
738 MaxUninitAnalysisBlockVisitsPerFunction =
739 std::max(MaxUninitAnalysisBlockVisitsPerFunction,
740 stats.NumBlockVisits);
745 // Collect statistics about the CFG if it was built.
746 if (S.CollectStats && AC.isCFGBuilt()) {
747 ++NumFunctionsAnalyzed;
748 if (CFG *cfg = AC.getCFG()) {
749 // If we successfully built a CFG for this context, record some more
750 // detail information about it.
751 NumCFGBlocks += cfg->getNumBlockIDs();
752 MaxCFGBlocksPerFunction = std::max(MaxCFGBlocksPerFunction,
753 cfg->getNumBlockIDs());
755 ++NumFunctionsWithBadCFGs;
760 void clang::sema::AnalysisBasedWarnings::PrintStats() const {
761 llvm::errs() << "\n*** Analysis Based Warnings Stats:\n";
763 unsigned NumCFGsBuilt = NumFunctionsAnalyzed - NumFunctionsWithBadCFGs;
764 unsigned AvgCFGBlocksPerFunction =
765 !NumCFGsBuilt ? 0 : NumCFGBlocks/NumCFGsBuilt;
766 llvm::errs() << NumFunctionsAnalyzed << " functions analyzed ("
767 << NumFunctionsWithBadCFGs << " w/o CFGs).\n"
768 << " " << NumCFGBlocks << " CFG blocks built.\n"
769 << " " << AvgCFGBlocksPerFunction
770 << " average CFG blocks per function.\n"
771 << " " << MaxCFGBlocksPerFunction
772 << " max CFG blocks per function.\n";
774 unsigned AvgUninitVariablesPerFunction = !NumUninitAnalysisFunctions ? 0
775 : NumUninitAnalysisVariables/NumUninitAnalysisFunctions;
776 unsigned AvgUninitBlockVisitsPerFunction = !NumUninitAnalysisFunctions ? 0
777 : NumUninitAnalysisBlockVisits/NumUninitAnalysisFunctions;
778 llvm::errs() << NumUninitAnalysisFunctions
779 << " functions analyzed for uninitialiazed variables\n"
780 << " " << NumUninitAnalysisVariables << " variables analyzed.\n"
781 << " " << AvgUninitVariablesPerFunction
782 << " average variables per function.\n"
783 << " " << MaxUninitAnalysisVariablesPerFunction
784 << " max variables per function.\n"
785 << " " << NumUninitAnalysisBlockVisits << " block visits.\n"
786 << " " << AvgUninitBlockVisitsPerFunction
787 << " average block visits per function.\n"
788 << " " << MaxUninitAnalysisBlockVisitsPerFunction
789 << " max block visits per function.\n";