Thread safety analysis:
* When we detect that a CFG block has inconsistent lock sets, point the
diagnostic at the location where we found the inconsistency, and point a note
at somewhere the inconsistently-locked mutex was locked.
* Fix the wording of the normal (non-loop, non-end-of-function) case of this
diagnostic to not suggest that the mutex is going out of scope.
* Fix the diagnostic emission code to keep a warning and its note together when
sorting the diagnostics into source location order.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@149669 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Analysis/ThreadSafety.cpp b/lib/Analysis/ThreadSafety.cpp
index 69ea830..f438653 100644
--- a/lib/Analysis/ThreadSafety.cpp
+++ b/lib/Analysis/ThreadSafety.cpp
@@ -290,6 +290,8 @@
class LocalVariableMap;
+/// A side (entry or exit) of a CFG node.
+enum CFGBlockSide { CBS_Entry, CBS_Exit };
/// CFGBlockInfo is a struct which contains all the information that is
/// maintained for each block in the CFG. See LocalVariableMap for more
@@ -299,8 +301,17 @@
Lockset ExitSet; // Lockset held at exit from block
LocalVarContext EntryContext; // Context held at entry to block
LocalVarContext ExitContext; // Context held at exit from block
+ SourceLocation EntryLoc; // Location of first statement in block
+ SourceLocation ExitLoc; // Location of last statement in block.
unsigned EntryIndex; // Used to replay contexts later
+ const Lockset &getSet(CFGBlockSide Side) const {
+ return Side == CBS_Entry ? EntrySet : ExitSet;
+ }
+ SourceLocation getLocation(CFGBlockSide Side) const {
+ return Side == CBS_Entry ? EntryLoc : ExitLoc;
+ }
+
private:
CFGBlockInfo(Lockset EmptySet, LocalVarContext EmptyCtx)
: EntrySet(EmptySet), ExitSet(EmptySet),
@@ -760,6 +771,51 @@
saveContext(0, BlockInfo[exitID].ExitContext);
}
+/// Find the appropriate source locations to use when producing diagnostics for
+/// each block in the CFG.
+static void findBlockLocations(CFG *CFGraph,
+ PostOrderCFGView *SortedGraph,
+ std::vector<CFGBlockInfo> &BlockInfo) {
+ for (PostOrderCFGView::iterator I = SortedGraph->begin(),
+ E = SortedGraph->end(); I!= E; ++I) {
+ const CFGBlock *CurrBlock = *I;
+ CFGBlockInfo *CurrBlockInfo = &BlockInfo[CurrBlock->getBlockID()];
+
+ // Find the source location of the last statement in the block, if the
+ // block is not empty.
+ if (const Stmt *S = CurrBlock->getTerminator()) {
+ CurrBlockInfo->EntryLoc = CurrBlockInfo->ExitLoc = S->getLocStart();
+ } else {
+ for (CFGBlock::const_reverse_iterator BI = CurrBlock->rbegin(),
+ BE = CurrBlock->rend(); BI != BE; ++BI) {
+ // FIXME: Handle other CFGElement kinds.
+ if (const CFGStmt *CS = dyn_cast<CFGStmt>(&*BI)) {
+ CurrBlockInfo->ExitLoc = CS->getStmt()->getLocStart();
+ break;
+ }
+ }
+ }
+
+ if (!CurrBlockInfo->ExitLoc.isInvalid()) {
+ // This block contains at least one statement. Find the source location
+ // of the first statement in the block.
+ for (CFGBlock::const_iterator BI = CurrBlock->begin(),
+ BE = CurrBlock->end(); BI != BE; ++BI) {
+ // FIXME: Handle other CFGElement kinds.
+ if (const CFGStmt *CS = dyn_cast<CFGStmt>(&*BI)) {
+ CurrBlockInfo->EntryLoc = CS->getStmt()->getLocStart();
+ break;
+ }
+ }
+ } else if (CurrBlock->pred_size() == 1 && *CurrBlock->pred_begin() &&
+ CurrBlock != &CFGraph->getExit()) {
+ // The block is empty, and has a single predecessor. Use its exit
+ // location.
+ CurrBlockInfo->EntryLoc = CurrBlockInfo->ExitLoc =
+ BlockInfo[(*CurrBlock->pred_begin())->getBlockID()].ExitLoc;
+ }
+ }
+}
/// \brief Class which implements the core thread safety analysis routines.
class ThreadSafetyAnalyzer {
@@ -772,7 +828,8 @@
public:
ThreadSafetyAnalyzer(ThreadSafetyHandler &H) : Handler(H) {}
- Lockset intersectAndWarn(const Lockset LSet1, const Lockset LSet2,
+ Lockset intersectAndWarn(const CFGBlockInfo &Block1, CFGBlockSide Side1,
+ const CFGBlockInfo &Block2, CFGBlockSide Side2,
LockErrorKind LEK);
Lockset addLock(Lockset &LSet, Expr *MutexExp, const NamedDecl *D,
@@ -1304,9 +1361,14 @@
/// A; if () then B; else C; D; we need to check that the lockset after B and C
/// are the same. In the event of a difference, we use the intersection of these
/// two locksets at the start of D.
-Lockset ThreadSafetyAnalyzer::intersectAndWarn(const Lockset LSet1,
- const Lockset LSet2,
+Lockset ThreadSafetyAnalyzer::intersectAndWarn(const CFGBlockInfo &Block1,
+ CFGBlockSide Side1,
+ const CFGBlockInfo &Block2,
+ CFGBlockSide Side2,
LockErrorKind LEK) {
+ Lockset LSet1 = Block1.getSet(Side1);
+ Lockset LSet2 = Block2.getSet(Side2);
+
Lockset Intersection = LSet1;
for (Lockset::iterator I = LSet2.begin(), E = LSet2.end(); I != E; ++I) {
const MutexID &LSet2Mutex = I.getKey();
@@ -1322,7 +1384,8 @@
}
} else {
Handler.handleMutexHeldEndOfScope(LSet2Mutex.getName(),
- LSet2LockData.AcquireLoc, LEK);
+ LSet2LockData.AcquireLoc,
+ Block1.getLocation(Side1), LEK);
}
}
@@ -1331,7 +1394,8 @@
const MutexID &Mutex = I.getKey();
const LockData &MissingLock = I.getData();
Handler.handleMutexHeldEndOfScope(Mutex.getName(),
- MissingLock.AcquireLoc, LEK);
+ MissingLock.AcquireLoc,
+ Block2.getLocation(Side2), LEK);
Intersection = LocksetFactory.remove(Intersection, Mutex);
}
}
@@ -1377,6 +1441,9 @@
// Compute SSA names for local variables
LocalVarMap.traverseCFG(CFGraph, SortedGraph, BlockInfo);
+ // Fill in source locations for all CFGBlocks.
+ findBlockLocations(CFGraph, SortedGraph, BlockInfo);
+
// Add locks from exclusive_locks_required and shared_locks_required
// to initial lockset.
if (!SortedGraph->empty() && D->hasAttrs()) {
@@ -1456,7 +1523,8 @@
LocksetInitialized = true;
} else {
CurrBlockInfo->EntrySet =
- intersectAndWarn(CurrBlockInfo->EntrySet, PrevBlockInfo->ExitSet,
+ intersectAndWarn(*CurrBlockInfo, CBS_Entry,
+ *PrevBlockInfo, CBS_Exit,
LEK_LockedSomePredecessors);
}
}
@@ -1482,7 +1550,7 @@
bool IsLoop = Terminator && isa<ContinueStmt>(Terminator);
// Do not update EntrySet.
- intersectAndWarn(CurrBlockInfo->EntrySet, PrevBlockInfo->ExitSet,
+ intersectAndWarn(*CurrBlockInfo, CBS_Entry, *PrevBlockInfo, CBS_Exit,
IsLoop ? LEK_LockedSomeLoopIterations
: LEK_LockedSomePredecessors);
}
@@ -1541,17 +1609,19 @@
continue;
CFGBlock *FirstLoopBlock = *SI;
- Lockset PreLoop = BlockInfo[FirstLoopBlock->getBlockID()].EntrySet;
- Lockset LoopEnd = BlockInfo[CurrBlockID].ExitSet;
- intersectAndWarn(LoopEnd, PreLoop, LEK_LockedSomeLoopIterations);
+ CFGBlockInfo &PreLoop = BlockInfo[FirstLoopBlock->getBlockID()];
+ CFGBlockInfo &LoopEnd = BlockInfo[CurrBlockID];
+ intersectAndWarn(LoopEnd, CBS_Exit, PreLoop, CBS_Entry,
+ LEK_LockedSomeLoopIterations);
}
}
- Lockset InitialLockset = BlockInfo[CFGraph->getEntry().getBlockID()].EntrySet;
- Lockset FinalLockset = BlockInfo[CFGraph->getExit().getBlockID()].ExitSet;
+ CFGBlockInfo &Initial = BlockInfo[CFGraph->getEntry().getBlockID()];
+ CFGBlockInfo &Final = BlockInfo[CFGraph->getExit().getBlockID()];
// FIXME: Should we call this function for all blocks which exit the function?
- intersectAndWarn(InitialLockset, FinalLockset, LEK_LockedAtEndOfFunction);
+ intersectAndWarn(Initial, CBS_Entry, Final, CBS_Exit,
+ LEK_LockedAtEndOfFunction);
}
} // end anonymous namespace
diff --git a/lib/Sema/AnalysisBasedWarnings.cpp b/lib/Sema/AnalysisBasedWarnings.cpp
index e2d1e8c..71bf335 100644
--- a/lib/Sema/AnalysisBasedWarnings.cpp
+++ b/lib/Sema/AnalysisBasedWarnings.cpp
@@ -592,7 +592,8 @@
//===----------------------------------------------------------------------===//
namespace clang {
namespace thread_safety {
-typedef std::pair<SourceLocation, PartialDiagnostic> DelayedDiag;
+typedef llvm::SmallVector<PartialDiagnosticAt, 1> OptionalNotes;
+typedef std::pair<PartialDiagnosticAt, OptionalNotes> DelayedDiag;
typedef llvm::SmallVector<DelayedDiag, 4> DiagList;
struct SortDiagBySourceLocation {
@@ -602,8 +603,8 @@
bool operator()(const DelayedDiag &left, const DelayedDiag &right) {
// Although this call will be slow, this is only called when outputting
// multiple warnings.
- return S.getSourceManager().isBeforeInTranslationUnit(left.first,
- right.first);
+ return S.getSourceManager().isBeforeInTranslationUnit(left.first.first,
+ right.first.first);
}
};
@@ -611,7 +612,7 @@
class ThreadSafetyReporter : public clang::thread_safety::ThreadSafetyHandler {
Sema &S;
DiagList Warnings;
- SourceLocation FunLocation;
+ SourceLocation FunLocation, FunEndLocation;
// Helper functions
void warnLockMismatch(unsigned DiagID, Name LockName, SourceLocation Loc) {
@@ -619,13 +620,13 @@
// precise source location.
if (!Loc.isValid())
Loc = FunLocation;
- PartialDiagnostic Warning = S.PDiag(DiagID) << LockName;
- Warnings.push_back(DelayedDiag(Loc, Warning));
+ PartialDiagnosticAt Warning(Loc, S.PDiag(DiagID) << LockName);
+ Warnings.push_back(DelayedDiag(Warning, OptionalNotes()));
}
public:
- ThreadSafetyReporter(Sema &S, SourceLocation FL)
- : S(S), FunLocation(FL) {}
+ ThreadSafetyReporter(Sema &S, SourceLocation FL, SourceLocation FEL)
+ : S(S), FunLocation(FL), FunEndLocation(FEL) {}
/// \brief Emit all buffered diagnostics in order of sourcelocation.
/// We need to output diagnostics produced while iterating through
@@ -635,13 +636,18 @@
SortDiagBySourceLocation SortDiagBySL(S);
sort(Warnings.begin(), Warnings.end(), SortDiagBySL);
for (DiagList::iterator I = Warnings.begin(), E = Warnings.end();
- I != E; ++I)
- S.Diag(I->first, I->second);
+ I != E; ++I) {
+ S.Diag(I->first.first, I->first.second);
+ const OptionalNotes &Notes = I->second;
+ for (unsigned NoteI = 0, NoteN = Notes.size(); NoteI != NoteN; ++NoteI)
+ S.Diag(Notes[NoteI].first, Notes[NoteI].second);
+ }
}
void handleInvalidLockExp(SourceLocation Loc) {
- PartialDiagnostic Warning = S.PDiag(diag::warn_cannot_resolve_lock) << Loc;
- Warnings.push_back(DelayedDiag(Loc, Warning));
+ PartialDiagnosticAt Warning(Loc,
+ S.PDiag(diag::warn_cannot_resolve_lock) << Loc);
+ Warnings.push_back(DelayedDiag(Warning, OptionalNotes()));
}
void handleUnmatchedUnlock(Name LockName, SourceLocation Loc) {
warnLockMismatch(diag::warn_unlock_but_no_lock, LockName, Loc);
@@ -651,12 +657,13 @@
warnLockMismatch(diag::warn_double_lock, LockName, Loc);
}
- void handleMutexHeldEndOfScope(Name LockName, SourceLocation Loc,
+ void handleMutexHeldEndOfScope(Name LockName, SourceLocation LocLocked,
+ SourceLocation LocEndOfScope,
LockErrorKind LEK){
unsigned DiagID = 0;
switch (LEK) {
case LEK_LockedSomePredecessors:
- DiagID = diag::warn_lock_at_end_of_scope;
+ DiagID = diag::warn_lock_some_predecessors;
break;
case LEK_LockedSomeLoopIterations:
DiagID = diag::warn_expecting_lock_held_on_loop;
@@ -665,18 +672,22 @@
DiagID = diag::warn_no_unlock;
break;
}
- warnLockMismatch(DiagID, LockName, Loc);
+ if (LocEndOfScope.isInvalid())
+ LocEndOfScope = FunEndLocation;
+
+ PartialDiagnosticAt Warning(LocEndOfScope, S.PDiag(DiagID) << LockName);
+ PartialDiagnosticAt Note(LocLocked, S.PDiag(diag::note_locked_here));
+ Warnings.push_back(DelayedDiag(Warning, OptionalNotes(1, Note)));
}
void handleExclusiveAndShared(Name LockName, SourceLocation Loc1,
SourceLocation Loc2) {
- PartialDiagnostic Warning =
- S.PDiag(diag::warn_lock_exclusive_and_shared) << LockName;
- PartialDiagnostic Note =
- S.PDiag(diag::note_lock_exclusive_and_shared) << LockName;
- Warnings.push_back(DelayedDiag(Loc1, Warning));
- Warnings.push_back(DelayedDiag(Loc2, Note));
+ PartialDiagnosticAt Warning(
+ Loc1, S.PDiag(diag::warn_lock_exclusive_and_shared) << LockName);
+ PartialDiagnosticAt Note(
+ Loc2, S.PDiag(diag::note_lock_exclusive_and_shared) << LockName);
+ Warnings.push_back(DelayedDiag(Warning, OptionalNotes(1, Note)));
}
void handleNoMutexHeld(const NamedDecl *D, ProtectedOperationKind POK,
@@ -686,9 +697,9 @@
unsigned DiagID = POK == POK_VarAccess?
diag::warn_variable_requires_any_lock:
diag::warn_var_deref_requires_any_lock;
- PartialDiagnostic Warning = S.PDiag(DiagID)
- << D->getName() << getLockKindFromAccessKind(AK);
- Warnings.push_back(DelayedDiag(Loc, Warning));
+ PartialDiagnosticAt Warning(Loc, S.PDiag(DiagID)
+ << D->getName() << getLockKindFromAccessKind(AK));
+ Warnings.push_back(DelayedDiag(Warning, OptionalNotes()));
}
void handleMutexNotHeld(const NamedDecl *D, ProtectedOperationKind POK,
@@ -705,15 +716,15 @@
DiagID = diag::warn_fun_requires_lock;
break;
}
- PartialDiagnostic Warning = S.PDiag(DiagID)
- << D->getName() << LockName << LK;
- Warnings.push_back(DelayedDiag(Loc, Warning));
+ PartialDiagnosticAt Warning(Loc, S.PDiag(DiagID)
+ << D->getName() << LockName << LK);
+ Warnings.push_back(DelayedDiag(Warning, OptionalNotes()));
}
void handleFunExcludesLock(Name FunName, Name LockName, SourceLocation Loc) {
- PartialDiagnostic Warning =
- S.PDiag(diag::warn_fun_excludes_mutex) << FunName << LockName;
- Warnings.push_back(DelayedDiag(Loc, Warning));
+ PartialDiagnosticAt Warning(Loc,
+ S.PDiag(diag::warn_fun_excludes_mutex) << FunName << LockName);
+ Warnings.push_back(DelayedDiag(Warning, OptionalNotes()));
}
};
}
@@ -897,7 +908,8 @@
// Check for thread safety violations
if (P.enableThreadSafetyAnalysis) {
SourceLocation FL = AC.getDecl()->getLocation();
- thread_safety::ThreadSafetyReporter Reporter(S, FL);
+ SourceLocation FEL = AC.getDecl()->getLocEnd();
+ thread_safety::ThreadSafetyReporter Reporter(S, FL, FEL);
thread_safety::runThreadSafetyAnalysis(AC, Reporter);
Reporter.emitDiagnostics();
}