PR13360: When deciding the earliest point which inevitably leads to an
uninitialized variable use, walk back over branches where we've reached all the
non-null successors, not just cases where we've reached all successors.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@160206 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Analysis/UninitializedValues.cpp b/lib/Analysis/UninitializedValues.cpp
index 1f97c58..c561b60 100644
--- a/lib/Analysis/UninitializedValues.cpp
+++ b/lib/Analysis/UninitializedValues.cpp
@@ -16,6 +16,7 @@
#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/PackedVector.h"
#include "llvm/ADT/DenseMap.h"
+#include "clang/AST/ASTContext.h"
#include "clang/AST/Decl.h"
#include "clang/Analysis/CFG.h"
#include "clang/Analysis/AnalysisContext.h"
@@ -25,6 +26,8 @@
using namespace clang;
+#define DEBUG_LOGGING 0
+
static bool isTrackedVar(const VarDecl *vd, const DeclContext *dc) {
if (vd->isLocalVarDecl() && !vd->hasGlobalStorage() &&
!vd->isExceptionVariable() &&
@@ -221,24 +224,15 @@
return vals[idx];
}
-#if 0
+#if DEBUG_LOGGING
static void printVector(const CFGBlock *block, ValueVector &bv,
unsigned num) {
-
llvm::errs() << block->getBlockID() << " :";
for (unsigned i = 0; i < bv.size(); ++i) {
llvm::errs() << ' ' << bv[i];
}
llvm::errs() << " : " << num << '\n';
}
-
-static void printVector(const char *name, ValueVector const &bv) {
- llvm::errs() << name << " : ";
- for (unsigned i = 0; i < bv.size(); ++i) {
- llvm::errs() << ' ' << bv[i];
- }
- llvm::errs() << "\n";
-}
#endif
void CFGBlockValues::setAllScratchValues(Value V) {
@@ -259,7 +253,7 @@
bool changed = (dst != scratch);
if (changed)
dst = scratch;
-#if 0
+#if DEBUG_LOGGING
printVector(block, scratch, 0);
#endif
return changed;
@@ -272,7 +266,7 @@
*newVals.second != *vals.second;
*vals.first = *newVals.first;
*vals.second = *newVals.second;
-#if 0
+#if DEBUG_LOGGING
printVector(block, *vals.first, 1);
printVector(block, *vals.second, 2);
#endif
@@ -463,7 +457,18 @@
// This block initializes the variable.
continue;
- if (++SuccsVisited[Pred->getBlockID()] == Pred->succ_size())
+ unsigned &SV = SuccsVisited[Pred->getBlockID()];
+ if (!SV) {
+ // When visiting the first successor of a block, mark all NULL
+ // successors as having been visited.
+ for (CFGBlock::const_succ_iterator SI = Pred->succ_begin(),
+ SE = Pred->succ_end();
+ SI != SE; ++SI)
+ if (!*SI)
+ ++SV;
+ }
+
+ if (++SV == Pred->succ_size())
// All paths from this block lead to the use and don't initialize the
// variable.
Queue.push_back(Pred);
@@ -831,7 +836,7 @@
vals.computeSetOfDeclarations(dc);
if (vals.hasNoDeclarations())
return;
-#if 0
+#if DEBUG_LOGGING
cfg.dump(dc.getParentASTContext().getLangOpts(), true);
#endif