Fix false negative reported in PR 10358 by using 'Unknown' in -Wuninitialized to avoid cascading warnings. Patch by Kaelyn Uhrain.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@135217 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 10 insertions, 8 deletions

diff --git a/lib/Analysis/UninitializedValues.cpp b/lib/Analysis/UninitializedValues.cpp
index 1d6959d81b..5e00eebec8 100644
--- a/lib/Analysis/UninitializedValues.cpp
+++ b/lib/Analysis/UninitializedValues.cpp
@@ -495,9 +495,11 @@ void TransferFunctions::VisitBinaryOperator(clang::BinaryOperator *bo) {
 
       ValueVector::reference val = vals[vd];
       if (isUninitialized(val)) {
-        if (bo->getOpcode() != BO_Assign)
+        if (bo->getOpcode() != BO_Assign) {
           reportUninit(res.getDeclRefExpr(), vd, isAlwaysUninit(val));
-        val = Initialized;
+          val = Unknown;
+        } else
+          val = Initialized;
       }
       return;
     }
@@ -526,7 +528,7 @@ void TransferFunctions::VisitUnaryOperator(clang::UnaryOperator *uo) {
         if (isUninitialized(val)) {
           reportUninit(res.getDeclRefExpr(), vd, isAlwaysUninit(val));
           // Don't cascade warnings.
-          val = Initialized;
+          val = Unknown;
         }
         return;
       }
@@ -558,7 +560,7 @@ void TransferFunctions::VisitCastExpr(clang::CastExpr *ce) {
         if (isUninitialized(val)) {
           reportUninit(res.getDeclRefExpr(), vd, isAlwaysUninit(val));
           // Don't cascade warnings.
-          vals[vd] = Initialized;
+          vals[vd] = Unknown;
         }
       }
       return;
diff --git a/test/Sema/uninit-variables.c b/test/Sema/uninit-variables.c
index b70a29519c..06abc76019 100644
--- a/test/Sema/uninit-variables.c
+++ b/test/Sema/uninit-variables.c
@@ -77,7 +77,7 @@ int test11(unsigned n) {
 }
 
 void test12(unsigned n) {
-  for (unsigned i ; n ; ++i) ; // expected-warning{{variable 'i' may be uninitialized when used here}} expected-note{{variable 'i' is declared here}} expected-note{{add initialization to silence this warning}}
+  for (unsigned i ; n ; ++i) ; // expected-warning{{variable 'i' is uninitialized when used here}} expected-note{{variable 'i' is declared here}} expected-note{{add initialization to silence this warning}}
 }
 
 int test13() {
@@ -237,7 +237,7 @@ void test36()
   void **pc; // expected-note{{variable 'pc' is declared here}} expected-note{{add initialization to silence this warning}}
   void *dummy[] = { &&L1, &&L2 };
  L1:
-    goto *pc; // expected-warning{{variable 'pc' may be uninitialized when used here}}
+    goto *pc; // expected-warning{{variable 'pc' is uninitialized when used here}}
  L2:
     goto *pc;
 }
@@ -289,7 +289,7 @@ void test43_aux(int x);
 void test43(int i) {
   int x; // expected-note {{variable 'x' is declared here}} expected-note{{add initialization to silence this warning}}
   for (i = 0 ; i < 10; i++)
-    test43_aux(x++); // expected-warning {{variable 'x' may be uninitialized when used here}}
+    test43_aux(x++); // expected-warning {{variable 'x' is uninitialized when used here}}
 }
 
 void test44(int i) {
@@ -297,7 +297,7 @@ void test44(int i) {
   int y; // expected-note {{variable 'y' is declared here}} expected-note{{add initialization to silence this warning}}
   for (i = 0; i < 10; i++ ) {
     test43_aux(x++); // no-warning
-    x += y; // expected-warning {{variable 'y' may be uninitialized when used here}}
+    x += y; // expected-warning {{variable 'y' is uninitialized when used here}}
   }
 }