Based on user feedback, swap -Wuninitialized diagnostics to have the warning refer to the bad use, and the note to the variable declaration.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@124758 91177308-0d34-0410-b5e6-96231b3b80d8

5 files changed, 86 insertions, 80 deletions

diff --git a/include/clang/Basic/DiagnosticSemaKinds.td b/include/clang/Basic/DiagnosticSemaKinds.td
index 1a9d694805..7bf12f26ec 100644
--- a/include/clang/Basic/DiagnosticSemaKinds.td
+++ b/include/clang/Basic/DiagnosticSemaKinds.td
@@ -836,12 +836,13 @@ def note_uninit_reference_member : Note<
   "uninitialized reference member is here">;
 def warn_field_is_uninit : Warning<"field is uninitialized when used here">,
   InGroup<Uninitialized>;
-def warn_uninit_var : Warning<"use of uninitialized variable %0">,
+def warn_uninit_var : Warning<"variable %0 is possibly uninitialized when used here">,
+  InGroup<Uninitialized>, DefaultIgnore;
+def note_uninit_var_def : Note<
+  "variable %0 is declared here">;
+def warn_uninit_var_captured_by_block : Note<
+  "variable %0 is possibly uninitialized when captured by block">,
   InGroup<Uninitialized>, DefaultIgnore;
-def note_uninit_var : Note<
-  "variable %0 is possibly uninitialized when used here">;
-def note_uninit_var_captured_by_block : Note<
-  "variable %0 is possibly uninitialized when captured by block">;
 def note_var_fixit_add_initialization : Note<
   "add initialization to silence this warning">;
 def err_init_incomplete_type : Error<"initialization of incomplete type %0">;
diff --git a/lib/Sema/AnalysisBasedWarnings.cpp b/lib/Sema/AnalysisBasedWarnings.cpp
index 3e6cd81b76..0e7846f021 100644
--- a/lib/Sema/AnalysisBasedWarnings.cpp
+++ b/lib/Sema/AnalysisBasedWarnings.cpp
@@ -393,14 +393,13 @@ public:
   void flushDiagnostics() {
     if (!uses)
       return;
-
+    
     for (UsesMap::iterator i = uses->begin(), e = uses->end(); i != e; ++i) {
       const VarDecl *vd = i->first;
       UsesVec *vec = i->second;
-      
-      S.Diag(vd->getLocStart(), diag::warn_uninit_var)
-        << vd->getDeclName() << vd->getSourceRange();
-      
+
+      bool fixitIssued = false;
+            
       // Sort the uses by their SourceLocations.  While not strictly
       // guaranteed to produce them in line/column order, this will provide
       // a stable ordering.
@@ -409,43 +408,49 @@ public:
       for (UsesVec::iterator vi = vec->begin(), ve = vec->end(); vi != ve; ++vi)
       {
         if (const DeclRefExpr *dr = dyn_cast<DeclRefExpr>(*vi)) {
-          S.Diag(dr->getLocStart(), diag::note_uninit_var)
-            << vd->getDeclName() << dr->getSourceRange();
+          S.Diag(dr->getLocStart(), diag::warn_uninit_var)
+            << vd->getDeclName() << dr->getSourceRange();          
         }
         else {
           const BlockExpr *be = cast<BlockExpr>(*vi);
-          S.Diag(be->getLocStart(), diag::note_uninit_var_captured_by_block)
+          S.Diag(be->getLocStart(), diag::warn_uninit_var_captured_by_block)
             << vd->getDeclName();
         }
-      }
+        
+        // Report where the variable was declared.
+        S.Diag(vd->getLocStart(), diag::note_uninit_var_def)
+          << vd->getDeclName();
+
+        // Only report the fixit once.
+        if (fixitIssued)
+          continue;
+      
+        fixitIssued = true;
 
-      // Suggest possible initialization (if any).
-      const char *initialization = 0;
-      QualType vdTy = vd->getType().getCanonicalType();
+        // Suggest possible initialization (if any).
+        const char *initialization = 0;
+        QualType vdTy = vd->getType().getCanonicalType();
       
-      if (vdTy->getAs<ObjCObjectPointerType>()) {
-        // Check if 'nil' is defined.
-        if (S.PP.getMacroInfo(&S.getASTContext().Idents.get("nil")))
-          initialization = " = nil";
-        else
+        if (vdTy->getAs<ObjCObjectPointerType>()) {
+          // Check if 'nil' is defined.
+          if (S.PP.getMacroInfo(&S.getASTContext().Idents.get("nil")))
+            initialization = " = nil";
+          else
+            initialization = " = 0";
+        }
+        else if (vdTy->isRealFloatingType())
+          initialization = " = 0.0";
+        else if (vdTy->isBooleanType() && S.Context.getLangOptions().CPlusPlus)
+          initialization = " = false";
+        else if (vdTy->isScalarType())
           initialization = " = 0";
-      }
-      else if (vdTy->isRealFloatingType()) {
-        initialization = " = 0.0";
-      }
-      else if (vdTy->isBooleanType() && S.Context.getLangOptions().CPlusPlus) {
-        initialization = " = false";
-      }
-      else if (vdTy->isScalarType()) {
-        initialization = " = 0";
-      }
       
-      if (initialization) {
-        SourceLocation loc = S.PP.getLocForEndOfToken(vd->getLocEnd());
-        S.Diag(loc, diag::note_var_fixit_add_initialization)
-          << FixItHint::CreateInsertion(loc, initialization);
+        if (initialization) {
+          SourceLocation loc = S.PP.getLocForEndOfToken(vd->getLocEnd());
+          S.Diag(loc, diag::note_var_fixit_add_initialization)
+            << FixItHint::CreateInsertion(loc, initialization);
+        }
       }
-
       delete vec;
     }
     delete uses;
diff --git a/test/Sema/uninit-variables.c b/test/Sema/uninit-variables.c
index f869ef2870..ce3f93d590 100644
--- a/test/Sema/uninit-variables.c
+++ b/test/Sema/uninit-variables.c
@@ -1,8 +1,8 @@
 // RUN: %clang_cc1 -fsyntax-only -Wuninitialized -fsyntax-only -fblocks %s -verify
 
 int test1() {
-  int x; // expected-warning{{use of uninitialized variable 'x'}} expected-note{{add initialization to silence this warning}}
-  return x; // expected-note{{variable 'x' is possibly uninitialized when used here}}
+  int x; // expected-note{{variable 'x' is declared here}} expected-note{{add initialization to silence this warning}}
+  return x; // expected-warning{{variable 'x' is possibly uninitialized when used here}}
 }
 
 int test2() {
@@ -17,28 +17,28 @@ int test3() {
 }
 
 int test4() {
-  int x; // expected-warning{{use of uninitialized variable 'x'}} expected-note{{add initialization to silence this warning}}
-  ++x; // expected-note{{variable 'x' is possibly uninitialized when used here}}
+  int x; // expected-note{{variable 'x' is declared here}} expected-note{{add initialization to silence this warning}}
+  ++x; // expected-warning{{variable 'x' is possibly uninitialized when used here}}
   return x; 
 }
 
 int test5() {
-  int x, y; // expected-warning{{use of uninitialized variable 'y'}} expected-note{{add initialization to silence this warning}}
-  x = y; // expected-note{{variable 'y' is possibly uninitialized when used here}}
+  int x, y; // expected-note{{variable 'y' is declared here}} expected-note{{add initialization to silence this warning}}
+  x = y; // expected-warning{{variable 'y' is possibly uninitialized when used here}}
   return x;
 }
 
 int test6() {
-  int x; // expected-warning{{use of uninitialized variable 'x'}} expected-note{{add initialization to silence this warning}}
-  x += 2; // expected-note{{variable 'x' is possibly uninitialized when used here}}
+  int x; // expected-note{{variable 'x' is declared here}} expected-note{{add initialization to silence this warning}}
+  x += 2; // expected-warning{{variable 'x' is possibly uninitialized when used here}}
   return x;
 }
 
 int test7(int y) {
-  int x; // expected-warning{{use of uninitialized variable 'x'}} expected-note{{add initialization to silence this warning}}
+  int x; // expected-note{{variable 'x' is declared here}} expected-note{{add initialization to silence this warning}}
   if (y)
     x = 1;
-  return x;  // expected-note{{variable 'x' is possibly uninitialized when used here}}
+  return x; // expected-warning{{variable 'x' is possibly uninitialized when used here}}
 }
 
 int test8(int y) {
@@ -47,37 +47,37 @@ int test8(int y) {
     x = 1;
   else
     x = 0;
-  return x; // no-warning
+  return x;
 }
 
 int test9(int n) {
-  int x; // expected-warning{{use of uninitialized variable 'x'}} expected-note{{add initialization to silence this warning}}
+  int x; // expected-note{{variable 'x' is declared here}} expected-note{{add initialization to silence this warning}}
   for (unsigned i = 0 ; i < n; ++i) {
     if (i == n - 1)
       break;
     x = 1;
   }
-  return x; // expected-note{{variable 'x' is possibly uninitialized when used here}}
+  return x; // expected-warning{{variable 'x' is possibly uninitialized when used here}}
 }
 
 int test10(unsigned n) {
-  int x; // expected-warning{{use of uninitialized variable 'x'}} expected-note{{add initialization to silence this warning}}
+  int x; // expected-note{{variable 'x' is declared here}} expected-note{{add initialization to silence this warning}}
   for (unsigned i = 0 ; i < n; ++i) {
     x = 1;
   }
-  return x; // expected-note{{variable 'x' is possibly uninitialized when used here}}
+  return x; // expected-warning{{variable 'x' is possibly uninitialized when used here}}
 }
 
 int test11(unsigned n) {
-  int x; // expected-warning{{use of uninitialized variable 'x'}} expected-note{{add initialization to silence this warning}}
+  int x; // expected-note{{variable 'x' is declared here}} expected-note{{add initialization to silence this warning}}
   for (unsigned i = 0 ; i <= n; ++i) {
     x = 1;
   }
-  return x; //expected-note{{variable 'x' is possibly uninitialized when used here}}
+  return x; // expected-warning{{variable 'x' is possibly uninitialized when used here}}
 }
 
 void test12(unsigned n) {
-  for (unsigned i ; n ; ++i) ; // expected-warning{{use of uninitialized variable 'i'}} expected-note{{variable 'i' is possibly uninitialized when used here}}} expected-note{{add initialization to silence this warning}}
+  for (unsigned i ; n ; ++i) ; // expected-warning{{variable 'i' is possibly uninitialized when used here}} expected-note{{variable 'i' is declared here}} expected-note{{add initialization to silence this warning}}
 }
 
 int test13() {
@@ -92,7 +92,7 @@ void test14() {
 }
 
 void test15() {
-  int x = x; // expected-warning{{use of uninitialized variable 'x'}} expected-note{{variable 'x' is possibly uninitialized when used here}} expected-note{{add initialization to silence this warning}}
+  int x = x; // expected-warning{{variable 'x' is possibly uninitialized when used here}} expected-note{{variable 'x' is declared here}} expected-note{{add initialization to silence this warning}}
 }
 
 // Don't warn in the following example; shows dataflow confluence.
@@ -106,8 +106,8 @@ void test16() {
 void test17() {
   // Don't warn multiple times about the same uninitialized variable
   // along the same path.
-  int *x; // expected-warning{{use of uninitialized variable 'x'}} expected-note{{add initialization to silence this warning}}
-  *x = 1; // expected-note{{variable 'x' is possibly uninitialized when used here}}
+  int *x; // expected-note{{variable 'x' is declared here}} expected-note{{add initialization to silence this warning}}
+  *x = 1; // expected-warning{{variable 'x' is possibly uninitialized when used here}}
   *x = 1; // no-warning
 }
 
@@ -130,16 +130,16 @@ int test19() {
 }
 
 int test20() {
-  int z; // expected-warning{{use of uninitialized variable 'z'}} expected-note{{add initialization to silence this warning}}
+  int z; // expected-note{{variable 'z' is declared here}} expected-note{{add initialization to silence this warning}}
   if ((test19_aux1() + test19_aux2() && test19_aux1()) || test19_aux3(&z))
-    return z; //  expected-note{{variable 'z' is possibly uninitialized when used here}}
+    return z; // expected-warning{{variable 'z' is possibly uninitialized when used here}}
   return 0;
 }
 
 int test21(int x, int y) {
-  int z; // expected-warning{{use of uninitialized variable 'z'}} expected-note{{add initialization to silence this warning}}
+  int z; // expected-note{{variable 'z' is declared here}} expected-note{{add initialization to silence this warning}}
   if ((x && y) || test19_aux3(&z) || test19_aux2())
-    return z; // expected-note{{variable 'z' is possibly uninitialized when used here}}
+    return z; // expected-warning{{variable 'z' is possibly uninitialized when used here}}
   return 0;
 }
 
@@ -162,23 +162,23 @@ int test23() {
 // conditionals.  This possibly can be handled by making the CFG itself
 // represent such control-dependencies, but it is a niche case.
 int test24(int flag) {
-  unsigned val; // expected-warning{{use of uninitialized variable 'val'}} expected-note{{add initialization to silence this warning}}
+  unsigned val; // expected-note{{variable 'val' is declared here}} expected-note{{add initialization to silence this warning}}
   if (flag)
     val = 1;
   if (!flag)
     val = 1;
-  return val; //  expected-note{{variable 'val' is possibly uninitialized when used here}}
+  return val; // expected-warning{{variable 'val' is possibly uninitialized when used here}}
 }
 
 float test25() {
-  float x; // expected-warning{{use of uninitialized variable 'x'}} expected-note{{add initialization to silence this warning}}
-  return x; // expected-note{{variable 'x' is possibly uninitialized when used here}}
+  float x; // expected-note{{variable 'x' is declared here}} expected-note{{add initialization to silence this warning}}
+  return x; // expected-warning{{variable 'x' is possibly uninitialized when used here}}
 }
 
 typedef int MyInt;
 MyInt test26() {
-  MyInt x; // expected-warning{{use of uninitialized variable 'x'}} expected-note{{add initialization to silence this warning}}
-  return x; // expected-note{{variable 'x' is possibly uninitialized when used here}}
+  MyInt x; // expected-note{{variable 'x' is declared here}} expected-note{{add initialization to silence this warning}}
+  return x; // expected-warning{{variable 'x' is possibly uninitialized when used here}}
 }
 
 // Test handling of sizeof().
@@ -188,13 +188,13 @@ int test27() {
 }
 
 int test28() {
-  int len; // expected-warning{{use of uninitialized variable 'len'}} expected-note{{add initialization to silence this warning}}
-  return sizeof(int[len]); // expected-note{{variable 'len' is possibly uninitialized when used here}}
+  int len; // expected-note{{variable 'len' is declared here}} expected-note{{add initialization to silence this warning}}
+  return sizeof(int[len]); // expected-warning{{variable 'len' is possibly uninitialized when used here}}
 }
 
 void test29() {
-  int x; // expected-warning{{use of uninitialized variable 'x'}} expected-note{{add initialization to silence this warning}}
-  (void) ^{ (void) x; }; // expected-note{{variable 'x' is possibly uninitialized when captured by block}}
+  int x;
+  (void) ^{ (void) x; };
 }
 
 void test30() {
@@ -218,9 +218,9 @@ void test_33() {
 }
 
 int test_34() {
-  int x; // expected-warning{{use of uninitialized variable 'x'}} expected-note{{add initialization to silence this warning}}
+  int x; // expected-note{{variable 'x' is declared here}} expected-note{{add initialization to silence this warning}}
   (void) x;
-  return x; // expected-note{{variable 'x' is possibly uninitialized when used here}}
+  return x; // expected-warning{{variable 'x' is possibly uninitialized when used here}}
 }
 
 // Test that this case doesn't crash.
@@ -232,10 +232,10 @@ void test35(int x) {
 // Test handling of indirect goto.
 void test36()
 {
-  void **pc; // expected-warning{{use of uninitialized variable 'pc'}} expected-note{{ add initialization to silence this warning}}
+  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-note{{variable 'pc' is possibly uninitialized when used here}}
+    goto *pc; // expected-warning{{variable 'pc' is possibly uninitialized when used here}}
  L2:
     goto *pc;
 }
diff --git a/test/SemaCXX/uninit-variables.cpp b/test/SemaCXX/uninit-variables.cpp
index 572e0aac81..cc5018a5e8 100644
--- a/test/SemaCXX/uninit-variables.cpp
+++ b/test/SemaCXX/uninit-variables.cpp
@@ -33,11 +33,11 @@ unsigned test3_b() {
   return x; // no-warning
 }
 unsigned test3_c() {
-  unsigned x ; // expected-warning{{use of uninitialized variable 'x'}} expected-note{{add initialization to silence this warning}}
+  unsigned x; // expected-note{{declared here}} expected-note{{add initialization}}
   const bool flag = false;
   if (flag && (x = test3_aux()) == 0) {
     x = 1;
   }
-  return x; // expected-note{{variable 'x' is possibly uninitialized when used here}}
+  return x; // expected-warning{{variable 'x' is possibly uninitialized when used here}}
 }
 
diff --git a/test/SemaObjC/uninit-variables.m b/test/SemaObjC/uninit-variables.m
index f3917f3922..22d44384b4 100644
--- a/test/SemaObjC/uninit-variables.m
+++ b/test/SemaObjC/uninit-variables.m
@@ -3,8 +3,8 @@
 // Duplicated from uninit-variables.c.
 // Test just to ensure the analysis is working.
 int test1() {
-  int x; // expected-warning{{use of uninitialized variable 'x'}} expected-note{{add initialization to silence this warning}}
-  return x; // expected-note{{variable 'x' is possibly uninitialized when used here}}
+  int x; // expected-note{{variable 'x' is declared here}} expected-note{{add initialization}}
+  return x; // expected-warning{{variable 'x' is possibly uninitialized when used here}}
 }
 
 // Test ObjC fast enumeration.