[analyzer] Change warnings to use the term uninitialized instead.

The prior change was using the message 'not meaningful and
undefined'.  This changes updates it to use the term
uninitialized based on PR review feedback and discussion.

Author: dtarditi

clang/lib/StaticAnalyzer/Checkers/UndefinedAssignmentChecker.cpp

@@ -23,7 +23,7 @@ using namespace ento;
 namespace {
 class UndefinedAssignmentChecker
   : public Checker<check::Bind> {
-  const BugType BT{this, "Assigned value is undefined and not meaningful"};
+  const BugType BT{this, "Assigned value is uninitialized"};
 
 public:
   void checkBind(SVal location, SVal val, const Stmt *S,
@@ -57,8 +57,7 @@ void UndefinedAssignmentChecker::checkBind(SVal location, SVal val,
 
   while (StoreE) {
     if (const UnaryOperator *U = dyn_cast<UnaryOperator>(StoreE)) {
-      OS << "The expression is an uninitialized value, so the computed value "
-         << "is not meaningful";
+      OS << "The expression uses uninitialized memory";
 
       ex = U->getSubExpr();
       break;
@@ -67,8 +66,8 @@ void UndefinedAssignmentChecker::checkBind(SVal location, SVal val,
     if (const BinaryOperator *B = dyn_cast<BinaryOperator>(StoreE)) {
       if (B->isCompoundAssignmentOp()) {
         if (C.getSVal(B->getLHS()).isUndef()) {
-          OS << "The left expression of the compound assignment is an "
-             << "uninitialized value, so the computed value is not meaningful";
+          OS << "The left expression of the compound assignment uses "
+             << "uninitialized memory";
           ex = B->getLHS();
           break;
         }
@@ -89,7 +88,7 @@ void UndefinedAssignmentChecker::checkBind(SVal location, SVal val,
         for (auto *I : CD->inits()) {
           if (I->getInit()->IgnoreImpCasts() == StoreE) {
             OS << "Value assigned to field '" << I->getMember()->getName()
-               << "' in implicit constructor is undefined and not meaningful.";
+               << "' in implicit constructor is uninitialized";
             break;
           }
         }

clang/test/Analysis/Inputs/expected-plists/edges-new.mm.plist

@@ -2578,17 +2578,17 @@
      </array>
      <key>depth</key><integer>0</integer>
      <key>extended_message</key>
-     <string>The left expression of the compound assignment is an uninitialized value, so the computed value is not meaningful</string>
+     <string>The left expression of the compound assignment uses uninitialized memory</string>
      <key>message</key>
-     <string>The left expression of the compound assignment is an uninitialized value, so the computed value is not meaningful</string>
+     <string>The left expression of the compound assignment uses uninitialized memory</string>
     </dict>
    </array>
-   <key>description</key><string>The left expression of the compound assignment is an uninitialized value, so the computed value is not meaningful</string>
+   <key>description</key><string>The left expression of the compound assignment uses uninitialized memory</string>
    <key>category</key><string>Logic error</string>
-   <key>type</key><string>Assigned value is undefined and not meaningful</string>
+   <key>type</key><string>Assigned value is uninitialized</string>
    <key>check_name</key><string>core.uninitialized.Assign</string>
    <!-- This hash is experimental and going to change! -->
-   <key>issue_hash_content_of_line_in_context</key><string>936a5fabf36091d0c1e1e1553232d6f5</string>
+   <key>issue_hash_content_of_line_in_context</key><string>324827600c298776167cd9562f71bda6</string>
   <key>issue_context_kind</key><string>function</string>
   <key>issue_context</key><string>test_objc_fast_enumeration_2</string>
   <key>issue_hash_function_offset</key><string>5</string>

clang/test/Analysis/Inputs/expected-plists/plist-output.m.plist

@@ -5864,17 +5864,17 @@
      </array>
      <key>depth</key><integer>0</integer>
      <key>extended_message</key>
-     <string>The left expression of the compound assignment is an uninitialized value, so the computed value is not meaningful</string>
+     <string>The left expression of the compound assignment uses uninitialized memory</string>
      <key>message</key>
-     <string>The left expression of the compound assignment is an uninitialized value, so the computed value is not meaningful</string>
+     <string>The left expression of the compound assignment uses uninitialized memory</string>
     </dict>
    </array>
-   <key>description</key><string>The left expression of the compound assignment is an uninitialized value, so the computed value is not meaningful</string>
+   <key>description</key><string>The left expression of the compound assignment uses uninitialized memory</string>
    <key>category</key><string>Logic error</string>
-   <key>type</key><string>Assigned value is undefined and not meaningful</string>
+   <key>type</key><string>Assigned value is uninitialized</string>
    <key>check_name</key><string>core.uninitialized.Assign</string>
    <!-- This hash is experimental and going to change! -->
-   <key>issue_hash_content_of_line_in_context</key><string>c1d7b1284317d7e45bda4bfa6b3a281e</string>
+   <key>issue_hash_content_of_line_in_context</key><string>faa8858031ed123ff98cc23cf14d462f</string>
   <key>issue_context_kind</key><string>function</string>
   <key>issue_context</key><string>test_loop_fast_enumeration</string>
   <key>issue_hash_function_offset</key><string>5</string>

clang/test/Analysis/a_flaky_crash.cpp

@@ -14,7 +14,7 @@ bool bar(S);
 void foo() {
   int x;
   if (true && bar(S()))
-    ++x; // expected-warning{{The expression is an uninitialized value, so the computed value is not meaningful}}
+    ++x; // expected-warning{{The expression uses uninitialized memory}}
 }
 
 // 256 copies of the same run-line to make it crash more often when it breaks.

clang/test/Analysis/analysis-after-multiple-dtors.cpp

@@ -23,6 +23,6 @@ int main() {
 
   int x;
   int y = x;
-  // expected-warning@-1{{Assigned value is undefined and not meaningful}}
+  // expected-warning@-1{{Assigned value is uninitialized}}
   (void)y;
 }

clang/test/Analysis/array-init-loop.cpp

@@ -19,7 +19,7 @@ void array_uninit() {
 
   auto [a, b, c, d, e] = arr;
 
-  int x = e; // expected-warning{{Assigned value is undefined and not meaningful}}
+  int x = e; // expected-warning{{Assigned value is uninitialized}}
 }
 
 void lambda_init() {
@@ -168,7 +168,7 @@ struct S3_duplicate {
 void array_uninit_non_pod() {
   S3 arr[1];
 
-  auto [a] = arr; // expected-warning@159{{ in implicit constructor is undefined and not meaningful}}
+  auto [a] = arr; // expected-warning@159{{ in implicit constructor is uninitialized}}
 }
 
 void lambda_init_non_pod() {
@@ -191,7 +191,7 @@ void lambda_init_non_pod() {
 void lambda_uninit_non_pod() {
   S3_duplicate arr[4];
 
-  int l = [arr] { return arr[3].i; }(); // expected-warning@164{{ in implicit constructor is undefined and not meaningful }}
+  int l = [arr] { return arr[3].i; }(); // expected-warning@164{{ in implicit constructor is uninitialized }}
 }
 
 // If this struct is being copy/move constructed by the implicit ctors, ArrayInitLoopExpr

clang/test/Analysis/array-punned-region.c

@@ -20,7 +20,7 @@ void array_struct_bitfield_1() {
 int array_struct_bitfield_2() {
   BITFIELD_CAST ff = {0};
   BITFIELD_CAST *pff = &ff;
-  int a = *((int *)pff + 2); // expected-warning{{Assigned value is undefined and not meaningful [core.uninitialized.Assign]}}
+  int a = *((int *)pff + 2); // expected-warning{{Assigned value is uninitialized [core.uninitialized.Assign]}}
   return a;
 }
 

clang/test/Analysis/builtin_overflow_notes.c

@@ -23,8 +23,8 @@ void test_overflow_note(int a, int b)
 
    if (__builtin_add_overflow(a, b, &res)) { // expected-note {{Assuming overflow}}
                                              // expected-note@-1 {{Taking true branch}}
-     int var = res; // expected-warning{{Assigned value is undefined and not meaningful}}
-                    // expected-note@-1 {{Assigned value is undefined and not meaningful}}
+     int var = res; // expected-warning{{Assigned value is uninitialized}}
+                    // expected-note@-1 {{Assigned value is uninitialized}}
      return;
    }
 }

clang/test/Analysis/call-invalidation.cpp

@@ -197,7 +197,7 @@ int testStdCtorDoesNotInvalidateParentObject() {
 int testStdCtorDoesNotInvalidateParentObjectSwapped() {
   StdWrappingOpaqueSwapped obj;
   int x = obj.o.nested_member; // no-garbage: std::Opaque::ctor might initialized this
-  int y = obj.uninit; // expected-warning {{Assigned value is undefined and not meaningful}}
+  int y = obj.uninit; // expected-warning {{Assigned value is uninitialized}}
   return x + y;
 }
 
@@ -277,6 +277,6 @@ struct StdWrappingFancyOpaque {
 int testNestedStdNamespacesAndRecords() {
   StdWrappingFancyOpaque obj;
   int x = obj.o.nested_member; // no-garbage: ctor
-  int y = obj.uninit; // expected-warning {{Assigned value is undefined and not meaningful}}
+  int y = obj.uninit; // expected-warning {{Assigned value is uninitialized}}
   return x + y;
 }

clang/test/Analysis/ctor-array.cpp

@@ -12,19 +12,19 @@ struct s {
 void a1(void) {
   s arr[3];
   int x = arr[0].x;
-  // expected-warning@-1{{Assigned value is undefined and not meaningful}}
+  // expected-warning@-1{{Assigned value is uninitialized}}
 }
 
 void a2(void) {
   s arr[3];
   int x = arr[1].x;
-  // expected-warning@-1{{Assigned value is undefined and not meaningful}}
+  // expected-warning@-1{{Assigned value is uninitialized}}
 }
 
 void a3(void) {
   s arr[3];
   int x = arr[2].x;
-  // expected-warning@-1{{Assigned value is undefined and not meaningful}}
+  // expected-warning@-1{{Assigned value is uninitialized}}
 }
 
 struct s2 {
@@ -37,23 +37,23 @@ void b1(void) {
 
   clang_analyzer_eval(arr[0].y == 2); // expected-warning{{TRUE}}
   int x = arr[0].x;
-  // expected-warning@-1{{Assigned value is undefined and not meaningful}}
+  // expected-warning@-1{{Assigned value is uninitialized}}
 }
 
 void b2(void) {
   s2 arr[3];
 
   clang_analyzer_eval(arr[1].y == 2); // expected-warning{{TRUE}}
   int x = arr[1].x;
-  // expected-warning@-1{{Assigned value is undefined and not meaningful}}
+  // expected-warning@-1{{Assigned value is uninitialized}}
 }
 
 void b3(void) {
   s2 arr[3];
 
   clang_analyzer_eval(arr[2].y == 2); // expected-warning{{TRUE}}
   int x = arr[2].x;
-  // expected-warning@-1{{Assigned value is undefined and not meaningful}}
+  // expected-warning@-1{{Assigned value is uninitialized}}
 }
 
 void c1(void) {
@@ -70,7 +70,7 @@ void c1(void) {
 
     clang_analyzer_eval(arr[1].y == 2); // expected-warning{{TRUE}}
     int x = arr[1].x;
-    // expected-warning@-1{{Assigned value is undefined and not meaningful}}
+    // expected-warning@-1{{Assigned value is uninitialized}}
   }
 }
 
@@ -100,15 +100,15 @@ void e1(void) {
   clang_analyzer_eval(arr[1].arr[1].y == 2); // expected-warning{{TRUE}}
 
   int x = arr[1].sarr[1].x;
-  // expected-warning@-1{{Assigned value is undefined and not meaningful}}
+  // expected-warning@-1{{Assigned value is uninitialized}}
 }
 
 void f1(void) {
   s2 arr[2][2];
 
   clang_analyzer_eval(arr[1][1].y == 2); // expected-warning{{TRUE}}
   int x = arr[1][1].x;
-  // expected-warning@-1{{Assigned value is undefined and not meaningful}}
+  // expected-warning@-1{{Assigned value is uninitialized}}
 }
 
 struct s5 {
@@ -168,14 +168,14 @@ void h2(void) {
   s a[2][2], b[2][2];
 
   int x = a[1][1].x;
-  // expected-warning@-1{{Assigned value is undefined and not meaningful}}
+  // expected-warning@-1{{Assigned value is uninitialized}}
 }
 
 void h3(void) {
   s a[2][2], b[2][2];
 
   int x = b[1][1].y;
-  // expected-warning@-1{{Assigned value is undefined and not meaningful}}
+  // expected-warning@-1{{Assigned value is uninitialized}}
 }
 
 struct Base {