r272755 - Add a "declared 'nonnull' here" note to warnings where an expression is checked against null.

[Nick Lewycky via cfe-commits]

Author: nicholas
Date: Wed Jun 15 00:18:39 2016
New Revision: 272755

URL: http://llvm.org/viewvc/llvm-project?rev=272755&view=rev
Log:
Add a "declared 'nonnull' here" note to warnings where an expression is checked against null.

Modified:
    cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td
    cfe/trunk/lib/Sema/SemaChecking.cpp
    cfe/trunk/test/Sema/nonnull.c

Modified: cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td?rev=272755&r1=272754&r2=272755&view=diff
==============================================================================
--- cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td (original)
+++ cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td Wed Jun 15 00:18:39 2016
@@ -2933,6 +2933,8 @@ def warn_attribute_nonnull_no_pointers :
 def warn_attribute_nonnull_parm_no_args : Warning<
   "'nonnull' attribute when used on parameters takes no arguments">,
   InGroup<IgnoredAttributes>;
+def note_declared_nonnull : Note<
+  "declared %select{'returns_nonnull'|'nonnull'}0 here">;
 def warn_attribute_sentinel_named_arguments : Warning<
   "'sentinel' attribute requires named arguments">,
   InGroup<IgnoredAttributes>;

Modified: cfe/trunk/lib/Sema/SemaChecking.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaChecking.cpp?rev=272755&r1=272754&r2=272755&view=diff
==============================================================================
--- cfe/trunk/lib/Sema/SemaChecking.cpp (original)
+++ cfe/trunk/lib/Sema/SemaChecking.cpp Wed Jun 15 00:18:39 2016
@@ -8460,7 +8460,8 @@ void Sema::DiagnoseAlwaysNonNullPointer(
     }
   }
 
-  auto ComplainAboutNonnullParamOrCall = [&](bool IsParam) {
+  auto ComplainAboutNonnullParamOrCall = [&](const Attr *NonnullAttr) {
+    bool IsParam = isa<NonNullAttr>(NonnullAttr);
     std::string Str;
     llvm::raw_string_ostream S(Str);
     E->printPretty(S, nullptr, getPrintingPolicy());
@@ -8468,13 +8469,14 @@ void Sema::DiagnoseAlwaysNonNullPointer(
                                 : diag::warn_cast_nonnull_to_bool;
     Diag(E->getExprLoc(), DiagID) << IsParam << S.str()
       << E->getSourceRange() << Range << IsEqual;
+    Diag(NonnullAttr->getLocation(), diag::note_declared_nonnull) << IsParam;
   };
 
   // If we have a CallExpr that is tagged with returns_nonnull, we can complain.
   if (auto *Call = dyn_cast<CallExpr>(E->IgnoreParenImpCasts())) {
     if (auto *Callee = Call->getDirectCallee()) {
-      if (Callee->hasAttr<ReturnsNonNullAttr>()) {
-        ComplainAboutNonnullParamOrCall(false);
+      if (const Attr *A = Callee->getAttr<ReturnsNonNullAttr>()) {
+        ComplainAboutNonnullParamOrCall(A);
         return;
       }
     }
@@ -8496,8 +8498,8 @@ void Sema::DiagnoseAlwaysNonNullPointer(
   if (const auto* PV = dyn_cast<ParmVarDecl>(D)) {
     if (getCurFunction() &&
         !getCurFunction()->ModifiedNonNullParams.count(PV)) {
-      if (PV->hasAttr<NonNullAttr>()) {
-        ComplainAboutNonnullParamOrCall(true);
+      if (const Attr *A = PV->getAttr<NonNullAttr>()) {
+        ComplainAboutNonnullParamOrCall(A);
         return;
       }
 
@@ -8508,13 +8510,13 @@ void Sema::DiagnoseAlwaysNonNullPointer(
 
         for (const auto *NonNull : FD->specific_attrs<NonNullAttr>()) {
           if (!NonNull->args_size()) {
-              ComplainAboutNonnullParamOrCall(true);
+              ComplainAboutNonnullParamOrCall(NonNull);
               return;
           }
 
           for (unsigned ArgNo : NonNull->args()) {
             if (ArgNo == ParamNo) {
-              ComplainAboutNonnullParamOrCall(true);
+              ComplainAboutNonnullParamOrCall(NonNull);
               return;
             }
           }

Modified: cfe/trunk/test/Sema/nonnull.c
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Sema/nonnull.c?rev=272755&r1=272754&r2=272755&view=diff
==============================================================================
--- cfe/trunk/test/Sema/nonnull.c (original)
+++ cfe/trunk/test/Sema/nonnull.c Wed Jun 15 00:18:39 2016
@@ -86,7 +86,7 @@ void redecl_test(void *p) {
 
 // rdar://18712242
 #define NULL (void*)0
-__attribute__((__nonnull__))
+__attribute__((__nonnull__))  // expected-note 2{{declared 'nonnull' here}}
 int evil_nonnull_func(int* pointer, void * pv)
 {
    if (pointer == NULL) {  // expected-warning {{comparison of nonnull parameter 'pointer' equal to a null pointer is 'false' on first encounter}}
@@ -105,7 +105,7 @@ int evil_nonnull_func(int* pointer, void
 }
 
 void set_param_to_null(int**);
-int another_evil_nonnull_func(int* pointer, char ch, void * pv) __attribute__((nonnull(1, 3)));
+int another_evil_nonnull_func(int* pointer, char ch, void * pv) __attribute__((nonnull(1, 3)));  // expected-note 2{{declared 'nonnull' here}}
 int another_evil_nonnull_func(int* pointer, char ch, void * pv) {
    if (pointer == NULL) { // expected-warning {{comparison of nonnull parameter 'pointer' equal to a null pointer is 'false' on first encounter}}
      return 0;
@@ -127,7 +127,7 @@ extern void FOO();
 extern void FEE();
 
 extern void *pv;
-__attribute__((__nonnull__))
+__attribute__((__nonnull__))  // expected-note {{declared 'nonnull' here}}
 void yet_another_evil_nonnull_func(int* pointer)
 {
  while (pv) {
@@ -141,7 +141,7 @@ void yet_another_evil_nonnull_func(int*
  }
 }
 
-void pr21668_1(__attribute__((nonnull)) const char *p, const char *s) {
+void pr21668_1(__attribute__((nonnull)) const char *p, const char *s) { // expected-note {{declared 'nonnull' here}}
   if (p) // expected-warning {{nonnull parameter 'p' will evaluate to 'true' on first encounter}}
     ;
   if (s) // No warning
@@ -154,7 +154,7 @@ void pr21668_2(__attribute__((nonnull))
     ;
 }
 
-__attribute__((returns_nonnull)) void *returns_nonnull_whee();
+__attribute__((returns_nonnull)) void *returns_nonnull_whee();  // expected-note 6{{declared 'returns_nonnull' here}}
 
 void returns_nonnull_warning_tests() {
   if (returns_nonnull_whee() == NULL) {} // expected-warning {{comparison of nonnull function call 'returns_nonnull_whee()' equal to a null pointer is 'false' on first encounter}}