From b8185153f35446c2a8db48ee711d2fb577674c18 Mon Sep 17 00:00:00 2001
From: David Bolvansky <david.bolvansky@gmail.com>
Date: Sat, 14 Sep 2019 19:38:55 +0000
Subject: [PATCH] [Diagnostics] Added silence note for -Wsizeof-array-div;
 suggest extra parens

llvm-svn: 371924
---
 clang/lib/Sema/SemaExpr.cpp          |  2 ++
 clang/test/Sema/div-sizeof-array.cpp | 23 ++++++++++++++++++++---
 2 files changed, 22 insertions(+), 3 deletions(-)

diff --git a/clang/lib/Sema/SemaExpr.cpp b/clang/lib/Sema/SemaExpr.cpp
index 8452005..99e4389 100644
--- a/clang/lib/Sema/SemaExpr.cpp
+++ b/clang/lib/Sema/SemaExpr.cpp
@@ -9200,6 +9200,8 @@ static void DiagnoseDivisionSizeofPointerOrArray(Sema &S, Expr *LHS, Expr *RHS,
         S.Diag(LHSArgDecl->getLocation(), diag::note_array_declared_here)
             << LHSArgDecl;
     }
+
+    S.Diag(Loc, diag::note_precedence_silence) << RHS;
   }
 }
 
diff --git a/clang/test/Sema/div-sizeof-array.cpp b/clang/test/Sema/div-sizeof-array.cpp
index 15da1da..cd9b307 100644
--- a/clang/test/Sema/div-sizeof-array.cpp
+++ b/clang/test/Sema/div-sizeof-array.cpp
@@ -9,21 +9,38 @@ int f(Ty (&Array)[N]) {
 typedef int int32;
 
 void test(void) {
-  int arr[12];                // expected-note 2 {{array 'arr' declared here}}
+  int arr[12]; // expected-note 2 {{array 'arr' declared here}}
   unsigned long long arr2[4];
   int *p = &arr[0];
   int a1 = sizeof(arr) / sizeof(*arr);
   int a2 = sizeof arr / sizeof p; // expected-warning {{expression does not compute the number of elements in this array; element type is 'int', not 'int *'}}
+  // expected-note@-1 {{place parentheses around the 'sizeof p' expression to silence this warning}}
   int a4 = sizeof arr2 / sizeof p;
   int a5 = sizeof(arr) / sizeof(short); // expected-warning {{expression does not compute the number of elements in this array; element type is 'int', not 'short'}}
+  // expected-note@-1 {{place parentheses around the 'sizeof(short)' expression to silence this warning}}
   int a6 = sizeof(arr) / sizeof(int32);
   int a7 = sizeof(arr) / sizeof(int);
   int a9 = sizeof(arr) / sizeof(unsigned int);
   const char arr3[2] = "A";
   int a10 = sizeof(arr3) / sizeof(char);
+  int a11 = sizeof(arr2) / (sizeof(unsigned));
+  int a12 = sizeof(arr) / (sizeof(short));
 
   int arr4[10][12];                         // expected-note 3 {{array 'arr4' declared here}}
   int b1 = sizeof(arr4) / sizeof(arr2[12]); // expected-warning {{expression does not compute the number of elements in this array; element type is 'int [12]', not 'unsigned long long'}}
-  int b2 = sizeof(arr4) / sizeof(int *);    // expected-warning {{expression does not compute the number of elements in this array; element type is 'int [12]', not 'int *'}}
-  int b3 = sizeof(arr4) / sizeof(short *);  // expected-warning {{expression does not compute the number of elements in this array; element type is 'int [12]', not 'short *'}}
+  // expected-note@-1 {{place parentheses around the 'sizeof (arr2[12])' expression to silence this warning}}
+  int b2 = sizeof(arr4) / sizeof(int *); // expected-warning {{expression does not compute the number of elements in this array; element type is 'int [12]', not 'int *'}}
+  // expected-note@-1 {{place parentheses around the 'sizeof(int *)' expression to silence this warning}}
+  int b3 = sizeof(arr4) / sizeof(short *); // expected-warning {{expression does not compute the number of elements in this array; element type is 'int [12]', not 'short *'}}
+  // expected-note@-1 {{place parentheses around the 'sizeof(short *)' expression to silence this warning}}
+
+  int arr5[][5] = { // expected-note 2 {{array 'arr5' declared here}}
+      {1, 2, 3, 4, 5},
+      {6, 7, 8, 9, 0},
+  };
+  int c1 = sizeof(arr5) / sizeof(*arr5);
+  int c2 = sizeof(arr5) / sizeof(**arr5); // expected-warning {{expression does not compute the number of elements in this array; element type is 'int [5]', not 'int'}}
+  // expected-note@-1 {{place parentheses around the 'sizeof (**arr5)' expression to silence this warning}}
+  int c3 = sizeof(arr5) / sizeof(int); // expected-warning {{expression does not compute the number of elements in this array; element type is 'int [5]', not 'int'}}
+  // expected-note@-1 {{place parentheses around the 'sizeof(int)' expression to silence this warning}}
 }
-- 
2.7.4