[PATCH] Add warnings so that Clang can catch most of the cases that GCC's -Waddress can catch

[David Majnemer]

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Comment at: include/clang/Basic/DiagnosticSemaKinds.td:2317
@@ -2299,1 +2316,3 @@
+  "pointer is always %select{true|false}1">,
+  InGroup<TautologicalPointerCompare>;
 
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`warn_null_array_compare`, `warn_null_function_compare`, and `warn_null_pointer_compare` could be combined using `%select`

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Comment at: lib/Sema/SemaChecking.cpp:5710
@@ +5709,3 @@
+  bool function = false;
+  bool addressOf = false;
+
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Shouldn't these be capitalized? Something like `IsArray`, `IsFunction`, etc.?

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Comment at: lib/Sema/SemaChecking.cpp:5751
@@ +5750,3 @@
+  // Pretty print the expression for the diagnostic.
+  std::string str;
+  llvm::raw_string_ostream S(str);
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Same goes for this variable.

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Comment at: lib/Sema/SemaChecking.cpp:5698
@@ +5697,3 @@
+/// \param Range Extra SourceRange to highlight in the diagnostic
+void Sema::DiagnosePointer(Expr *E, Expr::NullPointerConstantKind NullKind,
+                           bool IsEqual, SourceRange Range) {
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`DiagnosePointer` is rather vague, perhaps something like `diagnoseTautologicalPointerCompare` ?


http://llvm-reviews.chandlerc.com/D2645