Improve DiagnosticEngine's handling of ValueDecl arguments

docs/Diagnostics.md

@@ -128,14 +128,26 @@ If you run into any issues or have questions while following the steps above, fe
 
 - `%0`, `%1`, etc - Formats the specified diagnostic argument based on its type.
 
-- `%select{a|b|c}0` - Chooses from a list of alternatives, separated by vertical bars, based on the value of the given argument. In this example, a value of 2 in diagnostic argument 0 would result in "c" being output. The argument to the %select may be an integer, enum, or StringRef. If it's a StringRef, the specifier acts as an emptiness check.
+- `%select{a|b|c}0` - Chooses from a list of alternatives, separated by vertical bars, based on the value of the given argument. In this example, a value of 2 in diagnostic argument 0 would result in "c" being output. The argument to the %select may be an integer, enum, StringRef, Identifier, or Decl. If it's a StringRef or Identifier, the specifier acts as an emptiness check; if it's a Decl, it acts as a null check.
 
 - `%s0` - Produces an "s" if the given argument is anything other than 1, as meant for an English plural. This isn't particularly localizable without a more general `%plural` form, but most diagnostics try to avoid cases where a plural/singular distinction would be necessary in the first place.
 
 - `%error` - Represents a branch in a `%select` that should never be taken. In debug builds of the compiler this produces an assertion failure.
 
 - `%%` - Emits a literal percent sign.
 
+There are several format specifiers that are specific to `Decl` parameters:
+
+- `%kind0` - Prefixes the declaration's name with its descriptive decl kind (e.g. `instance method 'foo(x:)'`).
+
+- `%kindonly0` - Inserts only the descriptive decl kind (e.g. `instance method`).
+
+- `%base0` - Inserts only the base name, removing any argument labels (e.g. `'foo'`).
+
+- `%kindbase0` - Combines `kind` and `base` (e.g. `instance method 'foo'`).
+
+Note: If your diagnostic could apply to accessors, be careful how you format the declaration's name; accessors have an empty name, so you need to display their accessor kind and the name of their storage decl instead. Inserting the name with a `Decl *` parameter will handle these complications automatically; if you want to use `DeclName` or `Identifier` instead, you'll probably need a separate version of the diagnostic for accessors. 
+
 ### Diagnostic Verifier ###
 
 (This section is specific to the Swift compiler's diagnostic engine.)

include/swift/AST/DiagnosticEngine.h

@@ -38,11 +38,14 @@ class NamedDecl;
 }
 
 namespace swift {
+  class ConstructorDecl;
   class Decl;
   class DeclAttribute;
   class DiagnosticEngine;
+  class FuncDecl;
   class GeneratedSourceInfo;
   class SourceManager;
+  class TypeAliasDecl;
   class ValueDecl;
   class SourceFile;
 
@@ -109,7 +112,7 @@ namespace swift {
     Unsigned,
     Identifier,
     ObjCSelector,
-    ValueDecl,
+    Decl,
     Type,
     TypeRepr,
     FullyQualifiedType,
@@ -143,7 +146,7 @@ namespace swift {
       StringRef StringVal;
       DeclNameRef IdentifierVal;
       ObjCSelector ObjCSelectorVal;
-      const ValueDecl *TheValueDecl;
+      const Decl *TheDecl;
       Type TypeVal;
       TypeRepr *TyR;
       FullyQualified<Type> FullyQualifiedTypeVal;
@@ -194,8 +197,8 @@ namespace swift {
       : Kind(DiagnosticArgumentKind::ObjCSelector), ObjCSelectorVal(S) {
     }
 
-    DiagnosticArgument(const ValueDecl *VD)
-      : Kind(DiagnosticArgumentKind::ValueDecl), TheValueDecl(VD) {
+    DiagnosticArgument(const Decl *VD)
+      : Kind(DiagnosticArgumentKind::Decl), TheDecl(VD) {
     }
 
     DiagnosticArgument(Type T)
@@ -305,9 +308,9 @@ namespace swift {
       return ObjCSelectorVal;
     }
 
-    const ValueDecl *getAsValueDecl() const {
-      assert(Kind == DiagnosticArgumentKind::ValueDecl);
-      return TheValueDecl;
+    const Decl *getAsDecl() const {
+      assert(Kind == DiagnosticArgumentKind::Decl);
+      return TheDecl;
     }
 
     Type getAsType() const {
@@ -1497,13 +1500,6 @@ namespace swift {
     const StringRef Message;
   };
 
-/// Returns a value that can be used to select between accessor kinds in
-/// diagnostics.
-///
-/// This is correlated with diag::availability_deprecated and others.
-std::pair<unsigned, DeclName>
-getAccessorKindAndNameForDiagnostics(const ValueDecl *D);
-
 /// Retrieve the macro name for a generated source info that represents
 /// a macro expansion.
 DeclName getGeneratedSourceInfoMacroName(const GeneratedSourceInfo &info);

include/swift/AST/DiagnosticsIDE.def

@@ -38,17 +38,17 @@ NOTE(ide_redundant_import_indirect, none,
      "module %0 is already imported via another module import", (StringRef))
 
 WARNING(ide_availability_softdeprecated, Deprecation,
-        "%select{getter for |setter for |}0%1 will be deprecated"
-        " in %select{a future version|%select{a future version of %3|%3 %5}4}2"
-        "%select{|: %6}6",
-        (unsigned, DeclName, bool, StringRef, bool, llvm::VersionTuple,
+        "%0 will be deprecated"
+        " in %select{a future version|%select{a future version of %2|%2 %4}3}1"
+        "%select{|: %5}5",
+        (const ValueDecl *, bool, StringRef, bool, llvm::VersionTuple,
          StringRef))
 
 WARNING(ide_availability_softdeprecated_rename, Deprecation,
-        "%select{getter for |setter for |}0%1 will be deprecated"
-        " in %select{a future version|%select{a future version of %3|%3 %5}4}2"
-        ": renamed to '%6'",
-        (unsigned, DeclName, bool, StringRef, bool, llvm::VersionTuple, StringRef))
+        "%0 will be deprecated"
+        " in %select{a future version|%select{a future version of %2|%2 %4}3}1"
+        ": renamed to '%5'",
+        (const ValueDecl *, bool, StringRef, bool, llvm::VersionTuple, StringRef))
 
 WARNING(ide_recursive_accessor_reference,none,
         "attempting to %select{access|modify}1 %0 within its own "