Fixup all doxygen warnings

No idea why the operator<<() functions have started moaning now.

Change-Id: I338b96c53888f4ddb8e42283a6dcda7708e567f0
Reviewed-on: https://dawn-review.googlesource.com/c/tint/+/47431
Commit-Queue: Ben Clayton <bclayton@google.com>
Reviewed-by: Antonio Maiorano <amaiorano@google.com>

Doxyfile

@@ -787,7 +787,6 @@ WARN_LOGFILE           =
 
 INPUT                  = README.md  \
                          CODE_OF_CONDUCT.md \
-                         CONTRIBUTING.md \
                          src
 
 # This tag can be used to specify the character encoding of the source files

src/ast/access_control.h

@@ -30,6 +30,9 @@ enum class AccessControl {
   kReadWrite
 };
 
+/// @param out the std::ostream to write to
+/// @param access the AccessControl
+/// @return the std::ostream so calls can be chained
 std::ostream& operator<<(std::ostream& out, AccessControl access);
 
 }  // namespace ast

src/ast/binary_expression.h

@@ -182,6 +182,8 @@ inline bool BinaryExpression::IsBitshift() const {
   }
 }
 
+/// @returns the human readable name of the given BinaryOp
+/// @param op the BinaryOp
 constexpr const char* FriendlyName(BinaryOp op) {
   switch (op) {
     case BinaryOp::kNone:
@@ -226,6 +228,9 @@ constexpr const char* FriendlyName(BinaryOp op) {
   return "INVALID";
 }
 
+/// @param out the std::ostream to write to
+/// @param op the BinaryOp
+/// @return the std::ostream so calls can be chained
 inline std::ostream& operator<<(std::ostream& out, BinaryOp op) {
   out << FriendlyName(op);
   return out;

src/ast/builtin.h

@@ -41,6 +41,9 @@ enum class Builtin {
   kPointSize,
 };
 
+/// @param out the std::ostream to write to
+/// @param builtin the Builtin
+/// @return the std::ostream so calls can be chained
 std::ostream& operator<<(std::ostream& out, Builtin builtin);
 
 }  // namespace ast

src/ast/pipeline_stage.h

@@ -23,6 +23,9 @@ namespace ast {
 /// The pipeline stage
 enum class PipelineStage { kNone = -1, kVertex, kFragment, kCompute };
 
+/// @param out the std::ostream to write to
+/// @param stage the PipelineStage
+/// @return the std::ostream so calls can be chained
 std::ostream& operator<<(std::ostream& out, PipelineStage stage);
 
 }  // namespace ast

src/ast/storage_class.h

@@ -35,11 +35,15 @@ enum class StorageClass {
 };
 
 /// @returns true if the StorageClass is host-shareable
+/// @param sc the StorageClass
 /// @see https://gpuweb.github.io/gpuweb/wgsl.html#host-shareable
 inline bool IsHostShareable(StorageClass sc) {
   return sc == ast::StorageClass::kUniform || sc == ast::StorageClass::kStorage;
 }
 
+/// @param out the std::ostream to write to
+/// @param sc the StorageClass
+/// @return the std::ostream so calls can be chained
 std::ostream& operator<<(std::ostream& out, StorageClass sc);
 
 }  // namespace ast

src/ast/test_helper.h

@@ -21,11 +21,14 @@
 namespace tint {
 namespace ast {
 
-/// Helper class for testing
+/// Helper base class for testing
 template <typename BASE>
 class TestHelperBase : public BASE, public ProgramBuilder {};
+
+/// Helper class for testing that derives from testing::Test.
 using TestHelper = TestHelperBase<testing::Test>;
 
+/// Helper class for testing that derives from `T`.
 template <typename T>
 using TestParamHelper = TestHelperBase<testing::TestWithParam<T>>;
 

src/ast/unary_op.h

@@ -23,6 +23,9 @@ namespace ast {
 /// The unary op
 enum class UnaryOp { kNegation = 0, kNot };
 
+/// @param out the std::ostream to write to
+/// @param mod the UnaryOp
+/// @return the std::ostream so calls can be chained
 std::ostream& operator<<(std::ostream& out, UnaryOp mod);
 
 }  // namespace ast

src/semantic/member_accessor_expression.h

@@ -58,6 +58,7 @@ class StructMemberAccess
   /// Constructor
   /// @param declaration the AST node
   /// @param type the resolved type of the expression
+  /// @param statement the statement that owns this expression
   /// @param member the structure member
   StructMemberAccess(ast::MemberAccessorExpression* declaration,
                      type::Type* type,
@@ -81,6 +82,7 @@ class Swizzle : public Castable<Swizzle, MemberAccessorExpression> {
   /// Constructor
   /// @param declaration the AST node
   /// @param type the resolved type of the expression
+  /// @param statement the statement that
   /// @param indices the swizzle indices
   Swizzle(ast::MemberAccessorExpression* declaration,
           type::Type* type,