Add #[doc(hidden)] to struct fields to encourage accessor use

CHANGELOG.next.toml

@@ -148,3 +148,15 @@ message = "SDK crate READMEs now include an example of creating a client"
 references = ["smithy-rs#1571", "smithy-rs#1385"]
 meta = { "breaking" = false, "tada" = true, "bug" = false }
 author = "jdisanti"
+
+[[smithy-rs]]
+message = "Non-streaming struct members are now marked `#[doc(hidden)]` since they will be removed in the future"
+references = ["smithy-rs#1573", "smithy-rs#1569"]
+meta = { "breaking" = false, "tada" = false, "bug" = false }
+author = "jdisanti"
+
+[[aws-sdk-rust]]
+message = "Non-streaming struct members are now marked `#[doc(hidden)]` since they will be removed in the future"
+references = ["smithy-rs#1573", "smithy-rs#1569"]
+meta = { "breaking" = true, "tada" = false, "bug" = false }
+author = "jdisanti"

codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/RustCodegenServerPlugin.kt

@@ -70,7 +70,7 @@ class RustCodegenServerPlugin : SmithyBuildPlugin {
                 // Generate [ByteStream] instead of `Blob` for streaming binary shapes (e.g. S3 GetObject)
                 .let { StreamingShapeSymbolProvider(it, model) }
                 // Add Rust attributes (like `#[derive(PartialEq)]`) to generated shapes
-                .let { BaseSymbolMetadataProvider(it, additionalAttributes = listOf()) }
+                .let { BaseSymbolMetadataProvider(it, model, additionalAttributes = listOf()) }
                 // Streaming shapes need different derives (e.g. they cannot derive Eq)
                 .let { StreamingShapeMetadataProvider(it, model) }
                 // Rename shapes that clash with Rust reserved words & and other SDK specific features e.g. `send()` cannot

codegen/src/main/kotlin/software/amazon/smithy/rust/codegen/rustlang/RustTypes.kt

@@ -334,6 +334,7 @@ sealed class Attribute {
          */
         val NonExhaustive = Custom("non_exhaustive")
         val AllowUnusedMut = Custom("allow(unused_mut)")
+        val DocHidden = Custom("doc(hidden)")
         val DocInline = Custom("doc(inline)")
     }
 

codegen/src/main/kotlin/software/amazon/smithy/rust/codegen/smithy/RustCodegenPlugin.kt

@@ -66,7 +66,7 @@ class RustCodegenPlugin : SmithyBuildPlugin {
                 // Generate `ByteStream` instead of `Blob` for streaming binary shapes (e.g. S3 GetObject)
                 .let { StreamingShapeSymbolProvider(it, model) }
                 // Add Rust attributes (like `#[derive(PartialEq)]`) to generated shapes
-                .let { BaseSymbolMetadataProvider(it, additionalAttributes = listOf(NonExhaustive)) }
+                .let { BaseSymbolMetadataProvider(it, model, additionalAttributes = listOf(NonExhaustive)) }
                 // Streaming shapes need different derives (e.g. they cannot derive Eq)
                 .let { StreamingShapeMetadataProvider(it, model) }
                 // Rename shapes that clash with Rust reserved words & and other SDK specific features e.g. `send()` cannot

codegen/src/main/kotlin/software/amazon/smithy/rust/codegen/smithy/StreamingTraitSymbolProvider.kt

@@ -56,7 +56,10 @@ class StreamingShapeSymbolProvider(private val base: RustSymbolProvider, private
  *
  * Note that since streaming members can only be used on the root shape, this can only impact input and output shapes.
  */
-class StreamingShapeMetadataProvider(private val base: RustSymbolProvider, private val model: Model) : SymbolMetadataProvider(base) {
+class StreamingShapeMetadataProvider(
+    private val base: RustSymbolProvider,
+    private val model: Model,
+) : SymbolMetadataProvider(base) {
     override fun memberMeta(memberShape: MemberShape): RustMetadata {
         return base.toSymbol(memberShape).expectRustMetadata()
     }

codegen/src/main/kotlin/software/amazon/smithy/rust/codegen/smithy/SymbolMetadataProvider.kt

@@ -7,13 +7,15 @@ package software.amazon.smithy.rust.codegen.smithy
 
 import software.amazon.smithy.codegen.core.CodegenException
 import software.amazon.smithy.codegen.core.Symbol
+import software.amazon.smithy.model.Model
 import software.amazon.smithy.model.shapes.MemberShape
 import software.amazon.smithy.model.shapes.Shape
 import software.amazon.smithy.model.shapes.StringShape
 import software.amazon.smithy.model.shapes.StructureShape
 import software.amazon.smithy.model.shapes.UnionShape
 import software.amazon.smithy.model.traits.EnumDefinition
 import software.amazon.smithy.model.traits.EnumTrait
+import software.amazon.smithy.model.traits.StreamingTrait
 import software.amazon.smithy.rust.codegen.rustlang.Attribute
 import software.amazon.smithy.rust.codegen.rustlang.RustMetadata
 import software.amazon.smithy.rust.codegen.rustlang.Visibility
@@ -73,6 +75,7 @@ abstract class SymbolMetadataProvider(private val base: RustSymbolProvider) : Wr
  */
 class BaseSymbolMetadataProvider(
     base: RustSymbolProvider,
+    private val model: Model,
     additionalAttributes: List<Attribute>,
 ) : SymbolMetadataProvider(base) {
     private val containerDefault = RustMetadata(
@@ -82,7 +85,28 @@ class BaseSymbolMetadataProvider(
     )
 
     override fun memberMeta(memberShape: MemberShape): RustMetadata {
-        return RustMetadata(visibility = Visibility.PUBLIC)
+        val container = model.expectShape(memberShape.container)
+        return when {
+            container.isStructureShape -> {
+                // TODO(https://github.com/awslabs/smithy-rs/issues/943): Once streaming accessors are usable,
+                // then also make streaming members `#[doc(hidden)]`
+                if (memberShape.getMemberTrait(model, StreamingTrait::class.java).isPresent) {
+                    RustMetadata(visibility = Visibility.PUBLIC)
+                } else {
+                    RustMetadata(
+                        // At some point, visibility will be made PRIVATE, so make these `#[doc(hidden)]` for now
+                        visibility = Visibility.PUBLIC,
+                        additionalAttributes = listOf(Attribute.DocHidden)
+                    )
+                }
+            }
+            container.isUnionShape ||
+                container.isListShape ||
+                container.isSetShape ||
+                container.isMapShape
+            -> RustMetadata(visibility = Visibility.PUBLIC)
+            else -> TODO("Unrecognized container type: $container")
+        }
     }
 
     override fun structureMeta(structureShape: StructureShape): RustMetadata {