fix dca for encoding v1 autogenerated code (#6006)

## Description

This PR is part of #5727 and
fixes a problem with AbiEncode/AbiDecode code generation. The problem
lies in the fact that to encode/decode structs we need to "touch" all
fields. Which makes all fields to pass DCA.

Now, when a `StructFieldAccess` lives inside an autogenerated source,
the "code flow graph" will be built as usual, but no edge will be
created to the struct field, nor to the field owner struct declaration.

## Checklist

- [x] I have linked to any relevant issues.
- [x] I have commented my code, particularly in hard-to-understand
areas.
- [x] I have updated the documentation where relevant (API docs, the
reference, and the Sway book).
- [x] If my change requires substantial documentation changes, I have
[requested support from the DevRel
team](https://github.com/FuelLabs/devrel-requests/issues/new/choose)
- [x] I have added tests that prove my fix is effective or that my
feature works.
- [x] I have added (or requested a maintainer to add) the necessary
`Breaking*` or `New Feature` labels where relevant.
- [x] I have done my best to ensure that my PR adheres to [the Fuel Labs
Code Review
Standards](https://github.com/FuelLabs/rfcs/blob/master/text/code-standards/external-contributors.md).
- [x] I have requested a review from the relevant team or maintainers.

---------

Co-authored-by: Joshua Batty <[email protected]>

sway-core/src/control_flow_analysis/dead_code_analysis.rs

@@ -1643,13 +1643,21 @@ fn connect_expression<'eng: 'cfg, 'cfg>(
             for leaf in leaves {
                 graph.add_edge(*leaf, this_ix, "".into());
             }
-            graph.add_edge(this_ix, field_ix, "".into());
 
-            if let Some(struct_node_ix) = graph
-                .namespace
-                .find_struct_decl(resolved_type_of_parent.suffix.as_str())
+            // autogenerated code should not increase usage of a struct field
+            if !engines
+                .se()
+                .is_span_in_autogenerated(&expression_span)
+                .unwrap_or(false)
             {
-                graph.add_edge(this_ix, *struct_node_ix, "".into());
+                graph.add_edge(this_ix, field_ix, "".into());
+
+                if let Some(struct_node_ix) = graph
+                    .namespace
+                    .find_struct_decl(resolved_type_of_parent.suffix.as_str())
+                {
+                    graph.add_edge(this_ix, *struct_node_ix, "".into());
+                }
             }
 
             Ok(vec![this_ix])

sway-core/src/type_system/unify/unifier.rs

@@ -428,7 +428,6 @@ impl<'a> Unifier<'a> {
                 self.unify(handler, rtp.type_id, etp.type_id, span);
             });
         } else {
-            dbg!(rn == en, rvs.len() == evs.len(), rtps.len() == etps.len());
             let internal = format!("[{received:?}] versus [{expected:?}]");
             let (received, expected) = self.assign_args(received, expected);
             handler.emit_err(

sway-ir/src/verify.rs

@@ -816,16 +816,8 @@ impl<'a, 'eng> InstructionVerifier<'a, 'eng> {
 
     fn verify_load(&self, src_val: &Value) -> Result<(), IrError> {
         // Just confirm `src_val` is a pointer.
-        let r = self
-            .get_ptr_type(src_val, IrError::VerifyLoadFromNonPointer)
-            .map(|_| ());
-
-        if r.is_err() {
-            let meta = src_val.get_metadata(self.context).unwrap();
-            dbg!(&self.context.metadata[meta.0], &r);
-        }
-
-        r
+        self.get_ptr_type(src_val, IrError::VerifyLoadFromNonPointer)
+            .map(|_| ())
     }
 
     fn verify_log(&self, log_val: &Value, log_ty: &Type, log_id: &Value) -> Result<(), IrError> {

sway-types/src/source_engine.rs

@@ -40,6 +40,14 @@ impl Clone for SourceEngine {
 impl SourceEngine {
     const AUTOGENERATED_PATH: &'static str = "<autogenerated>";
 
+    pub fn is_span_in_autogenerated(&self, span: &crate::Span) -> Option<bool> {
+        span.source_id().map(|s| self.is_source_id_autogenerated(s))
+    }
+
+    pub fn is_source_id_autogenerated(&self, source_id: &SourceId) -> bool {
+        self.get_path(source_id).starts_with("<autogenerated>")
+    }
+
     /// This function retrieves an integer-based source ID for a provided path buffer.
     /// If an ID already exists for the given path, the function will return that
     /// existing ID. If not, a new ID will be created.

test/src/e2e_vm_tests/harness.rs

@@ -82,7 +82,7 @@ pub(crate) async fn deploy_contract(file_name: &str, run_config: &RunConfig) ->
             true => BuildProfile::RELEASE.to_string(),
             false => BuildProfile::DEBUG.to_string(),
         },
-        no_encoding_v1: !dbg!(run_config.experimental.new_encoding),
+        no_encoding_v1: !run_config.experimental.new_encoding,
         ..Default::default()
     })
     .await

test/src/e2e_vm_tests/test_programs/should_pass/dca/unused_fields/src/main.sw

@@ -3,7 +3,6 @@ script;
 mod utils;
 use utils::Foo;
 
-
 struct Bar {
     value: u64
 }

test/src/e2e_vm_tests/test_programs/should_pass/dca/unused_fields/test.toml

@@ -1,3 +1,6 @@
 category = "compile"
+expected_warnings = 1
 
-expected_warnings = 0
+# check: $()struct Bar {
+# nextln: $()value: u64
+# nextln: $()This struct field is never accessed.

test/src/e2e_vm_tests/test_programs/should_pass/return_in_strange_positions/test.toml

@@ -4,6 +4,14 @@ expected_result_new_encoding = { action = "return_data", value = "00000000000020
 validate_abi = true
 expected_warnings = 26
 
+#check: $()pub struct S
+#nextln: $()This struct field is never accessed.
+#nextln: $()pub enum Enum
+
+#check: $()pub struct S
+#nextln: $()This struct field is never accessed.
+#nextln: $()pub enum Enum
+
 #check: $()pub enum Enum
 #nextln: $()This enum is never used.
 

test/src/sdk-harness/Forc.toml

@@ -5,8 +5,6 @@ members = [
   "test_projects/asset_ops",
   "test_projects/block",
   "test_projects/call_frames",
-  # TODO Uncomment these when SDK supports encoding V1 for configurables
-  # https://github.com/FuelLabs/sway/issues/5727
   "test_projects/configurables_in_contract",
   "test_projects/configurables_in_script",
   "test_projects/context",