Fix UI test runner flag handling and recursive provenance resolution (#126)

This PR rewrites the UI test runner to actually respect `//@
compile-flags:` directives (previously silently ignored), and fixes a
panic in provenance type resolution that crashed on nested struct
fields.

- Rewrite `run_ui_tests.sh`: flag-based CLI, build-once-then-invoke
(eliminates cargo freshness overhead per test), arch-aware skip logic,
optional `--save-debug-output` for failure triage
- Add `extract_test_flags()` to both runners: parses `//@
compile-flags:`, `//@ edition:`, and `//@ rustc-env:` directives from
test files
- Fix `get_prov_ty` to recursively walk nested struct/tuple fields
instead of requiring an exact byte-offset match at the top level
- Replace panicking unwraps in `get_prov_ty` with graceful fallbacks

UI test results: 19 failing -> 2 failing, 2871 passing -> 2888 passing.

## What was wrong

Two independent problems, both surfaced by investigating the 19 UI test
failures on the `master` branch.

### 1. Test runner ignoring compile-flags directives

The UI test runners (`run_ui_tests.sh`, `remake_ui_tests.sh`) never
extracted `//@ compile-flags:`, `//@ edition:`, or `//@ rustc-env:`
directives from test files. Every test ran with bare `-Zno-codegen`
regardless of what the test required. 17 of the 19 failures were
compilation errors caused by missing flags (e.g., `--edition 2021`,
`--test`, `-Zunstable-options`, `-Ccodegen-units=1`).

These tests were "failing" for the wrong reason: they weren't testing
stable-mir-json at all, just failing to compile.

### 2. Provenance type resolution panicking on nested structs

`get_prov_ty` used `field_for_offset` (exact byte-offset match) to find
which field a provenance pointer belongs to, then returned that field's
type directly. This works when the pointer sits at the start of a
top-level field, but breaks on nested structs.

Concrete example: `TestDescAndFn` has fields at offsets 0 (`TestDesc`)
and 128 (`TestFn`). A pointer at byte offset 56 sits inside `TestDesc`
(which itself has a `&str` field at relative offset 56). The old code
looked for a field starting at exactly offset 56 in the top-level
struct, found nothing, and panicked.

The fix adds `field_containing_offset` (range-based: finds the field
with the largest start offset <= target) and makes the struct and tuple
branches recurse into the containing field with a relative offset,
walking down through the field hierarchy until reaching the actual
pointer type.

## Test runner changes

The rewritten `run_ui_tests.sh`:

- **Flag-based CLI**: `--verbose`, `--save-generated-output`,
`--save-debug-output` replace positional args and env vars
- **Build once**: runs `cargo build` upfront, then invokes the binary
directly with proper `DYLD_LIBRARY_PATH`/`LD_LIBRARY_PATH` setup (cuts
~2-3s of cargo freshness checking per test)
- **Arch filtering**: skips tests gated on foreign architectures via
path matching and `//@ only-<arch>` directive parsing
- **Flag extraction**: `extract_test_flags()` parses `//@
compile-flags:`, `//@ edition:`, and `//@ rustc-env:` directives
- **Debug output**: `--save-debug-output` captures stderr on failure to
`tests/ui/debug/<test_name>.stderr` and prints a 4-line snippet inline

`remake_ui_tests.sh` gets the same `extract_test_flags()` function so
regeneration respects directives too.

## Remaining failures

| Test | Exit | Root cause |
|------|------|------------|
| `tests/ui/issues/issue-26641.rs` | 101 | rustc internal panic
("escaping bound vars"); not a stable-mir-json bug |
| `tests/ui/sanitizer/cfi/drop-in-place.rs` | 101 | Missing
`-Ccodegen-units=1` in the test file's `//@ compile-flags:` directive;
every sibling CFI test has it, this one doesn't. Upstream test bug, not
ours. |

## Test plan

- [x] `cargo build` clean
- [x] Full UI test suite on Linux: 2888 passing, 2 failing (both known,
neither ours)
- [x] `make integration-test`

Author: cds-amal

.gitignore

@@ -1,3 +1,4 @@
 target/
 tests/ui/failing/*
-tests/ui/passing/*
+tests/ui/passing/*
+tests/ui/debug/*

CHANGELOG.md

@@ -27,10 +27,15 @@ retroactive best-effort summary; earlier changes were not formally tracked.
 - Restructured `printer.rs` into a declarative 3-phase pipeline: `collect_items` -> `collect_and_analyze_items` -> `assemble_smir`, with `CollectedCrate`/`DerivedInfo` interface types enforcing the boundary between collection and assembly
 - Added `AllocMap` with debug-mode coherence checking (`verify_coherence`): asserts that every `AllocId` in stored bodies exists in the alloc map and that no body is walked twice; zero cost in release builds
 - Removed dead static-item fixup from `assemble_smir` (violated the phase boundary, misclassified statics as functions; never triggered in integration tests)
+- Rewrote `run_ui_tests.sh`: flag-based CLI (`--verbose`, `--save-generated-output`, `--save-debug-output`), build-once-then-invoke (eliminates per-test cargo overhead), arch-aware skip logic for cross-platform test lists
+- UI test runners now extract and pass `//@ compile-flags:`, `//@ edition:`, and `//@ rustc-env:` directives from test files (previously silently ignored)
 - Switched from compiler build to `rustup`-managed toolchain ([#33])
 - Removed forked rust dependency ([#19])
 
 ### Fixed
+- Fixed `get_prov_ty` to recursively walk nested struct/tuple fields when resolving provenance types; previously used exact byte-offset matching which panicked on pointers inside nested structs (e.g., `&str` at offset 56 inside `TestDesc` inside `TestDescAndFn`)
+- Removed incorrect `builtin_deref` assertions from VTable and Static allocation collection that rejected valid non-pointer types (raw `*const ()` vtable pointers, non-pointer statics)
+- Replaced panicking `unwrap`/`assert` calls in `get_prov_ty` with graceful fallbacks for layout failures, non-rigid types, and unexpected offsets
 - Fixed early `return` in `BodyAnalyzer::visit_terminator` that skipped `super_terminator()`, causing alloc/type/span collection to miss everything inside `Call` terminators with non-`ZeroSized` function operands (const-evaluated function pointers); bug present since [`aff2dd0`](https://github.com/runtimeverification/stable-mir-json/commit/aff2dd0)
 - Avoided duplicate `inst.body()` calls that were reallocating `AllocId`s ([#120])
 - Prevented svg/png generation when `dot` is unavailable ([#117])

Makefile

@@ -63,12 +63,7 @@ remake-ui-tests:
 
 test-ui: VERBOSE?=0
 test-ui:
-	# Check if RUST_DIR_ROOT is set
-	if [ -z "$$RUST_DIR_ROOT" ]; then \
-	  echo "Error: RUST_DIR_ROOT is not set. Please set it to the absolute path to rust compiler checkout."; \
-	  exit 1; \
-	fi
-	bash tests/ui/run_ui_tests.sh "$$RUST_DIR_ROOT" "${VERBOSE}"
+	bash tests/ui/run_ui_tests.sh $(if $(filter 1,$(VERBOSE)),--verbose) "$$RUST_DIR_ROOT"
 
 .PHONY: dot svg png d2 clean-graphs check-graphviz
 

src/printer.rs

@@ -844,40 +844,72 @@ fn update_link_map<'tcx>(
 /// Returns the field index (source order) for a given offset and layout if
 /// the layout contains fields (shared between all variants), otherwise None.
 /// NB No search for fields within variants (needs recursive call).
-fn field_for_offset(l: LayoutShape, offset: usize) -> Option<usize> {
-    // FieldIdx
-    match l.fields {
+fn field_for_offset(l: &LayoutShape, offset: usize) -> Option<usize> {
+    match &l.fields {
         FieldsShape::Primitive | FieldsShape::Union(_) | FieldsShape::Array { .. } => None,
+        FieldsShape::Arbitrary { offsets } => offsets
+            .iter()
+            .enumerate()
+            .find(|(_, o)| o.bytes() == offset)
+            .map(|(i, _)| i),
+    }
+}
+
+/// Find the field whose byte range contains the given offset.
+/// Returns (field_index, field_start_byte_offset).
+fn field_containing_offset(l: &LayoutShape, offset: usize) -> Option<(usize, usize)> {
+    match &l.fields {
         FieldsShape::Arbitrary { offsets } => {
-            let fields: Vec<usize> = offsets.into_iter().map(|o| o.bytes()).collect();
-            fields
-                .into_iter()
+            let mut indexed: Vec<(usize, usize)> = offsets
+                .iter()
                 .enumerate()
-                .find(|(_, o)| *o == offset)
-                .map(|(i, _)| i)
+                .map(|(i, o)| (i, o.bytes()))
+                .collect();
+            indexed.sort_by_key(|&(_, o)| o);
+            // The containing field is the one with the largest start offset <= target.
+            indexed.into_iter().rev().find(|&(_, o)| o <= offset)
         }
+        _ => None,
     }
 }
 
 fn get_prov_ty(ty: stable_mir::ty::Ty, offset: &usize) -> Option<stable_mir::ty::Ty> {
     use stable_mir::ty::RigidTy;
     let ty_kind = ty.kind();
+    debug_log_println!("get_prov_ty: {:?} offset={}", ty_kind, offset);
     // if ty is a pointer, box, or Ref, expect no offset and dereference
-    if let Some(ty) = ty_kind.builtin_deref(true) {
-        assert!(*offset == 0);
-        return Some(ty.ty);
+    if let Some(derefed) = ty_kind.builtin_deref(true) {
+        if *offset != 0 {
+            eprintln!(
+                "get_prov_ty: unexpected non-zero offset {} for builtin_deref type {:?}",
+                offset, ty_kind
+            );
+            return None;
+        }
+        debug_log_println!("get_prov_ty: resolved -> pointee {:?}", derefed.ty.kind());
+        return Some(derefed.ty);
     }
 
     // Otherwise the allocation is a reference within another kind of data.
     // Decompose this outer data type to determine the reference type
-    let layout = ty
-        .layout()
-        .map(|l| l.shape())
-        .expect("Unable to get layout for {ty_kind:?}");
-    let ref_ty = match ty_kind
-        .rigid()
-        .expect("Non-rigid-ty allocation found! {ty_kind:?}")
-    {
+    let layout = match ty.layout().map(|l| l.shape()) {
+        Ok(l) => l,
+        Err(_) => {
+            eprintln!("get_prov_ty: unable to get layout for {:?}", ty_kind);
+            return None;
+        }
+    };
+    let rigid = match ty_kind.rigid() {
+        Some(r) => r,
+        None => {
+            eprintln!(
+                "get_prov_ty: non-rigid type in allocation: {:?} (offset={})",
+                ty_kind, offset
+            );
+            return None;
+        }
+    };
+    let ref_ty = match rigid {
         // homogenous, so no choice. Could check alignment of the offset...
         RigidTy::Array(ty, _) | RigidTy::Slice(ty) => Some(*ty),
         // cases covered above
@@ -887,16 +919,24 @@ fn get_prov_ty(ty: stable_mir::ty::Ty, offset: &usize) -> Option<stable_mir::ty:
         RigidTy::Adt(def, _) if def.is_box() => {
             unreachable!("Covered by builtin_deref above")
         }
-        // For other structs, consult layout to determine field type
+        // For structs, find the field containing this offset and recurse.
+        // The provenance offset may point into a nested struct field, so we
+        // walk down through the field hierarchy until we reach the pointer.
         RigidTy::Adt(adt_def, args) if ty_kind.is_struct() => {
-            let field_idx = field_for_offset(layout, *offset).unwrap();
+            let (field_idx, field_start) = field_containing_offset(&layout, *offset)?;
             // NB struct, single variant
-            let fields = adt_def.variants().pop().map(|v| v.fields()).unwrap();
-            fields.get(field_idx).map(|f| f.ty_with_args(args))
+            let fields = adt_def.variants().pop().map(|v| v.fields())?;
+            let field_ty = fields.get(field_idx)?.ty_with_args(args);
+            let relative_offset = *offset - field_start;
+            debug_log_println!(
+                "get_prov_ty: struct {:?} offset={} -> field {} (start={}) type {:?}, relative_offset={}",
+                adt_def, offset, field_idx, field_start, field_ty.kind(), relative_offset
+            );
+            return get_prov_ty(field_ty, &relative_offset);
         }
         RigidTy::Adt(_adt_def, _args) if ty_kind.is_enum() => {
             // we have to figure out which variant we are dealing with (requires the data)
-            match field_for_offset(layout, *offset) {
+            match field_for_offset(&layout, *offset) {
                 None =>
                 // FIXME we'd have to figure out which variant we are dealing with (requires the data)
                 {
@@ -909,9 +949,20 @@ fn get_prov_ty(ty: stable_mir::ty::Ty, offset: &usize) -> Option<stable_mir::ty:
                 }
             }
         }
+        // Same as structs: find containing field and recurse.
         RigidTy::Tuple(fields) => {
-            let field_idx = field_for_offset(layout, *offset)?;
-            fields.get(field_idx).copied()
+            let (field_idx, field_start) = field_containing_offset(&layout, *offset)?;
+            let field_ty = *fields.get(field_idx)?;
+            let relative_offset = *offset - field_start;
+            debug_log_println!(
+                "get_prov_ty: tuple offset={} -> field {} (start={}) type {:?}, relative_offset={}",
+                offset,
+                field_idx,
+                field_start,
+                field_ty.kind(),
+                relative_offset
+            );
+            return get_prov_ty(field_ty, &relative_offset);
         }
         RigidTy::FnPtr(_) => None,
         _unimplemented => {
@@ -972,21 +1023,11 @@ fn collect_alloc(
             }
         }
         GlobalAlloc::Static(_) => {
-            assert!(
-                kind.clone().builtin_deref(true).is_some(),
-                "Allocated pointer is not a built-in pointer type: {:?}",
-                kind
-            );
             val_collector
                 .visited_allocs
                 .insert(val, (ty, global_alloc.clone()));
         }
         GlobalAlloc::VTable(_, _) => {
-            assert!(
-                kind.clone().builtin_deref(true).is_some(),
-                "Allocated pointer is not a built-in pointer type: {:?}",
-                kind
-            );
             val_collector
                 .visited_allocs
                 .insert(val, (ty, global_alloc.clone()));

tests/ui/failing.tsv

@@ -1,25 +1,2 @@
-tests/ui/async-await/issue-60709.rs	101
-tests/ui/async-await/issues/issue-59972.rs	101
-tests/ui/box/thin_align.rs	101
-tests/ui/box/thin_drop.rs	101
-tests/ui/box/thin_new.rs	101
-tests/ui/box/thin_zst.rs	101
-tests/ui/cfg/cfg_attr.rs	101
-tests/ui/cfg/cfgs-on-items.rs	101
-tests/ui/consts/const-eval/const_fn_ptr.rs	101
-tests/ui/consts/const-int-arithmetic-overflow.rs	101
-tests/ui/consts/const-trait-to-trait.rs	101
-tests/ui/env-macro/env-env-overload.rs	101
-tests/ui/env-macro/env-env.rs	101
-tests/ui/fmt/fmt_debug/none.rs	101
-tests/ui/issues/issue-11205.rs	101
 tests/ui/issues/issue-26641.rs	101
-tests/ui/label/label_break_value_desugared_break.rs	101
-tests/ui/macros/macro-meta-items.rs	101
-tests/ui/rfcs/rfc-2091-track-caller/caller-location-fnptr-rt-ctfe-equiv.rs	101
-tests/ui/test-attrs/test-panic-while-printing.rs	101
-tests/ui/traits/const-traits/const-drop.rs	101
-tests/ui/try-block/issue-45124.rs	101
-tests/ui/try-block/try-block-in-match.rs	101
-tests/ui/try-block/try-block-in-return.rs	101
-tests/ui/try-block/try-block.rs	101
+tests/ui/sanitizer/cfi/drop-in-place.rs	101

tests/ui/passing.tsv

@@ -181,6 +181,8 @@ tests/ui/associated-types/issue-54467.rs
 tests/ui/associated-types/issue-55846.rs
 tests/ui/associated-types/object-method-numbering.rs
 tests/ui/async-await/context-is-sorta-unwindsafe.rs
+tests/ui/async-await/issue-60709.rs
+tests/ui/async-await/issues/issue-59972.rs
 tests/ui/attributes/tool_attributes.rs
 tests/ui/augmented-assignments-rpass.rs
 tests/ui/auto-instantiate.rs
@@ -350,6 +352,10 @@ tests/ui/box/into-boxed-slice.rs
 tests/ui/box/new-box-syntax.rs
 tests/ui/box/new-box.rs
 tests/ui/box/new.rs
+tests/ui/box/thin_align.rs
+tests/ui/box/thin_drop.rs
+tests/ui/box/thin_new.rs
+tests/ui/box/thin_zst.rs
 tests/ui/box/unit/expr-block-generic-unique1.rs
 tests/ui/box/unit/expr-block-generic-unique2.rs
 tests/ui/box/unit/expr-if-unique.rs
@@ -412,7 +418,9 @@ tests/ui/cfg/cfg-macros-notfoo.rs
 tests/ui/cfg/cfg-target-abi.rs
 tests/ui/cfg/cfg-target-compact.rs
 tests/ui/cfg/cfg-target-vendor.rs
+tests/ui/cfg/cfg_attr.rs
 tests/ui/cfg/cfg_stmt_expr.rs
+tests/ui/cfg/cfgs-on-items.rs
 tests/ui/cfg/conditional-compile.rs
 tests/ui/cfg/true-false.rs
 tests/ui/cfguard-run.rs
@@ -629,6 +637,7 @@ tests/ui/consts/const-enum-vec-index.rs
 tests/ui/consts/const-enum-vec-ptr.rs
 tests/ui/consts/const-enum-vector.rs
 tests/ui/consts/const-err-rpass.rs
+tests/ui/consts/const-eval/const_fn_ptr.rs
 tests/ui/consts/const-eval/enum_discr.rs
 tests/ui/consts/const-eval/float_methods.rs
 tests/ui/consts/const-eval/heap/alloc_intrinsic_nontransient.rs
@@ -654,6 +663,7 @@ tests/ui/consts/const-fn-type-name.rs
 tests/ui/consts/const-fn-val.rs
 tests/ui/consts/const-fn.rs
 tests/ui/consts/const-index-feature-gate.rs
+tests/ui/consts/const-int-arithmetic-overflow.rs
 tests/ui/consts/const-int-arithmetic.rs
 tests/ui/consts/const-int-conversion-rpass.rs
 tests/ui/consts/const-int-overflowing-rpass.rs
@@ -678,6 +688,7 @@ tests/ui/consts/const-repeated-values.rs
 tests/ui/consts/const-size_of-align_of.rs
 tests/ui/consts/const-size_of_val-align_of_val.rs
 tests/ui/consts/const-struct.rs
+tests/ui/consts/const-trait-to-trait.rs
 tests/ui/consts/const-tuple-struct.rs
 tests/ui/consts/const-typeid-of-rpass.rs
 tests/ui/consts/const-unit-struct.rs
@@ -959,6 +970,8 @@ tests/ui/enum/issue-19340-2.rs
 tests/ui/enum/issue-23304-1.rs
 tests/ui/enum/issue-23304-2.rs
 tests/ui/enum/issue-42747.rs
+tests/ui/env-macro/env-env-overload.rs
+tests/ui/env-macro/env-env.rs
 tests/ui/env-macro/option_env-not-defined.rs
 tests/ui/errors/remap-path-prefix-macro.rs
 tests/ui/explicit-i-suffix.rs
@@ -998,6 +1011,7 @@ tests/ui/float/classify-runtime-const.rs
 tests/ui/float/conv-bits-runtime-const.rs
 tests/ui/float/int-to-float-miscompile-issue-105626.rs
 tests/ui/fmt/fmt_debug/full.rs
+tests/ui/fmt/fmt_debug/none.rs
 tests/ui/fmt/fmt_debug/shallow.rs
 tests/ui/fmt/format-args-capture-macro-hygiene-pass.rs
 tests/ui/fmt/format-args-capture.rs
@@ -1249,6 +1263,7 @@ tests/ui/issues/issue-10802.rs
 tests/ui/issues/issue-10806.rs
 tests/ui/issues/issue-11047.rs
 tests/ui/issues/issue-11085.rs
+tests/ui/issues/issue-11205.rs
 tests/ui/issues/issue-11267.rs
 tests/ui/issues/issue-11382.rs
 tests/ui/issues/issue-11552.rs
@@ -1647,6 +1662,7 @@ tests/ui/iterators/iter-sum-overflow-debug.rs
 tests/ui/iterators/iter-sum-overflow-ndebug.rs
 tests/ui/iterators/iter-sum-overflow-overflow-checks.rs
 tests/ui/iterators/skip-count-overflow.rs
+tests/ui/label/label_break_value_desugared_break.rs
 tests/ui/last-use-in-cap-clause.rs
 tests/ui/last-use-is-capture.rs
 tests/ui/late-bound-lifetimes/issue-36381.rs
@@ -1742,6 +1758,7 @@ tests/ui/macros/macro-lifetime-used-with-labels.rs
 tests/ui/macros/macro-lifetime-used-with-static.rs
 tests/ui/macros/macro-lifetime.rs
 tests/ui/macros/macro-literal.rs
+tests/ui/macros/macro-meta-items.rs
 tests/ui/macros/macro-metavar-expr-concat/allowed-operations.rs
 tests/ui/macros/macro-metavar-expr-concat/repetitions.rs
 tests/ui/macros/macro-metavar-expr-concat/unicode-expansion.rs
@@ -2271,6 +2288,7 @@ tests/ui/rfcs/rfc-2008-non-exhaustive/structs_same_crate.rs
 tests/ui/rfcs/rfc-2008-non-exhaustive/variants_same_crate.rs
 tests/ui/rfcs/rfc-2027-dyn-compatible-for-dispatch/manual-self-impl-for-unsafe-obj.rs
 tests/ui/rfcs/rfc-2091-track-caller/call-chain.rs
+tests/ui/rfcs/rfc-2091-track-caller/caller-location-fnptr-rt-ctfe-equiv.rs
 tests/ui/rfcs/rfc-2091-track-caller/caller-location-intrinsic.rs
 tests/ui/rfcs/rfc-2091-track-caller/const-caller-location.rs
 tests/ui/rfcs/rfc-2091-track-caller/intrinsic-wrapper.rs
@@ -2308,7 +2326,6 @@ tests/ui/runtime/stdout-before-main.rs
 tests/ui/runtime/stdout-during-shutdown-unix.rs
 tests/ui/runtime/stdout-during-shutdown-windows.rs
 tests/ui/sanitizer/cfi/complex-receiver.rs
-tests/ui/sanitizer/cfi/drop-in-place.rs
 tests/ui/sanitizer/cfi/fn-ptr.rs
 tests/ui/sanitizer/cfi/self-ref.rs
 tests/ui/sanitizer/cfi/sized-associated-ty.rs
@@ -2527,6 +2544,7 @@ tests/ui/syntax-extension-minor.rs
 tests/ui/tail-call-arg-leak.rs
 tests/ui/tail-cps.rs
 tests/ui/test-attrs/test-main-not-dead.rs
+tests/ui/test-attrs/test-panic-while-printing.rs
 tests/ui/test-attrs/test-runner-hides-main.rs
 tests/ui/thread-local/tls.rs
 tests/ui/threads-sendsync/child-outlives-parent.rs
@@ -2602,6 +2620,7 @@ tests/ui/traits/bug-7295.rs
 tests/ui/traits/coercion-generic.rs
 tests/ui/traits/coercion.rs
 tests/ui/traits/conditional-dispatch.rs
+tests/ui/traits/const-traits/const-drop.rs
 tests/ui/traits/const-traits/specialization/const-default-const-specialized.rs
 tests/ui/traits/const-traits/specialization/non-const-default-const-specialized.rs
 tests/ui/traits/const-traits/trait-where-clause-run.rs
@@ -2713,6 +2732,10 @@ tests/ui/traits/with-bounds-default.rs
 tests/ui/transmute-non-immediate-to-immediate.rs
 tests/ui/transmute/transmute-zst-generics.rs
 tests/ui/trivial_casts-rpass.rs
+tests/ui/try-block/issue-45124.rs
+tests/ui/try-block/try-block-in-match.rs
+tests/ui/try-block/try-block-in-return.rs
+tests/ui/try-block/try-block.rs
 tests/ui/try-block/try-is-identifier-edition2015.rs
 tests/ui/try-from-int-error-partial-eq.rs
 tests/ui/try-operator-hygiene.rs