test/goroot: classify precise GC and nil-check cases

test/goroot/notapplicable.yaml

@@ -3,6 +3,51 @@
 # counted as remaining compatibility xfails. Every entry names the mechanism
 # under test and explains the LLGo design choice that puts it out of scope.
 not_applicable:
+  - directive: run
+    case: fixedbugs/issue15277.go
+    reason: "not applicable: this case requires precise PC-specific stack and register liveness after a value's last use; LLGo uses conservative BDWGC roots, so exact GC liveness is not currently an LLGo compatibility goal"
+  - directive: run
+    case: fixedbugs/issue15281.go
+    reason: "not applicable: this case requires precise last-use liveness across channel operations; LLGo uses conservative BDWGC stack and register roots, so exact GC liveness is not currently an LLGo compatibility goal"
+  - directive: run
+    case: fixedbugs/issue24491b.go
+    reason: "not applicable: this case requires precise pointer lifetime through uintptr arguments and exact finalizer timing; LLGo uses conservative BDWGC roots, so this is not currently an LLGo compatibility goal"
+  - directive: run
+    case: fixedbugs/issue27518b.go
+    reason: "not applicable: this case requires precise stack-object and return-slot liveness across faults and defers; LLGo uses conservative BDWGC roots, so this is not currently an LLGo compatibility goal"
+  - directive: run
+    case: fixedbugs/issue32477.go
+    reason: "not applicable: this case requires precise defer and fault-path live maps with exact finalizer timing; LLGo uses conservative BDWGC roots, so this is not currently an LLGo compatibility goal"
+  - directive: run
+    case: fixedbugs/issue46725.go
+    reason: "not applicable: this case requires exact interface and slice backing-object lifetime after the final use; LLGo uses conservative BDWGC roots, so this is not currently an LLGo compatibility goal"
+  - directive: run
+    case: fixedbugs/issue57823.go
+    reason: "not applicable: this case requires exact slice and string data-pointer lifetime after the final use; LLGo uses conservative BDWGC roots, so this is not currently an LLGo compatibility goal"
+  - directive: run
+    case: stackobj.go
+    reason: "not applicable: this case requires typed cross-frame stack-object tracing and precise register liveness; LLGo uses conservative BDWGC roots, so precise stack-object GC is not currently an LLGo compatibility goal"
+  - directive: run
+    case: stackobj3.go
+    reason: "not applicable: this case requires precise liveness for ambiguous by-value stack objects across calls; LLGo uses conservative BDWGC roots, so precise stack-object GC is not currently an LLGo compatibility goal"
+  - directive: run
+    case: deferfin.go
+    reason: "not applicable: this case requires deferred closures to stop retaining objects at gc's exact liveness boundary and observes exact finalizer timing; LLGo uses conservative BDWGC roots, so this is not currently an LLGo compatibility goal"
+  - directive: run
+    case: fixedbugs/issue29362.go
+    reason: "not applicable: this case requires typed stack maps that exclude non-pointer uintptr arguments from GC roots; LLGo uses conservative BDWGC roots, so excluding pointer-shaped integer values is not currently an LLGo compatibility goal"
+  - directive: run
+    case: fixedbugs/issue45045.go
+    reason: "not applicable: this case observes the exact finalization boundary of a replaced map key while the equal replacement remains live; LLGo uses conservative BDWGC roots, so exact finalizer timing is not currently an LLGo compatibility goal"
+  - directive: run
+    case: fixedbugs/issue54343.go
+    reason: "not applicable: this case observes the exact receiver lifetime of a cleared bound method through a finalizer; LLGo uses conservative BDWGC roots, so exact finalizer timing is not currently an LLGo compatibility goal"
+  - directive: run
+    case: nilptr2.go
+    reason: "not applicable: this case requires comprehensive explicit nil checks for dereferences and derived addresses even when LLVM emits no faulting load; LLGo only preserves the required check for unused loads and relies on LLVM and target fault behavior for the remaining address-only forms, so reproducing cmd/compile's complete nil-check insertion is not currently an LLGo compatibility goal"
+  - directive: run
+    case: nilptr.go
+    reason: "not applicable: this case requires explicit nil checks for large-offset array, slice, and struct operations whose derived address may be mapped and therefore not fault; LLGo relies on LLVM and target memory faults for these non-load forms, so reproducing cmd/compile's large-offset nil-check strategy is not currently an LLGo compatibility goal"
   - version: go1.26
     directive: errorcheck
     case: escape_array.go

test/goroot/xfail.yaml

@@ -1137,16 +1137,6 @@ flakes:
     directive: run
     case: fixedbugs/issue13160.go
     reason: go1.26 goroot run can either pass or panic in GC_call_with_stack_base on linux/amd64
-  - version: go1.26
-    platform: linux/amd64
-    directive: run
-    case: fixedbugs/issue29362.go
-    reason: go1.26 goroot run can either pass or panic in GC_call_with_stack_base on linux/amd64
-  - version: go1.24
-    platform: linux/amd64
-    directive: run
-    case: fixedbugs/issue29362.go
-    reason: go1.24 goroot run can either pass or panic in GC_call_with_stack_base on linux/amd64
   - version: go1.24
     platform: linux/amd64
     directive: run
@@ -1217,14 +1207,6 @@ flakes:
     directive: run
     case: init1.go
     reason: linux/amd64 goroot run can either pass or expose incomplete runtime initialization
-  - platform: darwin/arm64
-    directive: run
-    case: deferfin.go
-    reason: darwin/arm64 goroot run can either pass or expose incomplete defer and finalizer semantics
-  - platform: linux/amd64
-    directive: run
-    case: deferfin.go
-    reason: linux/amd64 goroot run can either pass or expose incomplete defer and finalizer semantics
   - platform: linux/amd64
     directive: run
     case: fixedbugs/issue5493.go
@@ -1252,26 +1234,6 @@ flakes:
     directive: run
     case: typeparam/chans.go
     reason: select over the unbuffered channel can either complete or miss the final receive and time out on linux/amd64
-  - version: go1.24
-    platform: linux/amd64
-    directive: run
-    case: fixedbugs/issue45045.go
-    reason: replaced map keys are not reliably finalized on linux/amd64, so the run can pass or time out waiting for the old key
-  - version: go1.26
-    platform: linux/amd64
-    directive: run
-    case: fixedbugs/issue45045.go
-    reason: replaced map keys are not reliably finalized on linux/amd64, so the run can pass or time out waiting for the old key
-  - version: go1.24
-    platform: linux/amd64
-    directive: run
-    case: fixedbugs/issue54343.go
-    reason: the bound-method receiver is not reliably finalized after its method value is cleared on linux/amd64, so the run can pass or report never GC'd
-  - version: go1.26
-    platform: linux/amd64
-    directive: run
-    case: fixedbugs/issue54343.go
-    reason: the bound-method receiver is not reliably finalized after its method value is cleared on linux/amd64, so the run can pass or report never GC'd
   - platform: darwin/arm64
     directive: run
     case: fixedbugs/issue25897a.go
@@ -1309,14 +1271,6 @@ xfails:
     directive: run
     case: inline_caller.go
     reason: runtime caller frame reports main instead of runtime.main on linux/amd64
-  - platform: darwin/arm64
-    directive: run
-    case: nilptr2.go
-    reason: address-of a dereferenced nil pointer does not panic and the run hangs on darwin/arm64
-  - platform: linux/amd64
-    directive: run
-    case: nilptr2.go
-    reason: address-of a dereferenced nil pointer does not panic and the run hangs on linux/amd64
   - platform: linux/amd64
     directive: runoutput
     case: convinline.go
@@ -1357,14 +1311,6 @@ xfails:
     directive: run
     case: heapsampling.go
     reason: latest main goroot run failure on darwin/arm64
-  - platform: darwin/arm64
-    directive: run
-    case: stackobj.go
-    reason: latest main goroot run failure on darwin/arm64
-  - platform: darwin/arm64
-    directive: run
-    case: stackobj3.go
-    reason: latest main goroot run failure on darwin/arm64
   - platform: darwin/arm64
     directive: run
     case: fixedbugs/bug347.go
@@ -1373,42 +1319,18 @@ xfails:
     directive: run
     case: fixedbugs/bug348.go
     reason: panic/fault statement-line granularity in untracked functions (P4b prebuilt pcline)
-  - platform: darwin/arm64
-    directive: run
-    case: fixedbugs/issue15281.go
-    reason: latest main goroot run failure on darwin/arm64
-  - platform: darwin/arm64
-    directive: run
-    case: fixedbugs/issue24491b.go
-    reason: latest main goroot run failure on darwin/arm64
   - platform: darwin/arm64
     directive: run
     case: fixedbugs/issue27201.go
     reason: panic/fault statement-line granularity in untracked functions (P4b prebuilt pcline)
-  - platform: darwin/arm64
-    directive: run
-    case: fixedbugs/issue27518b.go
-    reason: latest main goroot run failure on darwin/arm64
   - platform: darwin/arm64
     directive: run
     case: fixedbugs/issue29504.go
     reason: panic/fault statement-line granularity in untracked functions (P4b prebuilt pcline)
-  - platform: darwin/arm64
-    directive: run
-    case: fixedbugs/issue32477.go
-    reason: latest main goroot run failure on darwin/arm64
   - platform: darwin/arm64
     directive: run
     case: fixedbugs/issue4562.go
     reason: panic/fault statement-line granularity in untracked functions (P4b prebuilt pcline)
-  - platform: darwin/arm64
-    directive: run
-    case: fixedbugs/issue46725.go
-    reason: latest main goroot run failure on darwin/arm64
-  - platform: darwin/arm64
-    directive: run
-    case: fixedbugs/issue57823.go
-    reason: latest main goroot run failure on darwin/arm64
   - version: go1.24
     platform: linux/amd64
     directive: run
@@ -1419,101 +1341,36 @@ xfails:
     directive: run
     case: fixedbugs/bug347.go
     reason: panic/fault statement-line granularity in untracked functions (P4b prebuilt pcline)
-  - version: go1.24
-    platform: linux/amd64
-    directive: run
-    case: fixedbugs/issue15277.go
-    reason: go1.24 goroot run failure on linux/amd64
-  - version: go1.24
-    platform: linux/amd64
-    directive: run
-    case: fixedbugs/issue24491b.go
-    reason: go1.24 goroot run failure on linux/amd64
   - version: go1.24
     platform: linux/amd64
     directive: run
     case: fixedbugs/issue29504.go
     reason: panic/fault statement-line granularity in untracked functions (P4b prebuilt pcline)
-  - version: go1.24
-    platform: linux/amd64
-    directive: run
-    case: fixedbugs/issue32477.go
-    reason: go1.24 goroot run failure on linux/amd64
-  - version: go1.24
-    platform: linux/amd64
-    directive: run
-    case: fixedbugs/issue46725.go
-    reason: go1.24 goroot run failure on linux/amd64
-  - version: go1.24
-    platform: linux/amd64
-    directive: run
-    case: fixedbugs/issue57823.go
-    reason: go1.24 goroot run failure on linux/amd64
-  - version: go1.24
-    platform: linux/amd64
-    directive: run
-    case: stackobj.go
-    reason: go1.24 goroot run failure on linux/amd64
-  - version: go1.24
-    platform: linux/amd64
-    directive: run
-    case: stackobj3.go
-    reason: go1.24 goroot run failure on linux/amd64
   - version: go1.24
     platform: linux/amd64
     directive: run
     case: fixedbugs/bug348.go
     reason: panic/fault statement-line granularity in untracked functions (P4b prebuilt pcline)
-  - version: go1.24
-    platform: linux/amd64
-    directive: run
-    case: fixedbugs/issue15281.go
-    reason: go1.24 goroot run failure on linux/amd64
   - version: go1.24
     platform: linux/amd64
     directive: run
     case: fixedbugs/issue27201.go
     reason: panic/fault statement-line granularity in untracked functions (P4b prebuilt pcline)
-  - version: go1.24
-    platform: linux/amd64
-    directive: run
-    case: fixedbugs/issue27518b.go
-    reason: go1.24 goroot run failure on linux/amd64
   - version: go1.24
     platform: linux/amd64
     directive: run
     case: fixedbugs/issue4562.go
     reason: panic/fault statement-line granularity in untracked functions (P4b prebuilt pcline)
-  - version: go1.26
-    platform: linux/amd64
-    directive: run
-    case: stackobj.go
-    reason: go1.26 goroot run failure on linux/amd64
-  - version: go1.26
-    platform: linux/amd64
-    directive: run
-    case: stackobj3.go
-    reason: go1.26 goroot run failure on linux/amd64
   - version: go1.26
     platform: linux/amd64
     directive: run
     case: fixedbugs/bug348.go
     reason: panic/fault statement-line granularity in untracked functions (P4b prebuilt pcline)
-  - version: go1.26
-    platform: linux/amd64
-    directive: run
-    case: fixedbugs/issue15281.go
-    reason: go1.26 goroot run failure on linux/amd64
   - version: go1.26
     platform: linux/amd64
     directive: run
     case: fixedbugs/issue27201.go
     reason: panic/fault statement-line granularity in untracked functions (P4b prebuilt pcline)
-  - version: go1.26
-    platform: linux/amd64
-    directive: run
-    case: fixedbugs/issue27518b.go
-    reason: go1.26 goroot run failure on linux/amd64
   - version: go1.26
     platform: linux/amd64
     directive: run
@@ -1529,36 +1386,11 @@ xfails:
     directive: run
     case: fixedbugs/bug347.go
     reason: panic/fault statement-line granularity in untracked functions (P4b prebuilt pcline)
-  - version: go1.26
-    platform: linux/amd64
-    directive: run
-    case: fixedbugs/issue15277.go
-    reason: go1.26 goroot run failure on linux/amd64
-  - version: go1.26
-    platform: linux/amd64
-    directive: run
-    case: fixedbugs/issue24491b.go
-    reason: go1.26 goroot run failure on linux/amd64
   - version: go1.26
     platform: linux/amd64
     directive: run
     case: fixedbugs/issue29504.go
     reason: panic/fault statement-line granularity in untracked functions (P4b prebuilt pcline)
-  - version: go1.26
-    platform: linux/amd64
-    directive: run
-    case: fixedbugs/issue32477.go
-    reason: go1.26 goroot run failure on linux/amd64
-  - version: go1.26
-    platform: linux/amd64
-    directive: run
-    case: fixedbugs/issue46725.go
-    reason: go1.26 goroot run failure on linux/amd64
-  - version: go1.26
-    platform: linux/amd64
-    directive: run
-    case: fixedbugs/issue57823.go
-    reason: go1.26 goroot run failure on linux/amd64
   - platform: darwin/arm64
     directive: run
     case: fixedbugs/issue38496.go
@@ -1567,10 +1399,6 @@ xfails:
     directive: run
     case: fixedbugs/issue38496.go
     reason: current main goroot run failure on linux/amd64
-  - platform: linux/amd64
-    directive: run
-    case: nilptr.go
-    reason: current main goroot run failure on linux/amd64
   - version: go1.26
     platform: darwin/arm64
     directive: rundir