cmd/llvmplugin: accept non-ABI pointer parameter attributes

src/cmd/llvmplugin/CMakeLists.txt

@@ -129,6 +129,32 @@ if(BUILD_TESTING)
       "ptr nest %context"
   )
 
+  add_test(
+    NAME GoALLCStatepoints.SupportedParamAttrsRewrite
+    COMMAND
+      "${GOALLC_LLC_EXECUTABLE}"
+      "-load-pass-plugin=$<TARGET_FILE:GoALLCStatepoints>"
+      -goallc-pass-plugin-emit-ir
+      -filetype=null
+      -o -
+      "${CMAKE_CURRENT_SOURCE_DIR}/testdata/supported-param-attrs.ll"
+  )
+  set_tests_properties(GoALLCStatepoints.SupportedParamAttrsRewrite PROPERTIES
+    PASS_REGULAR_EXPRESSION
+      "ptr noundef nonnull align 8 %argument"
+  )
+
+  add_test(
+    NAME GoALLCStatepoints.SupportedParamAttrsCodegen
+    COMMAND
+      "${GOALLC_LLC_EXECUTABLE}"
+      "-load-pass-plugin=$<TARGET_FILE:GoALLCStatepoints>"
+      -verify-machineinstrs
+      -filetype=obj
+      -o "${CMAKE_CURRENT_BINARY_DIR}/supported-param-attrs.goobj"
+      "${CMAKE_CURRENT_SOURCE_DIR}/testdata/supported-param-attrs.ll"
+  )
+
   add_test(
     NAME GoALLCStatepoints.CallOnlyPointersNotLive
     COMMAND

src/cmd/llvmplugin/GoALLCStatepoints.cpp

@@ -692,13 +692,22 @@ Error validateSafepoint(const SafepointRecord &Record) {
         "GoALLC statepoints only support a single deopt call operand bundle");
   for (unsigned I = 0; I != Call.arg_size(); ++I) {
     for (Attribute Attr : Call.getAttributes().getParamAttrs(I)) {
+      // These non-ABI attributes remain valid after LLVM's generic
+      // RewriteStatepointsForGC pass and are natively accepted by both the
+      // statepoint verifier and SelectionDAG call lowering. O2 commonly
+      // infers them on otherwise ordinary runtime calls. Keep ABI-affecting
+      // attributes fail closed except for nest, whose Go closure ABI lowering
+      // is covered separately.
       if (!Attr.hasAttribute(Attribute::Nest) &&
           !Attr.hasAttribute(Attribute::Captures) &&
-          !Attr.hasAttribute(Attribute::ReadOnly))
+          !Attr.hasAttribute(Attribute::ReadOnly) &&
+          !Attr.hasAttribute(Attribute::NonNull) &&
+          !Attr.hasAttribute(Attribute::NoUndef) &&
+          !Attr.hasAttribute(Attribute::Alignment))
         return createStringError(
             std::errc::not_supported,
-            "GoALLC statepoints only support nest, captures, and readonly "
-            "call parameter attributes");
+            "GoALLC statepoints do not support call parameter attribute '%s'",
+            Attr.getAsString().c_str());
     }
   }
   for (Value *V : Record.Live) {

src/cmd/llvmplugin/testdata/supported-param-attrs.ll

@@ -0,0 +1,11 @@
+target triple = "aarch64-unknown-linux-goobj"
+
+declare goabiinternal void @supported_callee(ptr)
+
+define goabiinternal void @supported_param_attrs(ptr %argument) #0 gc "goallc" {
+entry:
+  call goabiinternal void @supported_callee(ptr noundef nonnull align 8 %argument)
+  ret void
+}
+
+attributes #0 = { "frame-pointer"="non-leaf" "go-stack-growth-statepoint" }