iASL: Emit remark for unreferenced objects declared in methods.

Adds support to detect names that are declared within a control method,
but are unused (these are temporary names that are only valid during
the time the method is executing). A remark is issued for these cases.
ACPICA BZ 1022.

2 files changed, 46 insertions, 12 deletions

diff --git a/source/compiler/asllookup.c b/source/compiler/asllookup.c
index 82a833476..259df47e7 100644
--- a/source/compiler/asllookup.c
+++ b/source/compiler/asllookup.c
@@ -177,7 +177,9 @@ LkFindUnreferencedObjects (
  * DESCRIPTION: Check for an unreferenced namespace object and emit a warning.
  *              We have to be careful, because some types and names are
  *              typically or always unreferenced, we don't want to issue
- *              excessive warnings.
+ *              excessive warnings. Note: Names that are declared within a
+ *              control method are temporary, so we always issue a remark
+ *              if they are not referenced.
  *
  ******************************************************************************/
 
@@ -189,6 +191,7 @@ LkIsObjectUsed (
     void                    **ReturnValue)
 {
     ACPI_NAMESPACE_NODE     *Node = ACPI_CAST_PTR (ACPI_NAMESPACE_NODE, ObjHandle);
+    ACPI_NAMESPACE_NODE     *Next;
 
 
     /* Referenced flag is set during the namespace xref */
@@ -198,23 +201,19 @@ LkIsObjectUsed (
         return (AE_OK);
     }
 
-    /*
-     * Ignore names that start with an underscore,
-     * these are the reserved ACPI names and are typically not referenced,
-     * they are called by the host OS.
-     */
-    if (Node->Name.Ascii[0] == '_')
+    if (!Node->Op)
     {
         return (AE_OK);
     }
 
-    /* There are some types that are typically not referenced, ignore them */
+    /* These types are typically never directly referenced, ignore them */
 
     switch (Node->Type)
     {
     case ACPI_TYPE_DEVICE:
     case ACPI_TYPE_PROCESSOR:
     case ACPI_TYPE_POWER:
+    case ACPI_TYPE_THERMAL:
     case ACPI_TYPE_LOCAL_RESOURCE:
 
         return (AE_OK);
@@ -224,12 +223,47 @@ LkIsObjectUsed (
         break;
     }
 
-    /* All others are valid unreferenced namespace objects */
+    /* Determine if the name is within a control method */
 
-    if (Node->Op)
+    Next = Node->Parent;
+    while (Next)
     {
-        AslError (ASL_WARNING2, ASL_MSG_NOT_REFERENCED, LkGetNameOp (Node->Op), NULL);
+        if (Next->Type == ACPI_TYPE_METHOD)
+        {
+            /*
+             * Name is within a method, therefore it is temporary.
+             * Issue a remark even if it is a reserved name (starts
+             * with an underscore).
+             */
+            sprintf (MsgBuffer, "Name is within method [%4.4s]",
+                Next->Name.Ascii);
+            AslError (ASL_REMARK, ASL_MSG_NOT_REFERENCED,
+                LkGetNameOp (Node->Op), MsgBuffer);
+            return (AE_OK);
+        }
+
+        Next = Next->Parent;
     }
+
+    /* The name is not within a control method */
+
+    /*
+     * Ignore names that start with an underscore. These are the reserved
+     * ACPI names and are typically not referenced since they are meant
+     * to be called by the host OS.
+     */
+    if (Node->Name.Ascii[0] == '_')
+    {
+        return (AE_OK);
+    }
+
+    /*
+     * What remains is an unresolved user name that is not within a method.
+     * However, the object could be referenced via another table, so issue
+     * the warning at level 2.
+     */
+    AslError (ASL_WARNING2, ASL_MSG_NOT_REFERENCED,
+        LkGetNameOp (Node->Op), NULL);
     return (AE_OK);
 }
 
diff --git a/source/compiler/aslmessages.h b/source/compiler/aslmessages.h
index 16c1d9469..a3f6c8bce 100644
--- a/source/compiler/aslmessages.h
+++ b/source/compiler/aslmessages.h
@@ -441,7 +441,7 @@ char                        *AslMessages [] =
 /*    ASL_MSG_NOT_METHOD */                 "Not a control method, cannot invoke",
 /*    ASL_MSG_NOT_PARAMETER */              "Not a parameter, used as local only",
 /*    ASL_MSG_NOT_REACHABLE */              "Object is not accessible from this scope",
-/*    ASL_MSG_NOT_REFERENCED */             "Namespace object is not referenced",
+/*    ASL_MSG_NOT_REFERENCED */             "Object is not referenced",
 /*    ASL_MSG_NULL_DESCRIPTOR */            "Min/Max/Length/Gran are all zero, but no resource tag",
 /*    ASL_MSG_NULL_STRING */                "Invalid zero-length (null) string",
 /*    ASL_MSG_OPEN */                       "Could not open file",