iASL: Add new warnings for method LocalX and ArgX variables.

1) Warn if a Local is set but never used
2) Warn if a ArgX is never used (for non-predefined method names)
3) Warn if a ArgX that is used as a local is never used

source/compiler/asllookup.c

@@ -191,8 +191,73 @@ LkIsObjectUsed (
 {
     ACPI_NAMESPACE_NODE     *Node = ACPI_CAST_PTR (ACPI_NAMESPACE_NODE, ObjHandle);
     ACPI_NAMESPACE_NODE     *Next;
+    ASL_METHOD_LOCAL        *MethodLocals;
+    ASL_METHOD_LOCAL        *MethodArgs;
+    UINT32                  i;
 
 
+    if (Node->Type == ACPI_TYPE_METHOD)
+    {
+        if (!Node->Op || !Node->MethodLocals)
+        {
+            return (AE_OK);
+        }
+
+        MethodLocals = (ASL_METHOD_LOCAL *) Node->MethodLocals;
+        MethodArgs = (ASL_METHOD_LOCAL *) Node->MethodArgs;
+
+        /*
+         * Analysis of LocalX variables
+         */
+        for (i = 0; i < ACPI_METHOD_NUM_LOCALS; i++)
+        {
+            /* Warn for Locals that are set but never referenced */
+
+            if ((MethodLocals[i].Flags & ASL_LOCAL_INITIALIZED) &&
+                (!(MethodLocals[i].Flags & ASL_LOCAL_REFERENCED)))
+            {
+                sprintf (MsgBuffer, "Local%u", i);
+                AslError (ASL_WARNING, ASL_MSG_LOCAL_NOT_USED,
+                    MethodLocals[i].Op, MsgBuffer);
+            }
+        }
+
+        /*
+         * Analysis of ArgX variables (standard method arguments,
+         * and remaining unused ArgX can also be used as locals)
+         */
+        for (i = 0; i < ACPI_METHOD_NUM_ARGS; i++)
+        {
+            if (MethodArgs[i].Flags & ASL_ARG_IS_LOCAL)
+            {
+                /* Warn if ArgX is being used as a local, but not referenced */
+
+                if ((MethodArgs[i].Flags & ASL_ARG_INITIALIZED) &&
+                    (!(MethodArgs[i].Flags & ASL_ARG_REFERENCED)))
+                {
+                    sprintf (MsgBuffer, "Arg%u", i);
+                    AslError (ASL_WARNING, ASL_MSG_ARG_AS_LOCAL_NOT_USED,
+                        MethodArgs[i].Op, MsgBuffer);
+                }
+            }
+            else
+            {
+                /*
+                 * Remark if a normal method ArgX is not referenced.
+                 * We ignore the predefined methods since often, not
+                 * all arguments are needed or used.
+                 */
+                if ((Node->Name.Ascii[0] != '_') &&
+                    (!(MethodArgs[i].Flags & ASL_ARG_REFERENCED)))
+                {
+                    sprintf (MsgBuffer, "Arg%u", i);
+                    AslError (ASL_REMARK, ASL_MSG_ARG_NOT_USED,
+                        MethodArgs[i].Op, MsgBuffer);
+                }
+            }
+        }
+    }
+
     /* Referenced flag is set during the namespace xref */
 
     if (Node->Flags & ANOBJ_IS_REFERENCED)

source/compiler/aslmessages.c

@@ -307,7 +307,11 @@ const char                      *AslCompilerMsgs [] =
 /*    ASL_MSG_BUFFER_ALLOCATION */          "Could not allocate line buffer",
 /*    ASL_MSG_MISSING_DEPENDENCY */         "Missing dependency",
 /*    ASL_MSG_ILLEGAL_FORWARD_REF */        "Illegal forward reference within a method",
-/*    ASL_MSG_ILLEGAL_METHOD_REF */         "Illegal reference across two methods"
+/*    ASL_MSG_ILLEGAL_METHOD_REF */         "Illegal reference across two methods",
+/*    ASL_MSG_LOCAL_NOT_USED */             "Method Local is set but never used",
+/*    ASL_MSG_ARG_AS_LOCAL_NOT_USED */      "Method Argument (as a local) is set but never used",
+/*    ASL_MSG_ARG_NOT_USED */               "Method Argument is never used"
+
 };
 
 /* Table compiler */

source/compiler/aslmessages.h

@@ -310,6 +310,9 @@ typedef enum
     ASL_MSG_MISSING_DEPENDENCY,
     ASL_MSG_ILLEGAL_FORWARD_REF,
     ASL_MSG_ILLEGAL_METHOD_REF,
+    ASL_MSG_LOCAL_NOT_USED,
+    ASL_MSG_ARG_AS_LOCAL_NOT_USED,
+    ASL_MSG_ARG_NOT_USED,
 
     /* These messages are used by the Data Table compiler only */
 

source/compiler/aslmethod.c

@@ -327,7 +327,7 @@ MtMethodAnalysisWalkBegin (
             return (AE_ERROR);
         }
 
-        RegisterNumber = (Op->Asl.AmlOpcode & 0x000F);
+        RegisterNumber = (Op->Asl.AmlOpcode & 0x0007);
 
         /*
          * If the local is being used as a target, mark the local

source/compiler/asltypes.h

@@ -374,5 +374,19 @@ typedef struct acpi_serial_info
 
 } ACPI_SERIAL_INFO;
 
+typedef struct asl_method_local
+{
+    ACPI_PARSE_OBJECT       *Op;
+    UINT8                   Flags;
+
+} ASL_METHOD_LOCAL;
+
+/* Values for Flags field above */
+
+#define ASL_LOCAL_INITIALIZED   (1)
+#define ASL_LOCAL_REFERENCED    (1<<1)
+#define ASL_ARG_IS_LOCAL        (1<<2)
+#define ASL_ARG_INITIALIZED     (1<<3)
+#define ASL_ARG_REFERENCED      (1<<4)
 
 #endif  /* __ASLTYPES_H */