TYP: add support for volatile global variables

chb/app/CHVersion.py

@@ -1 +1 @@
-chbversion: str = "0.3.0-20250821"
+chbversion: str = "0.3.0-20250823"

chb/app/GlobalMemoryMap.py

@@ -206,6 +206,10 @@ def gtype(self) -> Optional["BCTyp"]:
             return self.mmap.bcdictionary.typ(int(tix))
         return None
 
+    @property
+    def is_volatile(self) -> bool:
+        return self.gtype is not None and self.gtype.is_volatile
+
     @property
     def size(self) -> Optional[int]:
         s = self._xnode.get("size", None)

chb/arm/opcodes/ARMLoadRegisterHalfword.py

@@ -251,9 +251,8 @@ def has_cast() -> bool:
 
         if xd.is_ok:
             rhs = xd.cxrmem
-            rhsval = None if has_cast() else xd.cxrmem
             hl_lhs = XU.xvariable_to_ast_lval(
-                lhs, xdata, iaddr, astree, rhs=rhsval)
+                lhs, xdata, iaddr, astree, rhs=xd.cxrmem)
             hl_rhs = XU.xxpr_to_ast_def_expr(rhs, xdata, iaddr, astree)
 
         elif xd.is_cxaddr_ok:

chb/bctypes/BCAttribute.py

@@ -53,6 +53,10 @@ def name(self) -> str:
     def params(self) -> List["BCAttrParam"]:
         return [self.bcd.attrparam(i) for i in self.args]
 
+    @property
+    def is_volatile(self) -> bool:
+        return self.name == "volatile"
+
     def __str__(self) -> str:
         return self.name + "(" + ", ".join(str(p) for p in self.params) + ")"
 

chb/bctypes/BCTyp.py

@@ -4,7 +4,7 @@
 # ------------------------------------------------------------------------------
 # The MIT License (MIT)
 #
-# Copyright (c) 2021-2024 Aarno Labs LLC
+# Copyright (c) 2021-2025  Aarno Labs LLC
 #
 # Permission is hereby granted, free of charge, to any person obtaining a copy
 # of this software and associated documentation files (the "Software"), to deal
@@ -191,6 +191,10 @@ def is_typedef(self) -> bool:
     def is_unknown(self) -> bool:
         return False
 
+    @property
+    def is_volatile(self) -> bool:
+        return any(a.is_volatile for a in self.attrs)
+
     @property
     def attrs(self) -> List["BCAttribute"]:
         attrs = self.bcd.attributes(self.args[-1])

chb/cmdline/commandutil.py

@@ -2534,11 +2534,16 @@ def ddata_gvars(args: argparse.Namespace) -> NoReturn:
             sgtype = str(gtype)
         else:
             sgtype = ""
+        if gloc.is_volatile:
+            vt = " (volatile)"
+        else:
+            vt = ""
         print(gloc.addr.rjust(8)
               + "  "
               + gloc.name.ljust(60)
               + "  "
-              + sgtype.ljust(20))
+              + sgtype.ljust(20)
+              + vt)
 
     (count, coverage) = memmap.coverage()
 

chb/invariants/VAssemblyVariable.py

@@ -39,7 +39,7 @@
 
 """
 
-from typing import Any, Dict, List, Sequence, Tuple, TYPE_CHECKING
+from typing import Any, Dict, List, Optional, Sequence, Tuple, TYPE_CHECKING
 
 from chb.app.Register import Register
 
@@ -96,6 +96,9 @@ def is_auxiliary_variable(self) -> bool:
     def is_global_variable(self) -> bool:
         return False
 
+    def get_global_variable_address(self) -> Optional[str]:
+        return None
+
     @property
     def is_global_value(self) -> bool:
         return False
@@ -297,6 +300,12 @@ def argument_index(self) -> int:
                 "Assembly variable is not a stack argument: "
                 + str(self))
 
+    def get_global_variable_address(self) -> Optional[str]:
+        if self.is_global_variable:
+            if self.offset.is_constant_value_offset:
+                return hex(self.offset.offsetvalue())
+        return None
+
     def has_unknown_base(self) -> bool:
         return self.base.is_unknown
 
@@ -417,6 +426,11 @@ def is_auxiliary_variable(self) -> bool:
     def is_global_value(self) -> bool:
         return self.auxvar.is_global_value
 
+    def get_global_variable_address(self) -> Optional[str]:
+        if self.is_global_value:
+            return self.auxvar.get_global_variable_address()
+        return None
+
     @property
     def is_stack_base_address(self) -> bool:
         return self.auxvar.is_stack_base_address

chb/invariants/VConstantValueVariable.py

@@ -128,6 +128,9 @@ def is_bridge_variable(self) -> bool:
     def is_global_value(self) -> bool:
         return False
 
+    def get_global_variable_address(self) -> Optional[str]:
+        return None
+
     @property
     def is_function_return_value(self) -> bool:
         return False
@@ -350,6 +353,11 @@ def is_global_value(self) -> bool:
         avar = self.variable.denotation
         return avar.is_memory_variable and avar.is_global_variable
 
+    def get_global_variable_address(self) -> Optional[str]:
+        if self.is_global_value:
+            return self.variable.denotation.get_global_variable_address()
+        return None
+
     @property
     def is_argument_value(self) -> bool:
         avar = self.variable.denotation

chb/invariants/XVariable.py

@@ -28,7 +28,7 @@
 # ------------------------------------------------------------------------------
 """Symbolic value, identified by name and sequence number"""
 
-from typing import Any, cast, Dict, List, Tuple, TYPE_CHECKING
+from typing import Any, cast, Dict, List, Optional, Tuple, TYPE_CHECKING
 
 from chb.app.Register import Register
 
@@ -201,6 +201,11 @@ def is_global_variable(self) -> bool:
         return (self.has_denotation()
                 and (self.denotation.is_global_variable or self.is_global_value))
 
+    def get_global_variable_address(self) -> Optional[str]:
+        if self.is_global_variable:
+            return self.denotation.get_global_variable_address()
+        return None
+
     @property
     def is_structured_var(self) -> bool:
         return (self.has_denotation() and self.denotation.is_structured_var)

chb/invariants/XXpr.py

@@ -149,6 +149,9 @@ def is_global_address(self) -> bool:
     def is_global_variable(self) -> bool:
         return False
 
+    def get_global_variable_address(self) -> Optional[str]:
+        return None
+
     def is_int_const_value(self, n: int) -> bool:
         return False
 
@@ -381,6 +384,9 @@ def is_structured_expr(self) -> bool:
     def is_global_variable(self) -> bool:
         return self.variable.is_global_variable
 
+    def get_global_variable_address(self) -> Optional[str]:
+        return self.variable.get_global_variable_address()
+
     @property
     def is_function_return_value(self) -> bool:
         return (self.variable.has_denotation()

chb/invariants/XXprUtil.py

@@ -1768,8 +1768,27 @@ def xvariable_to_ast_lval(
     to an ssa value, while a high-level register that is part of some rhs
     should be delegated to its reaching definitions, and thus should stay
     confined to functions dealing with rhs values.
+
+    Note: another check should be added to this function as to whether the
+    rhs (if provided) is volatile. If so, it should not be used to propagate
+    that value.
     """
 
+    if (
+            astree.has_register_variable_intro(iaddr)
+            and astree.get_register_variable_intro(iaddr).has_cast()):
+        rhs = None
+
+    if (rhs is not None and rhs.is_global_variable):
+        gaddr = rhs.get_global_variable_address()
+        if gaddr is not None:
+            gmemmap = xdata.app.globalmemorymap
+            if gaddr in gmemmap.locations:
+                gloc = gmemmap.get_location(gaddr)
+                if gloc is not None and gloc.gtype is not None:
+                    if gloc.gtype.is_volatile:
+                        rhs = None
+
     # unknown memory value
     if xv.is_tmp or xv.has_unknown_memory_base():
         if memaddr is not None: