ASTI: prune empty if statements

Author: sipma

chb/astinterface/ASTICodeTransformer.py

@@ -68,7 +68,15 @@ def transform_loop_stmt(self, stmt: AST.ASTLoop) -> AST.ASTStmt:
             optlocationid=stmt.locationid)
 
     def transform_block_stmt(self, stmt: AST.ASTBlock) -> AST.ASTStmt:
-        newstmts = [s.transform(self) for s in stmt.stmts]
+        newstmts: List[AST.ASTStmt] = []
+        for s in stmt.stmts:
+            newstmt = s.transform(self)
+            # prune empty blocks that may have been created by the pruning
+            # of redundant if statements
+            if newstmt.is_ast_block and len((cast(AST.ASTBlock, newstmt)).stmts) == 0:
+                continue
+            newstmts.append(newstmt)
+
         return self.astinterface.mk_block(
             newstmts,
             labels=stmt.labels,
@@ -117,6 +125,9 @@ def transform_instruction_sequence_stmt(
     def transform_branch_stmt(self, stmt: AST.ASTBranch) -> AST.ASTStmt:
         newif = stmt.ifstmt.transform(self)
         newelse = stmt.elsestmt.transform(self)
+        if newif.is_empty() and newelse.is_empty():
+            return self.astinterface.mk_block([])
+
         return self.astinterface.mk_branch(
             stmt.condition,
             newif,

chb/astinterface/ASTIProvenance.py

@@ -428,6 +428,8 @@ def resolve_reaching_defs(self) -> None:
                 v = str(rd.variable)
                 addrs = [str(d) for d in rd.deflocations]
                 for addr in addrs:
+                    if addr == "init":
+                        continue
                     if addr in self.address_instructions:
                         instrids = self.address_instructions[addr]
                         for instrid in instrids:
@@ -442,6 +444,26 @@ def resolve_reaching_defs(self) -> None:
                                     # Allow for change of name of return value
                                     if str(instr.lhs) == v or v == "R0" or v == "S0":
                                         self.add_reaching_definition(xid, instrid)
+                                    else:
+                                        chklogger.logger.warning(
+                                            "Variable names don't match: %s vs %s",
+                                            str(instr.lhs), v)
+                                else:
+                                    chklogger.logger.warning(
+                                        "Expression is defined by unknown instruction: "
+                                        + "var: %s defined by %s",
+                                        str(v), str(instr))
+                            else:
+                                chklogger.logger.warning(
+                                    "Instruction id in reaching definitions for %s "
+                                    + "not found",
+                                    str(v))
+                    else:
+                        chklogger.logger.warning(
+                            "Reaching definition address %s for variable %s "
+                            + " not found",
+                            str(addr), str(v))
+
 
     def resolve_flag_reaching_defs(self) -> None:
         for (xid, frds) in self.flag_expr_rdefs.items():

chb/astinterface/ASTInterface.py

@@ -1470,6 +1470,14 @@ def mk_byte_sum(self, bytes: List[AST.ASTExpr]) -> AST.ASTExpr:
             shift += 8
         return result
 
+    def mk_doubleword_sum(
+            self, hiword: AST.ASTExpr, loword: AST.ASTExpr) -> AST.ASTExpr:
+        """Return concatenation 64 bit hiword:loword."""
+
+        shift = self.mk_integer_constant(32)
+        shifthi = self.mk_binary_op("lsl", hiword, shift)
+        return self.mk_binary_op("plus", shifthi, loword)
+
     def mk_binary_expression(
             self,
             op: str,