Handle nested ifdef in generate.py

This is required to properly handle the BEQ instruction with compressed
instructions disabled. Currently in this case invalid verilog output
is produced.

monitor/generate.py

@@ -590,77 +590,42 @@ def usage():
         insn_list.append(insn)
         replace_db.append((" rvfi_insn_%s " % insn, " %s_insn_%s " % (prefix, insn)))
 
+expected_flags = {
+    "RISCV_FORMAL_COMPRESSED": compressed,
+    "RISCV_FORMAL_ALIGNED_MEM": aligned,
+}
+
 def print_rewrite_file(filename):
     with open(filename) as f:
-        flag_compressed_ifdef = False
-        flag_compressed_ifndef = False
-        flag_aligned_ifdef = False
-        flag_aligned_ifndef = False
-        flag_ifdef = False
-        flag_ifndef = False
+        flag_stack = []
+        flags = {}
 
         for line in f:
-            if line.startswith("`ifdef RISCV_FORMAL_COMPRESSED"):
-                flag_compressed_ifdef = True
-                flag_compressed_ifndef = False
-                continue
-
-            if line.startswith("`ifndef RISCV_FORMAL_COMPRESSED"):
-                flag_compressed_ifdef = False
-                flag_compressed_ifndef = True
-                continue
-
-            if line.startswith("`ifdef RISCV_FORMAL_ALIGNED_MEM"):
-                flag_aligned_ifdef = True
-                flag_aligned_ifndef = False
-                continue
-
-            if line.startswith("`ifndef RISCV_FORMAL_ALIGNED_MEM"):
-                flag_aligned_ifdef = False
-                flag_aligned_ifndef = True
-                continue
-
             if line.startswith("`ifdef "):
-                flag_ifdef = True
-                flag_ifndef = False
+                flag_name = line.split()[1]
+                assert flag_name not in flags, (filename, flag_name, flags)
+                flag_stack.append(flag_name)
+                flags[flag_name] = True
                 continue
 
             if line.startswith("`ifndef "):
-                flag_ifdef = False
-                flag_ifndef = True
+                flag_name = line.split()[1]
+                assert flag_name not in flags
+                flag_stack.append(flag_name)
+                flags[flag_name] = False
                 continue
 
             if line.startswith("`else"):
-                flag_compressed_ifdef, flag_compressed_ifndef = flag_compressed_ifndef, flag_compressed_ifdef
-                flag_aligned_ifdef, flag_aligned_ifndef = flag_aligned_ifndef, flag_aligned_ifdef
-                flag_ifdef, flag_ifndef = flag_ifndef, flag_ifdef
+                flag_name = flag_stack[-1]
+                flags[flag_name] = not flags[flag_name]
                 continue
 
             if line.startswith("`endif"):
-                flag_compressed_ifdef = False
-                flag_compressed_ifndef = False
-                flag_aligned_ifdef = False
-                flag_aligned_ifndef = False
-                flag_ifdef = False
-                flag_ifndef = False
-                continue
-
-            if flag_compressed_ifdef and not compressed:
-                continue
-
-            if flag_compressed_ifndef and compressed:
-                continue
-
-            if flag_aligned_ifdef and not aligned:
-                continue
-
-            if flag_aligned_ifndef and aligned:
-                continue
-
-            if flag_ifdef and True:
+                flag_name = flag_stack.pop()
+                del flags[flag_name]
                 continue
 
-            if flag_ifndef and False:
+            if any(expected_flags.get(name, False) != val for name, val in flags.items()):
                 continue
 
             for a, b in replace_db: