style: Preserve indentation inside preprocessor blocks and re-run

Author: bobtista

scripts/cpp/convert_leading_spaces_to_tabs.py

@@ -184,6 +184,7 @@ def process_file(filepath, dry_run=False, verbose=False):
     in_asm_block = False
     asm_brace_depth = 0
     asm_pending = False
+    pp_depth = 0
 
     for line_idx, line in enumerate(lines):
         # Track block comments manually for reliability
@@ -235,6 +236,13 @@ def process_file(filepath, dry_run=False, verbose=False):
 
         # Preprocessor directives - always column 0
         if stripped.startswith('#'):
+            # Track preprocessor nesting depth
+            directive = stripped.lstrip('#').lstrip()
+            if directive.startswith(('if ', 'if\t', 'ifdef ', 'ifdef\t',
+                                     'ifndef ', 'ifndef\t')):
+                pp_depth += 1
+            elif directive.startswith('endif'):
+                pp_depth = max(0, pp_depth - 1)
             new_lines.append(line)
             in_macro_continuation = line_continues_macro
             continue
@@ -373,9 +381,16 @@ def process_file(filepath, dry_run=False, verbose=False):
         # Sanity check: if the line had significant indentation but we
         # computed depth 0, something is likely wrong (parse errors nearby,
         # inline assembly corrupting the AST, etc). Skip to be safe.
-        # Threshold of 4 spaces catches most misparses while allowing
-        # legitimate depth-0 code with minor (1-3 space) indentation errors.
+        # Also skip depth-0 lines inside preprocessor blocks — the codebase
+        # convention is to indent C++ code inside #if/#ifdef blocks, but
+        # tree-sitter doesn't model preprocessor nesting.
         space_count = len(leading_ws)
+        if depth == 0 and space_count > 0 and pp_depth > 0:
+            new_lines.append(line)
+            skipped += 1
+            if verbose:
+                print(f"  SKIP pp-indent L{line_idx+1}: depth=0 but pp_depth={pp_depth}: {line.rstrip()[:80]}")
+            continue
         if depth == 0 and space_count >= 4:
             new_lines.append(line)
             skipped += 1