From 0b1b4a8b29e0f7e1dba32b2708e9d5288a3146ac Mon Sep 17 00:00:00 2001
From: Jordan Bancino <jordan@bancino.net>
Date: Sat, 29 Apr 2023 15:24:46 +0000
Subject: [PATCH] Cope with preprocessor macro usage at the top level of the
 header.

This workaround allows us to parse the Routes.h properly, although it
notably lacks support for multi-word unknown expressions.
---
 src/HeaderParser.c         | 6 +++---
 src/include/HeaderParser.h | 1 +
 tools/src/hdoc.c           | 4 ++++
 3 files changed, 8 insertions(+), 3 deletions(-)

diff --git a/src/HeaderParser.c b/src/HeaderParser.c
index 6d754ab..0977788 100644
--- a/src/HeaderParser.c
+++ b/src/HeaderParser.c
@@ -651,9 +651,9 @@ HeaderParse(Stream * stream, HeaderExpr * expr)
         }
         else
         {
-            expr->type = HP_SYNTAX_ERROR;
-            expr->data.error.msg = "Expected comment, typedef, or extern.";
-            expr->data.error.lineNo = expr->state.lineNo;
+            /* Cope with preprocessor macro expansions at the top level. */
+            expr->type = HP_UNKNOWN;
+            strncpy(expr->data.text, word, HEADER_EXPR_MAX);
         }
 
         Free(word);
diff --git a/src/include/HeaderParser.h b/src/include/HeaderParser.h
index ae255aa..c5a7370 100644
--- a/src/include/HeaderParser.h
+++ b/src/include/HeaderParser.h
@@ -57,6 +57,7 @@ typedef enum HeaderExprType
     HP_TYPEDEF,
     HP_DECLARATION,
     HP_GLOBAL,
+    HP_UNKNOWN,
     HP_SYNTAX_ERROR,
     HP_PARSE_ERROR,
     HP_EOF
diff --git a/tools/src/hdoc.c b/tools/src/hdoc.c
index 5d04bc2..8a671fe 100644
--- a/tools/src/hdoc.c
+++ b/tools/src/hdoc.c
@@ -315,6 +315,10 @@ main(int argc, char **argv)
                     isDocumented = 0;
                 }
                 break;
+            case HP_UNKNOWN:
+                StreamPrintf(StreamStderr(), "Warning: Unknown expression: %s\n",
+                    expr.data.text);
+                break;
             default:
                 StreamPrintf(StreamStderr(), "Unknown header type: %d\n", expr.type);
                 StreamPrintf(StreamStderr(), "This is a programming error.\n");