From b7cc740b78ea636868c560871437b3beed45cf2e Mon Sep 17 00:00:00 2001
From: Marius Kintel <marius@kintel.net>
Date: Tue, 23 Oct 2012 20:41:50 -0400
Subject: [PATCH] Detect circular includes. Probably the final commit for #75

---
 src/lexer.l | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/src/lexer.l b/src/lexer.l
index 1e3bd5b1..63b00474 100644
--- a/src/lexer.l
+++ b/src/lexer.l
@@ -80,6 +80,7 @@ void includefile();
 fs::path sourcepath();
 std::vector<fs::path> path_stack;
 std::vector<FILE*> openfiles;
+std::vector<std::string> openfilenames;
 
 std::string filename;
 std::string filepath;
@@ -142,6 +143,7 @@ use[ \t\r\n>]*"<"	{ BEGIN(cond_use); }
 		assert(!openfiles.empty());
 		fclose(openfiles.back());
 		openfiles.pop_back();
+		openfilenames.pop_back();
 	}
 	yypop_buffer_state();
 	if (!YY_CURRENT_BUFFER)
@@ -227,10 +229,15 @@ void includefile()
     PRINTB("WARNING: Can't find 'include' file '%s'.", filename);
   }
 
+  std::string fullname = boosty::absolute(finfo).string();
+  // Detect circular includes
+  BOOST_FOREACH(std::string &s, openfilenames) {
+    if (s == fullname) return;
+  }
+
   filepath.clear();
   path_stack.push_back(finfo.parent_path());
 
-  std::string fullname = boosty::absolute(finfo).string();
   handle_dep(fullname);
   currmodule->registerInclude(fullname);
   yyin = fopen(fullname.c_str(), "r");
@@ -240,6 +247,7 @@ void includefile()
     return;
   }
   openfiles.push_back(yyin);
+  openfilenames.push_back(fullname);
   filename.clear();
   
   yypush_buffer_state(yy_create_buffer(yyin, YY_BUF_SIZE));
@@ -253,5 +261,6 @@ void lexerdestroy()
 {
   BOOST_FOREACH (FILE *f, openfiles) fclose(f);
   openfiles.clear();
+  openfilenames.clear();
   path_stack.clear();
 }