From f54fa0077a821ac574a70da336503a5ee52dbb63 Mon Sep 17 00:00:00 2001
From: David Nadlinger <code@klickverbot.at>
Date: Thu, 27 Sep 2012 20:22:52 +0200
Subject: [PATCH] Only allow a single D main() function.

Fixes DMD testcase 'fail5634'.
---
 gen/functions.cpp | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/gen/functions.cpp b/gen/functions.cpp
index 73eb433e..438a167d 100644
--- a/gen/functions.cpp
+++ b/gen/functions.cpp
@@ -522,6 +522,11 @@ void DtoDeclareFunction(FuncDeclaration* fdecl)
 
     // main
     if (fdecl->isMain()) {
+        // Detect multiple main functions, which is disallowed. DMD checks this
+        // in the glue code, so we need to do it here as well.
+        if (gIR->mainFunc) {
+            error(fdecl->loc, "only one main function allowed");
+        }
         gIR->mainFunc = func;
     }