From: Iain Buclaw <ibuclaw@gdcproject.org>
Date: Fri, 24 Sep 2021 08:59:47 +0000 (+0200)
Subject: libphobos: Define main function as extern(C) when compiling without D runtime (PR102476)
X-Git-Tag: basepoints/gcc-13~4328
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=d46a29d919058fb383d19fe35c234fab58286f71;p=thirdparty%2Fgcc.git

libphobos: Define main function as extern(C) when compiling without D runtime (PR102476)

The default supplied main function as read when compiling with `-fmain'
has extern(D) linkage.  However this does not work when mixing this
option together with `-fno-druntime'.

	PR d/102476

gcc/testsuite/ChangeLog:

	* gdc.dg/pr102476.d: New test.

libphobos/ChangeLog:

	* libdruntime/__main.di: Define main function as extern(C) when
	compiling without D runtime.
---

diff --git a/gcc/testsuite/gdc.dg/pr102476.d b/gcc/testsuite/gdc.dg/pr102476.d
new file mode 100644
index 000000000000..543716eb37d7
--- /dev/null
+++ b/gcc/testsuite/gdc.dg/pr102476.d
@@ -0,0 +1,3 @@
+// https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102476
+// { dg-do link }
+// { dg-options "-fmain -fno-druntime" }
diff --git a/libphobos/libdruntime/__main.di b/libphobos/libdruntime/__main.di
index 8062bf4d1e8f..ab1264b98f12 100644
--- a/libphobos/libdruntime/__main.di
+++ b/libphobos/libdruntime/__main.di
@@ -20,7 +20,17 @@
 
 module __main;
 
-int main(char[][])
+version (D_BetterC)
 {
-    return 0;
+    extern (C) int main(int, char**)
+    {
+        return 0;
+    }
+}
+else
+{
+    int main(char[][])
+    {
+        return 0;
+    }
 }