Manuel and I were looking into a problem with applications failing to link

(undefined reference to `main') when the .o file containing main was contained
in an static library(a '.a' ar archive).  It turns out that due to its single
pass nature, GNU ld was failing to pull it into the build.  This sticks a dummy
reference to main() into crt0.o, so that when an application is linked with the
main() function in a static library, we can be sure that main() actually gets
linked in.
 -Erik

2 files changed, 7 insertions, 0 deletions

diff --git a/libc/sysdeps/linux/i386/crt0.S b/libc/sysdeps/linux/i386/crt0.S
index 9e2c101e5..05d2704ba 100644
--- a/libc/sysdeps/linux/i386/crt0.S
+++ b/libc/sysdeps/linux/i386/crt0.S
@@ -77,3 +77,9 @@ _start:
 	/* Ok, now run uClibc's main() -- shouldn't return */
 	call __uClibc_main
 
+/* Stick in a dummy reference to main(), so that if an application
+ * is linking when the main() function is in a static library (.a)
+ * we can be sure that main() actually gets linked in */
+L_dummy_main_reference:
+	.long	main
+
diff --git a/libc/sysdeps/linux/i386/crt0.c b/libc/sysdeps/linux/i386/crt0.c
index 6e39caa7c..8e55e5895 100644
--- a/libc/sysdeps/linux/i386/crt0.c
+++ b/libc/sysdeps/linux/i386/crt0.c
@@ -32,6 +32,7 @@ void _start(unsigned int first_arg)
 	argc = *(stack - 1);
 	argv = (char **) stack;
 	envp = (char **)stack + argc + 1;
+	volatile void (*mainp)(int argc,void *argv,void *envp) = main;
 
 	__uClibc_main(argc, argv, envp);
 }