lib: Add mlibc

Signed-off-by: Ian Moffett <ian@osmora.org>

3 files changed, 80 insertions, 0 deletions

diff --git a/lib/mlibc/tests/rtdl/preinit/libfoo.c b/lib/mlibc/tests/rtdl/preinit/libfoo.c
new file mode 100644
index 0000000..9c834ea
--- /dev/null
+++ b/lib/mlibc/tests/rtdl/preinit/libfoo.c
@@ -0,0 +1,18 @@
+#include <stdio.h>
+#include <assert.h>
+
+int fooDone = 0;
+
+// DSOs do not support pre-initialization functions.
+
+__attribute__((constructor))
+void fooInit() {
+	dprintf(1, "initialization function called in foo\n");
+
+	assert(fooDone == 0);
+	fooDone++;
+}
+
+int isFooDone() {
+	return fooDone;
+}
diff --git a/lib/mlibc/tests/rtdl/preinit/meson.build b/lib/mlibc/tests/rtdl/preinit/meson.build
new file mode 100644
index 0000000..1a7f398
--- /dev/null
+++ b/lib/mlibc/tests/rtdl/preinit/meson.build
@@ -0,0 +1,18 @@
+if host_machine.cpu_family() == 'riscv64'
+	# gp isn't initialized until after crt1.o runs, so to access
+	# globals in our pre-initializers we must disable it.
+	test_additional_link_args = ['-Wl,--no-relax']
+endif
+
+libfoo = shared_library('foo', 'libfoo.c',
+	dependencies: libc_dep,
+	override_options: 'b_sanitize=none',
+	link_args: test_additional_link_args,
+)
+test_link_with = [libfoo]
+
+libfoo_native = shared_library('native-foo', 'libfoo.c',
+	link_args: ['-ldl'] + test_additional_link_args,
+	native: true
+)
+test_native_link_with = [libfoo_native]
diff --git a/lib/mlibc/tests/rtdl/preinit/test.c b/lib/mlibc/tests/rtdl/preinit/test.c
new file mode 100644
index 0000000..5b5d5e8
--- /dev/null
+++ b/lib/mlibc/tests/rtdl/preinit/test.c
@@ -0,0 +1,44 @@
+#include <stdio.h>
+#include <assert.h>
+
+int mainDone = 0;
+
+int isFooDone();
+
+void preInit1() {
+	// Use dprintf because stdout might not be initialized yet.
+	dprintf(1, "pre-initialization function 1 called in main executable\n");
+
+	assert(isFooDone() == 0);
+	assert(mainDone == 0);
+	mainDone++;
+}
+
+void preInit2() {
+	dprintf(1, "pre-initialization function 2 called in main executable\n");
+
+	assert(isFooDone() == 0);
+	assert(mainDone == 1);
+	mainDone++;
+}
+
+__attribute__((constructor))
+void mainInit() {
+	dprintf(1, "initialization function called in main executable\n");
+
+	assert(isFooDone() == 1);
+	assert(mainDone == 2);
+	mainDone++;
+}
+
+// Manually register the pre-initialization functions.
+__attribute__((used, section(".preinit_array")))
+static void (*preinitFunctions[])(void) = {
+	&preInit1,
+	&preInit2,
+};
+
+int main() {
+	assert(isFooDone() == 1);
+	assert(mainDone == 3);
+}