Implemented linking to a dummy ASan runtime

tests_lit/asan_tests/startinitcall.ll

Index: tests_lit/asan_tests/startinitcall.ll
diff --git a/tests_lit/asan_tests/startinitcall.ll b/tests_lit/asan_tests/startinitcall.ll
new file mode 100644
index 0000000000000000000000000000000000000000..0e225d4d5703252c44d6ec167ac5709fccec5983
--- /dev/null
+++ b/tests_lit/asan_tests/startinitcall.ll
@@ -0,0 +1,27 @@
+; Test for a call to __asan_init in _start
+
+; REQUIRES: allow_dump
+
+; RUN: %p2i -i %s --args -verbose=inst -threads=0 -fsanitize-address \
+; RUN:     | FileCheck --check-prefix=DUMP %s
+
+; notStart() should not be instrumented
+define internal void @notStart() {
+  ret void
+}
+
+; DUMP-LABEL: ================ Instrumented CFG ================
+; DUMP-NEXT: define internal void @notStart(

[Karl, 2016/06/15 14:19:28]

Wouldn't be safer to make this the DUMP-LABEL entry, since it has the name of
the function. By using that as the label, you protect this test from function
reordering during compilation,
or other forms of code insertion.

[tlively, 2016/06/15 16:32:00]

Done.

+; DUMP-NEXT: __0:
+; DUMP-NOT: __asan_init()
+; DUMP: }
+
+; _start() should be instrumented
+define void @_start() {
+  ret void
+}
+
+; DUMP-LABEL: ================ Instrumented CFG ================
+; DUMP-NEXT: define void @_start(

[Karl, 2016/06/15 14:19:28]

Same here.

[tlively, 2016/06/15 16:32:00]

Done.

+; DUMP-NEXT: __0:
+; DUMP-NEXT: call void @__asan_init()