Subzero: Replace global pointers to allocation functions

tests_lit/asan_tests/globalreplacement.ll

Index: tests_lit/asan_tests/globalreplacement.ll
diff --git a/tests_lit/asan_tests/globalreplacement.ll b/tests_lit/asan_tests/globalreplacement.ll
new file mode 100644
index 0000000000000000000000000000000000000000..d5c0b2b9b127e52929d4770998b06588ed0de73e
--- /dev/null
+++ b/tests_lit/asan_tests/globalreplacement.ll
@@ -0,0 +1,61 @@
+; Test that global pointers to allocation functions are replaced
+
+; REQUIRES: allow_dump
+
+; RUN: %p2i -i %s --args -verbose=global_init -threads=0 -fsanitize-address \
+; RUN:     -allow-externally-defined-symbols | FileCheck --check-prefix=DUMP %s
+
+declare external i32 @malloc(i32)
+declare external i32 @realloc(i32, i32)
+declare external i32 @calloc(i32, i32)
+declare external void @free(i32)
+
+@global_malloc = internal global i32 ptrtoint (i32 (i32)* @malloc to i32)
+@global_realloc = internal global i32 ptrtoint (i32 (i32, i32)* @realloc to i32)
+@global_calloc = internal global i32 ptrtoint (i32 (i32, i32)* @calloc to i32)
+@global_free = internal global i32 ptrtoint (void (i32)* @free to i32)

[Karl, 2016/08/15 21:43:46]

How about inserting a non-global pointer to show nothing happens.

Also how about one case where there is more than one initializer.

[tlively, 2016/08/15 22:24:59]

My next task is to instrument non-global pointers, but I added a global pointer
to a non-allocation function to show that nothing happens to it.

+
+@constant_malloc = internal constant i32 ptrtoint (i32 (i32)* @malloc to i32)
+@constant_realloc = internal constant i32 ptrtoint (i32 (i32, i32)* @realloc to i32)
+@constant_calloc = internal constant i32 ptrtoint (i32 (i32, i32)* @calloc to i32)
+@constant_free = internal constant i32 ptrtoint (void (i32)* @free to i32)
+
+define void @func() {
+  ret void
+}
+
+; DUMP: Instrumented Globals
+; DUMP-NEXT: @__$rz_array
+; DUMP-NEXT: @__$rz_sizes
+; DUMP-NEXT: @__$rz0
+; DUMP-NEXT: @global_malloc = internal global i32
+; DUMP-SAME:   ptrtoint (i32 (i32)* @__asan_malloc to i32)
+; DUMP-NEXT: @__$rz1
+; DUMP-NEXT: @__$rz2
+; DUMP-NEXT: @global_realloc = internal global i32
+; DUMP-SAME:   ptrtoint (i32 (i32, i32)* @__asan_realloc to i32)
+; DUMP-NEXT: @__$rz3
+; DUMP-NEXT: @__$rz4
+; DUMP-NEXT: @global_calloc = internal global i32
+; DUMP-SAME:   ptrtoint (i32 (i32, i32)* @__asan_calloc to i32)
+; DUMP-NEXT: @__$rz5
+; DUMP-NEXT: @__$rz6
+; DUMP-NEXT: @global_free = internal global i32
+; DUMP-SAME:   ptrtoint (void (i32)* @__asan_free to i32)
+; DUMP-NEXT: @__$rz7
+; DUMP-NEXT: @__$rz8
+; DUMP-NEXT: @constant_malloc = internal constant i32
+; DUMP-SAME:   ptrtoint (i32 (i32)* @__asan_malloc to i32)
+; DUMP-NEXT: @__$rz9
+; DUMP-NEXT: @__$rz10
+; DUMP-NEXT: @constant_realloc = internal constant i32
+; DUMP-SAME:   ptrtoint (i32 (i32, i32)* @__asan_realloc to i32)
+; DUMP-NEXT: @__$rz11
+; DUMP-NEXT: @__$rz12
+; DUMP-NEXT: @constant_calloc = internal constant i32
+; DUMP-SAME:   ptrtoint (i32 (i32, i32)* @__asan_calloc to i32)
+; DUMP-NEXT: @__$rz13
+; DUMP-NEXT: @__$rz14
+; DUMP-NEXT: @constant_free = internal constant i32
+; DUMP-SAME:   ptrtoint (void (i32)* @__asan_free to i32)
+; DUMP-NEXT: @__$rz15