cxa_demangle_test: expand accepted outputs
After updating libc++, the demangled output's float literal ends with
'L' and the <template-args> ends with a '>'. However, the input is
invalid, so the demangler probably should return nullptr.
Bug: http://b/175635923
Test: bionic-unit-tests
Change-Id: I8440118e4f5791a3464e15d6f9d2f5f3d006e54d
diff --git a/tests/__cxa_demangle_test.cpp b/tests/__cxa_demangle_test.cpp
index d400619..e13410c 100644
--- a/tests/__cxa_demangle_test.cpp
+++ b/tests/__cxa_demangle_test.cpp
@@ -28,11 +28,39 @@
#include <cxxabi.h>
#include <gtest/gtest.h>
+#include <string.h>
TEST(__cxa_demangle, cxa_demangle_fuzz_152588929) {
#if defined(__aarch64__)
+ // Test the C++ demangler on an invalid mangled string. libc++abi currently
+ // parses it like so:
+ // (1 "\006") (I (L e "eeEEEEEEEEEEEEEEEEEEEEEEEEEEEEEE" E) E)
+ // There are a few interesting things about this mangled input:
+ // - The IA64 C++ ABI specifies that an FP literal's hex chars are lowercase.
+ // The libc++abi demangler currently accepts uppercase A-F digits, which is
+ // confusing because 'E' is supposed to mark the end of the <expr-primary>.
+ // - libc++abi uses snprintf("%a") which puts an unspecified number of bits
+ // in the digit before the decimal point.
+ // - The identifier name is "\006", and the IA64 C++ ABI spec is explicit
+ // about not specifying the encoding for characters outside of
+ // [_A-Za-z0-9].
+ // - The 'e' type is documented as "long double, __float80", and in practice
+ // the length of the literal depends on the arch. For arm64, it is a
+ // 128-bit FP type encoded using 32 hex chars. The situation with x86-64
+ // Android OTOH is messy because Clang uses 'g' for its 128-bit
+ // long double.
char* p = abi::__cxa_demangle("1\006ILeeeEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEE", 0, 0, 0);
- ASSERT_STREQ("\x6<-0x1.cecececececececececececececep+11983", p);
+ if (p && !strcmp(p, "\x6<-0x1.cecececececececececececececep+11983")) {
+ // Prior to llvm.org/D77924, libc++abi left off the "L>" suffix.
+ } else if (p && !strcmp(p, "\x6<-0x1.cecececececececececececececep+11983L>")) {
+ // After llvm.org/D77924, the "L>" suffix is present. libc++abi
+ // accepts A-F digits but decodes each using (digit - 'a' + 10), turning 'E'
+ // into -18.
+ } else {
+ // TODO: Remove the other accepted outputs, because libc++abi probably
+ // should reject this input.
+ ASSERT_EQ(nullptr, p) << p;
+ }
free(p);
#endif
}