Check that names passed to cpptrace::detail::demangle look like mangled names before passing to abi::__cxa_demangle

src/demangle/demangle_with_cxxabi.cpp

@@ -2,6 +2,8 @@
 
 #include "demangle/demangle.hpp"
 
+#include "utils/utils.hpp"
+
 #include <cxxabi.h>
 
 #include <cstdlib>
@@ -11,6 +13,11 @@ namespace cpptrace {
 namespace detail {
     std::string demangle(const std::string& name) {
         int status;
+        // https://itanium-cxx-abi.github.io/cxx-abi/abi.html#demangler
+        // check both _Z and __Z, apple prefixes all symbols with an underscore
+        if(!(starts_with(name, "_Z") || starts_with(name, "__Z"))) {
+            return name;
+        }
         // presumably thread-safe
         // it appears safe to pass nullptr for status however the docs don't explicitly say it's safe so I don't
         // want to rely on it

src/utils/utils.hpp

@@ -83,6 +83,10 @@ namespace detail {
         return str.substr(left, right - left);
     }
 
+    inline bool starts_with(const std::string& str, const std::string& prefix) {
+        return str.size() >= prefix.size() && str.compare(0, prefix.size(), prefix) == 0;
+    }
+
     inline bool is_little_endian() {
         std::uint16_t num = 0x1;
         const auto* ptr = (std::uint8_t*)#

test/unit/internals/string_utils.cpp

@@ -9,6 +9,7 @@ using testing::ElementsAre;
 using cpptrace::detail::split;
 using cpptrace::detail::join;
 using cpptrace::detail::trim;
+using cpptrace::detail::starts_with;
 
 namespace {
 
@@ -77,4 +78,15 @@ TEST(TrimTest, Basic) {
     EXPECT_EQ(trim("\t   test\n "), "test");
 }
 
+TEST(StartsWith, Basic) {
+    EXPECT_TRUE(starts_with("", ""));
+    EXPECT_TRUE(starts_with("abc", ""));
+    EXPECT_FALSE(starts_with("", "abc"));
+    EXPECT_FALSE(starts_with("ab", "abc"));
+    EXPECT_TRUE(starts_with("test", "test"));
+    EXPECT_TRUE(starts_with("hello_world", "hello"));
+    EXPECT_FALSE(starts_with("hello_world", "world"));
+    EXPECT_FALSE(starts_with("abcd", "abce"));
+}
+
 }