Demangle in-VM backtraces from C++ and Rust plugins. (#299)

Before:

Proxy-Wasm plugin in-VM backtrace:
  0:  0x60c3 - rust_oom
  1:  0x6d2c - __rg_oom
  2:  0x38b1 - __rust_alloc_error_handler
  3:  0x6cb3 - _ZN5alloc5alloc18handle_alloc_error8rt_error17hc05c98d79426d4d3E
  4:  0x6ca5 - _ZN4core3ops8function6FnOnce9call_once17h104529aa81b44c4eE
  5:  0x6d1e - _ZN4core10intrinsics17const_eval_select17hbbf517c24e8eee9cE
  6:  0x6cc1 - _ZN5alloc5alloc18handle_alloc_error17hd51ecca19a6d9162E
  7:  0x519 - _ZN5alloc7raw_vec19RawVec$LT$T$C$A$GT$11allocate_in17h4065aea9ced9d1eeE
  8:  0x2b9 - _ZN5alloc7raw_vec19RawVec$LT$T$C$A$GT$16with_capacity_in17h2c8a17f6c910dc68E
  9:  0x303a - _ZN5alloc3vec16Vec$LT$T$C$A$GT$16with_capacity_in17hb7917fc637d55bb8E

After:

Proxy-Wasm plugin in-VM backtrace:
  0:  0x60c3 - rust_oom
  1:  0x6d2c - __rg_oom
  2:  0x38b1 - __rust_alloc_error_handler
  3:  0x6cb3 - alloc::alloc::handle_alloc_error::rt_error::hc05c98d79426d4d3
  4:  0x6ca5 - core::ops::function::FnOnce::call_once::h104529aa81b44c4e
  5:  0x6d1e - core::intrinsics::const_eval_select::hbbf517c24e8eee9c
  6:  0x6cc1 - alloc::alloc::handle_alloc_error::hd51ecca19a6d9162
  7:  0x519 - alloc::raw_vec::RawVec$LT$T$C$A$GT$::allocate_in::h4065aea9ced9d1ee
  8:  0x2b9 - alloc::raw_vec::RawVec$LT$T$C$A$GT$::with_capacity_in::h2c8a17f6c910dc68
  9:  0x303a - alloc::vec::Vec$LT$T$C$A$GT$::with_capacity_in::hb7917fc637d55bb8

Signed-off-by: Piotr Sikora <piotrsikora@google.com>

Author: PiotrSikora

src/bytecode_util.cc

@@ -14,6 +14,10 @@
 
 #include "include/proxy-wasm/bytecode_util.h"
 
+#if !defined(_MSC_VER)
+#include <cxxabi.h>
+#endif
+
 #include <cstring>
 
 namespace proxy_wasm {
@@ -165,7 +169,16 @@ bool BytecodeUtil::getFunctionNameIndex(std::string_view bytecode,
           if (!parseVarint(pos, end, func_name_size) || pos + func_name_size > end) {
             return false;
           }
-          ret.insert({func_index, std::string(pos, func_name_size)});
+          auto func_name = std::string(pos, func_name_size);
+#if !defined(_MSC_VER)
+          int status;
+          char *data = abi::__cxa_demangle(func_name.c_str(), nullptr, nullptr, &status);
+          if (data != nullptr) {
+            func_name = std::string(data);
+            ::free(data);
+          }
+#endif
+          ret.insert({func_index, func_name});
           pos += func_name_size;
         }
         if (start + subsection_size != pos) {

test/runtime_test.cc

@@ -139,6 +139,7 @@ TEST_P(TestVm, WasmMemoryLimit) {
     EXPECT_TRUE(host->isErrorLogged("Uncaught RuntimeError: unreachable"));
     EXPECT_TRUE(host->isErrorLogged("Proxy-Wasm plugin in-VM backtrace:"));
     EXPECT_TRUE(host->isErrorLogged(" - rust_oom"));
+    EXPECT_TRUE(host->isErrorLogged(" - alloc::alloc::handle_alloc_error"));
   }
 }
 
@@ -160,6 +161,7 @@ TEST_P(TestVm, Trap) {
   if (engine_ == "v8") {
     EXPECT_TRUE(host->isErrorLogged("Uncaught RuntimeError: unreachable"));
     EXPECT_TRUE(host->isErrorLogged("Proxy-Wasm plugin in-VM backtrace:"));
+    EXPECT_TRUE(host->isErrorLogged(" - std::panicking::begin_panic"));
     EXPECT_TRUE(host->isErrorLogged(" - trigger"));
   }
 }
@@ -182,6 +184,7 @@ TEST_P(TestVm, Trap2) {
   if (engine_ == "v8") {
     EXPECT_TRUE(host->isErrorLogged("Uncaught RuntimeError: unreachable"));
     EXPECT_TRUE(host->isErrorLogged("Proxy-Wasm plugin in-VM backtrace:"));
+    EXPECT_TRUE(host->isErrorLogged(" - std::panicking::begin_panic"));
     EXPECT_TRUE(host->isErrorLogged(" - trigger2"));
   }
 }