From 7417c5e9e2f4dbd3ae2c17512835f1d23e1b35fb Mon Sep 17 00:00:00 2001
From: Maxime Coste <frrrwww@gmail.com>
Date: Tue, 16 Jun 2015 18:49:56 +0100
Subject: [PATCH] Resolve symbol names in Cygwin Backtrace::desc implementation

---
 src/Makefile     |  3 +++
 src/backtrace.cc | 24 ++++++++++++++++++++----
 2 files changed, 23 insertions(+), 4 deletions(-)

diff --git a/src/Makefile b/src/Makefile
index 2945e536..9107794c 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -15,6 +15,9 @@ os := $(shell uname)
 
 ifeq ($(os),Darwin)
     LIBS += -lncurses -lboost_regex-mt
+else ifneq (,$(findstring CYGWIN,$(os)))
+    LIBS += -lncursesw -lboost_regex -ldbghelp
+    LDFLAGS += -rdynamic
 else
     LIBS += -lncursesw -lboost_regex
     LDFLAGS += -rdynamic
diff --git a/src/backtrace.cc b/src/backtrace.cc
index 7c195f67..adeb9301 100644
--- a/src/backtrace.cc
+++ b/src/backtrace.cc
@@ -7,6 +7,7 @@
 # include <stdlib.h>
 #elif defined(__CYGWIN__)
 # include <windows.h>
+# include <dbghelp.h>
 # include <stdio.h>
 #endif
 
@@ -39,12 +40,27 @@ String Backtrace::desc() const
     free(symbols);
     return res;
     #elif defined(__CYGWIN__)
-    String res; res.reserve(num_frames * 20);
+    HANDLE process = GetCurrentProcess();
+
+    static bool symbols_initialized = false;
+    if (not symbols_initialized)
+    {
+        SymInitialize(process, nullptr, true);
+        symbols_initialized = true;
+    }
+
+    alignas(SYMBOL_INFO) char symbol_info_buffer[sizeof(SYMBOL_INFO) + 256];
+    SYMBOL_INFO* symbol_info = reinterpret_cast<SYMBOL_INFO*>(symbol_info_buffer);
+    symbol_info->MaxNameLen = 255;
+    symbol_info->SizeOfStruct = sizeof(SYMBOL_INFO);
+
+    String res; // res.reserve(num_frames * 276);
     for (int i = 0; i < num_frames; ++i)
     {
-        char addr[20];
-        snprintf(addr, 20, "0x%p\n", stackframes[i]);
-        res += addr;
+        SymFromAddr(process, (DWORD64)stackframes[i], 0, symbol_info);
+        char desc[276];
+        snprintf(desc, 276, "0x%0llx (%s)\n", symbol_info->Address, symbol_info->Name);
+        res += desc;
     }
     return res;
     #else