util/debug: Cleanup/improve debug_symbol_name_dbghelp.

- use mgwhelp -- the successor for bfdhelp which does not have a hard
  dependency on BFD, and works on 64bits.
- use a macro instead of hand-typing to dispatch DbgHelp functions
- dump line numbers
- dump module names when symbols are not available
- support 64bits.
- add comments

Reviewed-by: Brian Paul <brianp@vmware.com>

src/gallium/auxiliary/util/u_debug_symbol.c

@@ -40,7 +40,8 @@
 #include "u_debug_symbol.h"
 #include "u_hash_table.h"
 
-#if defined(PIPE_OS_WINDOWS) && defined(PIPE_ARCH_X86)
+
+#if defined(PIPE_OS_WINDOWS)
    
 #include <windows.h>
 #include <stddef.h>
@@ -48,139 +49,221 @@
 #include "dbghelp.h"
 
 
-static BOOL bSymInitialized = FALSE;
-
-static HMODULE hModule_Dbghelp = NULL;
+/**
+ * SymInitialize() must be called once for each process (in this case, the
+ * current process), before any of the other functions can be called.
+ */
+static BOOL g_bSymInitialized = FALSE;
 
 
-static
-FARPROC WINAPI __GetProcAddress(LPCSTR lpProcName)
+/**
+ * Lookup the address of a DbgHelp function.
+ */
+static FARPROC WINAPI
+getDbgHelpProcAddress(LPCSTR lpProcName)
 {
+   static HMODULE hModule = NULL;
+
+   if (!hModule) {
+      static boolean bail = FALSE;
+
+      if (bail) {
+         return NULL;
+      }
+
 #ifdef PIPE_CC_GCC
-   if (!hModule_Dbghelp) {
       /*
-       * bfdhelp.dll is a dbghelp.dll look-alike replacement, which is able to
-       * understand MinGW symbols using BFD library.  It is available from
+       * DbgHelp does not understand the debug information generated by MinGW toolchain.
+       *
+       * mgwhelp.dll is a dbghelp.dll look-alike replacement, which is able to
+       * understand MinGW symbols, including on 64-bit builds.
+       */
+      if (!hModule) {
+         hModule = LoadLibraryA("mgwhelp.dll");
+         if (!hModule) {
+            _debug_printf("warning: mgwhelp.dll not found: symbol names will not be resolved\n"
+                          "warning: download it from http://code.google.com/p/jrfonseca/wiki/DrMingw#MgwHelp\n");
+         }
+      }
+
+      /*
+       * bfdhelp.dll was the predecessor of mgwhelp.dll.  It is available from
        * http://people.freedesktop.org/~jrfonseca/bfdhelp/ for now.
        */
-      hModule_Dbghelp = LoadLibraryA("bfdhelp.dll");
-   }
-#endif
+      if (!hModule) {
+         hModule = LoadLibraryA("bfdhelp.dll");
+      }
+   #endif
 
-   if (!hModule_Dbghelp) {
-      hModule_Dbghelp = LoadLibraryA("dbghelp.dll");
-      if (!hModule_Dbghelp) {
+      /*
+       * Fallback to the real DbgHelp.
+       */
+      if (!hModule) {
+         hModule = LoadLibraryA("dbghelp.dll");
+      }
+
+      if (!hModule) {
+         bail = TRUE;
          return NULL;
       }
    }
 
-   return GetProcAddress(hModule_Dbghelp, lpProcName);
+   return GetProcAddress(hModule, lpProcName);
 }
 
 
-typedef BOOL (WINAPI *PFNSYMINITIALIZE)(HANDLE, LPSTR, BOOL);
-static PFNSYMINITIALIZE pfnSymInitialize = NULL;
+/**
+ * Generic macro to dispatch a DbgHelp functions.
+ */
+#define DBGHELP_DISPATCH(_name, _ret_type, _ret_default, _arg_types, _arg_names) \
+   static _ret_type WINAPI \
+   j_##_name _arg_types \
+   { \
+      typedef BOOL (WINAPI *PFN) _arg_types; \
+      static PFN pfn = NULL; \
+      if (!pfn) { \
+         pfn = (PFN) getDbgHelpProcAddress(#_name); \
+         if (!pfn) { \
+            return _ret_default; \
+         } \
+      } \
+      return pfn _arg_names; \
+   }
 
-static
-BOOL WINAPI j_SymInitialize(HANDLE hProcess, PSTR UserSearchPath, BOOL fInvadeProcess)
-{
-   if(
-      (pfnSymInitialize || (pfnSymInitialize = (PFNSYMINITIALIZE) __GetProcAddress("SymInitialize")))
-   )
-      return pfnSymInitialize(hProcess, UserSearchPath, fInvadeProcess);
-   else
-      return FALSE;
-}
+DBGHELP_DISPATCH(SymInitialize,
+                 BOOL, 0,
+                 (HANDLE hProcess, PSTR UserSearchPath, BOOL fInvadeProcess),
+                 (hProcess, UserSearchPath, fInvadeProcess))
 
-typedef DWORD (WINAPI *PFNSYMSETOPTIONS)(DWORD);
-static PFNSYMSETOPTIONS pfnSymSetOptions = NULL;
+DBGHELP_DISPATCH(SymSetOptions,
+                 DWORD, FALSE,
+                 (DWORD SymOptions),
+                 (SymOptions))
 
-static
-DWORD WINAPI j_SymSetOptions(DWORD SymOptions)
-{
-   if(
-      (pfnSymSetOptions || (pfnSymSetOptions = (PFNSYMSETOPTIONS) __GetProcAddress("SymSetOptions")))
-   )
-      return pfnSymSetOptions(SymOptions);
-   else
-      return FALSE;
-}
+DBGHELP_DISPATCH(SymFromAddr,
+                 BOOL, FALSE,
+                 (HANDLE hProcess, DWORD64 Address, PDWORD64 Displacement, PSYMBOL_INFO Symbol),
+                 (hProcess, Address, Displacement, Symbol))
 
-typedef BOOL (WINAPI *PFNSYMGETSYMFROMADDR)(HANDLE, DWORD64, PDWORD64, PSYMBOL_INFO);
-static PFNSYMGETSYMFROMADDR pfnSymFromAddr = NULL;
-
-static
-BOOL WINAPI j_SymFromAddr(HANDLE hProcess, DWORD64 Address, PDWORD64 Displacement, PSYMBOL_INFO Symbol)
-{
-   if(
-      (pfnSymFromAddr || (pfnSymFromAddr = (PFNSYMGETSYMFROMADDR) __GetProcAddress("SymFromAddr")))
-   )
-      return pfnSymFromAddr(hProcess, Address, Displacement, Symbol);
-   else
-      return FALSE;
-}
+DBGHELP_DISPATCH(SymGetLineFromAddr64,
+                 BOOL, FALSE,
+                 (HANDLE hProcess, DWORD64 dwAddr, PDWORD pdwDisplacement, PIMAGEHLP_LINE64 Line),
+                 (hProcess, dwAddr, pdwDisplacement, Line))
 
 
-static INLINE void
+#undef DBGHELP_DISPATCH
+
+
+static INLINE boolean
 debug_symbol_name_dbghelp(const void *addr, char* buf, unsigned size)
 {
-   HANDLE hProcess;
-   BYTE symbolBuffer[1024];
-   PSYMBOL_INFO pSymbol = (PSYMBOL_INFO) symbolBuffer;
-   DWORD64 dwDisplacement = 0;  /* Displacement of the input address, relative to the start of the symbol */
+   DWORD64 dwAddr = (DWORD64)(uintptr_t)addr;
+   HANDLE hProcess = GetCurrentProcess();
 
-   hProcess = GetCurrentProcess();
+   /* General purpose buffer, to back pSymbol and other temporary stuff.
+    * Must not be too memory hungry here to avoid stack overflows.
+    */
+   CHAR buffer[512];
+
+   PSYMBOL_INFO pSymbol = (PSYMBOL_INFO) buffer;
+   DWORD64 dwDisplacement = 0;  /* Displacement of the input address, relative to the start of the symbol */
+   DWORD dwLineDisplacement = 0;
+   IMAGEHLP_LINE64 Line;
 
    memset(pSymbol, 0, sizeof *pSymbol);
-   pSymbol->SizeOfStruct = sizeof(symbolBuffer);
-   pSymbol->MaxNameLen = sizeof(symbolBuffer) - offsetof(SYMBOL_INFO, Name);
+   pSymbol->SizeOfStruct = sizeof buffer;
+   pSymbol->MaxNameLen = sizeof buffer - offsetof(SYMBOL_INFO, Name);
 
-   if(!bSymInitialized) {
+   if (!g_bSymInitialized) {
       j_SymSetOptions(/* SYMOPT_UNDNAME | */ SYMOPT_LOAD_LINES);
-      if(j_SymInitialize(hProcess, NULL, TRUE))
-         bSymInitialized = TRUE;
+      if (j_SymInitialize(hProcess, NULL, TRUE)) {
+         g_bSymInitialized = TRUE;
+      }
    }
 
-   if(!j_SymFromAddr(hProcess, (DWORD64)(uintptr_t)addr, &dwDisplacement, pSymbol))
-      buf[0] = 0;
-   else
-   {
-      strncpy(buf, pSymbol->Name, size);
-      buf[size - 1] = 0;
+   /* Lookup symbol name */
+   if (!g_bSymInitialized ||
+       !j_SymFromAddr(hProcess, dwAddr, &dwDisplacement, pSymbol)) {
+      /*
+       * We couldn't obtain symbol information.  At least tell which module the address belongs.
+       */
+
+      HMODULE hModule = NULL;
+
+      if (!GetModuleHandleEx(GET_MODULE_HANDLE_EX_FLAG_FROM_ADDRESS,
+                             (LPCTSTR)addr,
+                             &hModule)) {
+         return FALSE;
+      }
+
+      if (GetModuleFileNameA(hModule, buffer, sizeof buffer) == sizeof buffer) {
+         return FALSE;
+      }
+      util_snprintf(buf, size, "%p at %s+0x%lx",
+                    addr, buffer,
+                    (unsigned long)((uintptr_t)addr - (uintptr_t)hModule));
+
+      return TRUE;
    }
+
+   /*
+    * Try to get filename and line number.
+    */
+   memset(&Line, 0, sizeof Line);
+   Line.SizeOfStruct = sizeof Line;
+   if (!j_SymGetLineFromAddr64(hProcess, dwAddr, &dwLineDisplacement, &Line)) {
+      Line.FileName = NULL;
+   }
+
+   if (Line.FileName) {
+      util_snprintf(buf, size, "%s at %s:%lu", pSymbol->Name, Line.FileName, Line.LineNumber);
+   } else {
+      util_snprintf(buf, size, "%s", pSymbol->Name);
+   }
+
+   return TRUE;
 }
-#endif
+
+#endif /* PIPE_OS_WINDOWS */
+
 
 #if defined(__GLIBC__) && !defined(__UCLIBC__)
+
 #include <execinfo.h>
 
 /* This can only provide dynamic symbols, or binary offsets into a file.
  *
  * To fix this, post-process the output with tools/addr2line.sh
  */
-static INLINE void
+static INLINE boolean
 debug_symbol_name_glibc(const void *addr, char* buf, unsigned size)
 {
    char** syms = backtrace_symbols((void**)&addr, 1);
+   if (!syms) {
+      return FALSE;
+   }
    strncpy(buf, syms[0], size);
    buf[size - 1] = 0;
    free(syms);
+   return TRUE;
 }
-#endif
+
+#endif /* defined(__GLIBC__) && !defined(__UCLIBC__) */
+
 
 void
 debug_symbol_name(const void *addr, char* buf, unsigned size)
 {
-#if defined(PIPE_OS_WINDOWS) && defined(PIPE_ARCH_X86)
-   debug_symbol_name_dbghelp(addr, buf, size);
-   if(buf[0])
+#if defined(PIPE_OS_WINDOWS)
+   if (debug_symbol_name_dbghelp(addr, buf, size)) {
       return;
+   }
 #endif
 
 #if defined(__GLIBC__) && !defined(__UCLIBC__)
-   debug_symbol_name_glibc(addr, buf, size);
-   if(buf[0])
-      return;
+   if (debug_symbol_name_glibc(addr, buf, size)) {
+       return;
+   }
 #endif
 
    util_snprintf(buf, size, "%p", addr);