Typesafe strprintf/error/LogPrint functions

Switch to tinyformat-based formatting.

Tinyformat is a typesafe drop-in replacement for C99 printf functions:
https://github.com/c42f/tinyformat

configure.ac

@@ -189,7 +189,7 @@ case $host in
        AC_MSG_ERROR("windres not found")
      fi
 
-     CPPFLAGS="$CPPFLAGS -D_MT -DWIN32 -D_WINDOWS -DBOOST_THREAD_USE_LIB -D__USE_MINGW_ANSI_STDIO"
+     CPPFLAGS="$CPPFLAGS -D_MT -DWIN32 -D_WINDOWS -DBOOST_THREAD_USE_LIB"
      LEVELDB_TARGET_FLAGS="TARGET_OS=OS_WINDOWS_CROSSCOMPILE"
      if test "x$CXXFLAGS_overridden" = "xno"; then
        CXXFLAGS="$CXXFLAGS -w"

src/Makefile.am

@@ -60,6 +60,7 @@ BITCOIN_CORE_H = \
   serialize.h \
   sync.h \
   threadsafety.h \
+  tinyformat.h \
   txdb.h \
   txmempool.h \
   ui_interface.h \

src/main.cpp

@@ -1884,7 +1884,7 @@ bool SetBestChain(CValidationState &state, CBlockIndex* pindexNew)
             pindex = pindex->pprev;
         }
         if (nUpgraded > 0)
-            LogPrintf("SetBestChain: %d of last 100 blocks above version %d\n", nUpgraded, CBlock::CURRENT_VERSION);
+            LogPrintf("SetBestChain: %d of last 100 blocks above version %d\n", nUpgraded, (int)CBlock::CURRENT_VERSION);
         if (nUpgraded > 100/2)
             // strMiscWarning is read by GetWarnings(), called by Qt and the JSON-RPC code to warn the user:
             strMiscWarning = _("Warning: This version is obsolete, upgrade required!");

src/util.cpp

@@ -235,12 +235,12 @@ static void DebugPrintInit()
     mutexDebugLog = new boost::mutex();
 }
 
-int LogPrint(const char* category, const char* pszFormat, ...)
+bool LogAcceptCategory(const char* category)
 {
     if (category != NULL)
     {
         if (!fDebug)
-            return 0;
+            return false;
 
         // Give each thread quick access to -debug settings.
         // This helps prevent issues debugging global destructors,
@@ -258,17 +258,18 @@ int LogPrint(const char* category, const char* pszFormat, ...)
         // if not debugging everything and not debugging specific category, LogPrint does nothing.
         if (setCategories.count(string("")) == 0 &&
             setCategories.count(string(category)) == 0)
-            return 0;
+            return false;
     }
+    return true;
+}
 
+int LogPrintStr(const std::string &str)
+{
     int ret = 0; // Returns total number of characters written
     if (fPrintToConsole)
     {
         // print to console
-        va_list arg_ptr;
-        va_start(arg_ptr, pszFormat);
-        ret += vprintf(pszFormat, arg_ptr);
-        va_end(arg_ptr);
+        ret = fwrite(str.data(), 1, str.size(), stdout);
     }
     else if (fPrintToDebugLog)
     {
@@ -291,76 +292,17 @@ int LogPrint(const char* category, const char* pszFormat, ...)
         // Debug print useful for profiling
         if (fLogTimestamps && fStartedNewLine)
             ret += fprintf(fileout, "%s ", DateTimeStrFormat("%Y-%m-%d %H:%M:%S", GetTime()).c_str());
-        if (pszFormat[strlen(pszFormat) - 1] == '\n')
+        if (!str.empty() && str[str.size()-1] == '\n')
             fStartedNewLine = true;
         else
             fStartedNewLine = false;
 
-        va_list arg_ptr;
-        va_start(arg_ptr, pszFormat);
-        ret += vfprintf(fileout, pszFormat, arg_ptr);
-        va_end(arg_ptr);
+        ret = fwrite(str.data(), 1, str.size(), fileout);
     }
 
     return ret;
 }
 
-string vstrprintf(const char *format, va_list ap)
-{
-    char buffer[50000];
-    char* p = buffer;
-    int limit = sizeof(buffer);
-    int ret;
-    while (true)
-    {
-        va_list arg_ptr;
-        va_copy(arg_ptr, ap);
-        ret = vsnprintf(p, limit, format, arg_ptr);
-        va_end(arg_ptr);
-        if (ret >= 0 && ret < limit)
-            break;
-        if (p != buffer)
-            delete[] p;
-        limit *= 2;
-        p = new char[limit];
-        if (p == NULL)
-            throw std::bad_alloc();
-    }
-    string str(p, p+ret);
-    if (p != buffer)
-        delete[] p;
-    return str;
-}
-
-string real_strprintf(const char *format, int dummy, ...)
-{
-    va_list arg_ptr;
-    va_start(arg_ptr, dummy);
-    string str = vstrprintf(format, arg_ptr);
-    va_end(arg_ptr);
-    return str;
-}
-
-string real_strprintf(const std::string &format, int dummy, ...)
-{
-    va_list arg_ptr;
-    va_start(arg_ptr, dummy);
-    string str = vstrprintf(format.c_str(), arg_ptr);
-    va_end(arg_ptr);
-    return str;
-}
-
-bool error(const char *format, ...)
-{
-    va_list arg_ptr;
-    va_start(arg_ptr, format);
-    std::string str = vstrprintf(format, arg_ptr);
-    va_end(arg_ptr);
-    LogPrintf("ERROR: %s\n", str.c_str());
-    return false;
-}
-
-
 void ParseString(const string& str, char c, vector<string>& v)
 {
     if (str.empty())

src/util.h

@@ -12,6 +12,7 @@
 
 #include "compat.h"
 #include "serialize.h"
+#include "tinyformat.h"
 
 #include <cstdio>
 #include <exception>
@@ -99,21 +100,6 @@ inline void MilliSleep(int64_t n)
 #endif
 }
 
-/* This GNU C extension enables the compiler to check the format string against the parameters provided.
- * X is the number of the "format string" parameter, and Y is the number of the first variadic parameter.
- * Parameters count from 1.
- */
-#ifdef __GNUC__
-#define ATTR_WARN_PRINTF(X,Y) __attribute__((format(gnu_printf,X,Y)))
-#else
-#define ATTR_WARN_PRINTF(X,Y)
-#endif
-
-
-
-
-
-
 
 
 extern std::map<std::string, std::string> mapArgs;
@@ -130,27 +116,49 @@ extern volatile bool fReopenDebugLog;
 void RandAddSeed();
 void RandAddSeedPerfmon();
 
-// Print to debug.log if -debug=category switch is given OR category is NULL.
-int ATTR_WARN_PRINTF(2,3) LogPrint(const char* category, const char* pszFormat, ...);
+/* Return true if log accepts specified category */
+bool LogAcceptCategory(const char* category);
+/* Send a string to the log output */
+int LogPrintStr(const std::string &str);
+
+#define strprintf tfm::format
 #define LogPrintf(...) LogPrint(NULL, __VA_ARGS__)
 
-/*
-  Rationale for the real_strprintf / strprintf construction:
-    It is not allowed to use va_start with a pass-by-reference argument.
-    (C++ standard, 18.7, paragraph 3). Use a dummy argument to work around this, and use a
-    macro to keep similar semantics.
-*/
-
-/** Overload strprintf for char*, so that GCC format type warnings can be given */
-std::string ATTR_WARN_PRINTF(1,3) real_strprintf(const char *format, int dummy, ...);
-/** Overload strprintf for std::string, to be able to use it with _ (translation).
- * This will not support GCC format type warnings (-Wformat) so be careful.
+/* When we switch to C++11, this can be switched to variadic templates instead
+ * of this macro-based construction (see tinyformat.h).
+ */
+#define MAKE_ERROR_AND_LOG_FUNC(n)                                        \
+    /*   Print to debug.log if -debug=category switch is given OR category is NULL. */ \
+    template<TINYFORMAT_ARGTYPES(n)>                                          \
+    static inline int LogPrint(const char* category, const char* format, TINYFORMAT_VARARGS(n))  \
+    {                                                                         \
+        if(!LogAcceptCategory(category)) return 0;                            \
+        return LogPrintStr(tfm::format(format, TINYFORMAT_PASSARGS(n))); \
+    }                                                                         \
+    /*   Log error and return false */                                        \
+    template<TINYFORMAT_ARGTYPES(n)>                                          \
+    static inline bool error(const char* format, TINYFORMAT_VARARGS(n))                     \
+    {                                                                         \
+        LogPrintStr("ERROR: " + tfm::format(format, TINYFORMAT_PASSARGS(n))); \
+        return false;                                                         \
+    }
+
+TINYFORMAT_FOREACH_ARGNUM(MAKE_ERROR_AND_LOG_FUNC)
+
+/* Zero-arg versions of logging and error, these are not covered by
+ * TINYFORMAT_FOREACH_ARGNUM
  */
-std::string real_strprintf(const std::string &format, int dummy, ...);
-#define strprintf(format, ...) real_strprintf(format, 0, __VA_ARGS__)
-std::string vstrprintf(const char *format, va_list ap);
+static inline int LogPrint(const char* category, const char* format)
+{
+    if(!LogAcceptCategory(category)) return 0;
+    return LogPrintStr(format);
+}
+static inline bool error(const char* format)
+{
+    LogPrintStr(std::string("ERROR: ") + format);
+    return false;
+}
 
-bool ATTR_WARN_PRINTF(1,2) error(const char *format, ...);
 
 void LogException(std::exception* pex, const char* pszThread);
 void PrintException(std::exception* pex, const char* pszThread);