diff --git a/src/bele.h b/src/bele.h
index 965a4586..7eea80cd 100644
--- a/src/bele.h
+++ b/src/bele.h
@@ -192,7 +192,7 @@ __acc_static_forceinline int sign_extend(unsigned v, unsigned bits) {
 }
 
 __acc_static_forceinline upx_int64_t sign_extend(upx_uint64_t v, unsigned bits) {
-    const upx_uint64_t sign_bit = UPX_UINT64_C(1) << (bits - 1);
+    const upx_uint64_t sign_bit = 1ull << (bits - 1);
     v &= sign_bit | (sign_bit - 1);
     v |= 0 - (v & sign_bit);
     return ACC_ICAST(upx_int64_t, v);
diff --git a/src/c_init.cpp b/src/c_init.cpp
index c5700a31..b8faccb5 100644
--- a/src/c_init.cpp
+++ b/src/c_init.cpp
@@ -142,13 +142,13 @@ console_t console_init =
 };
 
 
-void __acc_cdecl_va con_fprintf(FILE *f, const char *format, ...)
+void con_fprintf(FILE *f, const char *format, ...)
 {
     va_list args;
     char buf[80*25];
 
     va_start(args, format);
-    upx_vsnprintf(buf, sizeof(buf), format,args);
+    upx_safe_vsnprintf(buf, sizeof(buf), format,args);
     va_end(args);
 
     if (con == me)
diff --git a/src/conf.h b/src/conf.h
index 52a28457..dfc198f9 100644
--- a/src/conf.h
+++ b/src/conf.h
@@ -42,14 +42,10 @@
 #if !defined(_FILE_OFFSET_BITS)
 #  define _FILE_OFFSET_BITS 64
 #endif
-// MinGW <stdio.h> confusion
 #if defined(_WIN32) && defined(__MINGW32__) && defined(__GNUC__)
 #  if !defined(_USE_MINGW_ANSI_STDIO)
 #    define _USE_MINGW_ANSI_STDIO 1
 #  endif
-#  if !defined(__printf__)
-#    define __printf__ __gnu_printf__
-#  endif
 #endif
 
 #undef NDEBUG
@@ -99,6 +95,8 @@ ACC_COMPILE_TIME_ASSERT_HEADER((char)(-1) > 0) // -funsigned-char
 #  pragma warning(disable: 4820) // padding added after data member
 #endif
 
+#undef snprintf
+#undef vsnprintf
 #define ACC_WANT_ACC_INCD_H 1
 #define ACC_WANT_ACC_INCE_H 1
 #define ACC_WANT_ACC_LIB_H 1
@@ -115,12 +113,6 @@ typedef acc_uint32_t    upx_uint32_t;
 typedef acc_int64_t     upx_int64_t;
 typedef acc_uint64_t    upx_uint64_t;
 typedef acc_uintptr_t   upx_uintptr_t;
-#define UPX_INT16_C     ACC_INT16_C
-#define UPX_UINT16_C    ACC_UINT16_C
-#define UPX_INT32_C     ACC_INT32_C
-#define UPX_UINT32_C    ACC_UINT32_C
-#define UPX_INT64_C     ACC_INT64_C
-#define UPX_UINT64_C    ACC_UINT64_C
 
 typedef unsigned char   upx_byte;
 #define upx_bytep       upx_byte *
@@ -290,14 +282,18 @@ typedef upx_int64_t upx_off_t;
 
 #define CLANG_FORMAT_DUMMY_STATEMENT /*empty*/
 
-#if (ACC_CC_CLANG || ACC_CC_GNUC || ACC_CC_LLVM || ACC_CC_PATHSCALE)
-__acc_static_forceinline void NO_printf(const char *, ...)
-    __attribute__((__format__(__printf__, 1, 2)));
-__acc_static_forceinline void NO_fprintf(FILE *, const char *, ...)
-    __attribute__((__format__(__printf__, 2, 3)));
+#if defined(_WIN32) && defined(__MINGW32__) && defined(__GNUC__) && !defined(__clang__)
+#  define attribute_format(a,b) __attribute__((__format__(__gnu_printf__,a,b)));
+#elif (ACC_CC_CLANG || ACC_CC_GNUC)
+#  define attribute_format(a,b) __attribute__((__format__(__printf__,a,b)));
+#else
+#  define attribute_format(a,b) /*empty*/
 #endif
-__acc_static_forceinline void NO_printf(const char *, ...) {}
-__acc_static_forceinline void NO_fprintf(FILE *, const char *, ...) {}
+
+inline void NO_printf(const char *, ...) attribute_format(1, 2);
+inline void NO_fprintf(FILE *, const char *, ...) attribute_format(2, 3);
+inline void NO_printf(const char *, ...) {}
+inline void NO_fprintf(FILE *, const char *, ...) {}
 
 #if !defined(__has_builtin)
 #  define __has_builtin(x)      0
@@ -724,29 +720,13 @@ void printSetNl(int need_nl);
 void printClearLine(FILE *f = nullptr);
 void printErr(const char *iname, const Throwable *e);
 void printUnhandledException(const char *iname, const std::exception *e);
-#if (ACC_CC_CLANG || ACC_CC_GNUC || ACC_CC_LLVM || ACC_CC_PATHSCALE)
-void __acc_cdecl_va printErr(const char *iname, const char *format, ...)
-        __attribute__((__format__(__printf__,2,3)));
-void __acc_cdecl_va printWarn(const char *iname, const char *format, ...)
-        __attribute__((__format__(__printf__,2,3)));
-#else
-void __acc_cdecl_va printErr(const char *iname, const char *format, ...);
-void __acc_cdecl_va printWarn(const char *iname, const char *format, ...);
-#endif
+void printErr(const char *iname, const char *format, ...) attribute_format(2, 3);
+void printWarn(const char *iname, const char *format, ...) attribute_format(2, 3);
 
-#if (ACC_CC_CLANG || ACC_CC_GNUC || ACC_CC_LLVM || ACC_CC_PATHSCALE)
-void __acc_cdecl_va infoWarning(const char *format, ...)
-        __attribute__((__format__(__printf__,1,2)));
-void __acc_cdecl_va infoHeader(const char *format, ...)
-        __attribute__((__format__(__printf__,1,2)));
-void __acc_cdecl_va info(const char *format, ...)
-        __attribute__((__format__(__printf__,1,2)));
-#else
-void __acc_cdecl_va infoWarning(const char *format, ...);
-void __acc_cdecl_va infoHeader(const char *format, ...);
-void __acc_cdecl_va info(const char *format, ...);
-#endif
-void infoHeader();
+void infoWarning(const char *format, ...) attribute_format(1, 2);
+void infoHeader(const char *format, ...) attribute_format(1, 2);
+void info(const char *format, ...) attribute_format(1, 2);
+void infoHeader(void);
 void infoWriting(const char *what, long size);
 
 
diff --git a/src/console.h b/src/console.h
index 50b589a9..f8ed94e4 100644
--- a/src/console.h
+++ b/src/console.h
@@ -122,12 +122,7 @@ typedef struct
 console_t;
 
 
-#if defined(__GNUC__)
-void __acc_cdecl_va con_fprintf(FILE *f, const char *format, ...)
-        __attribute__((__format__(__printf__,2,3)));
-#else
-void __acc_cdecl_va con_fprintf(FILE *f, const char *format, ...);
-#endif
+void con_fprintf(FILE *f, const char *format, ...) attribute_format(2, 3);
 
 
 #define FG_BLACK     0x00
diff --git a/src/linker.cpp b/src/linker.cpp
index 83798947..2403da5e 100644
--- a/src/linker.cpp
+++ b/src/linker.cpp
@@ -40,12 +40,12 @@ static bool update_capacity(unsigned size, unsigned *capacity) {
     return true;
 }
 
-static void __acc_cdecl_va internal_error(const char *format, ...) {
+static void internal_error(const char *format, ...) {
     static char buf[1024];
     va_list ap;
 
     va_start(ap, format);
-    upx_vsnprintf(buf, sizeof(buf), format, ap);
+    upx_safe_vsnprintf(buf, sizeof(buf), format, ap);
     va_end(ap);
 
     throwInternalError(buf);
@@ -426,7 +426,7 @@ void ElfLinker::addLoader(const char *s, va_list ap) {
     }
 }
 
-void __acc_cdecl_va ElfLinker::addLoaderVA(const char *s, ...) {
+void ElfLinker::addLoaderVA(const char *s, ...) {
     va_list ap;
     va_start(ap, s);
     addLoader(s, ap);
@@ -503,8 +503,8 @@ void ElfLinker::dumpSymbol(const Symbol *symbol, unsigned flags, FILE *fp) const
     if ((flags & 1) && symbol->section->output == nullptr)
         return;
     char d0[16 + 1], d1[16 + 1];
-    upx_snprintf(d0, sizeof(d0), "%016llx", (upx_uint64_t) symbol->offset);
-    upx_snprintf(d1, sizeof(d1), "%016llx", (upx_uint64_t) symbol->section->offset);
+    upx_safe_snprintf(d0, sizeof(d0), "%016llx", (upx_uint64_t) symbol->offset);
+    upx_safe_snprintf(d1, sizeof(d1), "%016llx", (upx_uint64_t) symbol->section->offset);
     fprintf(fp, "%-28s 0x%-16s | %-28s 0x%-16s\n", symbol->name, d0, symbol->section->name, d1);
 }
 void ElfLinker::dumpSymbols(unsigned flags, FILE *fp) const {
@@ -514,7 +514,7 @@ void ElfLinker::dumpSymbols(unsigned flags, FILE *fp) const {
         // default: dump symbols in used section order
         for (const Section *section = head; section; section = section->next) {
             char d1[16 + 1];
-            upx_snprintf(d1, sizeof(d1), "%016llx", (upx_uint64_t) section->offset);
+            upx_safe_snprintf(d1, sizeof(d1), "%016llx", (upx_uint64_t) section->offset);
             fprintf(fp, "%-42s%-28s 0x%-16s\n", "", section->name, d1);
             for (unsigned ic = 0; ic < nsymbols; ic++) {
                 const Symbol *symbol = symbols[ic];
diff --git a/src/linker.h b/src/linker.h
index 81c3fc75..cae5e8df 100644
--- a/src/linker.h
+++ b/src/linker.h
@@ -82,10 +82,10 @@ public:
     // virtual void setLoaderAlignOffset(int phase);
     virtual int addLoader(const char *sname);
     void addLoader(const char *s, va_list ap);
-#if 1 && (ACC_CC_CLANG || (ACC_CC_GNUC >= 0x040100))
-    void __acc_cdecl_va addLoaderVA(const char *s, ...) __attribute__((__sentinel__));
+#if (ACC_CC_CLANG || ACC_CC_GNUC)
+    void addLoaderVA(const char *s, ...) __attribute__((__sentinel__));
 #else
-    void __acc_cdecl_va addLoaderVA(const char *s, ...);
+    void addLoaderVA(const char *s, ...);
 #endif
     virtual Section *addSection(const char *sname, const void *sdata, int slen, unsigned p2align);
     virtual int getSection(const char *sname, int *slen = nullptr) const;
diff --git a/src/main.cpp b/src/main.cpp
index b56f1ac6..ffc00847 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -1342,7 +1342,7 @@ void upx_compiler_sanity_check(void) {
         assert(get_le32(d) == 0xfcfdfeff);
         assert(bele->get32(d) == 0xfcfdfeff);
         assert(get_le32_signed(d) == -50462977);
-        assert(get_le64_signed(d) == UPX_INT64_C(-506097522914230529));
+        assert(get_le64_signed(d) == -506097522914230529LL);
         assert(find_be16(d, 2, 0xfffe) == 0);
         assert(find_le16(d, 2, 0xfeff) == 0);
         assert(find_be32(d, 4, 0xfffefdfc) == 0);
@@ -1351,7 +1351,7 @@ void upx_compiler_sanity_check(void) {
         assert(get_be16_signed(d) == 32638);
         assert(get_be24_signed(d) == 8355453);
         assert(get_be32_signed(d) == 2138996092);
-        assert(get_be64_signed(d) == UPX_INT64_C(9186918263483431288));
+        assert(get_be64_signed(d) == 9186918263483431288LL);
     }
     {
         unsigned dd;
@@ -1574,7 +1574,7 @@ int __acc_cdecl_main main(int argc, char *argv[]) {
         long long ll = argc < 0 ? 0 : -1;
         unsigned long long llu = (unsigned long long) ll;
         char buf[256];
-        upx_snprintf(buf, sizeof(buf), ".%d.%ld.%lld.%u.%lu.%llu", -3, -2L, ll, 3U, 2LU, llu);
+        snprintf(buf, sizeof(buf), ".%d.%ld.%lld.%u.%lu.%llu", -3, -2L, ll, 3U, 2LU, llu);
         assert(strcmp(buf, ".-3.-2.-1.3.2.18446744073709551615") == 0);
     }
 #endif
diff --git a/src/msg.cpp b/src/msg.cpp
index 83be4e3e..a3f9bbc6 100644
--- a/src/msg.cpp
+++ b/src/msg.cpp
@@ -91,10 +91,10 @@ static void pr_error(const char *iname, const char *msg, bool is_warning)
     bool c = acc_isatty(STDERR_FILENO) ? 1 : 0;
 
     int fg = con_fg(stderr,FG_BRTRED);
-    upx_snprintf(buf+strlen(buf),sizeof(buf)-strlen(buf),"%s: ", progname);
+    snprintf(buf+strlen(buf),sizeof(buf)-strlen(buf),"%s: ", progname);
     pr_print(c,buf);
     //(void)con_fg(stderr,FG_RED);
-    upx_snprintf(buf,sizeof(buf),"%s: ", iname);
+    snprintf(buf,sizeof(buf),"%s: ", iname);
     pr_print(c,buf);
     //(void)con_fg(stderr,FG_BRTRED);
     pr_print(c,msg);
@@ -112,13 +112,13 @@ void printErr(const char *iname, const Throwable *e)
     char buf[1024];
     size_t l;
 
-    upx_snprintf(buf, sizeof(buf), "%s", prettyName(typeid(*e).name()));
+    snprintf(buf, sizeof(buf), "%s", prettyName(typeid(*e).name()));
     l = strlen(buf);
     if (l < sizeof(buf) && e->getMsg())
-        upx_snprintf(buf+l, sizeof(buf)-l, ": %s", e->getMsg());
+        snprintf(buf+l, sizeof(buf)-l, ": %s", e->getMsg());
     l = strlen(buf);
     if (l < sizeof(buf) && e->getErrno()) {
-        upx_snprintf(buf+l, sizeof(buf)-l, ": %s", strerror(e->getErrno()));
+        snprintf(buf+l, sizeof(buf)-l, ": %s", strerror(e->getErrno()));
 #if 1
         // some compilers (e.g. Borland C++) put a trailing '\n'
         // into strerror() result
@@ -131,26 +131,26 @@ void printErr(const char *iname, const Throwable *e)
 }
 
 
-void __acc_cdecl_va printErr(const char *iname, const char *format, ...)
+void printErr(const char *iname, const char *format, ...)
 {
     va_list args;
     char buf[1024];
 
     va_start(args,format);
-    upx_vsnprintf(buf,sizeof(buf),format,args);
+    upx_safe_vsnprintf(buf,sizeof(buf),format,args);
     va_end(args);
 
     pr_error(iname,buf,false);
 }
 
 
-void __acc_cdecl_va printWarn(const char *iname, const char *format, ...)
+void printWarn(const char *iname, const char *format, ...)
 {
     va_list args;
     char buf[1024];
 
     va_start(args,format);
-    upx_vsnprintf(buf,sizeof(buf),format,args);
+    upx_safe_vsnprintf(buf,sizeof(buf),format,args);
     va_end(args);
 
     pr_error(iname,buf,true);
@@ -201,21 +201,21 @@ void infoHeader()
     info_header = 0;
 }
 
-void __acc_cdecl_va infoHeader(const char *format, ...)
+void infoHeader(const char *format, ...)
 {
     if (opt->info_mode <= 0)
         return;
     va_list args;
     char buf[1024];
     va_start(args,format);
-    upx_vsnprintf(buf,sizeof(buf),format,args);
+    upx_safe_vsnprintf(buf,sizeof(buf),format,args);
     va_end(args);
     info_print(buf);
     info_header = 1;
 }
 
 
-void __acc_cdecl_va info(const char *format, ...)
+void info(const char *format, ...)
 {
     if (opt->info_mode <= 0)
         return;
@@ -224,13 +224,13 @@ void __acc_cdecl_va info(const char *format, ...)
     const int n = 4 * info_header;
     memset(buf, ' ', n);
     va_start(args,format);
-    upx_vsnprintf(buf+n,sizeof(buf)-n,format,args);
+    upx_safe_vsnprintf(buf+n,sizeof(buf)-n,format,args);
     va_end(args);
     info_print(buf);
 }
 
 
-void __acc_cdecl_va infoWarning(const char *format, ...)
+void infoWarning(const char *format, ...)
 {
     if (opt->info_mode <= 0)
     {
@@ -240,7 +240,7 @@ void __acc_cdecl_va infoWarning(const char *format, ...)
     va_list args;
     char buf[1024];
     va_start(args,format);
-    upx_vsnprintf(buf,sizeof(buf),format,args);
+    upx_safe_vsnprintf(buf,sizeof(buf),format,args);
     va_end(args);
     info("[WARNING] %s\n", buf);
 }
diff --git a/src/packer.cpp b/src/packer.cpp
index e853653a..7a92394e 100644
--- a/src/packer.cpp
+++ b/src/packer.cpp
@@ -1013,7 +1013,7 @@ void Packer::addLoader(C a, C b, C c, C d, C e, C f, C g, C h, C i, C j) {
 #undef C
 #undef N
 
-void __acc_cdecl_va Packer::addLoaderVA(const char *s, ...) {
+void Packer::addLoaderVA(const char *s, ...) {
     va_list ap;
     va_start(ap, s);
     linker->addLoader(s, ap);
diff --git a/src/packer.h b/src/packer.h
index ff00f66a..c091814c 100644
--- a/src/packer.h
+++ b/src/packer.h
@@ -223,10 +223,10 @@ protected:
     void addLoader(C, C, C, C, C, C, C, C, C);
     void addLoader(C, C, C, C, C, C, C, C, C, C);
 #undef C
-#if 1 && (ACC_CC_CLANG || (ACC_CC_GNUC >= 0x040100))
-    void __acc_cdecl_va addLoaderVA(const char *s, ...) __attribute__((__sentinel__));
+#if (ACC_CC_CLANG || ACC_CC_GNUC)
+    void addLoaderVA(const char *s, ...) __attribute__((__sentinel__));
 #else
-    void __acc_cdecl_va addLoaderVA(const char *s, ...);
+    void addLoaderVA(const char *s, ...);
 #endif
     virtual bool hasLoaderSection(const char *name) const;
     virtual int getLoaderSection(const char *name, int *slen = nullptr) const;
diff --git a/src/pefile.cpp b/src/pefile.cpp
index f232cfc1..0bc5e53c 100644
--- a/src/pefile.cpp
+++ b/src/pefile.cpp
@@ -632,7 +632,7 @@ class PeFile::ImportLinker : public ElfLinkerAMD64
         unsigned len = 1 + 2 * strlen(dll) + 1 + 2 * strlen(proc) + 1 + 1;
         tstr dlln(name_for_dll(dll, first_char));
         char *procn = New(char, len);
-        upx_snprintf(procn, len, "%s%c", (const char*) dlln, separator);
+        upx_safe_snprintf(procn, len, "%s%c", (const char*) dlln, separator);
         encode_name(proc, procn + strlen(procn));
         return procn;
     }
@@ -741,7 +741,7 @@ public:
         ACC_COMPILE_TIME_ASSERT(sizeof(C) == 1)  // "char" or "unsigned char"
         assert(ordinal > 0 && ordinal < 0x10000);
         char ord[1+5+1];
-        upx_snprintf(ord, sizeof(ord), "%c%05u", ordinal_id, ordinal);
+        upx_safe_snprintf(ord, sizeof(ord), "%c%05u", ordinal_id, ordinal);
         add((const char*) dll, ord, ordinal);
     }
 
@@ -803,7 +803,7 @@ public:
         ACC_COMPILE_TIME_ASSERT(sizeof(C) == 1)  // "char" or "unsigned char"
         assert(ordinal > 0 && ordinal < 0x10000);
         char ord[1+5+1];
-        upx_snprintf(ord, sizeof(ord), "%c%05u", ordinal_id, ordinal);
+        upx_safe_snprintf(ord, sizeof(ord), "%c%05u", ordinal_id, ordinal);
 
         const Section *s = getThunk((const char*) dll, ord, thunk_separator_first);
         if (s == nullptr
@@ -898,7 +898,7 @@ unsigned PeFile::processImports0(ord_mask_t ord_mask) // pass 1
             if (u2->ordinal) return 1;
             if (!u1->shname) return 1;
             if (!u2->shname) return -1;
-            rc = (int) (upx_strlen(u1->shname) - upx_strlen(u2->shname));
+            rc = (int) (upx_safe_strlen(u1->shname) - upx_safe_strlen(u2->shname));
             if (rc) return rc;
             return strcmp(u1->shname, u2->shname);
         }
@@ -1933,7 +1933,7 @@ void PeFile::processResources(Resource *res)
                 keep_icons = New(char, 1 + iconsin1stdir * 9);
                 *keep_icons = 0;
                 for (unsigned ic = 0; ic < iconsin1stdir; ic++)
-                    upx_snprintf(keep_icons + strlen(keep_icons), 9, "3/%u,",
+                    upx_safe_snprintf(keep_icons + strlen(keep_icons), 9, "3/%u,",
                                  get_le16(ibuf.subref("bad resoff %#x", res->offs() + 6 + ic * 14 + 12, 2)));
                 if (*keep_icons)
                     keep_icons[strlen(keep_icons) - 1] = 0;
@@ -2131,7 +2131,7 @@ void PeFile::checkHeaderValues(unsigned subsystem, unsigned mask,
     if ((1u << subsystem) & ~mask)
     {
         char buf[100];
-        upx_snprintf(buf, sizeof(buf), "PE: subsystem %u is not supported",
+        upx_safe_snprintf(buf, sizeof(buf), "PE: subsystem %u is not supported",
                      subsystem);
         throwCantPack(buf);
     }
diff --git a/src/s_vcsa.cpp b/src/s_vcsa.cpp
index 87e26d1d..0c91d1f8 100644
--- a/src/s_vcsa.cpp
+++ b/src/s_vcsa.cpp
@@ -258,10 +258,10 @@ static int init(screen_t *this, int fd) {
         int attr;
         Cell a;
 
-        upx_snprintf(vc_name, sizeof(vc_name), "/dev/vcsa%d", (int) MINOR(st.st_rdev));
+        upx_safe_snprintf(vc_name, sizeof(vc_name), "/dev/vcsa%d", (int) MINOR(st.st_rdev));
         this->data->fd = open(vc_name, O_RDWR);
         if (this->data->fd == -1) {
-            upx_snprintf(vc_name, sizeof(vc_name), "/dev/vcc/a%d", (int) MINOR(st.st_rdev));
+            upx_safe_snprintf(vc_name, sizeof(vc_name), "/dev/vcc/a%d", (int) MINOR(st.st_rdev));
             this->data->fd = open(vc_name, O_RDWR);
         }
         if (this->data->fd != -1) {
diff --git a/src/snprintf.cpp b/src/snprintf.cpp
index f1131338..5ac5b33d 100644
--- a/src/snprintf.cpp
+++ b/src/snprintf.cpp
@@ -1,10 +1,38 @@
+/* snprintf.cpp -- string wrapper
+
+   This file is part of the UPX executable compressor.
+
+   Copyright (C) 1996-2021 Markus Franz Xaver Johannes Oberhumer
+   Copyright (C) 1996-2021 Laszlo Molnar
+   All Rights Reserved.
+
+   UPX and the UCL library are free software; you can redistribute them
+   and/or modify them under the terms of the GNU General Public License as
+   published by the Free Software Foundation; either version 2 of
+   the License, or (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; see the file COPYING.
+   If not, write to the Free Software Foundation, Inc.,
+   59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+
+   Markus F.X.J. Oberhumer              Laszlo Molnar
+   <markus@oberhumer.com>               <ezerotven+github@gmail.com>
+ */
+
 #include "conf.h"
 
 /*************************************************************************
-// UPX version of string functions, with assertions
+// UPX version of string functions, with assertions and sane limits
 **************************************************************************/
 
-int upx_vsnprintf(char *str, upx_rsize_t max_size, const char *format, va_list ap) {
+#undef vsnprintf
+int upx_safe_vsnprintf(char *str, upx_rsize_t max_size, const char *format, va_list ap) {
     size_t size;
 
     // preconditions
@@ -17,7 +45,7 @@ int upx_vsnprintf(char *str, upx_rsize_t max_size, const char *format, va_list a
     long long n = vsnprintf(str, max_size, format, ap);
     assert(n >= 0);
     assert(n < UPX_RSIZE_MAX_STR);
-    size = (size_t)n + 1;
+    size = (size_t) n + 1;
 
     // postconditions
     assert(size > 0);
@@ -30,17 +58,17 @@ int upx_vsnprintf(char *str, upx_rsize_t max_size, const char *format, va_list a
     return ACC_ICONV(int, size - 1); // snprintf() returns length, not size
 }
 
-int __acc_cdecl_va upx_snprintf(char *str, upx_rsize_t max_size, const char *format, ...) {
+int upx_safe_snprintf(char *str, upx_rsize_t max_size, const char *format, ...) {
     va_list ap;
     int len;
 
     va_start(ap, format);
-    len = upx_vsnprintf(str, max_size, format, ap);
+    len = upx_safe_vsnprintf(str, max_size, format, ap);
     va_end(ap);
     return len;
 }
 
-int upx_vasprintf(char **ptr, const char *format, va_list ap) {
+int upx_safe_vasprintf(char **ptr, const char *format, va_list ap) {
     int len;
 
     assert(ptr != nullptr);
@@ -48,7 +76,7 @@ int upx_vasprintf(char **ptr, const char *format, va_list ap) {
 
     va_list ap_copy;
     va_copy(ap_copy, ap);
-    len = upx_vsnprintf(nullptr, 0, format, ap_copy);
+    len = upx_safe_vsnprintf(nullptr, 0, format, ap_copy);
     va_end(ap_copy);
 
     if (len >= 0) {
@@ -56,29 +84,41 @@ int upx_vasprintf(char **ptr, const char *format, va_list ap) {
         assert(*ptr != nullptr);
         if (*ptr == nullptr)
             return -1;
-        int len2 = upx_vsnprintf(*ptr, len + 1, format, ap);
+        int len2 = upx_safe_vsnprintf(*ptr, len + 1, format, ap);
         assert(len2 == len);
     }
     return len;
 }
 
-int __acc_cdecl_va upx_asprintf(char **ptr, const char *format, ...) {
+int upx_safe_asprintf(char **ptr, const char *format, ...) {
     va_list ap;
     int len;
 
     va_start(ap, format);
-    len = upx_vasprintf(ptr, format, ap);
+    len = upx_safe_vasprintf(ptr, format, ap);
     va_end(ap);
     return len;
 }
 
+char *upx_safe_xprintf(const char *format, ...) {
+    char *ptr = nullptr;
+    va_list ap;
+    int len;
+
+    va_start(ap, format);
+    len = upx_safe_vasprintf(&ptr, format, ap);
+    va_end(ap);
+    UNUSED(len);
+    assert(ptr != nullptr);
+    return ptr;
+}
+
 #undef strlen
-upx_rsize_t upx_strlen(const char *s) {
+upx_rsize_t upx_safe_strlen(const char *s) {
     assert(s != nullptr);
     size_t len = strlen(s);
     assert(len < UPX_RSIZE_MAX_STR);
     return len;
 }
 
-
 /* vim:set ts=4 sw=4 et: */
diff --git a/src/snprintf.h b/src/snprintf.h
index 35a9d6b8..dfb07b4c 100644
--- a/src/snprintf.h
+++ b/src/snprintf.h
@@ -29,30 +29,33 @@
 #define __UPX_SNPRINTF_H 1
 
 /*************************************************************************
-//
+// UPX version of string functions, with assertions and sane limits
 **************************************************************************/
 
-#ifdef __cplusplus
-extern "C" {
-#endif
-
 // info: snprintf() returns length and NOT size, but max_size is indeed size (incl NUL)
-int                upx_vsnprintf(char *str, upx_rsize_t max_size, const char *format, va_list ap);
-int __acc_cdecl_va upx_snprintf (char *str, upx_rsize_t max_size, const char *format, ...);
-int                upx_vasprintf(char **ptr, const char *format, va_list ap);
-int __acc_cdecl_va upx_asprintf (char **ptr, const char *format, ...);
 
-upx_rsize_t upx_strlen(const char *);
+int upx_safe_vsnprintf(char *str, upx_rsize_t max_size, const char *format, va_list ap);
+int upx_safe_snprintf (char *str, upx_rsize_t max_size, const char *format, ...) attribute_format(3, 4);
 
-#ifdef __cplusplus
-}
-#endif
+// malloc's *ptr
+int upx_safe_vasprintf(char **ptr, const char *format, va_list ap);
+int upx_safe_asprintf (char **ptr, const char *format, ...) attribute_format(2, 3);
+
+// returns a malloc'd pointer
+char *upx_safe_xprintf(const char *format, ...) attribute_format(1, 2);
+
+upx_rsize_t upx_safe_strlen(const char *);
 
 // globally redirect some functions
+#undef snprintf
 #undef sprintf
-#define sprintf error_sprintf_is_dangerous_use_snprintf
+#undef vsnprintf
+#define snprintf  upx_safe_snprintf
+#define sprintf   ERROR_sprintf_IS_DANGEROUS_USE_snprintf
+#define vsnprintf upx_safe_vsnprintf
+
 #undef strlen
-#define strlen upx_strlen
+#define strlen    upx_safe_strlen
 
 /*************************************************************************
 // some unsigned char string support functions
@@ -70,7 +73,9 @@ inline int strcasecmp(const unsigned char *s1, const unsigned char *s2) {
     return strcasecmp((const char *) s1, (const char *) s2);
 }
 
-inline upx_rsize_t upx_strlen(const unsigned char *s) { return upx_strlen((const char *) s); }
+inline upx_rsize_t upx_safe_strlen(const unsigned char *s) {
+    return upx_safe_strlen((const char *) s);
+}
 
 #endif /* already included */
 
diff --git a/src/ui.cpp b/src/ui.cpp
index a5f39144..26b8d077 100644
--- a/src/ui.cpp
+++ b/src/ui.cpp
@@ -140,14 +140,14 @@ static const char *mkline(upx_uint64_t fu_len, upx_uint64_t fc_len, upx_uint64_t
     if (ratio >= 1000 * 1000)
         strcpy(r, "overlay");
     else
-        upx_snprintf(r, sizeof(r), "%3u.%02u%%", ratio / 10000, (ratio % 10000) / 100);
+        upx_safe_snprintf(r, sizeof(r), "%3u.%02u%%", ratio / 10000, (ratio % 10000) / 100);
     if (decompress)
         f = "%10lld <-%10lld  %7s %15s %s";
     else
         f = "%10lld ->%10lld  %7s %15s %s";
     center_string(fn, sizeof(fn), format_name);
     assert(strlen(fn) == 15);
-    upx_snprintf(buf, sizeof(buf), f, (long long) fu_len, (long long) fc_len, r, fn, filename);
+    upx_safe_snprintf(buf, sizeof(buf), f, (long long) fu_len, (long long) fc_len, r, fn, filename);
     UNUSED(u_len);
     UNUSED(c_len);
     return buf;
@@ -259,8 +259,8 @@ void UiPacker::startCallback(unsigned u_len, unsigned step, int pass, int total_
             total_passes /= 10;
         } while (total_passes > 0);
         buflen = sizeof(s->msg_buf) - s->bar_pos;
-        l = upx_snprintf(&s->msg_buf[s->bar_pos], buflen, "%*d/%*d  ", s->pass_digits, s->pass,
-                         s->pass_digits, s->total_passes);
+        l = upx_safe_snprintf(&s->msg_buf[s->bar_pos], buflen, "%*d/%*d  ", s->pass_digits, s->pass,
+                              s->pass_digits, s->total_passes);
         if (l > 0 && s->bar_len - l > 10) {
             s->bar_len -= l;
             s->bar_pos += l;
@@ -408,8 +408,8 @@ void UiPacker::doCallback(unsigned isize, unsigned osize) {
         ratio = get_ratio(isize, osize);
 
     int buflen = (int) (&s->msg_buf[sizeof(s->msg_buf)] - m);
-    upx_snprintf(m, buflen, "  %3d.%1d%%  %c ", ratio / 10000, (ratio % 10000) / 1000,
-                 spinner[s->spin_counter & 3]);
+    upx_safe_snprintf(m, buflen, "  %3d.%1d%%  %c ", ratio / 10000, (ratio % 10000) / 1000,
+                      spinner[s->spin_counter & 3]);
     assert(strlen(s->msg_buf) < 1 + 80);
 
     s->pos = pos;
@@ -527,8 +527,8 @@ void UiPacker::uiListEnd() { uiUpdate(); }
 void UiPacker::uiListTotal(bool decompress) {
     if (opt->verbose >= 1 && total_files >= 2) {
         char name[32];
-        upx_snprintf(name, sizeof(name), "[ %u file%s ]", total_files_done,
-                     total_files_done == 1 ? "" : "s");
+        upx_safe_snprintf(name, sizeof(name), "[ %u file%s ]", total_files_done,
+                          total_files_done == 1 ? "" : "s");
         con_fprintf(
             stdout, "%s%s\n", header_line2,
             mkline(total_fu_len, total_fc_len, total_u_len, total_c_len, "", name, decompress));
diff --git a/src/util.cpp b/src/util.cpp
index 4d898ef3..ee58f246 100644
--- a/src/util.cpp
+++ b/src/util.cpp
@@ -28,12 +28,6 @@
 #include "conf.h"
 #include "util.h"
 
-#if (ACC_CC_MSC && (_MSC_VER >= 1000 && _MSC_VER < 1200))
-/* avoid -W4 warnings in <conio.h> */
-#pragma warning(disable : 4032)
-/* avoid -W4 warnings in <windows.h> */
-#pragma warning(disable : 4201 4214 4514)
-#endif
 #define ACC_WANT_ACC_INCI_H 1
 #include "miniacc.h"
 #define ACC_WANT_ACCLIB_GETOPT 1
@@ -394,9 +388,9 @@ bool set_method_name(char *buf, size_t size, int method, int level) {
         r = false;
     }
     if (level > 0)
-        upx_snprintf(buf, size, "%s/%d", alg, level);
+        upx_safe_snprintf(buf, size, "%s/%d", alg, level);
     else
-        upx_snprintf(buf, size, "%s", alg);
+        upx_safe_snprintf(buf, size, "%s", alg);
     return r;
 }
 
@@ -461,7 +455,7 @@ bool maketempname(char *ofilename, size_t size, const char *ifilename, const cha
             return true;
         if (!force)
             break;
-        upx_snprintf(ofext, 5, ".%03d", ofile);
+        upx_safe_snprintf(ofext, 5, ".%03d", ofile);
     }
 
     ofilename[0] = 0;
@@ -494,7 +488,7 @@ bool makebakname(char *ofilename, size_t size, const char *ifilename, bool force
             return true;
         if (!force)
             break;
-        upx_snprintf(ofext, 5, ".%03d", ofile);
+        upx_safe_snprintf(ofext, 5, ".%03d", ofile);
     }
 
     ofilename[0] = 0;
diff --git a/src/work.cpp b/src/work.cpp
index 28ad5c6a..75d3d8c7 100644
--- a/src/work.cpp
+++ b/src/work.cpp
@@ -33,9 +33,6 @@
 
 #if (ACC_OS_DOS32) && defined(__DJGPP__)
 #define USE_FTIME 1
-#elif (ACC_OS_WIN32 && ACC_CC_MWERKS) && defined(__MSL__)
-#include <utime.h>
-#define USE_UTIME 1
 #elif ((ACC_OS_WIN32 || ACC_OS_WIN64) && (ACC_CC_INTELC || ACC_CC_MSC))
 #define USE__FUTIME 1
 #elif (HAVE_UTIME)