Enable/fix compiler warning 4996 in host (#66431)

Author: elinor-fung

src/native/corehost/CMakeLists.txt

@@ -10,7 +10,6 @@ include(../../../eng/native/configurepaths.cmake)
 include(${CLR_ENG_NATIVE_DIR}/configurecompiler.cmake)
 
 if (MSVC)
-    add_compile_options($<$<COMPILE_LANGUAGE:C,CXX>:/wd4996>)
     add_compile_options($<$<COMPILE_LANGUAGE:C,CXX>:/wd4267>)
     add_compile_options($<$<COMPILE_LANGUAGE:C,CXX>:/wd4018>)
     add_compile_options($<$<COMPILE_LANGUAGE:C,CXX>:/wd4200>)

src/native/corehost/apphost/static/CMakeLists.txt

@@ -45,7 +45,6 @@ include(../../hostpolicy/files.cmake)
 include(../../hostcommon/files.cmake)
 
 if(MSVC)
-    add_compile_options($<$<COMPILE_LANGUAGE:C,CXX>:/wd4996>)
     add_compile_options($<$<COMPILE_LANGUAGE:C,CXX>:/wd4267>)
     add_compile_options($<$<COMPILE_LANGUAGE:C,CXX>:/wd4018>)
     add_compile_options($<$<COMPILE_LANGUAGE:C,CXX>:/wd4200>)

src/native/corehost/hostmisc/pal.h

@@ -158,21 +158,24 @@ namespace pal
 
     inline size_t strlen(const char_t* str) { return ::wcslen(str); }
 
-#pragma warning(suppress : 4996)  // error C4996: '_wfopen': This function or variable may be unsafe.
-    inline FILE* file_open(const string_t& path, const char_t* mode) { return ::_wfopen(path.c_str(), mode); }
+    inline FILE* file_open(const string_t& path, const char_t* mode) { return ::_wfsopen(path.c_str(), mode, _SH_DENYNO); }
 
     inline void file_vprintf(FILE* f, const char_t* format, va_list vl) { ::vfwprintf(f, format, vl); ::fputwc(_X('\n'), f); }
     inline void err_fputs(const char_t* message) { ::fputws(message, stderr); ::fputwc(_X('\n'), stderr); }
     inline void out_vprintf(const char_t* format, va_list vl) { ::vfwprintf(stdout, format, vl); ::fputwc(_X('\n'), stdout); }
 
-    // This API is being used correctly and querying for needed size first.
-#pragma warning(suppress : 4996)  // error C4996: '_vsnwprintf': This function or variable may be unsafe.
-    inline int str_vprintf(char_t* buffer, size_t count, const char_t* format, va_list vl) { return ::_vsnwprintf(buffer, count, format, vl); }
+    inline int str_vprintf(char_t* buffer, size_t count, const char_t* format, va_list vl) { return ::_vsnwprintf_s(buffer, count, _TRUNCATE, format, vl); }
+    inline int strlen_vprintf(const char_t* format, va_list vl) { return ::_vscwprintf(format, vl); }
 
-    // Suppressing warning since the 'safe' version requires an input buffer that is unnecessary for
-    // uses of this function.
-#pragma warning(suppress : 4996) //  error C4996: '_wcserror': This function or variable may be unsafe.
-    inline const char_t* strerror(int errnum) { return ::_wcserror(errnum); }
+    inline const string_t strerror(int errnum)
+    {
+        // Windows does not provide strerrorlen to get the actual error length.
+        // Use 1024 as the buffer size based on the buffer size used by glibc.
+        // _wcserror_s truncates (and null-terminates) if the buffer is too small
+        char_t buffer[1024];
+        ::_wcserror_s(buffer, sizeof(buffer) / sizeof(char_t), errnum);
+        return buffer;
+    }
 
     bool pal_utf8string(const string_t& str, std::vector<char>* out);
     bool pal_clrstring(const string_t& str, std::vector<char>* out);
@@ -226,7 +229,9 @@ namespace pal
     inline void err_fputs(const char_t* message) { ::fputs(message, stderr); ::fputc(_X('\n'), stderr); }
     inline void out_vprintf(const char_t* format, va_list vl) { ::vfprintf(stdout, format, vl); ::fputc('\n', stdout); }
     inline int str_vprintf(char_t* str, size_t size, const char_t* format, va_list vl) { return ::vsnprintf(str, size, format, vl); }
-    inline const char_t* strerror(int errnum) { return ::strerror(errnum); }
+    inline int strlen_vprintf(const char_t* format, va_list vl) { return ::vsnprintf(nullptr, 0, format, vl); }
+
+    inline const string_t strerror(int errnum) { return ::strerror(errnum); }
 
     inline bool pal_utf8string(const string_t& str, std::vector<char>* out) { out->assign(str.begin(), str.end()); out->push_back('\0'); return true; }
     inline bool pal_clrstring(const string_t& str, std::vector<char>* out) { return pal_utf8string(str, out); }

src/native/corehost/hostmisc/pal.unix.cpp

@@ -128,7 +128,7 @@ bool pal::getcwd(pal::string_t* recv)
             return false;
         }
 
-        trace::error(_X("getcwd() failed: %s"), strerror(errno));
+        trace::error(_X("getcwd() failed: %s"), strerror(errno).c_str());
         return false;
     }
 
@@ -401,7 +401,7 @@ bool pal::get_default_bundle_extraction_base_dir(pal::string_t& extraction_dir)
     }
     else if (errno != EEXIST)
     {
-        trace::error(_X("Failed to create default extraction directory [%s]. %s"), extraction_dir.c_str(), pal::strerror(errno));
+        trace::error(_X("Failed to create default extraction directory [%s]. %s"), extraction_dir.c_str(), pal::strerror(errno).c_str());
         return false;
     }
 
@@ -478,7 +478,7 @@ bool get_install_location_from_file(const pal::string_t& file_path, bool& file_f
         }
         else
         {
-            trace::error(_X("The install_location file ['%s'] failed to open: %s."), file_path.c_str(), pal::strerror(errno));
+            trace::error(_X("The install_location file ['%s'] failed to open: %s."), file_path.c_str(), pal::strerror(errno).c_str());
         }
     }
 
@@ -904,7 +904,7 @@ bool pal::realpath(pal::string_t* path, bool skip_error_logging)
 
         if (!skip_error_logging)
         {
-            trace::error(_X("realpath(%s) failed: %s"), path->c_str(), strerror(errno));
+            trace::error(_X("realpath(%s) failed: %s"), path->c_str(), strerror(errno).c_str());
         }
 
         return false;
@@ -1033,7 +1033,7 @@ bool pal::is_emulating_x64()
         trace::info(_X("Could not determine whether the current process is running under Rosetta."));
         if (errno != ENOENT)
         {
-            trace::info(_X("Call to sysctlbyname failed: %s"), strerror(errno));
+            trace::info(_X("Call to sysctlbyname failed: %s"), strerror(errno).c_str());
         }
 
         return false;

src/native/corehost/hostmisc/pal.windows.cpp

@@ -597,7 +597,7 @@ bool pal::get_default_bundle_extraction_base_dir(pal::string_t& extraction_dir)
     if (CreateDirectoryW(extraction_dir.c_str(), NULL) == 0 &&
         GetLastError() != ERROR_ALREADY_EXISTS)
     {
-        trace::error(_X("Failed to create default extraction directory [%s]. %s, error code: %d"), extraction_dir.c_str(), pal::strerror(errno), GetLastError());
+        trace::error(_X("Failed to create default extraction directory [%s]. %s, error code: %d"), extraction_dir.c_str(), pal::strerror(errno).c_str(), GetLastError());
         return false;
     }
 

src/native/corehost/hostmisc/trace.cpp

@@ -130,7 +130,7 @@ void trace::error(const pal::char_t* format, ...)
 
     va_list dup_args;
     va_copy(dup_args, args);
-    int count = pal::str_vprintf(nullptr, 0, format, args) + 1;
+    int count = pal::strlen_vprintf(format, args) + 1;
     std::vector<pal::char_t> buffer(count);
     pal::str_vprintf(&buffer[0], count, format, dup_args);
 

src/native/corehost/json_parser.cpp

@@ -135,7 +135,7 @@ bool json_parser_t::parse_file(const pal::string_t& path)
     pal::ifstream_t file{ path };
     if (!file.good())
     {
-        trace::error(_X("Cannot use file stream for [%s]: %s"), path.c_str(), pal::strerror(errno));
+        trace::error(_X("Cannot use file stream for [%s]: %s"), path.c_str(), pal::strerror(errno).c_str());
         return false;
     }