build: remove duplicate C++ standard flags from LIEF

LIEF's lief.gyp explicitly sets -std=gnu++17 in cflags_cc and
xcode_settings, while common.gypi already sets -std=gnu++20
project-wide. This results in both flags being passed to the compiler
(-std=gnu++20 -std=gnu++17). Since the last flag wins, LIEF was
silently compiling as C++17 instead of the intended project-wide C++20.

Remove the explicit -std=gnu++17 flags from cflags_cc and
xcode_settings.OTHER_CPLUSPLUSFLAGS, and the msvs_settings
LanguageStandard override (stdcpp17), so LIEF uses the project-wide
C++20 standard.

Additionally, fix LIEF compilation with C++20 by explicitly qualifying
fmt::format and fmt::join in Section.cpp, and converting joined views
into std::string values prior to passing them into final formatting
calls. This prevents conflicts between fmt::join_view and std::format
when compiling under C++20.

Fixes: #62129

Author: om-ghante

deps/LIEF/lief.gyp

@@ -453,14 +453,7 @@
       'cflags': [
         '-fPIC'
       ],
-      # We need c++17 to compile without std::format and avoid conflicts with spdlog.
-      'msvs_settings': {
-        'VCCLCompilerTool': {
-          'LanguageStandard': 'stdcpp17',
-        },
-      },
       'cflags_cc': [
-        '-std=gnu++17',
         '-fPIC',
         '-fvisibility=hidden',
         '-fvisibility-inlines-hidden',
@@ -473,7 +466,6 @@
       ],
       'xcode_settings': {
         'OTHER_CPLUSPLUSFLAGS': [
-          '-std=gnu++17',
           '-fPIC',
           '-fvisibility=hidden',
           '-fvisibility-inlines-hidden',

deps/LIEF/src/COFF/Section.cpp

@@ -122,7 +122,7 @@ std::string Section::to_string() const {
                  [] (const char c) { return format("{:02x}", c); });
 
   os << format("{:{}} {} ({})\n", "Name:", WIDTH, name(),
-               join(fullname_hex, " "));
+               fmt::to_string(join(fullname_hex, " ")));
 
   os << format("{:{}} 0x{:x}\n", "Virtual Size", WIDTH, virtual_size())
      << format("{:{}} 0x{:x}\n", "Virtual Address", WIDTH, virtual_address())
@@ -134,7 +134,7 @@ std::string Section::to_string() const {
      << format("{:{}} 0x{:x}\n", "Pointer to line numbers", WIDTH, pointerto_line_numbers())
      << format("{:{}} 0x{:x}\n", "Number of relocations", WIDTH, numberof_relocations())
      << format("{:{}} 0x{:x}\n", "Number of lines", WIDTH, numberof_line_numbers())
-     << format("{:{}} {}", "Characteristics", WIDTH, join(list_str, ", "));
+     << format("{:{}} {}", "Characteristics", WIDTH, fmt::to_string(join(list_str, ", ")));
 
   return os.str();
 

deps/LIEF/src/MachO/layout_check.cpp

@@ -86,7 +86,7 @@ class LayoutChecker {
 
   template <typename... Args>
   bool error(const char *fmt, const Args &... args) {
-    error_msg = fmt::format(fmt, args...);
+    error_msg = fmt::vformat(fmt, fmt::make_format_args(args...));
     return false;
   }
 

deps/LIEF/src/PE/LoadConfigurations/LoadConfiguration.cpp

@@ -917,7 +917,7 @@ std::string LoadConfiguration::to_string() const {
 
   if (auto val = guard_flags(); val && *val != 0) {
     oss << format("{:{}} {}\n", "Guard Flags:", WIDTH,
-                  fmt::join(guard_cf_flags_list(), ","));
+                  fmt::to_string(fmt::join(guard_cf_flags_list(), ",")));
   }
 
   if (const CodeIntegrity* CI = code_integrity()) {

deps/LIEF/src/PE/debug/ExDllCharacteristics.cpp

@@ -59,7 +59,7 @@ std::string ExDllCharacteristics::to_string() const {
   std::ostringstream os;
   using namespace fmt;
   os << Debug::to_string() << '\n'
-     << format("  Characteristics: {}", join(characteristics_list(), ", "));
+     << format("  Characteristics: {}", fmt::to_string(join(characteristics_list(), ", ")));
   return os.str();
 }
 

deps/LIEF/src/PE/layout_check.cpp

@@ -106,7 +106,7 @@ class LayoutChecker {
 
   template <typename... Args>
   bool error(const char *fmt, const Args &... args) {
-    error_msg = fmt::format(fmt, args...);
+    error_msg = fmt::vformat(fmt, fmt::make_format_args(args...));
     return false;
   }