libvterm @0.1.2:error: implicit declaration of function 'strdup' is invalid in C99

[keke-cute (小可可可爱多)]

--->  Building libvterm
Executing:  cd "/opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_macports_release_tarballs_ports_devel_libvterm/libvterm/work/libvterm-0.1.2" && /usr/bin/make -j4 -w all PREFIX=/opt/local
make: Entering directory `/opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_macports_release_tarballs_ports_devel_libvterm/libvterm/work/libvterm-0.1.2'
CC bin/vterm-ctrl.c
bin/vterm-ctrl.c:117:10: error: implicit declaration of function 'strdup' is invalid in C99 [-Werror,-Wimplicit-function-declaration]
  return strdup(csi);
         ^
bin/vterm-ctrl.c:117:10: note: did you mean 'strcmp'?
/Applications/Xcode-beta.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX11.0.sdk/usr/include/string.h:77:6: note: 'strcmp' declared here
int      strcmp(const char *__s1, const char *__s2);
         ^
bin/vterm-ctrl.c:117:10: warning: incompatible integer to pointer conversion returning 'int' from a function with result type 'char *' [-Wint-conversion]
  return strdup(csi);
         ^~~~~~~~~~~
bin/vterm-ctrl.c:142:10: error: implicit declaration of function 'strdup' is invalid in C99 [-Werror,-Wimplicit-function-declaration]
  return strdup(dcs);
         ^
bin/vterm-ctrl.c:142:10: warning: incompatible integer to pointer conversion returning 'int' from a function with result type 'char *' [-Wint-conversion]
  return strdup(dcs);
         ^~~~~~~~~~~
bin/vterm-ctrl.c:129:10: warning: result of comparison of constant 156 with expression of type 'char' is always false [-Wtautological-constant-out-of-range-compare]
    if(c == 0x9c) // ST
       ~ ^  ~~~~
3 warnings and 2 errors generated.
make: *** [bin/vterm-ctrl] Error 1
make: Leaving directory `/opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_macports_release_tarballs_ports_devel_libvterm/libvterm/work/libvterm-0.1.2'
Command failed:  cd "/opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_macports_release_tarballs_ports_devel_libvterm/libvterm/work/libvterm-0.1.2" && /usr/bin/make -j4 -w all PREFIX=/opt/local
Exit code: 2
Error: Failed to build libvterm: command execution failed

[keke-cute (小可可可爱多)]

version:1
:debug:sysinfo macOS 11.0 (darwin/20.1.0) arch i386
:debug:sysinfo MacPorts 2.6.99
:debug:sysinfo Xcode 12.0
:debug:sysinfo SDK 11.0
:debug:sysinfo MACOSX_DEPLOYMENT_TARGET: 11.0

[jmroot (Joshua Root)]

It's defining _XOPEN_SOURCE to 500 which is too low to make strdup visible. The upstream fix is ​https://bazaar.launchpad.net/~libvterm/libvterm/trunk/revision/769 and ​https://bazaar.launchpad.net/~libvterm/libvterm/trunk/revision/770 which effectively just change it to 600.

[kencu (Ken)]

apple bug? it seems it should be available with a setting of 500...

[jmroot (Joshua Root)]

No I think it's correct. Setting _XOPEN_SOURCE to 500 is equivalent to setting _POSIX_C_SOURCE to 199506, and strdup was only added to POSIX in POSIX.1-2001. Before that, strdup was an X/Open extension, and you had to define _XOPEN_SOURCE_EXTENDED to use it on systems that implemented those extensions. Understandably, Apple only implements the POSIX requirements and _XOPEN_SOURCE_EXTENDED does nothing on current macOS.

I would assume previous versions of clang were letting the implicit declaration through with a warning.

[kencu (Ken)]

I don't know... <​https://man7.org/linux/man-pages/man3/strdup.3.html>

  Feature Test Macro Requirements for glibc (see feature_test_macros(7)):

       strdup():
           _XOPEN_SOURCE >= 500
               || /* Since glibc 2.12: */ _POSIX_C_SOURCE >= 200809L
               || /* Glibc versions <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE

[jmroot (Joshua Root)]

Well, I guess you can open a bug with Apple if you think they are interpreting the standards wrong. But as far as macOS is concerned, it's been this way since 10.7: <​https://opensource.apple.com/source/Libc/Libc-763.11/include/string.h.auto.html>

[jmroot (Joshua Root)]

Upstream has released version 0.1.4.

[chrstphrchvz (Christopher Chavez)]

PR opened to update to 0.1.4: ​https://github.com/macports/macports-ports/pull/8506

[chrstphrchvz (Christopher Chavez)]

In bb993c11356f144a862701152ee1052755f1267f/macports-ports (master):

libvterm: update to 0.1.4

Disable silent rules

Fixes: #61145