Compiling nghttp2 with GCC 14 fails

[Kartatz]

I'm cross-compiling nghttp2 for FreeBSD 14 (riscv64) using GCC 14. It used to compile just fine with GCC 13, but now it's failing with GCC 14:

$ cmake \
    -DCMAKE_BUILD_TYPE=MinSizeRel \
    -DENABLE_LIB_ONLY=ON \
    -B build \
    ./
-- The CXX compiler identification is GNU 14.1.0
-- Detecting CXX compiler ABI info
-- Detecting CXX compiler ABI info - done
-- Check for working CXX compiler: /tmp/loki/bin/riscv64-unknown-freebsd14.0-g++ - skipped
-- Detecting CXX compile features
-- Detecting CXX compile features - done
-- Found Python3: /usr/bin/python3.10 (found version "3.10.12") found components: Interpreter
-- Found OpenSSL: /tmp/loki/riscv64-unknown-freebsd14.0/lib/libcrypto.so (found suitable version "3.0.13", minimum required is "1.1.1")
-- Could NOT find Libngtcp2 (missing: LIBNGTCP2_LIBRARY LIBNGTCP2_INCLUDE_DIR) (Required is at least version "1.0.0")
-- Could NOT find Libngtcp2_crypto_quictls (missing: LIBNGTCP2_CRYPTO_QUICTLS_LIBRARY LIBNGTCP2_CRYPTO_QUICTLS_INCLUDE_DIR) (Required is at least version "1.0.0")
-- Could NOT find Libnghttp3 (missing: LIBNGHTTP3_LIBRARY LIBNGHTTP3_INCLUDE_DIR) (Required is at least version "1.1.0")
-- Could NOT find Systemd (missing: SYSTEMD_INCLUDE_DIRS SYSTEMD_LIBRARIES) (Required is at least version "209")
-- Could NOT find Jansson (missing: JANSSON_LIBRARY JANSSON_INCLUDE_DIR) (Required is at least version "2.5")
-- Could NOT find Libevent (missing: LIBEVENT_CORE_LIBRARY LIBEVENT_EXTRA_LIBRARY LIBEVENT_OPENSSL_LIBRARY LIBEVENT_INCLUDE_DIR core extra openssl) (Required is at least version "2.0.8")
-- Could NOT find LibXml2 (missing: LIBXML2_LIBRARY LIBXML2_INCLUDE_DIR) (Required is at least version "2.6.26")
-- Could NOT find Jemalloc (missing: JEMALLOC_LIBRARY JEMALLOC_INCLUDE_DIR) 
-- Performing Test CXX_FLAG__std_c_20
-- Performing Test CXX_FLAG__std_c_20 - Success
-- Performing Test HAVE_STD_FUTURE
-- Performing Test HAVE_STD_FUTURE - Success
-- Performing Test HAVE_STD_MAP_EMPLACE
-- Performing Test HAVE_STD_MAP_EMPLACE - Success
-- Performing Test CMAKE_HAVE_LIBC_PTHREAD
-- Performing Test CMAKE_HAVE_LIBC_PTHREAD - Failed
-- Looking for pthread_create in pthreads
-- Looking for pthread_create in pthreads - not found
-- Looking for pthread_create in pthread
-- Looking for pthread_create in pthread - found
-- Found Threads: TRUE
-- Looking for inttypes.h
-- Looking for inttypes.h - found
-- Looking for limits.h
-- Looking for limits.h - found
-- Looking for netinet/ip.h
-- Looking for netinet/ip.h - not found
-- Looking for syslog.h
-- Looking for syslog.h - found
-- Looking for windows.h
-- Looking for windows.h - not found
-- Performing Test HAVE_STRUCT_TM_TM_GMTOFF
-- Performing Test HAVE_STRUCT_TM_TM_GMTOFF - Success
-- Looking for _Exit
-- Looking for _Exit - found
-- Looking for accept4
-- Looking for accept4 - found
-- Looking for clock_gettime
-- Looking for clock_gettime - found
-- Looking for mkostemp
-- Looking for mkostemp - found
-- Looking for GetTickCount64
-- Looking for GetTickCount64 - not found
-- Looking for initgroups
-- Looking for initgroups - not found
-- Looking for initgroups
-- Looking for initgroups - found
-- Looking for CLOCK_MONOTONIC
-- Looking for CLOCK_MONOTONIC - found
-- Performing Test OPT_Wpragmas
-- Performing Test OPT_Wpragmas - Success
-- summary of build options:
    Package version: 1.62.90
    Library version: 42:1:28
    Install prefix:  /home/kartz/nghttp2/build/riscv64-unknown-freebsd
    Target system:   FreeBSD
    Compiler:
      Build type:     MinSizeRel
      C compiler:     /tmp/loki/bin/riscv64-unknown-freebsd14.0-gcc
      CFLAGS:         -Os  
      C++ compiler:   /tmp/loki/bin/riscv64-unknown-freebsd14.0-g++
      CXXFLAGS:       -Os  
      WARNCFLAGS:       -W -Wall -Wconversion -Winline -Wmissing-declarations -Wmissing-prototypes -Wnested-externs -Wpointer-arith -Wshadow -Wundef -Wwrite-strings -Waddress -Wattributes -Wcast-align -Wdeclaration-after-statement -Wdiv-by-zero -Wempty-body -Wendif-labels -Wfloat-equal -Wformat-nonliteral -Wformat-security -Wmissing-field-initializers -Wmissing-noreturn -Wno-format-nonliteral -Wredundant-decls -Wsign-conversion -Wstrict-prototypes -Wunreachable-code -Wunused-parameter -Wvla -Wclobbered -Wpragmas
      CXX1XCXXFLAGS:  -std=c++20
      WARNCXXFLAGS:     -Wall -Wformat-security
    Python:
      Python:          /usr/bin/python3.10
      Python3_VERSION: 3.10.12
    Test:
      Failmalloc:     ON
      Build Test:     OFF
    Libs:
      OpenSSL:        TRUE (LIBS='/tmp/loki/riscv64-unknown-freebsd14.0/lib/libssl.so;/tmp/loki/riscv64-unknown-freebsd14.0/lib/libcrypto.so')
      Libxml2:        FALSE (LIBS='')
      Libev:           (LIBS='')
      Libc-ares:       (LIBS='')
      Libngtcp2:       (LIBS='')
      Libngtcp2_crypto_quictls:  (LIBS='')
      Libnghttp3:      (LIBS='')
      Libbpf:          (LIBS='')
      Libevent(SSL):  FALSE (LIBS='')
      Jansson:        FALSE (LIBS='')
      Jemalloc:       FALSE (LIBS='')
      Zlib:            (LIBS='')
      Systemd:        FALSE (LIBS='SYSTEMD_LIBRARIES-NOTFOUND')
      Libbrotlienc:    (LIBS='')
-- Configuring FFmpeg
      Libbrotlidec:    (LIBS='')
    Third-party:
      http-parser:    
      MRuby:          0
      Neverbleed:     0
    Features:
      Applications:   OFF
      HPACK tools:    OFF
      Examples:       OFF
      Threading:      ON
      HTTP/3(EXPERIMENTAL): OFF
-- Configuring done (24.9s)
-- Generating done (0.7s)
-- Build files have been written to: /home/kartz/nghttp2/build
$ cmake --build ./
/home/kartz/nghttp2/lib/nghttp2_helper.c: In function ‘nghttp2_put_uint16be’:
/home/kartz/nghttp2/lib/nghttp2_helper.c:33:16: error: implicit declaration of function ‘htons’ [-Wimplicit-function-declaration]
   33 |   uint16_t x = htons(n);
      |                ^~~~~
/home/kartz/nghttp2/lib/nghttp2_helper.c:33:16: warning: nested extern declaration of ‘htons’ [-Wnested-externs]
/home/kartz/nghttp2/lib/nghttp2_helper.c:33:16: warning: conversion from ‘int’ to ‘uint16_t’ {aka ‘short unsigned int’} may change value [-Wconversion]
/home/kartz/nghttp2/lib/nghttp2_helper.c: In function ‘nghttp2_put_uint32be’:
/home/kartz/nghttp2/lib/nghttp2_helper.c:38:16: error: implicit declaration of function ‘htonl’ [-Wimplicit-function-declaration]
   38 |   uint32_t x = htonl(n);
      |                ^~~~~
/home/kartz/nghttp2/lib/nghttp2_helper.c:38:16: warning: nested extern declaration of ‘htonl’ [-Wnested-externs]
/home/kartz/nghttp2/lib/nghttp2_helper.c:38:16: warning: conversion to ‘uint32_t’ {aka ‘unsigned int’} from ‘int’ may change the sign of the result [-Wsign-conversion]
/home/kartz/nghttp2/lib/nghttp2_helper.c: In function ‘nghttp2_get_uint16’:
/home/kartz/nghttp2/lib/nghttp2_helper.c:45:10: error: implicit declaration of function ‘ntohs’ [-Wimplicit-function-declaration]
   45 |   return ntohs(n);
      |          ^~~~~
/home/kartz/nghttp2/lib/nghttp2_helper.c:45:10: warning: nested extern declaration of ‘ntohs’ [-Wnested-externs]
/home/kartz/nghttp2/lib/nghttp2_helper.c:45:10: warning: conversion from ‘int’ to ‘uint16_t’ {aka ‘short unsigned int’} may change value [-Wconversion]
   45 |   return ntohs(n);
      |          ^~~~~~~~
/home/kartz/nghttp2/lib/nghttp2_helper.c: In function ‘nghttp2_get_uint32’:
/home/kartz/nghttp2/lib/nghttp2_helper.c:51:10: error: implicit declaration of function ‘ntohl’ [-Wimplicit-function-declaration]
   51 |   return ntohl(n);
      |          ^~~~~
/home/kartz/nghttp2/lib/nghttp2_helper.c:51:10: warning: nested extern declaration of ‘ntohl’ [-Wnested-externs]
/home/kartz/nghttp2/lib/nghttp2_helper.c:51:10: warning: conversion to ‘uint32_t’ {aka ‘unsigned int’} from ‘int’ may change the sign of the result [-Wsign-conversion]
   51 |   return ntohl(n);
      |          ^~~~~~~~
gmake[2]: *** [nghttp2/lib/CMakeFiles/nghttp2.dir/build.make:202: nghttp2/lib/CMakeFiles/nghttp2.dir/nghttp2_helper.c.o] Error 1
gmake[2]: *** Waiting for unfinished jobs....
/home/kartz/nghttp2/lib/nghttp2_hd_huffman.c: In function ‘nghttp2_hd_huff_encode’:
/home/kartz/nghttp2/lib/nghttp2_hd_huffman.c:65:11: error: implicit declaration of function ‘htonl’ [-Wimplicit-function-declaration]
   65 |       x = htonl((uint32_t)(code >> 32));
      |           ^~~~~
/home/kartz/nghttp2/lib/nghttp2_hd_huffman.c:65:11: warning: nested extern declaration of ‘htonl’ [-Wnested-externs]
/home/kartz/nghttp2/lib/nghttp2_hd_huffman.c:65:11: warning: conversion to ‘uint32_t’ {aka ‘unsigned int’} from ‘int’ may change the sign of the result [-Wsign-conversion]
gmake[2]: *** [nghttp2/lib/CMakeFiles/nghttp2.dir/build.make:244: nghttp2/lib/CMakeFiles/nghttp2.dir/nghttp2_hd_huffman.c.o] Error 1

I'm on latest master (20d21b2).

[tatsuhiro-t]

I have not tried compiling nghttp2 with gcc-14. This might be another picky gcc behavior, which may be good for us.

[tatsuhiro-t]

It looks like your cmake does not fully check header files, arpa/inet.h in particular.
I have no idea why. Maybe your CMakeList.txt is corrupted or edited or cmake is broken.