Merge branch 'es/meson-cleanup' into seen

Code clean-up for meson-based build infrastructure.

* es/meson-cleanup:
  meson: only check for missing networking syms on non-Windows; add compat impls
  meson: fix typo in function check that prevented checking for hstrerror
  meson: add a couple missing networking dependencies
  meson: do a full usage-based compile check for sysinfo
  meson: check for getpagesize before using it
  meson: simplify and parameterize various standard function checks

Author: gitster

meson.build

@@ -1109,10 +1109,6 @@ if compiler.has_header('alloca.h')
   libgit_c_args += '-DHAVE_ALLOCA_H'
 endif
 
-if compiler.has_header('sys/sysinfo.h')
-  libgit_c_args += '-DHAVE_SYSINFO'
-endif
-
 # Windows has libgen.h and a basename implementation, but we still need our own
 # implementation to threat things like drive prefixes specially.
 if host_machine.system() == 'windows' or not compiler.has_header('libgen.h')
@@ -1135,18 +1131,22 @@ if host_machine.system() == 'windows'
     networking_dependencies += winsock
   endif
 else
-  libresolv = compiler.find_library('resolv', required: false)
-  if libresolv.found()
-    networking_dependencies += libresolv
-  endif
+  networking_dependencies += [
+    compiler.find_library('nsl', required: false),
+    compiler.find_library('resolv', required: false),
+    compiler.find_library('socket', required: false),
+  ]
 endif
 libgit_dependencies += networking_dependencies
 
-foreach symbol : ['inet_ntop', 'inet_pton', 'strerror']
-  if not compiler.has_function(symbol, dependencies: networking_dependencies)
-    libgit_c_args += '-DNO_' + symbol.to_upper()
-  endif
-endforeach
+if host_machine.system() != 'windows'
+  foreach symbol : ['inet_ntop', 'inet_pton', 'hstrerror']
+    if not compiler.has_function(symbol, dependencies: networking_dependencies)
+      libgit_c_args += '-DNO_' + symbol.to_upper()
+      libgit_sources += 'compat/' + symbol + '.c'
+    endif
+  endforeach
+endif
 
 has_ipv6 = compiler.has_function('getaddrinfo', dependencies: networking_dependencies)
 if not has_ipv6
@@ -1323,6 +1323,10 @@ if host_machine.system() != 'windows'
   endif
 endif
 
+if compiler.has_member('struct sysinfo', 'totalram', prefix: '#include <sys/sysinfo.h>')
+  libgit_c_args += '-DHAVE_SYSINFO'
+endif
+
 if compiler.has_member('struct stat', 'st_mtimespec.tv_nsec', prefix: '#include <sys/stat.h>')
   libgit_c_args += '-DUSE_ST_TIMESPEC'
 elif not compiler.has_member('struct stat', 'st_mtim.tv_nsec', prefix: '#include <sys/stat.h>')
@@ -1341,23 +1345,42 @@ if not compiler.has_member('struct passwd', 'pw_gecos', prefix: '#include <pwd.h
   libgit_c_args += '-DNO_GECOS_IN_PWENT'
 endif
 
-if compiler.has_function('sync_file_range')
-  libgit_c_args += '-DHAVE_SYNC_FILE_RANGE'
-endif
+checkfuncs = [
+  'strcasestr',
+  'memmem',
+  'strlcpy',
+  # no compat
+  'strtoull',
+  'setenv',
+  'mkdtemp',
+  # no compat
+  'initgroups',
+  # no compat
+  'getpagesize',
+]
 
-if not compiler.has_function('strcasestr')
-  libgit_c_args += '-DNO_STRCASESTR'
-  libgit_sources += 'compat/strcasestr.c'
+if host_machine.system() == 'windows'
+  libgit_c_args += '-DUSE_WIN32_MMAP'
+else
+  checkfuncs += [
+    'mmap',
+    # unsetenv is provided by compat/mingw.c.
+    'unsetenv',
+  ]
 endif
 
-if not compiler.has_function('memmem')
-  libgit_c_args += '-DNO_MEMMEM'
-  libgit_sources += 'compat/memmem.c'
-endif
+foreach func: checkfuncs
+  if not compiler.has_function(func)
+    libgit_c_args += '-DNO_' + func.to_upper()
+    impl = 'compat/' + func + '.c'
+    if fs.exists(impl)
+      libgit_sources += impl
+    endif
+  endif
+endforeach
 
-if not compiler.has_function('strlcpy')
-  libgit_c_args += '-DNO_STRLCPY'
-  libgit_sources += 'compat/strlcpy.c'
+if compiler.has_function('sync_file_range')
+  libgit_c_args += '-DHAVE_SYNC_FILE_RANGE'
 endif
 
 if not compiler.has_function('strdup')
@@ -1373,45 +1396,15 @@ if not compiler.has_function('strtoumax')
   ]
 endif
 
-if not compiler.has_function('strtoull')
-  libgit_c_args += '-DNO_STRTOULL'
-endif
-
-if not compiler.has_function('setenv')
-  libgit_c_args += '-DNO_SETENV'
-  libgit_sources += 'compat/setenv.c'
-endif
-
 if not compiler.has_function('qsort')
   libgit_c_args += '-DINTERNAL_QSORT'
 endif
 libgit_sources += 'compat/qsort_s.c'
 
-# unsetenv is provided by compat/mingw.c.
-if host_machine.system() != 'windows' and not compiler.has_function('unsetenv')
-  libgit_c_args += '-DNO_UNSETENV'
-  libgit_sources += 'compat/unsetenv.c'
-endif
-
-if not compiler.has_function('mkdtemp')
-  libgit_c_args += '-DNO_MKDTEMP'
-  libgit_sources += 'compat/mkdtemp.c'
-endif
-
-if not compiler.has_function('initgroups')
-  libgit_c_args += '-DNO_INITGROUPS'
-endif
-
 if compiler.has_function('getdelim')
   libgit_c_args += '-DHAVE_GETDELIM'
 endif
 
-if host_machine.system() == 'windows'
-  libgit_c_args += '-DUSE_WIN32_MMAP'
-elif not compiler.has_function('mmap')
-  libgit_c_args += '-DNO_MMAP'
-  libgit_sources += 'compat/mmap.c'
-endif
 
 if compiler.has_function('clock_gettime')
   libgit_c_args += '-DHAVE_CLOCK_GETTIME'