refactor(build): remove unused stdlib function and include checks

In addition: merge some checks for the same feature into one
test_compile. This reduces the total number of test compiles
which speeds up the cmake configure stage.

src/nvim/CMakeLists.txt

@@ -240,13 +240,15 @@ endif()
 if(UNIX)
   # -fstack-protector breaks non Unix builds even in Mingw-w64
   check_c_compiler_flag(-fstack-protector-strong HAS_FSTACK_PROTECTOR_STRONG_FLAG)
-  check_c_compiler_flag(-fstack-protector HAS_FSTACK_PROTECTOR_FLAG)
   if(HAS_FSTACK_PROTECTOR_STRONG_FLAG)
     target_compile_options(main_lib INTERFACE -fstack-protector-strong)
     target_link_libraries(main_lib INTERFACE -fstack-protector-strong)
-  elseif(HAS_FSTACK_PROTECTOR_FLAG)
-    target_compile_options(main_lib INTERFACE -fstack-protector --param ssp-buffer-size=4)
-    target_link_libraries(main_lib INTERFACE -fstack-protector --param ssp-buffer-size=4)
+  else()
+    check_c_compiler_flag(-fstack-protector HAS_FSTACK_PROTECTOR_FLAG)
+    if(HAS_FSTACK_PROTECTOR_FLAG)
+      target_compile_options(main_lib INTERFACE -fstack-protector --param ssp-buffer-size=4)
+      target_link_libraries(main_lib INTERFACE -fstack-protector --param ssp-buffer-size=4)
+    endif()
   endif()
 endif()
 

src/nvim/charset.c

@@ -1446,7 +1446,7 @@ long getdigits_long(char **pp, bool strict, long def)
 int32_t getdigits_int32(char **pp, bool strict, long def)
 {
   intmax_t number = getdigits(pp, strict, def);
-#if SIZEOF_INTMAX_T > SIZEOF_INT32_T
+#if SIZEOF_INTMAX_T > 4
   if (strict) {
     assert(number >= INT32_MIN && number <= INT32_MAX);
   } else if (!(number >= INT32_MIN && number <= INT32_MAX)) {

src/nvim/fileio.c

@@ -68,7 +68,7 @@
 # include "nvim/charset.h"
 #endif
 
-#if defined(HAVE_FLOCK) && defined(HAVE_DIRFD)
+#ifdef HAVE_DIRFD_AND_FLOCK
 # include <dirent.h>
 # include <sys/file.h>
 #endif
@@ -5146,7 +5146,7 @@ void forward_slash(char *fname)
 
 /// Path to Nvim's own temp dir. Ends in a slash.
 static char *vim_tempdir = NULL;
-#if defined(HAVE_FLOCK) && defined(HAVE_DIRFD)
+#ifdef HAVE_DIRFD_AND_FLOCK
 DIR *vim_tempdir_dp = NULL;  ///< File descriptor of temp dir
 #endif
 
@@ -5316,7 +5316,7 @@ int delete_recursive(const char *name)
   return result;
 }
 
-#if defined(HAVE_FLOCK) && defined(HAVE_DIRFD)
+#ifdef HAVE_DIRFD_AND_FLOCK
 /// Open temporary directory and take file lock to prevent
 /// to be auto-cleaned.
 static void vim_opentempdir(void)
@@ -5353,7 +5353,7 @@ void vim_deltempdir(void)
     return;
   }
 
-#if defined(HAVE_FLOCK) && defined(HAVE_DIRFD)
+#ifdef HAVE_DIRFD_AND_FLOCK
   vim_closetempdir();
 #endif
   // remove the trailing path separator
@@ -5391,7 +5391,7 @@ static bool vim_settempdir(char *tempdir)
   vim_FullName(tempdir, buf, MAXPATHL, false);
   add_pathsep(buf);
   vim_tempdir = xstrdup(buf);
-#if defined(HAVE_FLOCK) && defined(HAVE_DIRFD)
+#ifdef HAVE_DIRFD_AND_FLOCK
   vim_opentempdir();
 #endif
   xfree(buf);

src/nvim/os/os_defs.h

@@ -36,10 +36,9 @@
 // Command-processing buffer. Use large buffers for all platforms.
 #define CMDBUFFSIZE 1024
 
-// Note: Some systems need both string.h and strings.h (Savage).  However,
-// some systems can't handle both, only use string.h in that case.
+// Note: Some systems need both string.h and strings.h (Savage).
 #include <string.h>
-#if defined(HAVE_STRINGS_H) && !defined(NO_STRINGS_WITH_STRING_H)
+#ifdef HAVE_STRINGS_H
 # include <strings.h>
 #endif
 

src/nvim/os/shell.c

@@ -399,8 +399,8 @@ int os_expand_wildcards(int num_pat, char **pat, int *num_file, char ***file, in
     fclose(fd);
     return FAIL;
   }
-#if SIZEOF_LONG_LONG > SIZEOF_SIZE_T
-  assert(templen <= (long long)SIZE_MAX);  // NOLINT(runtime/int)
+#if 8 > SIZEOF_SIZE_T
+  assert(templen <= SIZE_MAX);  // NOLINT(runtime/int)
 #endif
   len = (size_t)templen;
   fseek(fd, 0L, SEEK_SET);

src/nvim/os/users.c

@@ -15,7 +15,7 @@
 #include "nvim/os/os.h"
 #include "nvim/types.h"
 #include "nvim/vim.h"
-#ifdef HAVE_PWD_H
+#ifdef HAVE_PWD_FUNCS
 # include <pwd.h>
 #endif
 #ifdef MSWIN
@@ -50,7 +50,7 @@ int os_get_usernames(garray_T *users)
   }
   ga_init(users, sizeof(char *), 20);
 
-#if defined(HAVE_GETPWENT) && defined(HAVE_PWD_H)
+#ifdef HAVE_PWD_FUNCS
   {
     struct passwd *pw;
 
@@ -81,7 +81,7 @@ int os_get_usernames(garray_T *users)
     }
   }
 #endif
-#if defined(HAVE_GETPWNAM)
+#ifdef HAVE_PWD_FUNCS
   {
     const char *user_env = os_getenv("USER");
 
@@ -141,7 +141,7 @@ int os_get_username(char *s, size_t len)
 /// @return OK if a username was found, else FAIL.
 int os_get_uname(uv_uid_t uid, char *s, size_t len)
 {
-#if defined(HAVE_PWD_H) && defined(HAVE_GETPWUID)
+#ifdef HAVE_PWD_FUNCS
   struct passwd *pw;
 
   if ((pw = getpwuid(uid)) != NULL  // NOLINT(runtime/threadsafe_fn)
@@ -159,7 +159,7 @@ int os_get_uname(uv_uid_t uid, char *s, size_t len)
 /// Caller must free() the returned string.
 char *os_get_userdir(const char *name)
 {
-#if defined(HAVE_GETPWNAM) && defined(HAVE_PWD_H)
+#ifdef HAVE_PWD_FUNCS
   if (name == NULL || *name == NUL) {
     return NULL;
   }