[PATCH v3 1/8] Revert "compat/posix: introduce writev(3p) wrapper"

[Olamide Caleb Bello <belkid98@gmail.com>]

From: Junio C Hamano <gitster@pobox.com>

This reverts commit 3b9b2c2a29a1d529ca9884fa0a6529f6e2496abe; let's
not use writev() for now.
---
 Makefile         |  4 ----
 compat/posix.h   | 14 --------------
 compat/writev.c  | 44 --------------------------------------------
 config.mak.uname |  2 --
 meson.build      |  1 -
 5 files changed, 65 deletions(-)
 delete mode 100644 compat/writev.c

diff --git a/Makefile b/Makefile
index 5d22394c2e..cedc234173 100644
--- a/Makefile
+++ b/Makefile
@@ -2029,10 +2029,6 @@ ifdef NO_PREAD
 	COMPAT_CFLAGS += -DNO_PREAD
 	COMPAT_OBJS += compat/pread.o
 endif
-ifdef NO_WRITEV
-	COMPAT_CFLAGS += -DNO_WRITEV
-	COMPAT_OBJS += compat/writev.o
-endif
 ifdef NO_FAST_WORKING_DIRECTORY
 	BASIC_CFLAGS += -DNO_FAST_WORKING_DIRECTORY
 endif
diff --git a/compat/posix.h b/compat/posix.h
index 94699a03fa..faaae1b655 100644
--- a/compat/posix.h
+++ b/compat/posix.h
@@ -137,9 +137,6 @@
 #include <sys/socket.h>
 #include <sys/ioctl.h>
 #include <sys/statvfs.h>
-#ifndef NO_WRITEV
-#include <sys/uio.h>
-#endif
 #include <termios.h>
 #ifndef NO_SYS_SELECT_H
 #include <sys/select.h>
@@ -326,17 +323,6 @@ int git_lstat(const char *, struct stat *);
 ssize_t git_pread(int fd, void *buf, size_t count, off_t offset);
 #endif
 
-#ifdef NO_WRITEV
-#define writev git_writev
-#define iovec git_iovec
-struct git_iovec {
-	void *iov_base;
-	size_t iov_len;
-};
-
-ssize_t git_writev(int fd, const struct iovec *iov, int iovcnt);
-#endif
-
 #ifdef NO_SETENV
 #define setenv gitsetenv
 int gitsetenv(const char *, const char *, int);
diff --git a/compat/writev.c b/compat/writev.c
deleted file mode 100644
index 3a94870a2f..0000000000
--- a/compat/writev.c
+++ /dev/null
@@ -1,44 +0,0 @@
-#include "../git-compat-util.h"
-#include "../wrapper.h"
-
-ssize_t git_writev(int fd, const struct iovec *iov, int iovcnt)
-{
-	size_t total_written = 0;
-	size_t sum = 0;
-
-	/*
-	 * According to writev(3p), the syscall shall error with EINVAL in case
-	 * the sum of `iov_len` overflows `ssize_t`.
-	 */
-	 for (int i = 0; i < iovcnt; i++) {
-		if (iov[i].iov_len > maximum_signed_value_of_type(ssize_t) ||
-		    iov[i].iov_len + sum > maximum_signed_value_of_type(ssize_t)) {
-			errno = EINVAL;
-			return -1;
-		}
-
-		sum += iov[i].iov_len;
-	}
-
-	for (int i = 0; i < iovcnt; i++) {
-		const char *bytes = iov[i].iov_base;
-		size_t iovec_written = 0;
-
-		while (iovec_written < iov[i].iov_len) {
-			ssize_t bytes_written = xwrite(fd, bytes + iovec_written,
-						       iov[i].iov_len - iovec_written);
-			if (bytes_written < 0) {
-				if (total_written)
-					goto out;
-				return bytes_written;
-			}
-			if (!bytes_written)
-				goto out;
-			iovec_written += bytes_written;
-			total_written += bytes_written;
-		}
-	}
-
-out:
-	return (ssize_t) total_written;
-}
diff --git a/config.mak.uname b/config.mak.uname
index ccb3f71881..5feb582558 100644
--- a/config.mak.uname
+++ b/config.mak.uname
@@ -459,7 +459,6 @@ ifeq ($(uname_S),Windows)
 	SANE_TOOL_PATH ?= $(msvc_bin_dir_msys)
 	HAVE_ALLOCA_H = YesPlease
 	NO_PREAD = YesPlease
-	NO_WRITEV = YesPlease
 	NEEDS_CRYPTO_WITH_SSL = YesPlease
 	NO_LIBGEN_H = YesPlease
 	NO_POLL = YesPlease
@@ -675,7 +674,6 @@ ifeq ($(uname_S),MINGW)
 	pathsep = ;
 	HAVE_ALLOCA_H = YesPlease
 	NO_PREAD = YesPlease
-	NO_WRITEV = YesPlease
 	NEEDS_CRYPTO_WITH_SSL = YesPlease
 	NO_LIBGEN_H = YesPlease
 	NO_POLL = YesPlease
diff --git a/meson.build b/meson.build
index 8309942d18..11488623bf 100644
--- a/meson.build
+++ b/meson.build
@@ -1429,7 +1429,6 @@ checkfuncs = {
   'initgroups' : [],
   'strtoumax' : ['strtoumax.c', 'strtoimax.c'],
   'pread' : ['pread.c'],
-  'writev' : ['writev.c'],
 }
 
 if host_machine.system() == 'windows'
-- 
2.53.0.155.g9f36b15afa