Drop Windows 7 support (#6325)

Git for Windows dropped Windows 7 support a long time ago.

There is a patch (introduced in
#5042 and in #5059) to detect
when Git LFS failed to start because of lack of Windows 7 support (which
was lost somewhat surprisingly, via a Go upgrade that slipped that
change in), and to provid a helpful message to the user in that
instance.

Since Git for Windows itself does not support Windows 7 anymore, that
patch is no longer necessary, either.

Author: dscho

compat/win32/path-utils.c

@@ -2,9 +2,6 @@
 
 #include "../../git-compat-util.h"
 #include "../../environment.h"
-#include "../../wrapper.h"
-#include "../../strbuf.h"
-#include "../../versioncmp.h"
 
 int win32_has_dos_drive_prefix(const char *path)
 {
@@ -92,199 +89,3 @@ int win32_fspathcmp(const char *a, const char *b)
 {
 	return win32_fspathncmp(a, b, (size_t)-1);
 }
-
-static int read_at(int fd, char *buffer, size_t offset, size_t size)
-{
-	if (lseek(fd, offset, SEEK_SET) < 0) {
-		fprintf(stderr, "could not seek to 0x%x\n", (unsigned int)offset);
-		return -1;
-	}
-
-	return read_in_full(fd, buffer, size);
-}
-
-static size_t le16(const char *buffer)
-{
-	unsigned char *u = (unsigned char *)buffer;
-	return u[0] | (u[1] << 8);
-}
-
-static size_t le32(const char *buffer)
-{
-	return le16(buffer) | (le16(buffer + 2) << 16);
-}
-
-/*
- * Determine the Go version of a given executable, if it was built with Go.
- *
- * This recapitulates the logic from
- * https://github.com/golang/go/blob/master/src/cmd/go/internal/version/version.go
- * (without requiring the user to install `go.exe` to find out).
- */
-static ssize_t get_go_version(const char *path, char *go_version, size_t go_version_size)
-{
-	int fd = open(path, O_RDONLY);
-	char buffer[1024];
-	off_t offset;
-	size_t num_sections, opt_header_size, i;
-	char *p = NULL, *q;
-	ssize_t res = -1;
-
-	if (fd < 0)
-		return -1;
-
-	if (read_in_full(fd, buffer, 2) < 0)
-		goto fail;
-
-	/*
-	 * Parse the PE file format, for more details, see
-	 * https://en.wikipedia.org/wiki/Portable_Executable#Layout and
-	 * https://learn.microsoft.com/en-us/windows/win32/debug/pe-format
-	 */
-	if (buffer[0] != 'M' || buffer[1] != 'Z')
-		goto fail;
-
-	if (read_at(fd, buffer, 0x3c, 4) < 0)
-		goto fail;
-
-	/* Read the `PE\0\0` signature and the COFF file header */
-	offset = le32(buffer);
-	if (read_at(fd, buffer, offset, 24) < 0)
-		goto fail;
-
-	if (buffer[0] != 'P' || buffer[1] != 'E' || buffer[2] != '\0' || buffer[3] != '\0')
-		goto fail;
-
-	num_sections = le16(buffer + 6);
-	opt_header_size = le16(buffer + 20);
-	offset += 24; /* skip file header */
-
-	/*
-	 * Validate magic number 0x10b or 0x20b, for full details see
-	 * https://learn.microsoft.com/en-us/windows/win32/debug/pe-format#optional-header-standard-fields-image-only
-	 */
-	if (read_at(fd, buffer, offset, 2) < 0 ||
-	    ((i = le16(buffer)) != 0x10b && i != 0x20b))
-		goto fail;
-
-	offset += opt_header_size;
-
-	for (i = 0; i < num_sections; i++) {
-		if (read_at(fd, buffer, offset + i * 40, 40) < 0)
-			goto fail;
-
-		/*
-		 * For full details about the section headers, see
-		 * https://learn.microsoft.com/en-us/windows/win32/debug/pe-format#section-table-section-headers
-		 */
-		if ((le32(buffer + 36) /* characteristics */ & ~0x600000) /* IMAGE_SCN_ALIGN_32BYTES */ ==
-		    (/* IMAGE_SCN_CNT_INITIALIZED_DATA */ 0x00000040 |
-		     /* IMAGE_SCN_MEM_READ */ 0x40000000 |
-		     /* IMAGE_SCN_MEM_WRITE */ 0x80000000)) {
-			size_t size = le32(buffer + 16); /* "SizeOfRawData " */
-			size_t pointer = le32(buffer + 20); /* "PointerToRawData " */
-
-			/*
-			 * Skip the section if either size or pointer is 0, see
-			 * https://github.com/golang/go/blob/go1.21.0/src/debug/buildinfo/buildinfo.go#L333
-			 * for full details.
-			 *
-			 * Merely seeing a non-zero size will not actually do,
-			 * though: he size must be at least `buildInfoSize`,
-			 * i.e. 32, and we expect a UVarint (at least another
-			 * byte) _and_ the bytes representing the string,
-			 * which we expect to start with the letters "go" and
-			 * continue with the Go version number.
-			 */
-			if (size < 32 + 1 + 2 + 1 || !pointer)
-				continue;
-
-			p = malloc(size);
-
-			if (!p || read_at(fd, p, pointer, size) < 0)
-				goto fail;
-
-			/*
-			 * Look for the build information embedded by Go, see
-			 * https://github.com/golang/go/blob/go1.21.0/src/debug/buildinfo/buildinfo.go#L165-L175
-			 * for full details.
-			 *
-			 * Note: Go contains code to enforce alignment along a
-			 * 16-byte boundary. In practice, no `.exe` has been
-			 * observed that required any adjustment, therefore
-			 * this here code skips that logic for simplicity.
-			 */
-			q = memmem(p, size - 18, "\xff Go buildinf:", 14);
-			if (!q)
-				goto fail;
-			/*
-			 * Decode the build blob. For full details, see
-			 * https://github.com/golang/go/blob/go1.21.0/src/debug/buildinfo/buildinfo.go#L177-L191
-			 *
-			 * Note: The `endianness` values observed in practice
-			 * were always 2, therefore the complex logic to handle
-			 * any other value is skipped for simplicty.
-			 */
-			if ((q[14] == 8 || q[14] == 4) && q[15] == 2) {
-				/*
-				 * Only handle a Go version string with fewer
-				 * than 128 characters, so the Go UVarint at
-				 * q[32] that indicates the string's length must
-				 * be only one byte (without the high bit set).
-				 */
-				if ((q[32] & 0x80) ||
-				    !q[32] ||
-				    (q + 33 + q[32] - p) > (ssize_t)size ||
-				    q[32] + 1 > (ssize_t)go_version_size)
-					goto fail;
-				res = q[32];
-				memcpy(go_version, q + 33, res);
-				go_version[res] = '\0';
-				break;
-			}
-		}
-	}
-
-fail:
-	free(p);
-	close(fd);
-	return res;
-}
-
-void win32_warn_about_git_lfs_on_windows7(int exit_code, const char *argv0)
-{
-	char buffer[128], *git_lfs = NULL;
-	const char *p;
-
-	/*
-	 * Git LFS v3.5.1 fails with an Access Violation on Windows 7; That
-	 * would usually show up as an exit code 0xc0000005. For some reason
-	 * (probably because at this point, we no longer have the _original_
-	 * HANDLE that was returned by `CreateProcess()`) we observe other
-	 * values like 0xb00 and 0x2 instead. Since the exact exit code
-	 * seems to be inconsistent, we check for a non-zero exit status.
-	 */
-	if (exit_code == 0)
-		return;
-	if (GetVersion() >> 16 > 7601)
-		return; /* Warn only on Windows 7 or older */
-	if (!istarts_with(argv0, "git-lfs ") &&
-	    strcasecmp(argv0, "git-lfs"))
-		return;
-	if (!(git_lfs = locate_in_PATH("git-lfs")))
-		return;
-	if (get_go_version(git_lfs, buffer, sizeof(buffer)) > 0 &&
-	    skip_prefix(buffer, "go", &p) &&
-	    versioncmp("1.21.0", p) <= 0)
-		warning("This program was built with Go v%s\n"
-			"i.e. without support for this Windows version:\n"
-			"\n\t%s\n"
-			"\n"
-			"To work around this, you can download and install a "
-			"working version from\n"
-			"\n"
-			"\thttps://github.com/git-lfs/git-lfs/releases/tag/"
-			"v3.4.1\n",
-			p, git_lfs);
-	free(git_lfs);
-}

compat/win32/path-utils.h

@@ -34,7 +34,4 @@ int win32_fspathcmp(const char *a, const char *b);
 int win32_fspathncmp(const char *a, const char *b, size_t count);
 #define fspathncmp win32_fspathncmp
 
-void win32_warn_about_git_lfs_on_windows7(int exit_code, const char *argv0);
-#define warn_about_git_lfs_on_windows7 win32_warn_about_git_lfs_on_windows7
-
 #endif

git-compat-util.h

@@ -263,13 +263,6 @@ static inline int git_offset_1st_component(const char *path)
 #define fspathncmp git_fspathncmp
 #endif
 
-#ifndef warn_about_git_lfs_on_windows7
-static inline void warn_about_git_lfs_on_windows7(int exit_code UNUSED,
-						  const char *argv0 UNUSED)
-{
-}
-#endif
-
 #ifndef is_valid_path
 #define is_valid_path(path) 1
 #endif

run-command.c

@@ -582,7 +582,6 @@ static int wait_or_whine(pid_t pid, const char *argv0, int in_signal)
 		 */
 		code += 128;
 	} else if (WIFEXITED(status)) {
-		warn_about_git_lfs_on_windows7(status, argv0);
 		code = WEXITSTATUS(status);
 	} else {
 		if (!in_signal)