0002862: error: use of undeclared identifier 'AT_SYMLINK_NOFOLLOW'

View Issue Details [ Jump to Notes ]

[ Issue History ] [ Print ]

Project

Category

View Status

Date Submitted

Last Update

0002862

NetSurf

[All Projects] General

public

2024-01-15 22:28

Reporter

Ryan Carsten Schmidt

Assigned To

Severity

minor

Reproducibility

always

Status

new

Resolution

open

Platform

x86_64

OS X

OS Version

10.9

Product Version

3.11

Target Version

Fixed in Version

Summary

0002862: error: use of undeclared identifier 'AT_SYMLINK_NOFOLLOW'

Description

NetSurf 3.11 fails to build on an old version of macOS, OS X 10.9:

utils/file.c:349:7: warning: implicit declaration of function 'fstatat' is invalid in C99 [-Wimplicit-function-declaration]
                if (fstatat(dirfd(parent), entry->d_name, &ent_stat,
                    ^
utils/file.c:350:5: error: use of undeclared identifier 'AT_SYMLINK_NOFOLLOW'
                                AT_SYMLINK_NOFOLLOW) != 0) {
                                ^
utils/file.c:365:8: warning: implicit declaration of function 'unlinkat' is invalid in C99 [-Wimplicit-function-declaration]
                        if (unlinkat(dirfd(parent), entry->d_name, 0) != 0) {
                            ^
2 warnings and 1 error generated.

This problem does not occur on OS X 10.10 or later. This isn't surprising since fstatat was introduced in OS X 10.10.

What is surprising is that the code in file.c and filename.c—the only places where fstatat is used—is guarded by "#if (defined(HAVE_DIRFD) && defined(HAVE_FSTATAT))". So somehow HAVE_FSTATAT is defined even though the system doesn't have it.

I initially assumed there was a problem with your configure test for fstatat when I was reminded that NetSurf doesn't use a configure script. HAVE_FSTATAT is defined unconditionally in netsurf/utils/config.h and is then undefined on a few systems. I guess if you don't use something like a configure script to see what's actually available, you'll have to hardcode a decision into config.h not to use fstatat when building *for* those older OS X versions that don't have it. (I say *for*, not *on*; *for* means looking at the deployment target (the MAC_OS_X_VERSION_MIN_REQUIRED preprocessor macro), not the SDK version (the MAC_OS_X_VERSION_MAX_ALLOWED preprocessor macro)). I don't see any existing occurrences of either of these macros in any of your source code so perhaps you're using another method to deal with this problem as it has arisen for other functions, or perhaps you haven't had to deal with this problem yet. Using either of these macros requires including <AvailabilityMacros.h> first, which you should only do when __APPLE__ is defined.

Steps To Reproduce

Build NetSurf 3.11 on OS X 10.9.

Date Modified	Username	Field
Issue History
2024-01-15 22:28	Ryan Carsten Schmidt	New Issue
2024-01-15 22:28	Ryan Carsten Schmidt	File Added: build.log

Relationships

Notes
There are no notes attached to this issue.