libredirect: add support for unlink, unlinkat, rmdir

add coverage of these and mkdir functions in tests

pkgs/build-support/libredirect/default.nix

@@ -57,7 +57,7 @@ else stdenv.mkDerivation rec {
     ''}
 
     if [ -n "$doInstallCheck" ]; then
-      $CC -Wall -std=c99 -O3 test.c -o test
+      $CC -Wall -std=c99 -D_POSIX_C_SOURCE=200809L -O3 test.c -o test
     fi
 
     runHook postBuild
@@ -91,7 +91,7 @@ else stdenv.mkDerivation rec {
   installCheckPhase = ''
     (
       source "$hook/nix-support/setup-hook"
-      NIX_REDIRECTS="/foo/bar/test=${coreutils}/bin/true" ./test
+      NIX_REDIRECTS="/foo/bar/test=${coreutils}/bin/true:/bar/baz=$(mktemp -d)" ./test
     )
   '';
 

pkgs/build-support/libredirect/libredirect.c

@@ -354,3 +354,27 @@ WRAPPER(int, mkdirat)(int dirfd, const char *path, mode_t mode)
     return mkdirat_real(dirfd, rewrite(path, buf), mode);
 }
 WRAPPER_DEF(mkdirat)
+
+WRAPPER(int, unlink)(const char *path)
+{
+    int (*unlink_real) (const char *path) = LOOKUP_REAL(unlink);
+    char buf[PATH_MAX];
+    return unlink_real(rewrite(path, buf));
+}
+WRAPPER_DEF(unlink)
+
+WRAPPER(int, unlinkat)(int dirfd, const char *path, int flags)
+{
+    int (*unlinkat_real) (int dirfd, const char *path, int flags) = LOOKUP_REAL(unlinkat);
+    char buf[PATH_MAX];
+    return unlinkat_real(dirfd, rewrite(path, buf), flags);
+}
+WRAPPER_DEF(unlinkat)
+
+WRAPPER(int, rmdir)(const char *path)
+{
+    int (*rmdir_real) (const char *path) = LOOKUP_REAL(rmdir);
+    char buf[PATH_MAX];
+    return rmdir_real(rewrite(path, buf));
+}
+WRAPPER_DEF(rmdir)

pkgs/build-support/libredirect/test.c

@@ -1,4 +1,5 @@
 #include <assert.h>
+#include <errno.h>
 #include <fcntl.h>
 #include <spawn.h>
 #include <stdio.h>
@@ -9,6 +10,7 @@
 #include <sys/types.h>
 #include <sys/wait.h>
 
+#define TESTDIR "/bar/baz"
 #define TESTPATH "/foo/bar/test"
 #define SUBTEST "./test sub"
 
@@ -59,6 +61,22 @@ int main(int argc, char *argv[])
 
     assert(stat(TESTPATH, &testsb) != -1);
 
+    assert(mkdir(TESTDIR "/dir-mkdir", 0777) == 0);
+    assert(unlink(TESTDIR "/dir-mkdir") == -1); // it's a directory!
+#ifndef __APPLE__
+    assert(errno == EISDIR);
+#endif
+    assert(rmdir(TESTDIR "/dir-mkdir") == 0);
+    assert(unlink(TESTDIR "/dir-mkdir") == -1);
+    assert(errno == ENOENT);
+
+    assert(mkdirat(123, TESTDIR "/dir-mkdirat", 0777) == 0);
+    assert(unlinkat(123, TESTDIR "/dir-mkdirat", 0) == -1); // it's a directory!
+#ifndef __APPLE__
+    assert(errno == EISDIR);
+#endif
+    assert(unlinkat(123, TESTDIR "/dir-mkdirat", AT_REMOVEDIR) == 0);
+
     test_spawn();
     test_system();