utils-std

commit: 21c374ab77399a99e0e8b5fe1b6f67fdb25cb180
parent 50f9d24bb94d4595555872641eea33f902cebab7
Author: Haelwenn (lanodan) Monnier <contact@hacktivis.me>
Date:   Thu, 28 Mar 2024 18:17:28 +0100

cmd/rm: Add assert(errno == 0) before functions known to change errno

Risky as different systems could change errno in extra places, but this way
we're sure errno is reset, in fact I forgot to reset it for faccessat(…W_OK…)

Diffstat:
M
cmd/rm.c
49
+++++++++++++++++++++++++++++++------------------

1 file changed, 31 insertions(+), 18 deletions(-)
diff --git a/cmd/rm.c b/cmd/rm.c
@@ -9,6 +9,7 @@
 #define _NETBSD_SOURCE
 #endif
 
+#include <assert.h>
 #include <ctype.h>  // isprint
 #include <dirent.h> // fdopendir, readdir, closedir
 #include <errno.h>  // errno
@@ -35,30 +36,31 @@ consentf(const char *restrict fmt, ...)
 
 	va_list ap;
 
-	errno = 0;
-
+	assert(errno == 0);
 	va_start(ap, fmt);
 	int ret = vfprintf(stderr, fmt, ap);
 	va_end(ap);
 
-	if(!ret)
+	if(ret < 0)
 	{
 		fprintf(stderr, "%s: Failed to print user prompt: %s\n", argv0, strerror(errno));
+		errno = 0;
 		goto end;
 	}
 
-	errno = 0;
-
+	assert(errno == 0);
 	ssize_t nread = getline(&line, &len, stdin);
 	if(nread < 0)
 	{
 		fprintf(stderr, "\n%s: Failed getting user entry via getline: %s\n", argv0, strerror(errno));
+		errno = 0;
 		goto end;
 	}
 
 	if(nread == 0)
 	{
 		fprintf(stderr, "%s: Got empty response, considering it false\n", argv0);
+		errno = 0;
 		goto end;
 	}
 
@@ -97,12 +99,17 @@ do_unlinkat(int fd, char *name, char *acc_path)
 	struct stat stats;
 	int err = 0;
 
-	errno = 0;
+	assert(errno == 0);
 	if(fstatat(fd, name, &stats, AT_SYMLINK_NOFOLLOW) != 0)
 	{
-		if(force && errno == ENOENT) return 0;
+		if(force && errno == ENOENT)
+		{
+			errno = 0;
+			return 0;
+		}
 
 		fprintf(stderr, "rm: Failed getting status for '%s': %s\n", acc_path, strerror(errno));
+		errno = 0;
 		return 1;
 	}
 
@@ -119,44 +126,44 @@ do_unlinkat(int fd, char *name, char *acc_path)
 		if(!force && opt_i)
 			if(!consentf("rm: Recurse into '%s' ? [y/N] ", acc_path)) return 0;
 
-		errno   = 0;
+		assert(errno == 0);
 		int dir = openat(fd, name, O_RDONLY | O_DIRECTORY | O_CLOEXEC);
 		if(dir == -1)
 		{
 			fprintf(stderr, "rm: Couldn't open '%s' as directory: %s\n", acc_path, strerror(errno));
+			errno = 0;
 			return 1;
 		}
 
-		errno = 0;
-
+		assert(errno == 0);
 		DIR *dirp = fdopendir(dir);
 		if(dirp == NULL)
 		{
 			fprintf(
 			    stderr, "rm: Couldn't get DIR entry for opened '%s': %s\n", acc_path, strerror(errno));
+			errno = 0;
 			return 1;
 		}
 
 		while(true)
 		{
-			errno = 0;
-
+			assert(errno == 0);
 			struct dirent *dp = readdir(dirp);
 			if(dp == NULL)
 			{
 				if(errno == 0) break;
 
 				fprintf(stderr, "rm: Failed reading directory '%s': %s\n", acc_path, strerror(errno));
-				closedir(dirp);
+				closedir(dirp); // error ignored
+				errno = 0;
 				return 1;
 			}
 
 			if(strcmp(dp->d_name, ".") == 0) continue;
 			if(strcmp(dp->d_name, "..") == 0) continue;
 
-			errno = 0;
-
 			char new_path[PATH_MAX] = "";
+			assert(errno == 0);
 			if(snprintf(new_path, PATH_MAX, "%s/%s", acc_path, dp->d_name) < 0)
 			{
 				fprintf(stderr,
@@ -164,7 +171,8 @@ do_unlinkat(int fd, char *name, char *acc_path)
 				        name,
 				        acc_path,
 				        strerror(errno));
-				err = 1;
+				err   = 1;
+				errno = 0;
 				continue;
 			}
 
@@ -174,13 +182,14 @@ do_unlinkat(int fd, char *name, char *acc_path)
 		}
 
 		// fdopendir allocates memory for DIR, needs closedir
-		errno = 0;
+		assert(errno == 0);
 		if(closedir(dirp) != 0)
 		{
 			fprintf(stderr,
 			        "rm: Deallocating directory entry for '%s' failed: %s\n",
 			        acc_path,
 			        strerror(errno));
+			errno = 0;
 			return 1;
 		}
 	}
@@ -189,13 +198,17 @@ do_unlinkat(int fd, char *name, char *acc_path)
 	{
 		// FIXME: Terminal always considered to be present for tests reason
 		if(faccessat(fd, name, W_OK, AT_SYMLINK_NOFOLLOW) != 0 || opt_i)
+		{
+			errno = 0;
 			if(!consentf("rm: Remove '%s' ? [y/N] ", acc_path)) return 0;
+		}
 	}
 
-	errno = 0;
+	assert(errno == 0);
 	if(unlinkat(fd, name, is_dir ? AT_REMOVEDIR : 0) != 0)
 	{
 		fprintf(stderr, "rm: Couldn't remove '%s': %s\n", acc_path, strerror(errno));
+		errno = 0;
 		return 1;
 	}
 	else if(verbose)