Merge pull request #148 from hartwork/fix-warnings

Fix compile warnings (including a serious one) + cover FUSE 2 in CI + add `-Wextra` to `configure.ac`

7 files changed, 73 insertions, 20 deletions

diff --git a/.github/workflows/linux.yml b/.github/workflows/linux.yml
index cef2939..71e0759 100644
--- a/.github/workflows/linux.yml
+++ b/.github/workflows/linux.yml
@@ -12,27 +12,38 @@ on:
 
 jobs:
   linux:
-    name: Build (${{ matrix.cc }} on ${{ matrix.runs-on }})
+    name: Build (${{ matrix.cc }} and ${{ matrix.fuse_package }} on ${{ matrix.runs-on }})
     runs-on: ${{ matrix.runs-on }}
     strategy:
       fail-fast: false
       matrix:
         include:
+          # FUSE 2
           - cc: gcc-13
             cxx: g++-13
             clang_major_version: null
             clang_repo_suffix: null
             runs-on: ubuntu-22.04
+            fuse_package: libfuse-dev
+          # FUSE 3
+          - cc: gcc-13
+            cxx: g++-13
+            clang_major_version: null
+            clang_repo_suffix: null
+            runs-on: ubuntu-22.04
+            fuse_package: libfuse3-dev
           - cc: clang-17
             cxx: clang++-17
             clang_major_version: 17
             clang_repo_suffix: -17
             runs-on: ubuntu-22.04
+            fuse_package: libfuse3-dev
           - cc: clang-18
             cxx: clang++-18
             clang_major_version: 18
             clang_repo_suffix:
             runs-on: ubuntu-22.04
+            fuse_package: libfuse3-dev
     steps:
       - name: Add Clang/LLVM repositories
         if: "${{ contains(matrix.cxx, 'clang') }}"
@@ -48,7 +59,7 @@ jobs:
           sudo apt-get install --yes --no-install-recommends \
             autoconf \
             automake \
-            libfuse3-dev \
+            ${{ matrix.fuse_package }} \
             libtool \
             pkg-config
 
diff --git a/configure.ac b/configure.ac
index 00f8ebc..0598619 100644
--- a/configure.ac
+++ b/configure.ac
@@ -35,7 +35,7 @@ AM_CONDITIONAL([BUILD_OS_IS_DARWIN], [case $build_os in darwin* ) true ;; * ) fa
 # _DARWIN_BETTER_REALPATH fixes MacOS realpath() broken around Catalina (#83).
 my_CPPFLAGS="-D_REENTRANT -D_FILE_OFFSET_BITS=64 -D_XOPEN_SOURCE=700 -D__BSD_VISIBLE=1 -D_BSD_SOURCE -D_DEFAULT_SOURCE -D_DARWIN_BETTER_REALPATH"
 
-my_CFLAGS="-std=c99 -Wall -Wpedantic -fno-common"
+my_CFLAGS="-std=c99 -Wall -Wextra -Wpedantic -fno-common"
 my_LDFLAGS="-pthread"
 AC_SUBST([my_CPPFLAGS])
 AC_SUBST([my_CFLAGS])
diff --git a/src/bindfs.c b/src/bindfs.c
index b4a1f5a..5f52395 100644
--- a/src/bindfs.c
+++ b/src/bindfs.c
@@ -446,9 +446,9 @@ static int getattr_common(const char *procpath, struct stat *stbuf)
     }
 
     /* Report user-defined owner/group if specified */
-    if (settings.new_uid != -1)
+    if (settings.new_uid != (uid_t)-1)
         stbuf->st_uid = settings.new_uid;
-    if (settings.new_gid != -1)
+    if (settings.new_gid != (gid_t)-1)
         stbuf->st_gid = settings.new_gid;
 
     /* Mirrored user? */
@@ -549,12 +549,12 @@ static int chown_new_file(const char *path, struct fuse_context *fc, int (*chown
         }
     }
 
-    if (settings.create_for_uid != -1)
+    if (settings.create_for_uid != (uid_t)-1)
         file_owner = settings.create_for_uid;
-    if (settings.create_for_gid != -1)
+    if (settings.create_for_gid != (gid_t)-1)
         file_group = settings.create_for_gid;
 
-    if ((file_owner != -1) || (file_group != -1)) {
+    if ((file_owner != (uid_t)-1) || (file_group != (gid_t)-1)) {
         if (chown_func(path, file_owner, file_group) == -1) {
             DPRINTF("Failed to chown new file or directory (%d)", errno);
         }
@@ -750,6 +750,7 @@ static void *bindfs_init()
 
 static void bindfs_destroy(void *private_data)
 {
+    (void)private_data;
 }
 
 #ifdef HAVE_FUSE_3
@@ -761,6 +762,9 @@ static int bindfs_getattr(const char *path, struct stat *stbuf)
 {
     int res;
     char *real_path;
+#ifdef HAVE_FUSE_3
+    (void)fi;
+#endif
 
     real_path = process_path(path, true);
     if (real_path == NULL)
@@ -827,6 +831,11 @@ static int bindfs_readdir(const char *path, void *buf, fuse_fill_dir_t filler,
                           off_t offset, struct fuse_file_info *fi)
 #endif
 {
+    (void)offset;
+    (void)fi;
+#ifdef HAVE_FUSE_3
+    (void)flags;
+#endif
     char *real_path = process_path(path, true);
     if (real_path == NULL) {
         return -errno;
@@ -1116,6 +1125,9 @@ static int bindfs_chmod(const char *path, mode_t mode)
     struct stat st;
     mode_t diff = 0;
     char *real_path;
+#ifdef HAVE_FUSE_3
+    (void)fi;
+#endif
 
     real_path = process_path(path, true);
     if (real_path == NULL)
@@ -1181,8 +1193,11 @@ static int bindfs_chown(const char *path, uid_t uid, gid_t gid)
 {
     int res;
     char *real_path;
+#ifdef HAVE_FUSE_3
+    (void)fi;
+#endif
 
-    if (uid != -1) {
+    if (uid != (uid_t)-1) {
         switch (settings.chown_policy) {
         case CHOWN_NORMAL:
             uid = usermap_get_uid_or_default(settings.usermap_reverse, uid, uid);
@@ -1198,7 +1213,7 @@ static int bindfs_chown(const char *path, uid_t uid, gid_t gid)
         }
     }
 
-    if (gid != -1) {
+    if (gid != (gid_t)-1) {
         switch (settings.chgrp_policy) {
         case CHGRP_NORMAL:
             gid = usermap_get_gid_or_default(settings.usermap_reverse, gid, gid);
@@ -1214,7 +1229,7 @@ static int bindfs_chown(const char *path, uid_t uid, gid_t gid)
         }
     }
 
-    if (uid != -1 || gid != -1) {
+    if (uid != (uid_t)-1 || gid != (gid_t)-1) {
         real_path = process_path(path, true);
         if (real_path == NULL)
             return -errno;
@@ -1237,6 +1252,9 @@ static int bindfs_truncate(const char *path, off_t size)
 {
     int res;
     char *real_path;
+#ifdef HAVE_FUSE_3
+    (void)fi;
+#endif
 
     real_path = process_path(path, true);
     if (real_path == NULL)
@@ -1273,6 +1291,9 @@ static int bindfs_utimens(const char *path, const struct timespec ts[2])
 {
     int res;
     char *real_path;
+#ifdef HAVE_FUSE_3
+    (void)fi;
+#endif
 
     real_path = process_path(path, true);
     if (real_path == NULL)
@@ -1437,6 +1458,7 @@ static int bindfs_write(const char *path, const char *buf, size_t size,
 static int bindfs_lock(const char *path, struct fuse_file_info *fi, int cmd,
                        struct flock *lock)
 {
+  (void)path;
   int res = fcntl(fi->fh, cmd, lock);
   if (res == -1) {
     return -errno;
@@ -1447,6 +1469,7 @@ static int bindfs_lock(const char *path, struct fuse_file_info *fi, int cmd,
 /* This callback is only installed if lock forwarding is enabled. */
 static int bindfs_flock(const char *path, struct fuse_file_info *fi, int op)
 {
+    (void)path;
     int res = flock(fi->fh, op);
     if (res == -1) {
         return -errno;
@@ -1464,6 +1487,9 @@ static int bindfs_ioctl(const char *path, int cmd, void *arg,
                         void *data)
 #endif
 {
+    (void)path;
+    (void)arg;
+    (void)flags;
     int res = ioctl(fi->fh, cmd, data);
     if (res == -1) {
       return -errno;
@@ -1891,6 +1917,8 @@ enum OptionKey {
 static int process_option(void *data, const char *arg, int key,
                           struct fuse_args *outargs)
 {
+    (void)data;
+    (void)outargs;
     switch ((enum OptionKey)key)
     {
     case OPTKEY_HELP:
@@ -2322,6 +2350,7 @@ static void setup_signal_handling()
 
 static void signal_handler(int sig)
 {
+    (void)sig;
     invalidate_user_cache();
 }
 
diff --git a/src/misc.c b/src/misc.c
index 122497d..fdebff9 100644
--- a/src/misc.c
+++ b/src/misc.c
@@ -19,6 +19,7 @@
 
 #include "misc.h"
 #include <stdarg.h>
+#include <stdint.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
@@ -166,7 +167,7 @@ bool path_starts_with(const char *path, const char* prefix, size_t prefix_len)
 
         const char* path_part = path + (prefix_part - prefix);
         const char* path_slash = strchr(path_part, '/');
-        size_t path_part_len = path_slash ? path_slash - path_part : path_len - (path_part - path);
+        size_t path_part_len = path_slash ? (size_t)(path_slash - path_part) : path_len - (path_part - path);
 
         return prefix_part_len == path_part_len;
     }
@@ -328,12 +329,12 @@ void grow_memory_block(struct memory_block *a, size_t amount)
             if (new_cap == 0) {
                 new_cap = 8;
             } else {
+                if (new_cap > SIZE_MAX / 2) {
+                    fprintf(stderr, "Memory block too large.");
+                    abort();
+                }
                 new_cap *= 2;
             }
-            if (new_cap < 0) {  // Overflow
-                fprintf(stderr, "Memory block too large.");
-                abort();
-            }
         }
         a->ptr = (char *)realloc(a->ptr, new_cap);
         a->capacity = new_cap;
diff --git a/src/permchain.c b/src/permchain.c
index b95bd8b..d101aa1 100644
--- a/src/permchain.c
+++ b/src/permchain.c
@@ -67,6 +67,8 @@ static int add_chmod_rule_to_permchain(const char *start, const char *end,
 
     int len = end - start;
     char *buf = malloc((len + 1) * sizeof(char));
+    if (buf == NULL)
+        return -1;
     const char *p = buf;
 
     enum {LHS, RHS} state = LHS;
@@ -149,8 +151,18 @@ error:
 static int add_octal_rule_to_permchain(const char *start, const char *end,
                                        struct permchain *pc)
 {
+    // Make [start..end[ available as a null-terminated string to `strtol`
+    const int len = end - start;
+    char * const buf = malloc((len + 1) * sizeof(char));
+    if (buf == NULL)
+        return -1;
+    memcpy(buf, start, len);
+    buf[len] = '\0';
+
     struct permchain *newpc = permchain_create();
-    long mode = strtol(start, NULL, 8);
+
+    long mode = strtol(buf, NULL, 8);
+    free(buf);
 
     if (mode < 0 || mode > 0777) {
         permchain_destroy(newpc);
diff --git a/src/usermap.c b/src/usermap.c
index f745e74..eb7b61c 100644
--- a/src/usermap.c
+++ b/src/usermap.c
@@ -52,7 +52,7 @@ UsermapStatus usermap_add_uid(UserMap *map, uid_t from, uid_t to)
         map->user_from = (uid_t*)realloc(map->user_from, map->user_capacity * sizeof(uid_t));
         map->user_to = (uid_t*)realloc(map->user_to, map->user_capacity * sizeof(uid_t));
     }
-    if (usermap_get_uid_or_default(map, from, -1) != -1) {
+    if (usermap_get_uid_or_default(map, from, -1) != (uid_t)-1) {
         return usermap_status_duplicate_key;
     }
     i = map->user_size;
@@ -77,7 +77,7 @@ UsermapStatus usermap_add_gid(UserMap *map, gid_t from, gid_t to)
         map->group_from = (gid_t*)realloc(map->group_from, map->group_capacity * sizeof(gid_t));
         map->group_to = (gid_t*)realloc(map->group_to, map->group_capacity * sizeof(gid_t));
     }
-    if (usermap_get_gid_or_default(map, from, -1) != -1) {
+    if (usermap_get_gid_or_default(map, from, -1) != (gid_t)-1) {
         return usermap_status_duplicate_key;
     }
     i = map->group_size;
diff --git a/tests/odirect_write.c b/tests/odirect_write.c
index 10b63f9..bc9040f 100644
--- a/tests/odirect_write.c
+++ b/tests/odirect_write.c
@@ -55,7 +55,7 @@ int main(int argc, char** argv) {
             perror("failed to write");
             return 1;
         }
-        if (res != buf_size) {
+        if ((size_t)res != buf_size) {
             // Too lazy to write a loop here unless it turns out to be necessary.
             fprintf(stderr, "Failed to write exactly %lu bytes", (unsigned long)amt_read);
         }