Bug #17793: `shorten-64-to-32` error for 32-bit Android due to `struct stat` definition

• Status: Closed
• Assignee: -
• Target version: -
• Backport: 2.6: UNKNOWN, 2.7: UNKNOWN, 3.0: UNKNOWN

[xtkoba (Tee KOBAYASHI)]

Here is a failure log for armv7a-android from CI.

This failure is because struct stat for 32-bit Android is defined as follows. Note that the member st_dev is of type unsigned long long (instead of dev_t), and st_mode is of type unsigned int (instead of mode_t).

struct stat {
  unsigned long long st_dev;
  unsigned char __pad0[4];
  unsigned long __st_ino;
  unsigned int st_mode;
  nlink_t st_nlink;
  uid_t st_uid;
  gid_t st_gid;
  unsigned long long st_rdev;
  unsigned char __pad3[4];
  long long st_size;
  unsigned long st_blksize;
  unsigned long long st_blocks;
  struct timespec st_atim;
  struct timespec st_mtim;
  struct timespec st_ctim;
  unsigned long long st_ino;
};

I personally avoid these errors by passing the following two arguments to ./configure. I am not 100% sure this results in no other problems.

rb_cv_dev_t_convertible=ULL
rb_cv_mode_t_convertible=UINT

[nobu (Nobuyoshi Nakada)]

Do these work?

diff --git i/configure.ac w/configure.ac
index 6fe43bfc8dd..f08597a007c 100644
--- i/configure.ac
+++ w/configure.ac
@@ -1703,6 +1703,10 @@ AS_IF([test "$ac_cv_member_struct_stat_st_blocks" = yes], [
     RUBY_CHECK_SIZEOF([struct stat.st_blocks], [off_t int long "long long"], [], [@%:@include <sys/stat.h>])
 ])
 RUBY_CHECK_SIZEOF([struct stat.st_ino], [long "long long"], [], [@%:@include <sys/stat.h>])
+RUBY_CHECK_SIZEOF([struct stat.st_dev], [dev_t int long "long long"], [], [@%:@include <sys/stat.h>])
+AS_IF([test "$ac_cv_member_struct_stat_st_rdev" = yes], [
+    RUBY_CHECK_SIZEOF([struct stat.st_rdev], [dev_t int long "long long"], [], [@%:@include <sys/stat.h>])
+])
 AC_CHECK_MEMBERS([struct stat.st_atim])
 AC_CHECK_MEMBERS([struct stat.st_atimespec])
 AC_CHECK_MEMBERS([struct stat.st_atimensec])
diff --git a/file.c b/file.c
index 6e6dfbca172..3a758c1c3c4 100644
--- a/file.c
+++ b/file.c
@@ -577,7 +577,13 @@ rb_stat_cmp(VALUE self, VALUE other)
 static VALUE
 rb_stat_dev(VALUE self)
 {
+#if SIZEOF_STRUCT_STAT_ST_DEV <= SIZEOF_DEV_T
     return DEVT2NUM(get_stat(self)->st_dev);
+#elif SIZEOF_STRUCT_STAT_ST_DEV <= SIZEOF_LONG
+    return ULONG2NUM(get_stat(self)->st_dev);
+#else
+    return ULL2NUM(get_stat(self)->st_dev);
+#endif
 }
 
 /*
@@ -747,7 +753,13 @@ static VALUE
 rb_stat_rdev(VALUE self)
 {
 #ifdef HAVE_STRUCT_STAT_ST_RDEV
+# if SIZEOF_STRUCT_STAT_ST_RDEV <= SIZEOF_DEV_T
     return DEVT2NUM(get_stat(self)->st_rdev);
+# elif SIZEOF_STRUCT_STAT_ST_RDEV <= SIZEOF_LONG
+    return ULONG2NUM(get_stat(self)->st_rdev);
+# else
+    return ULL2NUM(get_stat(self)->st_rdev);
+# endif
 #else
     return Qnil;
 #endif

diff --git a/file.c b/file.c
index 6e6dfbca172..3a758c1c3c4 100644
--- a/file.c
+++ b/file.c
@@ -6254,7 +6254,11 @@ path_check_0(VALUE path)
 #endif
 	    && !access(p0, W_OK)) {
 	    rb_enc_warn(enc, "Insecure world writable dir %s in PATH, mode 0%"
+#if SIZEOF_DEV_T > SIZEOF_INT
 			PRI_MODET_PREFIX"o",
+#else
+			"o",
+#endif
 			p0, st.st_mode);
 	    if (p) *p = '/';
 	    RB_GC_GUARD(path);

[xtkoba (Tee KOBAYASHI)]

nobu (Nobuyoshi Nakada) Thanks, it builds for armv7a-android without error or format warning.

[nobu (Nobuyoshi Nakada)]

Sorry, the second patch had a typo, SIZEOF_DEVT should be SIZEOF_DEV_T.
Is it fine?

[nobu (Nobuyoshi Nakada)]

All SIZEOF_DEVT were typo.

[xtkoba (Tee KOBAYASHI)]

It makes no difference because neither SIZEOF_DEVT nor SIZEOF_DEV_T is defined on Android (both for 32- and 64-bit). Is this as expected?

For armv7a-android16:

$ clang (...snip...) -o file.o -c ../file.c -Wundef
../file.c:580:34: warning: 'SIZEOF_DEV_T' is not defined, evaluates to 0 [-Wundef]
#if SIZEOF_STRUCT_STAT_ST_DEV <= SIZEOF_DEV_T
                                 ^
../file.c:756:36: warning: 'SIZEOF_DEV_T' is not defined, evaluates to 0 [-Wundef]
# if SIZEOF_STRUCT_STAT_ST_RDEV <= SIZEOF_DEV_T
                                   ^
../file.c:6269:5: warning: 'SIZEOF_DEV_T' is not defined, evaluates to 0 [-Wundef]
#if SIZEOF_DEV_T > SIZEOF_INT
    ^
3 warnings generated.

For aarch64-android21:

$ clang (...snip...) -o file.o -c ../file.c -Wundef
../file.c:580:5: warning: 'SIZEOF_DEV_T' is not defined, evaluates to 0 [-Wundef]
#if SIZEOF_STRUCT_STAT_ST_DEV <= SIZEOF_DEV_T
    ^
.ext/include/aarch64-linux-android/ruby/config.h:170:35: note: expanded from macro 'SIZEOF_STRUCT_STAT_ST_DEV'
#define SIZEOF_STRUCT_STAT_ST_DEV SIZEOF_DEV_T
                                  ^
../file.c:580:34: warning: 'SIZEOF_DEV_T' is not defined, evaluates to 0 [-Wundef]
#if SIZEOF_STRUCT_STAT_ST_DEV <= SIZEOF_DEV_T
                                 ^
../file.c:756:6: warning: 'SIZEOF_DEV_T' is not defined, evaluates to 0 [-Wundef]
# if SIZEOF_STRUCT_STAT_ST_RDEV <= SIZEOF_DEV_T
     ^
.ext/include/aarch64-linux-android/ruby/config.h:171:36: note: expanded from macro 'SIZEOF_STRUCT_STAT_ST_RDEV'
#define SIZEOF_STRUCT_STAT_ST_RDEV SIZEOF_DEV_T
                                   ^
../file.c:756:36: warning: 'SIZEOF_DEV_T' is not defined, evaluates to 0 [-Wundef]
# if SIZEOF_STRUCT_STAT_ST_RDEV <= SIZEOF_DEV_T
                                   ^
../file.c:6269:5: warning: 'SIZEOF_DEV_T' is not defined, evaluates to 0 [-Wundef]
#if SIZEOF_DEV_T > SIZEOF_INT
    ^
5 warnings generated.

[nobu (Nobuyoshi Nakada)]

• File 0001-Bug-17793-Support-non-standard-struct-stat.patch 0001-Bug-17793-Support-non-standard-struct-stat.patch added

Patch updated.

[xtkoba (Tee KOBAYASHI)]

With the patch in #note-6 applied, file.c is compiled without any error or warning (including -Wundef) for armv7a- and aarch64-android.

[nobu (Nobuyoshi Nakada)]

• Status changed from Open to Closed

Applied in changeset git|a5688b5ce6e87a5b881a4d52d4e59b6fe807e807.

---

Support non-standard struct stat [Bug #17793]

On 32-bit Android:

• st_dev/st_rdev are not dev_t
• st_mode is not mode_t