about summary refs log tree commit diff
path: root/stdio-common/vfprintf-internal.c
diff options
context:
space:
mode:
authorFlorian Weimer <fweimer@redhat.com>2021-12-23 15:01:07 +0100
committerFlorian Weimer <fweimer@redhat.com>2021-12-23 15:02:50 +0100
commit9702a7901e18460e8ffc5f56a493d41294a8e936 (patch)
tree0e7147c9c7e3d4cb14d3474c9dd947dcf64b38a9 /stdio-common/vfprintf-internal.c
parentcd0c333d2ea82d0ae14719bdbef86d99615bdb00 (diff)
downloadglibc-9702a7901e18460e8ffc5f56a493d41294a8e936.tar.gz
glibc-9702a7901e18460e8ffc5f56a493d41294a8e936.tar.xz
glibc-9702a7901e18460e8ffc5f56a493d41294a8e936.zip
stdio: Implement %#m for vfprintf and related functions
%#m prints errno as an error constant if one is available, or
a decimal number as a fallback.  This intends to address the gap
that strerrorname_np does not work well with printf for unknown
error codes due to its NULL return values in those cases.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
Diffstat (limited to 'stdio-common/vfprintf-internal.c')
-rw-r--r--stdio-common/vfprintf-internal.c25
1 files changed, 20 insertions, 5 deletions
diff --git a/stdio-common/vfprintf-internal.c b/stdio-common/vfprintf-internal.c
index e717f50073..8547090d45 100644
--- a/stdio-common/vfprintf-internal.c
+++ b/stdio-common/vfprintf-internal.c
@@ -950,11 +950,26 @@ static const uint8_t jump_table[] =
 									      \
     LABEL (form_strerror):						      \
       /* Print description of error ERRNO.  */				      \
-      string =								      \
-	(CHAR_T *) __strerror_r (save_errno, (char *) work_buffer,	      \
-				 WORK_BUFFER_SIZE * sizeof (CHAR_T));	      \
-      is_long = 0;		/* This is no wide-char string.  */	      \
-      goto LABEL (print_string)
+      if (alt)								      \
+	string = (CHAR_T *) __get_errname (save_errno);			      \
+      else								      \
+	string = (CHAR_T *) __strerror_r (save_errno, (char *) work_buffer,   \
+					  WORK_BUFFER_SIZE * sizeof (CHAR_T));\
+      if (string == NULL)						\
+	{								      \
+          /* Print as a decimal number. */				      \
+          base = 10;							      \
+	  is_negative = save_errno < 0;					      \
+	  number.word = save_errno;					      \
+	  if (is_negative)						      \
+	    number.word = -number.word;					      \
+	  goto LABEL (number);						      \
+	}								      \
+      else								      \
+	{								      \
+	  is_long = 0;	/* This is no wide-char string.  */		      \
+	  goto LABEL (print_string);					      \
+	}
 
 #ifdef COMPILE_WPRINTF
 # define process_string_arg()						      \