read-file: add flags to modify reading behavior

* lib/read-file.h (RF_BINARY): New define.
(fread_file, read_file): Take FLAGS argument.
(read_binary_file): Remove.
* lib/read-file.c (internal_read_file): Merge into ...
(read_file): ... here.
* modules/read-file-tests (Files): Add "tests/macros.h".
* tests/test-read-file.c (main): Refactor using ASSERT macro.
* NEWS: Mention this change.

6 files changed, 50 insertions, 35 deletions

diff --git a/ChangeLog b/ChangeLog
index aa7bc100da..291fd0788b 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,15 @@
+2020-05-27  Daiki Ueno  <ueno@gnu.org>
+
+	read-file: add flags to modify reading behavior
+	* lib/read-file.h (RF_BINARY): New define.
+	(fread_file, read_file): Take FLAGS argument.
+	(read_binary_file): Remove.
+	* lib/read-file.c (internal_read_file): Merge into ...
+	(read_file): ... here.
+	* modules/read-file-tests (Files): Add "tests/macros.h".
+	* tests/test-read-file.c (main): Refactor using ASSERT macro.
+	* NEWS: Mention this change.
+
 2020-05-26  Bernhard Voelker  <mail@bernhard-voelker.de>
 
 	doc/gnulib-intro.texi: add missing "to" in sentence
diff --git a/NEWS b/NEWS
index 99973c5c39..c8f78ea161 100644
--- a/NEWS
+++ b/NEWS
@@ -58,6 +58,11 @@ User visible incompatible changes
 
 Date        Modules         Changes
 
+2020-05-27  read-file       The functions provided by this module now take an
+                            'int flags' argument to modify the file reading
+                            behavior.  The read_binary_file function has been
+                            removed as it is no longer necessary.
+
 2020-04-27  getdate         This deprecated module is removed. Use the module
                             'parse-datetime' instead. Instead of
                               #include "getdate.h"
diff --git a/lib/read-file.c b/lib/read-file.c
index 293bc3e8a5..904f1c9018 100644
--- a/lib/read-file.c
+++ b/lib/read-file.c
@@ -40,7 +40,7 @@
    *LENGTH.  On errors, *LENGTH is undefined, errno preserves the
    values set by system functions (if any), and NULL is returned.  */
 char *
-fread_file (FILE *stream, size_t *length)
+fread_file (FILE *stream, int flags _GL_UNUSED, size_t *length)
 {
   char *buf = NULL;
   size_t alloc = BUFSIZ;
@@ -134,9 +134,19 @@ fread_file (FILE *stream, size_t *length)
   }
 }
 
-static char *
-internal_read_file (const char *filename, size_t *length, const char *mode)
+/* Open and read the contents of FILENAME, and return a newly
+   allocated string with the content, and set *LENGTH to the length of
+   the string.  The string is zero-terminated, but the terminating
+   zero byte is not counted in *LENGTH.  On errors, *LENGTH is
+   undefined, errno preserves the values set by system functions (if
+   any), and NULL is returned.
+
+   If the RF_BINARY flag is set in FLAGS, the file is opened in binary
+   mode.  */
+char *
+read_file (const char *filename, int flags, size_t *length)
 {
+  const char *mode = (flags & RF_BINARY) ? "rbe" : "re";
   FILE *stream = fopen (filename, mode);
   char *out;
   int save_errno;
@@ -144,7 +154,7 @@ internal_read_file (const char *filename, size_t *length, const char *mode)
   if (!stream)
     return NULL;
 
-  out = fread_file (stream, length);
+  out = fread_file (stream, flags, length);
 
   save_errno = errno;
 
@@ -161,28 +171,3 @@ internal_read_file (const char *filename, size_t *length, const char *mode)
 
   return out;
 }
-
-/* Open and read the contents of FILENAME, and return a newly
-   allocated string with the content, and set *LENGTH to the length of
-   the string.  The string is zero-terminated, but the terminating
-   zero byte is not counted in *LENGTH.  On errors, *LENGTH is
-   undefined, errno preserves the values set by system functions (if
-   any), and NULL is returned.  */
-char *
-read_file (const char *filename, size_t *length)
-{
-  return internal_read_file (filename, length, "re");
-}
-
-/* Open (on non-POSIX systems, in binary mode) and read the contents
-   of FILENAME, and return a newly allocated string with the content,
-   and set LENGTH to the length of the string.  The string is
-   zero-terminated, but the terminating zero byte is not counted in
-   the LENGTH variable.  On errors, *LENGTH is undefined, errno
-   preserves the values set by system functions (if any), and NULL is
-   returned.  */
-char *
-read_binary_file (const char *filename, size_t *length)
-{
-  return internal_read_file (filename, length, "rbe");
-}
diff --git a/lib/read-file.h b/lib/read-file.h
index bb28abd65e..7ff82ca77d 100644
--- a/lib/read-file.h
+++ b/lib/read-file.h
@@ -24,10 +24,11 @@
 /* Get FILE.  */
 #include <stdio.h>
 
-extern char *fread_file (FILE * stream, size_t * length);
+/* Indicate that the file is treated as binary.  */
+#define RF_BINARY 0x1
 
-extern char *read_file (const char *filename, size_t * length);
+extern char *fread_file (FILE * stream, int flags, size_t * length);
 
-extern char *read_binary_file (const char *filename, size_t * length);
+extern char *read_file (const char *filename, int flags, size_t * length);
 
 #endif /* READ_FILE_H */
diff --git a/modules/read-file-tests b/modules/read-file-tests
index 361bca8065..2996316444 100644
--- a/modules/read-file-tests
+++ b/modules/read-file-tests
@@ -1,5 +1,6 @@
 Files:
 tests/test-read-file.c
+tests/macros.h
 
 Depends-on:
 
diff --git a/tests/test-read-file.c b/tests/test-read-file.c
index 930cf4acb0..84b9049940 100644
--- a/tests/test-read-file.c
+++ b/tests/test-read-file.c
@@ -23,11 +23,13 @@
 #include <stdlib.h>
 #include <sys/stat.h>
 
+#include "macros.h"
+
 #define FILE1 "/etc/resolv.conf"
 #define FILE2 "/dev/null"
 
 int
-main (void)
+test_read_file (int flags)
 {
   struct stat statbuf;
   int err = 0;
@@ -37,7 +39,7 @@ main (void)
   if (stat (FILE1, &statbuf) >= 0)
     {
       size_t len;
-      char *out = read_file (FILE1, &len);
+      char *out = read_file (FILE1, flags, &len);
 
       if (!out)
         {
@@ -80,7 +82,7 @@ main (void)
   if (stat (FILE2, &statbuf) >= 0)
     {
       size_t len;
-      char *out = read_file (FILE2, &len);
+      char *out = read_file (FILE2, flags, &len);
 
       if (!out)
         {
@@ -109,3 +111,12 @@ main (void)
 
   return err;
 }
+
+int
+main (void)
+{
+  ASSERT (!test_read_file (0));
+  ASSERT (!test_read_file (RF_BINARY));
+
+  return 0;
+}