libc: minimal: stubs getc_unlocked & getchar_unlocked

Add stub implementation and test for `getc_unlocked()` & `getchar_unlocked()`. Signed-off-by: Yong Cong Sin <ycsin@meta.com>
zephyrproject-rtos · Jun 18, 2024 · f69126e · f69126e
1 parent cf04ada
commit f69126e
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Showing 4 changed files with 34 additions and 4 deletions.
diff --git a/doc/services/portability/posix/option_groups/index.rst b/doc/services/portability/posix/option_groups/index.rst
@@ -567,8 +567,8 @@ This table lists service support status in Zephyr for `POSIX_FD_MGMT`:
     flockfile(), yes
     ftrylockfile(), yes
     funlockfile(), yes
-    getc_unlocked(),
-    getchar_unlocked(),
+    getc_unlocked(), yes :ref:`†<posix_undefined_behaviour>`
+    getchar_unlocked(), yes :ref:`†<posix_undefined_behaviour>`
     putc_unlocked(), yes
     putchar_unlocked(), yes
 
@@ -904,8 +904,8 @@ _POSIX_THREAD_SAFE_FUNCTIONS
     flockfile(), yes
     ftrylockfile(), yes
     funlockfile(), yes
-    getc_unlocked(),
-    getchar_unlocked(),
+    getc_unlocked(), yes :ref:`†<posix_undefined_behaviour>`
+    getchar_unlocked(), yes :ref:`†<posix_undefined_behaviour>`
     getgrgid_r(),
     getgrnam_r(),
     getpwnam_r(),

diff --git a/lib/libc/minimal/include/stdio.h b/lib/libc/minimal/include/stdio.h
@@ -64,6 +64,8 @@ size_t fwrite(const void *ZRESTRICT ptr, size_t size, size_t nitems,
 #define putchar(c) putc(c, stdout)
 #define putc_unlocked(c, stream) putc(c, stream)
 #define putchar_unlocked(c) putchar(c)
+int getc_unlocked(FILE *stream);
+int getchar_unlocked(void);
 
 void flockfile(FILE *file);
 int ftrylockfile(FILE *file);

diff --git a/lib/posix/options/file_locking.c b/lib/posix/options/file_locking.c
@@ -4,6 +4,7 @@
  * SPDX-License-Identifier: Apache-2.0
  */
 
+#include <errno.h>
 #include <stdio.h>
 
 #include <zephyr/sys/util.h>
@@ -47,3 +48,17 @@ int putchar_unlocked(int c)
 {
 	return putchar(c);
 }
+
+#undef getc_unlocked
+int getc_unlocked(FILE *stream)
+{
+	ARG_UNUSED(stream);
+
+	return ENOSYS;
+}
+
+#undef getchar_unlocked
+int getchar_unlocked(void)
+{
+	return getc_unlocked(stdin);
+}
diff --git a/tests/posix/common/src/file_locking.c b/tests/posix/common/src/file_locking.c
@@ -13,6 +13,8 @@ int ftrylockfile(FILE *file);
 void funlockfile(FILE *file);
 int putc_unlocked(int c, FILE *file);
 int putchar_unlocked(int c);
+int getc_unlocked(FILE *stream);
+int getchar_unlocked(void);
 #endif
 
 #include <zephyr/sys/fdtable.h>
@@ -123,4 +125,15 @@ ZTEST(file_locking, test_stdio)
 	ret = putc_unlocked('T', stdout);
 	zassert_equal(ret, 84, "putc \'T\' failed");
 }
+
+/**
+ * @brief Existence test for the stubs, these function are not implemented and will simply return
+ * `ENOSYS`.
+ */
+ZTEST(file_locking, test_stubs)
+{
+	zassert_equal(getchar_unlocked(), ENOSYS);
+	zassert_equal(getc_unlocked(stdin), ENOSYS);
+}
+
 ZTEST_SUITE(file_locking, NULL, NULL, NULL, NULL, NULL);