test: Add test for fgetc when reading from a non readable stream

For more details according to the test case,
see this discussion: picolibc#717

Signed-off-by: Mohamed Moawad <[email protected]>

Author: M-Moawad

test/meson.build

@@ -533,7 +533,7 @@ foreach target : targets
 
     # legacy stdio doesn't work on semihosting, so just skip it
     if tinystdio
-      plain_tests += ['test-fopen', 'test-mktemp', 'test-tmpnam', 'test-fread-fwrite', 'test-ungetc-ftell']
+      plain_tests += ['test-fopen', 'test-mktemp', 'test-tmpnam', 'test-fread-fwrite', 'test-ungetc-ftell', 'test-fgetc']
     endif
   endif
 

test/test-fgetc.c

@@ -0,0 +1,80 @@
+/*
+ * SPDX-License-Identifier: BSD-3-Clause
+ *
+ * Copyright © 2024, Synopsys Inc.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above
+ *    copyright notice, this list of conditions and the following
+ *    disclaimer in the documentation and/or other materials provided
+ *    with the distribution.
+ *
+ * 3. Neither the name of the copyright holder nor the names of its
+ *    contributors may be used to endorse or promote products derived
+ *    from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
+ * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
+ * OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+#define _DEFAULT_SOURCE
+#include <stdio.h>
+#include <stdlib.h>
+
+#ifndef TEST_FILE_NAME
+#define TEST_FILE_NAME "FGETC.TXT"
+#endif
+
+#define check(condition, message) do {                  \
+        if (!(condition)) {                             \
+            printf("%s: %s\n", message, #condition);    \
+            if (f)                                      \
+                fclose(f);                              \
+            (void) remove(TEST_FILE_NAME);              \
+            exit(1);                                    \
+        }                                               \
+    } while(0)
+
+
+int
+main(void)
+{
+    FILE *f;
+    int ch;
+
+    /* Make sure we can create a file */
+    f = fopen(TEST_FILE_NAME, "w");
+    check(f != NULL, "Error opening file");
+
+    // Get error indicator before reading
+    check(ferror(f) == 0, "Error occured before reading");
+
+    // Attempt to read from the file
+    ch = fgetc(f);
+    check(ch == EOF, "fgetc returns non EOF");
+
+    // Get error indicator after reading
+    check(ferror(f) != 0, "After reading from non readable stream, the error flag of straem f is not set");
+
+    // Close the file
+    fclose(f);
+
+    (void) remove(TEST_FILE_NAME);
+
+    exit(0);
+}