From c659bf11f9f23fd65159c71949677bcb31018616 Mon Sep 17 00:00:00 2001
From: Darley Barreto <darleybarreto@gmail.com>
Date: Tue, 9 May 2023 14:23:25 +0000
Subject: [PATCH] Implementing ungetwc
---
src/header/wchar/mod.rs | 21 ++++++++++++++++++---
tests/Makefile | 1 +
tests/wchar/ungetwc.c | 26 ++++++++++++++++++++++++++
tests/wchar/ungetwc.in | 1 +
4 files changed, 46 insertions(+), 3 deletions(-)
create mode 100644 tests/wchar/ungetwc.c
create mode 100644 tests/wchar/ungetwc.in
diff --git a/src/header/wchar/mod.rs b/src/header/wchar/mod.rs
index c947a4e4c..bf345e142 100644
--- a/src/header/wchar/mod.rs
+++ b/src/header/wchar/mod.rs
@@ -237,9 +237,24 @@ pub extern "C" fn swscanf(s: *const wchar_t, format: *const wchar_t, ap: va_list
unimplemented!();
}
-// #[no_mangle]
-pub extern "C" fn ungetwc(wc: wint_t, stream: *mut FILE) -> wint_t {
- unimplemented!();
+/// Push wide character `wc` back onto `stream` so it'll be read next
+#[no_mangle]
+pub unsafe extern "C" fn ungetwc(wc: wint_t, stream: &mut FILE) -> wint_t {
+ if wc == WEOF {
+ return wc;
+ }
+ static mut INTERNAL: mbstate_t = mbstate_t;
+ let mut bytes: [c_char; MB_CUR_MAX as usize] = [0; MB_CUR_MAX as usize];
+
+ let amount = wcrtomb(bytes.as_mut_ptr(), wc as wchar_t, &mut INTERNAL);
+ if amount == usize::MAX {
+ return WEOF;
+ }
+ for i in 0..amount {
+ ungetc(bytes[i] as c_int, &mut *stream);
+ }
+
+ wc
}
// #[no_mangle]
diff --git a/tests/Makefile b/tests/Makefile
index 84d51f740..e3295ba65 100644
--- a/tests/Makefile
+++ b/tests/Makefile
@@ -43,6 +43,7 @@ EXPECT_NAMES=\
stdio/printf_space_pad \
stdio/ungetc_ftell \
stdio/ungetc_multiple \
+ stdio/ungetwc \
stdio/fscanf_offby1 \
stdio/fscanf \
stdio/printf_neg_pad \
diff --git a/tests/wchar/ungetwc.c b/tests/wchar/ungetwc.c
new file mode 100644
index 000000000..015ba174e
--- /dev/null
+++ b/tests/wchar/ungetwc.c
@@ -0,0 +1,26 @@
+#include <wchar.h>
+#include <wctype.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <assert.h>
+
+int main()
+{
+ FILE *stream;
+ wint_t wc;
+ wint_t wc2;
+
+ if (NULL == (stream = fopen("wchar/ungetwc.in", "r+")))
+ return 1;
+
+ while (WEOF != (wc = fgetwc(stream)) && iswdigit(wc)) {}
+
+ if (WEOF != wc)
+ ungetwc(wc, stream);
+
+ wc2 = fgetwc(stream);
+ assert(WEOF != wc2);
+ assert(wc == wc2);
+
+ return 0;
+}
\ No newline at end of file
diff --git a/tests/wchar/ungetwc.in b/tests/wchar/ungetwc.in
new file mode 100644
index 000000000..5e6162a56
--- /dev/null
+++ b/tests/wchar/ungetwc.in
@@ -0,0 +1 @@
+123A
\ No newline at end of file
--
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