[lib++][print] Don't pad the ostream output. #128354
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Per [ostream.formatted.reqmts]/3 padding should only be done when explicitly stated. Fixes: llvm#116054
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@llvm/pr-subscribers-libcxx Author: Mark de Wever (mordante) ChangesPer [ostream.formatted.reqmts]/3 padding should only be done when explicitly stated. Fixes: #116054 Full diff: https://github.com/llvm/llvm-project/pull/128354.diff 4 Files Affected:
diff --git a/libcxx/include/__ostream/print.h b/libcxx/include/__ostream/print.h
index eb4233342214d..a4d7506cffc48 100644
--- a/libcxx/include/__ostream/print.h
+++ b/libcxx/include/__ostream/print.h
@@ -49,21 +49,11 @@ __vprint_nonunicode(ostream& __os, string_view __fmt, format_args __args, bool _
if (__write_nl)
__o += '\n';
- const char* __str = __o.data();
- size_t __len = __o.size();
-
# if _LIBCPP_HAS_EXCEPTIONS
try {
# endif // _LIBCPP_HAS_EXCEPTIONS
- typedef ostreambuf_iterator<char> _Ip;
- if (std::__pad_and_output(
- _Ip(__os),
- __str,
- (__os.flags() & ios_base::adjustfield) == ios_base::left ? __str + __len : __str,
- __str + __len,
- __os,
- __os.fill())
- .failed())
+ if (auto __rdbuf = __os.rdbuf();
+ !__rdbuf || __rdbuf->sputn(__o.data(), __o.size()) != static_cast<streamsize>(__o.size()))
__os.setstate(ios_base::badbit | ios_base::failbit);
# if _LIBCPP_HAS_EXCEPTIONS
diff --git a/libcxx/test/std/input.output/iostream.format/output.streams/ostream.formatted/ostream.formatted.print/print.pass.cpp b/libcxx/test/std/input.output/iostream.format/output.streams/ostream.formatted/ostream.formatted.print/print.pass.cpp
index 711152ba6f32a..1f188b36db9a3 100644
--- a/libcxx/test/std/input.output/iostream.format/output.streams/ostream.formatted/ostream.formatted.print/print.pass.cpp
+++ b/libcxx/test/std/input.output/iostream.format/output.streams/ostream.formatted/ostream.formatted.print/print.pass.cpp
@@ -133,6 +133,7 @@ static void test_write_failure() {
assert(os.fail());
}
+// Test the formatting does no padding.
static void test_stream_formatting() {
std::stringstream sstr;
auto test = [&]<class... Args>(std::string_view expected, test_format_string<char, Args...> fmt, Args&&... args) {
@@ -148,37 +149,20 @@ static void test_stream_formatting() {
test("hello", "{}", "hello");
sstr.width(10);
- test(" hello", "{}", "hello");
+ test("hello", "{}", "hello");
+ assert(sstr.width() == 10);
sstr.fill('+');
sstr.width(10);
- test("+++++hello", "{}", "hello");
+ test("hello", "{}", "hello");
+ assert(sstr.width() == 10);
// *** Test embedded NUL character ***
using namespace std::literals;
sstr.width(15);
- test("++++hello\0world"sv, "hello{}{}", '\0', "world");
-
- // *** Test Unicode ***
- // Streams count code units not code points
- // 2-byte code points
- sstr.width(5);
- test("+++\u00a1", "{}", "\u00a1"); // INVERTED EXCLAMATION MARK
- sstr.width(5);
- test("+++\u07ff", "{}", "\u07ff"); // NKO TAMAN SIGN
-
- // 3-byte code points
- sstr.width(5);
- test("++\u0800", "{}", "\u0800"); // SAMARITAN LETTER ALAF
- sstr.width(5);
- test("++\ufffd", "{}", "\ufffd"); // REPLACEMENT CHARACTER
-
- // 4-byte code points
- sstr.width(5);
- test("+\U00010000", "{}", "\U00010000"); // LINEAR B SYLLABLE B008 A
- sstr.width(5);
- test("+\U0010FFFF", "{}", "\U0010FFFF"); // Undefined Character
+ test("hello\0world"sv, "hello{}{}", '\0', "world");
+ assert(sstr.width() == 15);
}
int main(int, char**) {
diff --git a/libcxx/test/std/input.output/iostream.format/output.streams/ostream.formatted/ostream.formatted.print/vprint_nonunicode.pass.cpp b/libcxx/test/std/input.output/iostream.format/output.streams/ostream.formatted/ostream.formatted.print/vprint_nonunicode.pass.cpp
index 73ad19132f17f..7aa7390216adc 100644
--- a/libcxx/test/std/input.output/iostream.format/output.streams/ostream.formatted/ostream.formatted.print/vprint_nonunicode.pass.cpp
+++ b/libcxx/test/std/input.output/iostream.format/output.streams/ostream.formatted/ostream.formatted.print/vprint_nonunicode.pass.cpp
@@ -149,6 +149,7 @@ static void test_write_failure() {
assert(os.fail());
}
+// Test the formatting does no padding.
static void test_stream_formatting() {
std::stringstream sstr;
auto test = [&]<class... Args>(std::string_view expected, test_format_string<char, Args...> fmt, Args&&... args) {
@@ -164,37 +165,20 @@ static void test_stream_formatting() {
test("hello", "{}", "hello");
sstr.width(10);
- test(" hello", "{}", "hello");
+ test("hello", "{}", "hello");
+ assert(sstr.width() == 10);
sstr.fill('+');
sstr.width(10);
- test("+++++hello", "{}", "hello");
+ test("hello", "{}", "hello");
+ assert(sstr.width() == 10);
// *** Test embedded NUL character ***
using namespace std::literals;
sstr.width(15);
- test("++++hello\0world"sv, "hello{}{}", '\0', "world");
-
- // *** Test Unicode ***
- // Streams count code units not code points
- // 2-byte code points
- sstr.width(5);
- test("+++\u00a1", "{}", "\u00a1"); // INVERTED EXCLAMATION MARK
- sstr.width(5);
- test("+++\u07ff", "{}", "\u07ff"); // NKO TAMAN SIGN
-
- // 3-byte code points
- sstr.width(5);
- test("++\u0800", "{}", "\u0800"); // SAMARITAN LETTER ALAF
- sstr.width(5);
- test("++\ufffd", "{}", "\ufffd"); // REPLACEMENT CHARACTER
-
- // 4-byte code points
- sstr.width(5);
- test("+\U00010000", "{}", "\U00010000"); // LINEAR B SYLLABLE B008 A
- sstr.width(5);
- test("+\U0010FFFF", "{}", "\U0010FFFF"); // Undefined Character
+ test("hello\0world"sv, "hello{}{}", '\0', "world");
+ assert(sstr.width() == 15);
}
int main(int, char**) {
diff --git a/libcxx/test/std/input.output/iostream.format/output.streams/ostream.formatted/ostream.formatted.print/vprint_unicode.pass.cpp b/libcxx/test/std/input.output/iostream.format/output.streams/ostream.formatted/ostream.formatted.print/vprint_unicode.pass.cpp
index 21f6654d5f9cf..8b43a71215ade 100644
--- a/libcxx/test/std/input.output/iostream.format/output.streams/ostream.formatted/ostream.formatted.print/vprint_unicode.pass.cpp
+++ b/libcxx/test/std/input.output/iostream.format/output.streams/ostream.formatted/ostream.formatted.print/vprint_unicode.pass.cpp
@@ -149,6 +149,7 @@ static void test_write_failure() {
assert(os.fail());
}
+// Test the formatting does no padding.
static void test_stream_formatting() {
std::stringstream sstr;
auto test = [&]<class... Args>(std::string_view expected, test_format_string<char, Args...> fmt, Args&&... args) {
@@ -164,37 +165,20 @@ static void test_stream_formatting() {
test("hello", "{}", "hello");
sstr.width(10);
- test(" hello", "{}", "hello");
+ test("hello", "{}", "hello");
+ assert(sstr.width() == 10);
sstr.fill('+');
sstr.width(10);
- test("+++++hello", "{}", "hello");
+ test("hello", "{}", "hello");
+ assert(sstr.width() == 10);
// *** Test embedded NUL character ***
using namespace std::literals;
sstr.width(15);
- test("++++hello\0world"sv, "hello{}{}", '\0', "world");
-
- // *** Test Unicode ***
- // Streams count code units not code points
- // 2-byte code points
- sstr.width(5);
- test("+++\u00a1", "{}", "\u00a1"); // INVERTED EXCLAMATION MARK
- sstr.width(5);
- test("+++\u07ff", "{}", "\u07ff"); // NKO TAMAN SIGN
-
- // 3-byte code points
- sstr.width(5);
- test("++\u0800", "{}", "\u0800"); // SAMARITAN LETTER ALAF
- sstr.width(5);
- test("++\ufffd", "{}", "\ufffd"); // REPLACEMENT CHARACTER
-
- // 4-byte code points
- sstr.width(5);
- test("+\U00010000", "{}", "\U00010000"); // LINEAR B SYLLABLE B008 A
- sstr.width(5);
- test("+\U0010FFFF", "{}", "\U0010FFFF"); // Undefined Character
+ test("hello\0world"sv, "hello{}{}", '\0', "world");
+ assert(sstr.width() == 15);
}
int main(int, char**) {
|
ldionne
approved these changes
Feb 25, 2025
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Per [ostream.formatted.reqmts]/3 padding should only be done when explicitly stated.
Fixes: #116054