1//===-- Unittests for snprintf --------------------------------------------===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8
9#include "src/stdio/snprintf.h"
10
11#include "test/UnitTest/Test.h"
12
13// The sprintf test cases cover testing the shared printf functionality, so
14// these tests will focus on snprintf exclusive features.
15
16TEST(LlvmLibcSNPrintfTest, CutOff) {
17 char buff[100];
18 int written;
19
20 written = LIBC_NAMESPACE::snprintf(buffer: buff, buffsz: 16,
21 format: "A simple string with no conversions.");
22 EXPECT_EQ(written, 36);
23 ASSERT_STREQ(buff, "A simple string");
24
25 written = LIBC_NAMESPACE::snprintf(buffer: buff, buffsz: 5, format: "%s", "1234567890");
26 EXPECT_EQ(written, 10);
27 ASSERT_STREQ(buff, "1234");
28
29 written = LIBC_NAMESPACE::snprintf(buffer: buff, buffsz: 67, format: "%-101c", 'a');
30 EXPECT_EQ(written, 101);
31 ASSERT_STREQ(buff, "a "
32 " " // Each of these is 8 spaces, and there are 8.
33 " " // In total there are 65 spaces
34 " " // 'a' + 65 spaces + '\0' = 67
35 " "
36 " "
37 " "
38 " "
39 " ");
40
41 // passing null as the output pointer is allowed as long as buffsz is 0.
42 written = LIBC_NAMESPACE::snprintf(buffer: nullptr, buffsz: 0, format: "%s and more", "1234567890");
43 EXPECT_EQ(written, 19);
44}
45
46TEST(LlvmLibcSNPrintfTest, NoCutOff) {
47 char buff[64];
48 int written;
49
50 written = LIBC_NAMESPACE::snprintf(buffer: buff, buffsz: 37,
51 format: "A simple string with no conversions.");
52 EXPECT_EQ(written, 36);
53 ASSERT_STREQ(buff, "A simple string with no conversions.");
54
55 written = LIBC_NAMESPACE::snprintf(buffer: buff, buffsz: 20, format: "%s", "1234567890");
56 EXPECT_EQ(written, 10);
57 ASSERT_STREQ(buff, "1234567890");
58}
59

source code of libc/test/src/stdio/snprintf_test.cpp