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(buff, 16,
21 "A simple string with no conversions.");
22 EXPECT_EQ(written, 36);
23 ASSERT_STREQ(buff, "A simple string");
24
25 written = LIBC_NAMESPACE::snprintf(buff, 5, "%s", "1234567890");
26 EXPECT_EQ(written, 10);
27 ASSERT_STREQ(buff, "1234");
28
29 written = LIBC_NAMESPACE::snprintf(buff, 67, "%-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(nullptr, 0, "%s and more", "1234567890");
43 EXPECT_EQ(written, 19);
44
45 written = LIBC_NAMESPACE::snprintf(nullptr, 0, "%*s", INT_MIN, "nothing");
46 EXPECT_EQ(written, INT_MAX);
47}
48
49TEST(LlvmLibcSNPrintfTest, NoCutOff) {
50 char buff[64];
51 int written;
52
53 written = LIBC_NAMESPACE::snprintf(buff, 37,
54 "A simple string with no conversions.");
55 EXPECT_EQ(written, 36);
56 ASSERT_STREQ(buff, "A simple string with no conversions.");
57
58 written = LIBC_NAMESPACE::snprintf(buff, 20, "%s", "1234567890");
59 EXPECT_EQ(written, 10);
60 ASSERT_STREQ(buff, "1234567890");
61}
62

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