xref: /aosp_15_r20/external/llvm-libc/test/src/stdio/snprintf_test.cpp (revision 71db0c75aadcf003ffe3238005f61d7618a3fead)
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 
TEST(LlvmLibcSNPrintfTest,CutOff)16 TEST(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 
TEST(LlvmLibcSNPrintfTest,NoCutOff)49 TEST(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