diff --git a/libc/src/__support/CMakeLists.txt b/libc/src/__support/CMakeLists.txt --- a/libc/src/__support/CMakeLists.txt +++ b/libc/src/__support/CMakeLists.txt @@ -54,6 +54,12 @@ integer_operations.h ) +add_header_library( + vlist_holder + HDRS + vlist_holder.h +) + # Thread support is used by other support libraries. So, we add the "threads" # before other directories. add_subdirectory(threads) diff --git a/libc/src/__support/vlist_holder.h b/libc/src/__support/vlist_holder.h new file mode 100644 --- /dev/null +++ b/libc/src/__support/vlist_holder.h @@ -0,0 +1,31 @@ +//===-- Holder Class for manipulating va_lists ------------------*- C++ -*-===// +// +// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. +// See https://llvm.org/LICENSE.txt for license information. +// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception +// +//===----------------------------------------------------------------------===// + +#ifndef LLVM_LIBC_SRC_SUPPORT_VLIST_HOLDER_H +#define LLVM_LIBC_SRC_SUPPORT_VLIST_HOLDER_H + +#include + +namespace __llvm_libc { +namespace internal { + +class VListHolder { + va_list vlist; + +public: + VListHolder(va_list vlist) { va_copy(this->vlist, vlist); } + VListHolder(VListHolder &other) { va_copy(this->vlist, other.vlist); } + ~VListHolder() { va_end(this->vlist); } + + template T inline next_var() { return va_arg(vlist, T); } +}; + +} // namespace internal +} // namespace __llvm_libc + +#endif // LLVM_LIBC_SRC_SUPPORT_VLIST_HOLDER_H diff --git a/libc/test/src/__support/CMakeLists.txt b/libc/test/src/__support/CMakeLists.txt --- a/libc/test/src/__support/CMakeLists.txt +++ b/libc/test/src/__support/CMakeLists.txt @@ -30,6 +30,16 @@ libc.src.__support.str_to_float ) +add_libc_unittest( + vlist_holder_test + SUITE + libc_support_unittests + SRCS + vlist_holder_test.cpp + DEPENDS + libc.src.__support.vlist_holder +) + add_executable( libc_str_to_float_comparison_test str_to_float_comparison_test.cpp diff --git a/libc/test/src/__support/vlist_holder_test.cpp b/libc/test/src/__support/vlist_holder_test.cpp new file mode 100644 --- /dev/null +++ b/libc/test/src/__support/vlist_holder_test.cpp @@ -0,0 +1,58 @@ +//===-- Unittests for str_to_float ----------------------------------------===// +// +// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. +// See https://llvm.org/LICENSE.txt for license information. +// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception +// +//===----------------------------------------------------------------------===// + +#include "src/__support/vlist_holder.h" + +#include "utils/UnitTest/Test.h" + +int get_nth_int(int n, ...) { + va_list vlist; + va_start(vlist, n); + __llvm_libc::internal::VListHolder v(vlist); + va_end(vlist); + + for (int i = 0; i < n; ++i) { + v.next_var(); + } + return v.next_var(); +} + +TEST(LlvmLibcVListHolderTest, BasicUsage) { + ASSERT_EQ(get_nth_int(5, 0, 10, 20, 30, 40, 50, 60, 70, 80, 90), 50); +} + +int sum_two_nums(int first, int second, ...) { + va_list vlist; + va_start(vlist, second); + __llvm_libc::internal::VListHolder v1(vlist); + va_end(vlist); + + __llvm_libc::internal::VListHolder v2 = v1; + + int first_val; + for (int i = 0; i < first; ++i) { + v1.next_var(); + } + first_val = v1.next_var(); + + int second_val; + for (int i = 0; i < second; ++i) { + v2.next_var(); + } + second_val = v2.next_var(); + + return first_val + second_val; +} + +TEST(LlvmLibcVListHolderTest, CopyConstructor) { + ASSERT_EQ(sum_two_nums(3, 1, 1, 2, 4, 8, 16, 32, 64, 128, 256, 512, 1024), + 10); + + ASSERT_EQ(sum_two_nums(3, 5, 1, 2, 4, 8, 16, 32, 64, 128, 256, 512, 1024), + 40); +}