Restore ELF32_ST_INFO/ELF64_ST_INFO.

Mistakenly removed years ago, along with its genuinely duplicated companions.
This patch also redefines one of those rather than use the Linux uapi header
definition, which leads to signed/unsigned warnings in calling code.

Bug: https://github.com/android-ndk/ndk/issues/377
Test: ran tests
Change-Id: Ib25b17949f04969f12b945ca88ab87d080677cf9

libc/include/elf.h

@@ -184,6 +184,12 @@ typedef struct {
 
 #define PT_GNU_RELRO 0x6474e552
 
+#undef ELF_ST_TYPE
+#define ELF_ST_TYPE(x) ((x) & 0xf)
+#define ELF_ST_INFO(b,t) (((b) << 4) + ((t) & 0xf))
+#define ELF32_ST_INFO(b,t) ELF_ST_INFO(b,t)
+#define ELF64_ST_INFO(b,t) ELF_ST_INFO(b,t)
+
 #define STB_LOOS      10
 #define STB_HIOS      12
 #define STB_LOPROC    13

tests/Android.bp

@@ -58,6 +58,7 @@ cc_test_library {
         "complex_test.cpp",
         "ctype_test.cpp",
         "dirent_test.cpp",
+        "elf_test.cpp",
         "endian_test.cpp",
         "error_test.cpp",
         "eventfd_test.cpp",

tests/elf_test.cpp

@@ -0,0 +1,44 @@
+/*
+ * Copyright (C) 2017 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <elf.h>
+
+#include <gtest/gtest.h>
+
+// https://github.com/android-ndk/ndk/issues/377
+TEST(elf, have_ELF_ST_INFO_macros) {
+  uint8_t info;
+
+  // 0x0f
+  info = ELF32_ST_INFO(STB_LOCAL, STT_HIPROC);
+  ASSERT_EQ(STB_LOCAL, ELF32_ST_BIND(info));
+  ASSERT_EQ(STT_HIPROC, ELF32_ST_TYPE(info));
+
+  // 0x0f
+  info = ELF64_ST_INFO(STB_LOCAL, STT_HIPROC);
+  ASSERT_EQ(STB_LOCAL, ELF64_ST_BIND(info));
+  ASSERT_EQ(STT_HIPROC, ELF64_ST_TYPE(info));
+
+  // 0xf0
+  info = ELF32_ST_INFO(STB_LOCAL, STT_HIPROC);
+  ASSERT_EQ(STB_LOCAL, ELF32_ST_BIND(info));
+  ASSERT_EQ(STT_HIPROC, ELF32_ST_TYPE(info));
+
+  // 0xf0
+  info = ELF64_ST_INFO(STB_LOCAL, STT_HIPROC);
+  ASSERT_EQ(STB_LOCAL, ELF64_ST_BIND(info));
+  ASSERT_EQ(STT_HIPROC, ELF64_ST_TYPE(info));
+}