Add dummy vndk library libmkbootimg to enable abi checks on boot_img_hdr.

Bug: 74763691

Test: m -j libmkbootimg creates libmkbootimg.so.lsdump.

Test: make -j64

Change-Id: I8d716c560467aaf090f4f7ee9cfbc53a9405f05d
(cherry picked from commit 4cc755dce527434dc4b79c1734185faeab084bac)

4 files changed, 98 insertions, 14 deletions

diff --git a/mkbootimg/Android.bp b/mkbootimg/Android.bp
new file mode 100644
index 000000000..b49434679
--- /dev/null
+++ b/mkbootimg/Android.bp
@@ -0,0 +1,32 @@
+// Copyright 2012 The Android Open Source Project
+
+cc_library_headers {
+    name: "libmkbootimg_abi_headers",
+    vendor_available: true,
+    export_include_dirs: ["include"],
+}
+
+cc_library_headers {
+    name: "bootimg_headers",
+    vendor_available: true,
+    export_include_dirs: ["include/bootimg"],
+    host_supported: true,
+    target: {
+        windows: {
+            enabled: true,
+        },
+    },
+}
+
+cc_library {
+    name: "libmkbootimg_abi_check",
+    vendor_available: true,
+    vndk: {
+        enabled: true,
+    },
+    srcs: [
+        "mkbootimg_dummy.cpp",
+    ],
+    header_libs: ["libmkbootimg_abi_headers"],
+    export_header_lib_headers: ["libmkbootimg_abi_headers"],
+}
diff --git a/mkbootimg/include/abi_check/mkbootimg_abi_check.h b/mkbootimg/include/abi_check/mkbootimg_abi_check.h
new file mode 100644
index 000000000..d478aba09
--- /dev/null
+++ b/mkbootimg/include/abi_check/mkbootimg_abi_check.h
@@ -0,0 +1,28 @@
+/*
+ * Copyright (C) 2018 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 <bootimg/bootimg.h>
+
+// This header has been created for the following reaons:
+//    1) In order for a change in a user defined type to be classified as API /
+//       ABI breaking, it needs to be referenced by an 'exported interface'
+//       (in this case the function mkbootimg_dummy).
+//    2) Since 'mkbootimg_dummy' needs to be exported, we need to have it
+//       exposed through a public header.
+//    3) It is desirable not to pollute bootimg.h with interfaces which are not
+//       'used' in reality by on device binaries. Furthermore, bootimg.h might
+//       be exported by a library in the future, so we must avoid polluting it.
+void mkbootimg_dummy(boot_img_hdr*);
diff --git a/mkbootimg/bootimg.h b/mkbootimg/include/bootimg/bootimg.h
index 1be8c229c..4311b46f9 100644
--- a/mkbootimg/bootimg.h
+++ b/mkbootimg/include/bootimg/bootimg.h
@@ -2,16 +2,16 @@
 **
 ** Copyright 2007, 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 
+** 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 
+**     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 
+** 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.
 */
 
@@ -34,17 +34,17 @@
 struct boot_img_hdr_v0 {
     uint8_t magic[BOOT_MAGIC_SIZE];
 
-    uint32_t kernel_size;  /* size in bytes */
-    uint32_t kernel_addr;  /* physical load addr */
+    uint32_t kernel_size; /* size in bytes */
+    uint32_t kernel_addr; /* physical load addr */
 
     uint32_t ramdisk_size; /* size in bytes */
     uint32_t ramdisk_addr; /* physical load addr */
 
-    uint32_t second_size;  /* size in bytes */
-    uint32_t second_addr;  /* physical load addr */
+    uint32_t second_size; /* size in bytes */
+    uint32_t second_addr; /* physical load addr */
 
-    uint32_t tags_addr;    /* physical addr for kernel tags */
-    uint32_t page_size;    /* flash page size we assume */
+    uint32_t tags_addr; /* physical addr for kernel tags */
+    uint32_t page_size; /* flash page size we assume */
     /*
      * version for the boot image header.
      */
diff --git a/mkbootimg/mkbootimg_dummy.cpp b/mkbootimg/mkbootimg_dummy.cpp
new file mode 100644
index 000000000..410d37909
--- /dev/null
+++ b/mkbootimg/mkbootimg_dummy.cpp
@@ -0,0 +1,24 @@
+/*
+ * Copyright (C) 2018 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 <abi_check/mkbootimg_abi_check.h>
+
+void mkbootimg_dummy(boot_img_hdr* hdr) {
+    // TODO: Hack to trigger abi checks, remove this.
+    if (hdr) {
+        hdr--;
+    }
+}