Export bionic's execinfo functions to musl

Musl doesn't provide the execinfo function.  Export the from bionic.

Bug: 190084016
Test: m USE_HOST_MUSL=true host-native
Change-Id: I0361b84b0160d419cd857f5bb1314a58d0a69234

libc/Android.bp

@@ -2572,6 +2572,24 @@ cc_library_host_static {
             enabled: true,
         },
     },
+    stl: "none",
+}
+
+cc_library_host_static {
+    name: "libexecinfo",
+    visibility: ["//external/musl"],
+    srcs: ["bionic/execinfo.cpp"],
+    export_include_dirs: ["execinfo/include"],
+    local_include_dirs: ["private"],
+    enabled: false,
+    target: {
+        musl: {
+            enabled: true,
+            system_shared_libs: [],
+            header_libs: ["libc_musl_headers"],
+        },
+    },
+    stl: "none",
 }
 
 subdirs = [

libc/execinfo/include/bionic/execinfo.h

@@ -0,0 +1 @@
+../../../include/execinfo.h

libc/execinfo/include/execinfo.h

@@ -0,0 +1,37 @@
+/*
+ * Copyright (C) 2021 The Android Open Source Project
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *  * Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *  * Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#pragma once
+
+/*
+ * This file is exported as part of libexecinfo for use with musl, which doesn't
+ * define __INTRODUCED_IN.  Stub it out.
+ */
+#define __INTRODUCED_IN(x)
+#include <bionic/execinfo.h>
+#undef __INTRODUCED_IN

tests/Android.bp

@@ -474,9 +474,6 @@ cc_test_library {
                 // musl doesn't have error.h
                 "error_test.cpp",
 
-                // musl doesn't have execinfo.h
-                "execinfo_test.cpp",
-
                 // musl doesn't define noreturn for C++
                 "stdnoreturn_test.cpp",