Snap for 8558685 from 9b8c5479211a1a1dc5d35d399f88344fd1f18610 to tm-frc-extservices-releaset_frc_ext_330443000android13-frc-extservices-release

Change-Id: I568c2fc532ae88cd7b3ae4565da9af0ffd5f4872

2 files changed, 50 insertions, 10 deletions

diff --git a/Android.bp b/Android.bp
index 8d298ab..13951ff 100644
--- a/Android.bp
+++ b/Android.bp
@@ -176,3 +176,30 @@ cc_fuzz {
         "src/cxa_demangle.cpp",
     ],
 }
+
+// Export libc++abi headers for inclusion in the musl sysroot.
+genrule {
+    name: "libc_musl_sysroot_libc++abi_headers",
+    visibility: ["//external/musl"],
+    srcs: [
+        "NOTICE",
+        "include/**/*",
+    ],
+    out: ["libc_musl_sysroot_libc++abi_headers.zip"],
+    tools: [
+        "soong_zip",
+        "zip2zip",
+    ],
+    cmd: "LIBCXXABI_DIR=$$(dirname $(location NOTICE)) && " +
+        "$(location soong_zip) -o $(genDir)/sysroot.zip -symlinks=false" +
+        // NOTICE
+        " -j -f $(location NOTICE) " +
+        // headers
+        " -P include/c++ " +
+        "  -C $${LIBCXXABI_DIR}/include " +
+        "  -D $${LIBCXXABI_DIR}/include " +
+        " && " +
+        "$(location zip2zip) -i $(genDir)/sysroot.zip -o $(out) " +
+        " include/**/*:include " +
+        " NOTICE:NOTICE.libc++abi",
+}
diff --git a/src/cxa_exception.cpp b/src/cxa_exception.cpp
index 8d30e5c..9e650b5 100644
--- a/src/cxa_exception.cpp
+++ b/src/cxa_exception.cpp
@@ -343,8 +343,11 @@ unwinding with _Unwind_Resume.
 According to ARM EHABI 8.4.1, __cxa_end_cleanup() should not clobber any
 register, thus we have to write this function in assembly so that we can save
 {r1, r2, r3}.  We don't have to save r0 because it is the return value and the
-first argument to _Unwind_Resume().  In addition, we are saving r4 in order to
-align the stack to 16 bytes, even though it is a callee-save register.
+first argument to _Unwind_Resume().  The function also saves/restores r4 to
+keep the stack aligned and to provide a temp register.  _Unwind_Resume never
+returns and we need to keep the original lr so just branch to it.  When
+targeting bare metal, the function also clobbers ip/r12 to hold the address of
+_Unwind_Resume, which may be too far away for an ordinary branch.
 */
 __attribute__((used)) static _Unwind_Exception *
 __cxa_end_cleanup_impl()
@@ -374,20 +377,30 @@ __cxa_end_cleanup_impl()
     return &exception_header->unwindHeader;
 }
 
-asm (
-    "	.pushsection	.text.__cxa_end_cleanup,\"ax\",%progbits\n"
+asm("	.pushsection	.text.__cxa_end_cleanup,\"ax\",%progbits\n"
     "	.globl	__cxa_end_cleanup\n"
     "	.type	__cxa_end_cleanup,%function\n"
     "__cxa_end_cleanup:\n"
+#if defined(__ARM_FEATURE_BTI_DEFAULT)
+    "	bti\n"
+#endif
     "	push	{r1, r2, r3, r4}\n"
+    "	mov	r4, lr\n"
     "	bl	__cxa_end_cleanup_impl\n"
+    "	mov	lr, r4\n"
+#if defined(LIBCXXABI_BAREMETAL)
+    "	ldr	r4,	=_Unwind_Resume\n"
+    "	mov	ip,	r4\n"
+#endif
     "	pop	{r1, r2, r3, r4}\n"
-    "	bl	_Unwind_Resume\n"
-    "	bl	abort\n"
-    "	.popsection"
-);
-#endif  // defined(_LIBCXXABI_ARM_EHABI)
-    
+#if defined(LIBCXXABI_BAREMETAL)
+    "	bx	ip\n"
+#else
+    "	b	_Unwind_Resume\n"
+#endif
+    "	.popsection");
+#endif // defined(_LIBCXXABI_ARM_EHABI)
+
 /*
 This routine can catch foreign or native exceptions.  If native, the exception
 can be a primary or dependent variety.  This routine may remain blissfully