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SR-2309: embed BlocksRuntime in libdispatch to eliminate external dependency
Eliminate the external dependency on libBlocksRuntime.so by copying the blocks runtime code from swift-corelibs-foundation/closure and building it into libdispatch. Added a configure option to control whether or not the blocks runtime is embedded; defaults to embedded on Linux and not embedded on other platforms. Since the blocks runtime is embedded; we can take the link directive out of the module.modulemap file. This change enables dispatch to be built and run on a system without the libblocksruntime-dev package installed.
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8 files changed

+1162
-44
lines changed

8 files changed

+1162
-44
lines changed

‎dispatch/module.modulemap

Lines changed: 0 additions & 2 deletions
Original file line numberDiff line numberDiff line change
@@ -2,7 +2,6 @@ module Dispatch {
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requires blocks
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export *
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link "dispatch"
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link "BlocksRuntime"
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}
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module DispatchIntrospection [system] [extern_c] {
@@ -16,5 +15,4 @@ module CDispatch [system] [extern_c] {
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export *
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requires blocks
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link "dispatch"
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link "BlocksRuntime"
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}

‎m4/blocks.m4

Lines changed: 62 additions & 42 deletions
Original file line numberDiff line numberDiff line change
@@ -10,6 +10,21 @@ AC_ARG_WITH([blocks-runtime],
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LIBS="$LIBS -L$blocks_runtime"]
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)
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#
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# Configure argument to enable/disable using an embedded blocks runtime
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#
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AC_ARG_ENABLE([embedded_blocks_runtime],
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[AS_HELP_STRING([--enable_embedded_blocks_runtime],
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[Enable usage of blocks runtime embedded in libdispatch])],,
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[case $target_os in
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linux*)
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enable_embedded_blocks_runtime=yes
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;;
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*)
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enable_embedded_blocks_runtime=no
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esac]
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)
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#
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# Detect compiler support for Blocks; perhaps someday -fblocks won't be
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# required, in which case we'll need to change this.
@@ -29,30 +44,32 @@ AC_CACHE_CHECK([for C Blocks support], [dispatch_cv_cblocks], [
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AS_IF([test "x$dispatch_cv_cblocks" != "xno"], [
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CBLOCKS_FLAGS="$dispatch_cv_cblocks"
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#
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# It may be necessary to directly link the Blocks runtime on some
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# systems, so give it a try if we can't link a C program that uses
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# Blocks. We will want to remove this at somepoint, as really -fblocks
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# should force that linkage already.
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#
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saveCFLAGS="$CFLAGS"
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CFLAGS="$CFLAGS -fblocks -O0"
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AC_MSG_CHECKING([whether additional libraries are required for the Blocks runtime])
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AC_TRY_LINK([], [
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^{ int j; j=0; }();
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], [
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AC_MSG_RESULT([no]);
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], [
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saveLIBS="$LIBS"
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LIBS="$LIBS -lBlocksRuntime"
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AC_TRY_LINK([], [
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^{ int k; k=0; }();
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], [
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AC_MSG_RESULT([-lBlocksRuntime])
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], [
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AC_MSG_ERROR([can't find Blocks runtime])
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])
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])
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AS_IF([test "x$enable_embedded_blocks_runtime" != "xyes"], [
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#
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# It may be necessary to directly link the Blocks runtime on some
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# systems, so give it a try if we can't link a C program that uses
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# Blocks. We will want to remove this at somepoint, as really -fblocks
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# should force that linkage already.
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#
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saveCFLAGS="$CFLAGS"
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CFLAGS="$CFLAGS -fblocks -O0"
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AC_MSG_CHECKING([whether additional libraries are required for the Blocks runtime])
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AC_TRY_LINK([], [
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^{ int j; j=0; }();
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], [
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AC_MSG_RESULT([no]);
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], [
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saveLIBS="$LIBS"
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LIBS="$LIBS -lBlocksRuntime"
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AC_TRY_LINK([], [
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^{ int k; k=0; }();
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], [
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AC_MSG_RESULT([-lBlocksRuntime])
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], [
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AC_MSG_ERROR([can't find Blocks runtime])
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])
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])
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])
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CFLAGS="$saveCFLAGS"
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have_cblocks=true
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], [
@@ -61,6 +78,7 @@ AS_IF([test "x$dispatch_cv_cblocks" != "xno"], [
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])
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AM_CONDITIONAL(HAVE_CBLOCKS, $have_cblocks)
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AC_SUBST([CBLOCKS_FLAGS])
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AM_CONDITIONAL([BUILD_OWN_BLOCKS_RUNTIME], [test "x$enable_embedded_blocks_runtime" = "xyes"])
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#
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# Because a different C++ compiler may be specified than C compiler, we have
@@ -82,24 +100,26 @@ AC_CACHE_CHECK([for C++ Blocks support], [dispatch_cv_cxxblocks], [
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AS_IF([test "x$dispatch_cv_cxxblocks" != "xno"], [
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CXXBLOCKS_FLAGS="$dispatch_cv_cxxblocks"
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saveCXXFLAGS="$CXXFLAGS"
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CXXFLAGS="$CXXFLAGS -fblocks -O0"
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AC_MSG_CHECKING([whether additional libraries are required for the Blocks runtime])
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AC_TRY_LINK([], [
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^{ int j; j=0; }();
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], [
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AC_MSG_RESULT([no]);
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], [
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saveLIBS="$LIBS"
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LIBS="$LIBS -lBlocksRuntime"
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AC_TRY_LINK([], [
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^{ int k; k=0; }();
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], [
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AC_MSG_RESULT([-lBlocksRuntime])
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], [
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AC_MSG_ERROR([can't find Blocks runtime])
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])
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])
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AS_IF([test "x$enable_embedded_blocks_runtime" != "xyes"], [
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saveCXXFLAGS="$CXXFLAGS"
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CXXFLAGS="$CXXFLAGS -fblocks -O0"
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AC_MSG_CHECKING([whether additional libraries are required for the Blocks runtime])
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AC_TRY_LINK([], [
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^{ int j; j=0; }();
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], [
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AC_MSG_RESULT([no]);
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], [
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saveLIBS="$LIBS"
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LIBS="$LIBS -lBlocksRuntime"
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AC_TRY_LINK([], [
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^{ int k; k=0; }();
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], [
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AC_MSG_RESULT([-lBlocksRuntime])
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], [
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AC_MSG_ERROR([can't find Blocks runtime])
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])
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])
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])
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CXXFLAGS="$saveCXXFLAGS"
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have_cxxblocks=true
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], [

‎src/BlocksRuntime/Block.h

Lines changed: 54 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,54 @@
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// This source file is part of the Swift.org open source project
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//
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// Copyright (c) 2014 - 2015 Apple Inc. and the Swift project authors
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// Licensed under Apache License v2.0 with Runtime Library Exception
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//
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// See http://swift.org/LICENSE.txt for license information
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// See http://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
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//
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#ifndef _Block_H_
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#define _Block_H_
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#if !defined(BLOCK_EXPORT)
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# if defined(__cplusplus)
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# define BLOCK_EXPORT extern "C" __attribute__((visibility("default")))
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# else
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# define BLOCK_EXPORT extern __attribute__((visibility("default")))
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# endif
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#endif
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#if __cplusplus
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extern "C" {
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#endif
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// Create a heap based copy of a Block or simply add a reference to an existing one.
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// This must be paired with Block_release to recover memory, even when running
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// under Objective-C Garbage Collection.
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BLOCK_EXPORT void *_Block_copy(const void *aBlock);
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// Lose the reference, and if heap based and last reference, recover the memory
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BLOCK_EXPORT void _Block_release(const void *aBlock);
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// Used by the compiler. Do not call this function yourself.
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BLOCK_EXPORT void _Block_object_assign(void *, const void *, const int);
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// Used by the compiler. Do not call this function yourself.
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BLOCK_EXPORT void _Block_object_dispose(const void *, const int);
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// Used by the compiler. Do not use these variables yourself.
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BLOCK_EXPORT void * _NSConcreteGlobalBlock[32];
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BLOCK_EXPORT void * _NSConcreteStackBlock[32];
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44+
#if __cplusplus
45+
}
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#endif
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48+
// Type correct macros
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50+
#define Block_copy(...) ((__typeof(__VA_ARGS__))_Block_copy((const void *)(__VA_ARGS__)))
51+
#define Block_release(...) _Block_release((const void *)(__VA_ARGS__))
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#endif

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