From 95c97833a68adeec55ffeed622d18056423d48b6 Mon Sep 17 00:00:00 2001
From: Damian Krolik <damian.krolik@nordicsemi.no>
Date: Thu, 19 Oct 2023 13:19:14 +0200
Subject: [PATCH] [nrfconnect] Do not link libCHIPShell.a with --whole-archive

libCHIPShell.a is already part of libCHIP.a but the former
had to be linked additionally with --whole-archive flag to
process the shell and init objects defined with SHELL_XXX
and SYS_INIT Zephyr macros and, in turn, register Matter
shell commands properly.

This symbol duplication between the two libraries causes
issues when building Matter with LTO, so replace the current
approach with explicitly pulling in one symbol from
MainLoopZephyr.cpp file.

Signed-off-by: Damian Krolik <damian.krolik@nordicsemi.no>
---
 config/nrfconnect/chip-module/CMakeLists.txt | 11 ++++++++++-
 src/lib/shell/MainLoopZephyr.cpp             |  4 ++--
 src/platform/Zephyr/SysHeapMalloc.cpp        |  4 ++--
 3 files changed, 14 insertions(+), 5 deletions(-)

diff --git a/config/nrfconnect/chip-module/CMakeLists.txt b/config/nrfconnect/chip-module/CMakeLists.txt
index 1de4545ca9..1ac044f566 100644
--- a/config/nrfconnect/chip-module/CMakeLists.txt
+++ b/config/nrfconnect/chip-module/CMakeLists.txt
@@ -184,7 +184,6 @@ matter_generate_args_tmp_file()
 # ==============================================================================
 
 matter_build(chip
-    LIB_SHELL   ${CONFIG_CHIP_LIB_SHELL}
     LIB_TESTS   ${CONFIG_CHIP_BUILD_TESTS}
     DEVICE_INFO_EXAMPLE_PROVIDER ${CONFIG_CHIP_EXAMPLE_DEVICE_INFO_PROVIDER}
     GN_DEPENDENCIES kernel
@@ -206,6 +205,16 @@ if (CONFIG_CHIP_MALLOC_SYS_HEAP_OVERRIDE)
     )
 endif()
 
+if (CONFIG_CHIP_LIB_SHELL)
+    # Force pulling chip::Shell::Engine::RunMainLoop() in the final binary.
+    # Without this workaround, the linker script does not process the shell and
+    # init objects defined in MainLoopZephyr.cpp unless the Matter library or
+    # the Matter shell library is linked using the '--whole-archive' flag.
+    target_link_options(chip INTERFACE
+        -Wl,-u,_ZN4chip5Shell6Engine11RunMainLoopEv
+    )
+endif()
+
 # ==============================================================================
 # Define 'chip-ota-image' target for building CHIP OTA image
 # ==============================================================================
diff --git a/src/lib/shell/MainLoopZephyr.cpp b/src/lib/shell/MainLoopZephyr.cpp
index 84fca4ef9d..108ed2e438 100644
--- a/src/lib/shell/MainLoopZephyr.cpp
+++ b/src/lib/shell/MainLoopZephyr.cpp
@@ -91,7 +91,7 @@ int ExecCommandInShellThread(const struct shell * shell, size_t argc, char ** ar
     return error == CHIP_NO_ERROR ? 0 : -ENOEXEC;
 }
 
-int RegisterCommands()
+int RegisterMatterCommands()
 {
     Shell::Engine::Root().RegisterDefaultCommands();
     return 0;
@@ -99,7 +99,7 @@ int RegisterCommands()
 
 } // namespace
 
-SYS_INIT(RegisterCommands, POST_KERNEL, CONFIG_KERNEL_INIT_PRIORITY_DEFAULT);
+SYS_INIT(RegisterMatterCommands, POST_KERNEL, CONFIG_KERNEL_INIT_PRIORITY_DEFAULT);
 SHELL_CMD_ARG_REGISTER(matter, NULL, "Matter commands", ExecCommandInShellThread, 1, CHIP_SHELL_MAX_TOKENS);
 
 namespace chip {
diff --git a/src/platform/Zephyr/SysHeapMalloc.cpp b/src/platform/Zephyr/SysHeapMalloc.cpp
index 4c944fae1e..fbd7ba09fc 100644
--- a/src/platform/Zephyr/SysHeapMalloc.cpp
+++ b/src/platform/Zephyr/SysHeapMalloc.cpp
@@ -64,7 +64,7 @@ LockGuard::~LockGuard()
     }
 }
 
-int initHeap()
+int InitSysHeapMalloc()
 {
     sys_heap_init(&sHeap, sHeapMemory, sizeof(sHeapMemory));
     return 0;
@@ -74,7 +74,7 @@ int initHeap()
 
 // Initialize the heap in the POST_KERNEL phase to make sure that it is ready even before
 // C++ static constructors are called (which happens prior to the APPLICATION initialization phase).
-SYS_INIT(initHeap, POST_KERNEL, CONFIG_KERNEL_INIT_PRIORITY_DEFAULT);
+SYS_INIT(InitSysHeapMalloc, POST_KERNEL, CONFIG_KERNEL_INIT_PRIORITY_DEFAULT);
 
 namespace chip {
 namespace DeviceLayer {