Add s390x cross build instructions

docs/en/development/build-cross-s390x.md

@@ -0,0 +1,123 @@
+---
+slug: /en/development/build-cross-s390x
+sidebar_position: 69
+title: How to Build, Run and Debug ClickHouse on Linux for s390x (zLinux)
+sidebar_label: Build on Linux for s390x (zLinux)
+---
+
+As of writing (2023/3/10) building for s390x considered to be experimental. Not all features can be enabled, has broken features and is currently under active development. 
+
+
+## Building
+
+As s390x does not support boringSSL, it uses openSSL and has two related build options. 
+- By default, the s390x build will create dynamiclly link to openSSL libraries. It will build openSSL, so its not neccessary to install openSSL beforehand. This is recommended in all cases.
+- Another option is to build openSSL in-tree. In this case two build options need to be supplied to cmake
+```bash
+-DENABLE_OPENSSL_DYNAMIC=0 -DENABLE_OPENSSL=1
+```
+
+These instructions assume that the host machine is x86_64 and has all the tooling required to build natively base based on the [Build instructions](../development/build.md). It also assumes that the host is Ubuntu 22.04 but should work on Ubuntu 20.04.
+
+In addition to installing the tooling used to build natively the following additional pacakges need to be installed:
+
+```bash
+apt-get install binutils-s390x-linux-gnu libc6-dev-s390x-cross gcc-s390x-linux-gnu binfmt-support qemu-user-static
+```
+
+If you wish to cross compile rust code..
+```bash
+rustup target add s390x-unknown-linux-gnu
+```
+
+To build for s390x, 
+```bash
+cmake -DCMAKE_TOOLCHAIN_FILE=cmake/linux/toolchain-s390x.cmake ..
+ninja
+```
+
+## Running
+
+Once built, the binary can be run with:
+
+```bash
+qemu-s390x-static -L /usr/s390x-linux-gnu ./clickhouse
+```
+
+## Debugging
+
+Install lldb:
+
+```bash
+apt-get install lldb-15
+```
+
+To Debug a s390x executable run clickhouse using qemu debug mode:
+
+```bash
+qemu-s390x-static -g 31338 -L /usr/s390x-linux-gnu ./clickhouse
+```
+
+In antother shell run lldb and attach, replace `<Clickhouse Parent Directory>` and `<build directory>` with the values corresponding to your environment.
+```bash
+lldb-15
+(lldb) target create ./clickhouse
+Current executable set to '/<Clickhouse Parent Directory>/ClickHouse/<build directory>/programs/clickhouse' (s390x).
+(lldb) settings set target.source-map <build directory> /<Clickhouse Parent Directory>/ClickHouse
+(lldb) gdb-remote 31338
+Process 1 stopped
+* thread #1, stop reason = signal SIGTRAP
+    frame #0: 0x0000004020e74cd0
+->  0x4020e74cd0: lgr    %r2, %r15
+    0x4020e74cd4: aghi   %r15, -160
+    0x4020e74cd8: xc     0(8,%r15), 0(%r15)
+    0x4020e74cde: brasl  %r14, 275429939040
+(lldb) b main
+Breakpoint 1: 9 locations.
+(lldb) c
+Process 1 resuming
+Process 1 stopped
+* thread #1, stop reason = breakpoint 1.1
+    frame #0: 0x0000004005cd9fc0 clickhouse`main(argc_=1, argv_=0x0000004020e594a8) at main.cpp:450:17
+   447  #if !defined(FUZZING_MODE)
+   448  int main(int argc_, char ** argv_)
+   449  {
+-> 450      inside_main = true;
+   451      SCOPE_EXIT({ inside_main = false; });
+   452
+   453      /// PHDR cache is required for query profiler to work reliably
+```
+
+## Visual Studio Code integration
+
+- (CodeLLDB extension)[https://github.com/vadimcn/vscode-lldb] is required for visual debugging, (Command Variable)[https://github.com/rioj7/command-variable] extension can help dynamic lauches if using cmake variants.
+- Make sure to set the backend to your llvm installation ex. `"lldb.library": "/usr/lib/x86_64-linux-gnu/liblldb-15.so"`
+- Launcher:
+```json
+{
+    "version": "0.2.0",
+    "configurations": [
+        {
+            "name": "Debug",
+            "type": "lldb",
+            "request": "custom",
+            "targetCreateCommands": ["target create ${command:cmake.launchTargetDirectory}/clickhouse"],
+            "processCreateCommands": ["settings set target.source-map ${input:targetdir} ${workspaceFolder}", "gdb-remote 31338"],
+            "sourceMap": { "${input:targetdir}": "${workspaceFolder}" },
+        }
+    ],
+	"inputs": [
+        {
+            "id": "targetdir",
+            "type": "command",
+            "command": "extension.commandvariable.transform",
+            "args": {
+                "text": "${command:cmake.launchTargetDirectory}",
+                "find": ".*/([^/]+)/[^/]+$",
+                "replace": "$1"
+            }
+        }
+    ]
+}
+```
+- Make sure to run the clickhouse executable in debug mode prior to launch. (It is possible to create a preLaunchTask that automates this)

docs/en/development/contrib.md

@@ -1,6 +1,6 @@
 ---
 slug: /en/development/contrib
-sidebar_position: 71
+sidebar_position: 72
 sidebar_label: Third-Party Libraries
 description: A list of third-party libraries used
 ---

docs/en/development/style.md

@@ -1,6 +1,6 @@
 ---
 slug: /en/development/style
-sidebar_position: 69
+sidebar_position: 70
 sidebar_label: C++ Guide
 description: A list of recommendations regarding coding style, naming convention, formatting and more
 ---

docs/en/development/tests.md

@@ -1,6 +1,6 @@
 ---
 slug: /en/development/tests
-sidebar_position: 70
+sidebar_position: 71
 sidebar_label: Testing
 title: ClickHouse Testing
 description: Most of ClickHouse features can be tested with functional tests and they are mandatory to use for every change in ClickHouse code that can be tested that way.