CMake-based build system tracking issue

[hebasto]

This issue will be updated to reflect the current state of CMake integration.

A brief historical context:

1. build: Add CMake-based build system #25797 proposed a CMake-based build system with 100% feature parity to the Autotools-based one.
2. The reviewing process is happening in this repo as suggested in build: Add CMake-based build system (1 of N) #27060 (comment).
3. The recent discussion at CoreDev -- https://btctranscripts.com/bitcoin-core-dev-tech/2023-09/cmake/

How reviewing happens:

1. Pull requests are opened against the https://github.com/hebasto/bitcoin/tree/cmake-staging branch.
2. After reviewing and merging them, the staging branch get synced with the main branch from this repo.
3. This loop continues until all commits from build: Add CMake-based build system #25797 get reviewed.

The planned chunks of work:

• The root CMakeLists.txt and config/bitcoin-config.h files -- build: Add CMake-based build system (1 of N) hebasto/bitcoin#5
• Project-wide system introspections; the leveldb build target -- build: Add CMake-based build system (2 of N)  hebasto/bitcoin#6
• The bitcoind build target -- build: Add CMake-based build system (3 of N) hebasto/bitcoin#7
• Cross-compiling support -- build: Add CMake-based build system (4 of N) hebasto/bitcoin#10
• Ccache support; libnatpmp, libminiupnpc, libzmq and systemtap-sdt optional packages support -- build: Add CMake-based build system (5 of N) hebasto/bitcoin#13
• Utility binaries, wallet functionality, bench_bitcoin and test_bitcoin -- build: Add CMake-based build system (6 of N) hebasto/bitcoin#15
• Handling different build configurations -- build: Add CMake-based build system (8 of N) hebasto/bitcoin#18
• Hardening, shared libraries -- cmake: Add hardening, reduce exports, werror and install hebasto/bitcoin#32
• Build libbitcoinconsensus library -- cmake: Build libbitcoinconsensus library hebasto/bitcoin#41 See RFC: Deprecate libconsensus #29189
• Qt stuff -- cmake: Build bitcoin-qt executable hebasto/bitcoin#77
• Guix builds -- cmake: Migrate Guix build scripts to CMake hebasto/bitcoin#67
• Building for fuzzing -- cmake: Add fuzzing facilities hebasto/bitcoin#43
• multiprocess support -- cmake: Add MULTIPROCESS option hebasto/bitcoin#118
• libbitcoin-kernel and bitcoin-chainstate -- cmake: Build libbitcoinkernel and bitcoin-chainstate hebasto/bitcoin#134
• CI stuff -- ci: Migrate CI scripts to CMake hebasto/bitcoin#142
• Building for Android See build, test, doc: Temporarily remove Android-related stuff #30049

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The current minimum required CMake version is 3.13, which is the system package on Debian 10. Considering the timings of Debian 10 LTS EOL and integrating CMake into this repo, it seems reasonable to bump the minimum supported version up to 3.16, which is the system package on Ubuntu 20.04 LTS.

• Bump minimum supported CMake version from 3.13 up to 3.16 -- Bump minimum CMake version up to 3.16 hebasto/bitcoin#33

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To hold the 100% feature parity, the current CMake-based build system implementation can autodetect an optional package and enable it as Autotools-based one does. However, it was suggested to make all optional package opt-in by default. See:

• build: Add CMake-based build system (5 of N)  hebasto/bitcoin#12 (comment)

• build: Add CMake-based build system (5 of N)  hebasto/bitcoin#12 (comment)

• build: Add CMake-based build system (5 of N) hebasto/bitcoin#13 (comment)

• Make all optional package opt-in by default

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Autotools vs CMake Feature Parity Table is available here.

To list CMake's options, one might add the -LH option during configuring step.

---

Updated build docs:

• Building Bitcoin Core with Visual Studio

[hebasto]

cc @theuni @TheCharlatan

[maflcko]

The current minimum required CMake version is 3.13, which is the system package on Debian 10. Considering the timings of Debian 10 LTS EOL and integrating CMake into this repo, it seems reasonable to bump the minimum supported version up to 3.16, which is the system package on Ubuntu 20.04 LTS.

Buster Backports has 3.18: https://packages.debian.org/buster-backports/cmake

[maflcko]

Also, on a general note, it would be good to have a "cheat sheet" table for each configure option to list the corresponding cmake option. Maybe also one auto-generated and enforced with a script, to check equality, similar to curl/curl#11964

[hebasto]

Also, on a general note, it would be good to have a "cheat sheet" table for each configure option to list the corresponding cmake option. Maybe also one auto-generated and enforced with a script, to check equality, similar to curl/curl#11964

Thanks! It is available here. It has been added to the top post.

[hebasto]

The next PR to review is hebasto#32.

[hebasto]

The current minimum required CMake version is 3.13, which is the system package on Debian 10. Considering the timings of Debian 10 LTS EOL and integrating CMake into this repo, it seems reasonable to bump the minimum supported version up to 3.16, which is the system package on Ubuntu 20.04 LTS.

Buster Backports has 3.18: packages.debian.org/buster-backports/cmake

The CMake minimum required version has been bumped up to 3.16 in hebasto#33.

[ajtowns]

libbitcoin-kernel and bitcoin-chainstate should be on this list too?

[hebasto]

libbitcoin-kernel and bitcoin-chainstate should be on this list too?

Sure. Added.

[hebasto]

The new Building Bitcoin Core with Visual Studio doc has been added to the issue description.

[paulocoutinhox]

+1

[hebasto]

Heads up: here are suggestions regarding the current features that are not expected being ported to the CMake-based build system:

• build: remove --enable-lto #29185
• RFC: Deprecate libconsensus #29189
• build: Drop ALLOW_HOST_PACKAGES support in depends #29203