cmake: Improve build script correctness #31357

1. 
   hebasto commented at 3:38 pm on November 23, 2024: member

   When no build targets are specified, it is reasonable to expect the configuration step to succeed and produce a build system that does not build any targets.

   This PR updates the code to ensure this behaviour:

   0$ cmake -B build -G "Ninja" -DBUILD_DAEMON=OFF -DBUILD_CLI=OFF -DBUILD_TX=OFF -DBUILD_UTIL=OFF -DENABLE_WALLET=OFF -DBUILD_TESTS=OFF
   1$ cmake --build build
   2ninja: no work to do.
   

2. cmake: Ensure script correctness when no targets are specified 76a3a540a4
3. cmake: Build `secp256k1` only when required ab5c63edcc
4. hebasto added the label Build system on Nov 23, 2024
5. 
   DrahtBot commented at 3:39 pm on November 23, 2024: contributor

   The following sections might be updated with supplementary metadata relevant to reviewers and maintainers.

   Code Coverage & Benchmarks

   For details see: https://corecheck.dev/bitcoin/bitcoin/pulls/31357.

   Reviews

   See the guideline for information on the review process.

   Type	Reviewers
   ACK	TheCharlatan, tdb3

   If your review is incorrectly listed, please react with 👎 to this comment and the bot will ignore it on the next update.

6. 
   hebasto commented at 3:40 pm on November 23, 2024: member

   When no build targets are specified, it is reasonable to expect the configuration step to succeed…

   The issue was reported offline by @TheCharlatan.

7. TheCharlatan approved
8. 
   TheCharlatan commented at 3:55 pm on November 23, 2024: contributor

   ACK ab5c63edccea7957e2c7b3b9d8b04655a7f82f22
9. tdb3 approved
10. 
    tdb3 commented at 2:14 am on November 30, 2024: contributor

    light test ACK ab5c63edccea7957e2c7b3b9d8b04655a7f82f22

    On master (dbc8ba12f3b3548dd6955293c5d650320ca39c5b):

    Native (Make)

     0$ cmake -B build -DBUILD_DAEMON=OFF -DBUILD_CLI=OFF -DBUILD_TX=OFF -DBUILD_UTIL=OFF -DENABLE_WALLET=OFF -DBUILD_TESTS=OFF
     1...
     2-- Configuring done
     3CMake Error at src/CMakeLists.txt:289 (target_link_libraries):
     4  Target "bitcoin_node" links to:
     5
     6    libevent::core
     7
     8  but the target was not found.  Possible reasons include:
     9
    10    * There is a typo in the target name.
    11    * A find_package call is missing for an IMPORTED target.
    12    * An ALIAS target is missing.
    

    0$ cmake --build build
    1[100%] Building C object src/secp256k1/src/CMakeFiles/secp256k1_precomputed.dir/precomputed_ecmult.c.o
    2[100%] Building C object src/secp256k1/src/CMakeFiles/secp256k1_precomputed.dir/precomputed_ecmult_gen.c.o
    3[100%] Built target secp256k1_precomputed
    4[100%] Building C object src/secp256k1/src/CMakeFiles/secp256k1.dir/secp256k1.c.o
    5[100%] Linking C static library ../lib/libsecp256k1.a
    6[100%] Built target secp256k1
    

    Ninja

     0$ cmake -B build -G "Ninja" -DBUILD_DAEMON=OFF -DBUILD_CLI=OFF -DBUILD_TX=OFF -DBUILD_UTIL=OFF -DENABLE_WALLET=OFF -DBUILD_TESTS=OFF
     1...
     2-- Configuring done
     3CMake Error at src/CMakeLists.txt:289 (target_link_libraries):
     4  Target "bitcoin_node" links to:
     5
     6    libevent::core
     7
     8  but the target was not found.  Possible reasons include:
     9
    10    * There is a typo in the target name.
    11    * A find_package call is missing for an IMPORTED target.
    12    * An ALIAS target is missing.
    

    0$ cmake --build build
    1ninja: error: loading 'build.ninja': No such file or directory
    

    On PR branch (ab5c63edccea7957e2c7b3b9d8b04655a7f82f22): No error observed when generating the buildsystem (Make or Ninja)

    Make

    0$ cmake --build build
    1<no output>
    

    Ninja

    0$ cmake --build build
    1ninja: no work to do.
    

11. fanquake merged this on Dec 2, 2024
12. fanquake closed this on Dec 2, 2024

    ---

13. hebasto deleted the branch on Dec 2, 2024

Contributors
hebasto DrahtBot TheCharlatan tdb3

Labels
Build system