cmake: Rework tests target for Coverage configuartion and multi-config generators #1592

1. 
   hebasto commented at 3:15 pm on August 18, 2024: member

   The “experimental” status of the CMake-based build system can be reconsidered once it is adopted in the Bitcoin Core project. Fixing all known bugs is essential before this reconsideration.

   Currently, I’m aware of a single issue: when using a multi-config generator, such as “Ninja Multi-Config”, the build system still builds the tests binary for the “Coverage” configuration, which is meaningless:

   0$ cmake -B build -G "Ninja Multi-Config"
   1$ cmake --build build --config Coverage
   2[18/19] Building C object src/CMakeFiles/tests.dir/Coverage/tests.c.o
   3/home/hebasto/git/secp256k1/secp256k1/src/tests.c:18:13: note: ‘#pragma message: Defining VERIFY for tests being built for coverage analysis support is meaningless.’
   4   18 |     #pragma message("Defining VERIFY for tests being built for coverage analysis support is meaningless.")
   5      |             ^~~~~~~
   6[19/19] Linking C executable src/Coverage/tests
   

   This PR fixes the issue.

   It is an alternative to #1251 and #1291.

   The last commit aaditionally addresses that comment.

2. cmake: Rework `tests` target for Coverage and multi-config generators 87534e72a1
3. autotools, docs: Adjust help string for `--enable-coverage` option 5a2b84b4c9
4. hebasto marked this as a draft on Aug 18, 2024
5. 
   real-or-random commented at 2:55 pm on August 19, 2024: contributor

   @hebasto Can you summarize what this PR does and why is it preferable to #1291? The approach in #1291 seemed natural to me.

Contributors
hebasto real-or-random