cmake [KILL 3-STATE]: Switch WITH_CCACHE to boolean

`WITH_CCACHE` is an opportunistic option now and its default is `ON`.

.github/workflows/ci.yml

@@ -133,7 +133,6 @@ jobs:
     if: github.repository != 'bitcoin-core/gui' || github.event_name == 'pull_request'
 
     env:
-      CCACHE_MAXSIZE: '200M'
       PYTHONUTF8: 1
       TEST_RUNNER_TIMEOUT_FACTOR: 40
 
@@ -163,10 +162,6 @@ jobs:
           py -3 --version
           Write-Host "PowerShell version $($PSVersionTable.PSVersion.ToString())"
 
-      - name: Install Ccache
-        run: |
-          choco install --yes --no-progress ccache
-
       - name: Using vcpkg with MSBuild
         run: |
           Set-Location "$env:VCPKG_INSTALLATION_ROOT"
@@ -197,32 +192,12 @@ jobs:
           path: ~/AppData/Local/vcpkg/archives
           key: ${{ github.job }}-vcpkg-binary-${{ hashFiles('cmake_version', 'msbuild_version', 'toolset_version', 'vcpkg.json') }}
 
-      - name: Restore Ccache cache
-        id: ccache-cache
-        uses: actions/cache/restore@v4
-        with:
-          path: ~/AppData/Local/ccache
-          key: ${{ github.job }}-ccache-
-
       - name: Build
         working-directory: build
         run: |
           ccache --zero-stats
           cmake --build . -j $env:NUMBER_OF_PROCESSORS --config Release
 
-      - name: Ccache stats
-        run: |
-          ccache --version | head -n 1
-          ccache --show-stats --verbose
-
-      - name: Save Ccache cache
-        uses: actions/cache/save@v4
-        if: github.event_name != 'pull_request' && steps.ccache-cache.outputs.cache-hit != 'true'
-        with:
-          path: ~/AppData/Local/ccache
-          # https://github.com/actions/cache/blob/main/tips-and-workarounds.md#update-a-cache
-          key: ${{ github.job }}-ccache-${{ github.run_id }}
-
       - name: Run test suite
         working-directory: build
         run: |

.github/workflows/cmake.yml

@@ -456,10 +456,6 @@ jobs:
           path: ~/AppData/Local/vcpkg/archives
           key: ${{ matrix.conf.triplet }}-vcpkg-binary-${{ hashFiles('cmake_version', 'msbuild_version', 'toolset_version', 'vcpkg.json') }}
 
-      - name: Install Ccache
-        run: |
-          choco install --yes --no-progress ccache
-
       - name: Generate build system
         run: |
           cmake -B build --preset ${{ matrix.conf.preset }} -DCMAKE_TOOLCHAIN_FILE="$env:VCPKG_INSTALLATION_ROOT\scripts\buildsystems\vcpkg.cmake" -DBUILD_BENCH=ON -DBUILD_FUZZ_BINARY=ON -DWERROR=ON
@@ -471,32 +467,12 @@ jobs:
           path: ~/AppData/Local/vcpkg/archives
           key: ${{ matrix.conf.triplet }}-vcpkg-binary-${{ hashFiles('cmake_version', 'msbuild_version', 'toolset_version', 'vcpkg.json') }}
 
-      - name: Restore Ccache cache
-        id: ccache-cache
-        uses: actions/cache/restore@v4
-        with:
-          path: ~/AppData/Local/ccache
-          key: ${{ matrix.conf.triplet }}-ccache-${{ github.run_id }}
-          restore-keys: ${{ matrix.conf.triplet }}-ccache-
-
       - name: Build Release configuration
         working-directory: build
         run: |
           ccache --zero-stats
           cmake --build . -j $env:NUMBER_OF_PROCESSORS --config Release
 
-      - name: Ccache stats
-        run: |
-          ccache --version | head -n 1
-          ccache --show-stats --verbose
-
-      - name: Save Ccache cache
-        uses: actions/cache/save@v4
-        if: github.event_name != 'pull_request' && steps.ccache-cache.outputs.cache-hit != 'true'
-        with:
-          path: ~/AppData/Local/ccache
-          key: ${{ matrix.conf.triplet }}-ccache-${{ github.run_id }}
-
       - name: Inspect build artifacts
         working-directory: build
         run: |

CMakeLists.txt

@@ -107,11 +107,7 @@ cmake_dependent_option(BUILD_WALLET_TOOL "Build bitcoin-wallet tool." ${BUILD_TE
 option(ENABLE_HARDENING "Attempt to harden the resulting executables." ON)
 option(REDUCE_EXPORTS "Attempt to reduce exported symbols in the resulting executables." OFF)
 option(WERROR "Treat compiler warnings as errors." OFF)
-
-# TODO: These tri-state options will be removed and most features
-#       will become opt-in by default before merging into master.
-include(TristateOption)
-tristate_option(WITH_CCACHE "Use ccache for compiling." "if ccache is found." AUTO)
+option(WITH_CCACHE "Attempt to use ccache for compiling." ON)
 
 option(WITH_NATPMP "Enable NAT-PMP." OFF)
 if(WITH_NATPMP)
@@ -365,6 +361,8 @@ endif()
 
 include(cmake/introspection.cmake)
 
+include(cmake/ccache.cmake)
+
 include(cmake/crc32c.cmake)
 include(cmake/leveldb.cmake)
 include(cmake/minisketch.cmake)
@@ -498,8 +496,6 @@ configure_file(cmake/script/CoverageFuzz.cmake CoverageFuzz.cmake COPYONLY)
 configure_file(cmake/script/CoverageInclude.cmake.in CoverageInclude.cmake @ONLY)
 configure_file(contrib/filter-lcov.py filter-lcov.py COPYONLY)
 
-include(cmake/optional.cmake)
-
 # Don't allow extended (non-ASCII) symbols in identifiers. This is easier for code review.
 try_append_cxx_flags("-fno-extended-identifiers" TARGET core_base_interface SKIP_LINK)
 

cmake/ccache.cmake

@@ -0,0 +1,25 @@
+# Copyright (c) 2023-present The Bitcoin Core developers
+# Distributed under the MIT software license, see the accompanying
+# file COPYING or https://opensource.org/license/mit/.
+
+if(NOT MSVC)
+  find_program(CCACHE_EXECUTABLE ccache)
+  if(CCACHE_EXECUTABLE)
+    execute_process(
+      COMMAND readlink -f ${CMAKE_CXX_COMPILER}
+      OUTPUT_VARIABLE compiler_resolved_link
+      ERROR_QUIET
+      OUTPUT_STRIP_TRAILING_WHITESPACE
+    )
+    if(CCACHE_EXECUTABLE STREQUAL compiler_resolved_link)
+      set(WITH_CCACHE "ccache masquerades as the compiler")
+    elseif(WITH_CCACHE)
+      list(APPEND CMAKE_C_COMPILER_LAUNCHER ${CCACHE_EXECUTABLE})
+      list(APPEND CMAKE_CXX_COMPILER_LAUNCHER ${CCACHE_EXECUTABLE})
+    endif()
+  else()
+    set(WITH_CCACHE OFF)
+  endif()
+endif()
+
+mark_as_advanced(CCACHE_EXECUTABLE)