Build acceleration: ccache, unity build, precompiled headers

- Auto-detect and use ccache as compiler launcher when available
- Add ENABLE_UNITY_BUILD option for jumbo builds (batch size 8)
- Precompile heavy STL/Boost/OpenSSL headers for C++ targets
- Exclude hash9 crypto from unity builds (colliding static symbols)
- Fix RAND_screen() compile error on OpenSSL 3.x (removed API)

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

CMakeLists.txt

@@ -17,6 +17,24 @@ set(CMAKE_CXX_STANDARD_REQUIRED ON)
 set(CMAKE_CXX_EXTENSIONS OFF)
 set(CMAKE_C_STANDARD 11)
 
+# ── Build acceleration ──
+# ccache: auto-detect and use if available
+find_program(CCACHE_PROGRAM ccache)
+if(CCACHE_PROGRAM)
+    set(CMAKE_C_COMPILER_LAUNCHER "${CCACHE_PROGRAM}")
+    set(CMAKE_CXX_COMPILER_LAUNCHER "${CCACHE_PROGRAM}")
+    message(STATUS "ccache found: ${CCACHE_PROGRAM}")
+else()
+    message(STATUS "ccache not found — install it for faster rebuilds")
+endif()
+
+# Unity (jumbo) build: batch source files to reduce header parsing overhead
+option(ENABLE_UNITY_BUILD "Enable CMake unity (jumbo) builds" OFF)
+if(ENABLE_UNITY_BUILD)
+    set(CMAKE_UNITY_BUILD ON)
+    set(CMAKE_UNITY_BUILD_BATCH_SIZE 8)
+endif()
+
 # ── Output directories ──
 set(CMAKE_RUNTIME_OUTPUT_DIRECTORY "${CMAKE_BINARY_DIR}/bin")
 set(CMAKE_ARCHIVE_OUTPUT_DIRECTORY "${CMAKE_BINARY_DIR}/lib")
@@ -113,4 +131,7 @@ message(STATUS "  D-Bus:              ${USE_DBUS}")
 message(STATUS "  ZMQ:                ${USE_ZMQ}")
 message(STATUS "  Embedded Tor:       ${USE_TOR_EMBEDDED}")
 message(STATUS "  Static linking:     ${ENABLE_STATIC}")
+message(STATUS "  ccache:             ${CCACHE_PROGRAM}")
+message(STATUS "  Unity build:        ${ENABLE_UNITY_BUILD}")
+message(STATUS "  Precompiled header: ON")
 message(STATUS "")

src/CMakeLists.txt

@@ -23,6 +23,8 @@ add_library(hash9_crypto STATIC
 )
 target_include_directories(hash9_crypto PUBLIC "${CMAKE_CURRENT_SOURCE_DIR}")
 set_target_properties(hash9_crypto PROPERTIES LINKER_LANGUAGE C)
+# Hash9 C files have colliding static symbols (IV512, DECL_STATE, etc.) — skip unity
+set_target_properties(hash9_crypto PROPERTIES UNITY_BUILD OFF)
 
 # ═══════════════════════════════════════════════════════════════════════════════
 # 2. JSON library (header-only nlohmann/json via json_compat.h shim)
@@ -185,6 +187,31 @@ endif()
 
 add_dependencies(triangles_common generate_build_info build_leveldb)
 
+# ── Precompiled header (heavy STL + Boost + OpenSSL includes, C++ only) ──
+target_precompile_headers(triangles_common PRIVATE
+    "$<$<COMPILE_LANGUAGE:CXX>:<string$<ANGLE-R>>"
+    "$<$<COMPILE_LANGUAGE:CXX>:<vector$<ANGLE-R>>"
+    "$<$<COMPILE_LANGUAGE:CXX>:<map$<ANGLE-R>>"
+    "$<$<COMPILE_LANGUAGE:CXX>:<deque$<ANGLE-R>>"
+    "$<$<COMPILE_LANGUAGE:CXX>:<algorithm$<ANGLE-R>>"
+    "$<$<COMPILE_LANGUAGE:CXX>:<sstream$<ANGLE-R>>"
+    "$<$<COMPILE_LANGUAGE:CXX>:<stdexcept$<ANGLE-R>>"
+    "$<$<COMPILE_LANGUAGE:CXX>:<cstdint$<ANGLE-R>>"
+    "$<$<COMPILE_LANGUAGE:CXX>:<cstring$<ANGLE-R>>"
+    "$<$<COMPILE_LANGUAGE:CXX>:<memory$<ANGLE-R>>"
+    "$<$<COMPILE_LANGUAGE:CXX>:<functional$<ANGLE-R>>"
+    "$<$<COMPILE_LANGUAGE:CXX>:<boost/filesystem.hpp$<ANGLE-R>>"
+    "$<$<COMPILE_LANGUAGE:CXX>:<boost/filesystem/fstream.hpp$<ANGLE-R>>"
+    "$<$<COMPILE_LANGUAGE:CXX>:<boost/thread.hpp$<ANGLE-R>>"
+    "$<$<COMPILE_LANGUAGE:CXX>:<boost/thread/mutex.hpp$<ANGLE-R>>"
+    "$<$<COMPILE_LANGUAGE:CXX>:<boost/thread/condition_variable.hpp$<ANGLE-R>>"
+    "$<$<COMPILE_LANGUAGE:CXX>:<boost/algorithm/string.hpp$<ANGLE-R>>"
+    "$<$<COMPILE_LANGUAGE:CXX>:<openssl/sha.h$<ANGLE-R>>"
+    "$<$<COMPILE_LANGUAGE:CXX>:<openssl/crypto.h$<ANGLE-R>>"
+    "$<$<COMPILE_LANGUAGE:CXX>:<openssl/rand.h$<ANGLE-R>>"
+    "$<$<COMPILE_LANGUAGE:CXX>:<openssl/evp.h$<ANGLE-R>>"
+)
+
 # ═══════════════════════════════════════════════════════════════════════════════
 # 4. Headless daemon (trianglesd)
 # ═══════════════════════════════════════════════════════════════════════════════
@@ -196,6 +223,7 @@ if(BUILD_DAEMON)
     )
     # No QT_GUI define — daemon gets the #if !defined(QT_GUI) code paths
     target_link_libraries(trianglesd PRIVATE triangles_common)
+    target_precompile_headers(trianglesd REUSE_FROM triangles_common)
 
     if(WIN32)
         set_target_properties(trianglesd PROPERTIES SUFFIX ".exe")

src/util.cpp

@@ -111,8 +111,9 @@ public:
         CRYPTO_set_locking_callback(locking_callback);
 #endif
 
-#ifdef WIN32
+#if defined(WIN32) && OPENSSL_VERSION_NUMBER < 0x30000000L
         // Seed random number generator with screen scrape and other hardware sources
+        // (removed in OpenSSL 3.x — auto-seeded via BCryptGenRandom)
         RAND_screen();
 #endif