cmake_minimum_required(VERSION 3.18)   # find_program(... REQUIRED)

set(VMIE_VERSION "0.2.1" CACHE STRING "Library version (MAJOR.MINOR.PATCH); CI passes the tag")
project(vmi-engine VERSION ${VMIE_VERSION} LANGUAGES C)

set(CMAKE_C_STANDARD 17)               # generation B uses no C23 feature
set(CMAKE_C_STANDARD_REQUIRED ON)
set(CMAKE_C_EXTENSIONS ON)             # deliberate: strnlen (POSIX) + void* arithmetic (GNU)
set(CMAKE_POSITION_INDEPENDENT_CODE ON) # -fPIC on all objects: static lib stays linkable into a shared object

include(GNUInstallDirs)

option(VMIE_LTO "Enable LTO" OFF)      # build-only; shipped default is -O2, no LTO

# ---- optional semantic-signature backend (operand disassembler) ----------
# VMIE_DISASM selects the OPTIONAL operand-decode backend for the semantic
# signature feature (semsig.h). OFF (default) ships the 0.1.6 behaviour: the
# generic symbol exists via semsig_stub.c, returns 0, VMIE_HAVE_DISASM=0, and no
# external library is pulled - CI and the .deb packages are unchanged. A backend
# (zydis|capstone) is NEVER vendored: it is brought from OUTSIDE the tree, either
# by VMIE_DISASM_SRC (a path to the backend's own source tree, add_subdirectory'd)
# or, failing that, by find_package of an already-installed library.
set(VMIE_DISASM "OFF" CACHE STRING "Semantic-signature backend: OFF | zydis | capstone")
set_property(CACHE VMIE_DISASM PROPERTY STRINGS OFF zydis capstone)
set(VMIE_DISASM_SRC "" CACHE PATH "Path to the disassembler backend source tree (external; add_subdirectory'd)")

# ---- host: VMI core objects (single owner of the source list) -----------
add_library(vmie_obj OBJECT
        src/core/gpa.c
        src/engine/gva.c
        src/engine/sigphys.c
        src/engine/win32/host.c
        src/engine/win32/pe.c
        src/engine/win32/proc.c
        src/engine/win32/profile.c
        src/engine/win32/text.c
        src/handlers/scan.c
        src/handlers/sigscan.c
        src/handlers/sigset.c
        src/handlers/codescan.c
        src/handlers/codeanalysis.c
        src/handlers/siggen.c
        src/handlers/x86dec.c
        src/handlers/pmap.c
        src/handlers/snapdiff.c)

# semantic-signature TUs: OFF compiles ONLY the stub (which carries the whole
# generic symbol and returns 0); a backend compiles the core (semsig.c) + the one
# backend TU that talks to the disassembler. semsig.c is never built in OFF (it
# calls the backend decode, absent there) - so there is no dead/unresolved call.
if(VMIE_DISASM STREQUAL "OFF")
    target_sources(vmie_obj PRIVATE src/handlers/semsig_stub.c
                                    src/handlers/insndec_stub.c)
elseif(VMIE_DISASM STREQUAL "zydis")
    target_sources(vmie_obj PRIVATE src/handlers/semsig.c
                                    src/handlers/insndec.c
                                    src/handlers/codetrace.c
                                    src/handlers/semsig_backend_zydis.c)
elseif(VMIE_DISASM STREQUAL "capstone")
    target_sources(vmie_obj PRIVATE src/handlers/semsig.c
                                    src/handlers/insndec.c
                                    src/handlers/codetrace.c
                                    src/handlers/semsig_backend_capstone.c)
else()
    message(FATAL_ERROR "VMIE_DISASM must be OFF, zydis, or capstone (got '${VMIE_DISASM}')")
endif()

target_include_directories(vmie_obj
        PUBLIC  ${CMAKE_CURRENT_SOURCE_DIR}/include              # public API: include/*.h
        PRIVATE ${CMAKE_CURRENT_SOURCE_DIR}/src/core/include     # private: core.h
                ${CMAKE_CURRENT_SOURCE_DIR}/src/engine/include   # private: engine-arch.h, pe.h
                ${CMAKE_CURRENT_SOURCE_DIR}/src/engine/win32)    # private: engine-win32.h, contract.h
target_compile_options(vmie_obj PRIVATE -O2 -Wall -Wextra)
if(VMIE_LTO)
    target_compile_options(vmie_obj PRIVATE -flto)
    target_link_options(vmie_obj PRIVATE -flto)
endif()

# Resolve the backend target/package name (the actual link/define is applied to
# vmie_obj here AND re-applied to the static/shared libs below, because
# $<TARGET_OBJECTS:vmie_obj> carries object files only - not link/define usage
# requirements). The backend is PRIVATE (an implementation detail), while
# VMIE_HAVE_DISASM is PUBLIC (visible through semsig.h). The backend comes from
# VMIE_DISASM_SRC (external sources) or find_package - never from in-tree sources.
if(NOT VMIE_DISASM STREQUAL "OFF")
    if(VMIE_DISASM STREQUAL "zydis")
        set(VMIE_DISASM_LINK "Zydis::Zydis")
        set(_vmie_disasm_pkg "Zydis")
    else()
        set(VMIE_DISASM_LINK "capstone::capstone")
        set(_vmie_disasm_pkg "capstone")
    endif()

    if(VMIE_DISASM_SRC)
        # Build the backend from its OWN external source tree (kept out of this
        # repo). Its CMake exports the imported target linked below.
        add_subdirectory(${VMIE_DISASM_SRC} ${CMAKE_CURRENT_BINARY_DIR}/_disasm_backend)
    else()
        find_package(${_vmie_disasm_pkg} REQUIRED)
    endif()

    target_link_libraries(vmie_obj PRIVATE ${VMIE_DISASM_LINK})
    target_compile_definitions(vmie_obj PUBLIC VMIE_HAVE_DISASM=1)
else()
    set(VMIE_DISASM_LINK "")
    target_compile_definitions(vmie_obj PUBLIC VMIE_HAVE_DISASM=0)
endif()

# ---- host: static library (in-tree consumers: CLIs + test) --------------
# $<TARGET_OBJECTS:> carries object files only, not usage requirements:
# re-declare the PUBLIC include scope so vmie_cli/vmie_scan still see include/.
add_library(vmie STATIC $<TARGET_OBJECTS:vmie_obj>)
target_include_directories(vmie PUBLIC ${CMAKE_CURRENT_SOURCE_DIR}/include)
# Re-apply the feature macro (PUBLIC: seen by in-tree consumers + the test) and
# the backend link (PRIVATE), which $<TARGET_OBJECTS> does not carry over.
if(VMIE_DISASM STREQUAL "OFF")
    target_compile_definitions(vmie PUBLIC VMIE_HAVE_DISASM=0)
else()
    target_compile_definitions(vmie PUBLIC VMIE_HAVE_DISASM=1)
    target_link_libraries(vmie PRIVATE ${VMIE_DISASM_LINK})
endif()

# ---- host: shared library (external delivery: libvmie.so.*) -------------
add_library(vmie_shared SHARED $<TARGET_OBJECTS:vmie_obj>)
target_include_directories(vmie_shared PUBLIC ${CMAKE_CURRENT_SOURCE_DIR}/include)
set_target_properties(vmie_shared PROPERTIES
        OUTPUT_NAME vmie
        SOVERSION   ${PROJECT_VERSION_MAJOR}
        VERSION     ${PROJECT_VERSION})
if(VMIE_LTO)
    target_link_options(vmie_shared PRIVATE -flto)
endif()
if(VMIE_DISASM STREQUAL "OFF")
    target_compile_definitions(vmie_shared PUBLIC VMIE_HAVE_DISASM=0)
else()
    target_compile_definitions(vmie_shared PUBLIC VMIE_HAVE_DISASM=1)
    target_link_libraries(vmie_shared PRIVATE ${VMIE_DISASM_LINK})
endif()

# ---- host: CLI demonstrator over the library ----------------------------
add_executable(vmie_cli src/cli.c)
target_link_libraries(vmie_cli PRIVATE vmie)   # public include/ comes via vmie (PUBLIC)
target_compile_options(vmie_cli PRIVATE -Wall -Wextra)

# ---- host: dump-scan demonstrator (OS-agnostic, no win32) ----------------
add_executable(vmie_scan src/scan_cli.c)
target_link_libraries(vmie_scan PRIVATE vmie)
target_compile_options(vmie_scan PRIVATE -Wall -Wextra)

# ---- guest: cross-compile to Windows x86-64 via mingw-w64 ---------------
find_program(MINGW_CC NAMES x86_64-w64-mingw32-gcc REQUIRED)
set(VMIE_STARTUP ${CMAKE_CURRENT_BINARY_DIR}/vmie-startup.exe)
add_custom_command(
        OUTPUT  ${VMIE_STARTUP}
        COMMAND ${MINGW_CC} -O2 -Wall -Wextra -static -s
                -I${CMAKE_CURRENT_SOURCE_DIR}/src/engine/win32
                -o ${VMIE_STARTUP} ${CMAKE_CURRENT_SOURCE_DIR}/src/engine/win32/guest.c
        DEPENDS ${CMAKE_CURRENT_SOURCE_DIR}/src/engine/win32/guest.c
                ${CMAKE_CURRENT_SOURCE_DIR}/src/engine/win32/contract.h
        COMMENT "Cross-compiling vmie-startup.exe (mingw-w64, x86-64)"
        VERBATIM)
add_custom_target(vmie-startup ALL DEPENDS ${VMIE_STARTUP})

# ---- install: shared library + public headers ---------------------------
# Versioned file + SONAME symlink -> runtime; unversioned linker symlink -> dev.
install(TARGETS vmie_shared
        LIBRARY
          DESTINATION ${CMAKE_INSTALL_LIBDIR}
          COMPONENT runtime
          NAMELINK_COMPONENT dev)
install(DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}/include/
        DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}/vmie
        COMPONENT dev
        FILES_MATCHING PATTERN "*.h")

# ---- package: two Debian packages (runtime + dev) -----------------------
set(CPACK_GENERATOR "DEB")
set(CPACK_DEB_COMPONENT_INSTALL ON)
set(CPACK_COMPONENTS_ALL runtime dev)
set(CPACK_PACKAGE_VERSION ${PROJECT_VERSION})

# component -> Debian package name (Debian shared-library convention)
set(CPACK_DEBIAN_RUNTIME_PACKAGE_NAME "libvmie${PROJECT_VERSION_MAJOR}")
set(CPACK_DEBIAN_DEV_PACKAGE_NAME     "libvmie-dev")

set(CPACK_DEBIAN_PACKAGE_ARCHITECTURE "amd64")
set(VMIE_DEB_MAINTAINER "Gregory Lirent <opensource@lirent.ru>"
    CACHE STRING "Debian package Maintainer field")
set(CPACK_DEBIAN_PACKAGE_MAINTAINER "${VMIE_DEB_MAINTAINER}")
set(CPACK_DEBIAN_PACKAGE_SECTION "libs")
set(CPACK_DEBIAN_PACKAGE_PRIORITY "optional")
set(CPACK_DEBIAN_FILE_NAME "DEB-DEFAULT")

set(CPACK_COMPONENT_RUNTIME_DESCRIPTION
    "VM introspection engine (Windows-guest memory introspection) - shared library")
set(CPACK_COMPONENT_DEV_DESCRIPTION
    "VM introspection engine (Windows-guest memory introspection) - development files")

# dev depends on the exact runtime version; runtime libc dependency via shlibdeps
set(CPACK_DEBIAN_DEV_PACKAGE_DEPENDS "libvmie${PROJECT_VERSION_MAJOR} (= ${PROJECT_VERSION})")
set(CPACK_DEBIAN_PACKAGE_SHLIBDEPS ON)

include(CPack)
