CMake Integration for Conan Packages

Overview

This document describes the integration of Conan packages into TDinternal's CMake build system.

Updated Files

cmake/conan.cmake

This file has been updated to support the newly created Conan packages:

• cppstub (v1.0.0) - Header-only testing stub library
• fast-lzma2 (v1.0.1) - Already configured
• avro-c (v1.11.3) - Already configured

Changes Made

1. Added cppstub Package Discovery

Location: Lines 33-34

# Testing
if(${BUILD_TEST})
    find_package(GTest REQUIRED)
    find_package(cppstub REQUIRED)  # Header-only stub library for unit tests
endif()

This ensures that when BUILD_TEST is enabled, CMake will find and load the cppstub Conan package.

2. Updated DEP_ext_cppstub Macros

Location: Lines 447-463

DEP_ext_cppstub (Main Macro)

macro(DEP_ext_cppstub tgt)
    # cppstub is now available as a Conan package (header-only library)
    if(TARGET cppstub::cppstub)
        target_link_libraries(${tgt} PUBLIC cppstub::cppstub)
    endif()
endmacro()

DEP_ext_cppstub_INC (Include-only)

macro(DEP_ext_cppstub_INC tgt)
    # Header-only library, handled by target_link_libraries above
    if(TARGET cppstub::cppstub)
        target_link_libraries(${tgt} INTERFACE cppstub::cppstub)
    endif()
endmacro()

DEP_ext_cppstub_LIB (Library-only)

macro(DEP_ext_cppstub_LIB tgt)
    # Header-only library, no libs to link
endmacro()

3. Updated Documentation Comments

Location: Lines 355-358

Added to the list of successfully migrated dependencies:

# Successfully migrated to Conan:
# - cppstub (testing stub library) - now available as Conan package
# - fast-lzma2 - now available as Conan package

How It Works

For Test Targets

When a test target uses DEP_ext_cppstub(my_test_target), the macro will:

1. Check if the cppstub::cppstub CMake target exists
2. If it exists, link it to the target using target_link_libraries
3. Since it's header-only, this only adds include directories (no actual linking)

Example Usage in CMakeLists.txt

# In source/util/test/CMakeLists.txt
add_executable(memPoolTest "memPoolTest.cpp")
DEP_ext_gtest(memPoolTest)
DEP_ext_cppstub(memPoolTest)  # Now properly links cppstub headers
target_link_libraries(memPoolTest PRIVATE os util common)

Benefits

1. Automatic Include Paths: Headers from cppstub are automatically available
2. Platform-Specific: Correct addr_any.h is selected based on OS
3. No Manual Configuration: CMake handles all the details
4. Conditional: Only loads when BUILD_TEST is enabled
5. Safe Fallback: Uses if(TARGET ...) checks to avoid errors

Backward Compatibility

The macros maintain the same interface as before:

• DEP_ext_cppstub(target) - Main dependency injection
• DEP_ext_cppstub_INC(target) - Include paths only
• DEP_ext_cppstub_LIB(target) - Library linking (no-op for header-only)

Existing code that uses these macros will work without modification.

Testing the Integration

1. Verify Package is Available

conan list "cppstub/*"

Expected output:

Local Cache
  cppstub
    cppstub/1.0.0

2. Configure CMake

cd build
cmake .. -DBUILD_TEST=true

You should see:

-- Loading Conan dependencies...
-- Found cppstub: 1.0.0
-- All Conan dependencies loaded successfully

3. Build a Test Target

cmake --build . --target memPoolTest

The build should succeed without "addr_any.h: No such file or directory" errors.

Migration Status

✅ Completed

• cppstub (header-only)
• fast-lzma2 (compiled library)

⏳ Pending

• Other dependencies listed in cmake/conan.cmake comments

Troubleshooting

Error: "Could not find cppstub"

Solution: Create the cppstub Conan package:

cd conan/cppstub
conan create . --build=missing

Error: "addr_any.h: No such file or directory"

Possible causes:

1. cppstub package not installed
2. DEP_ext_cppstub not called for the target
3. BUILD_TEST not enabled

Solution: Verify all three conditions are met.

Error: "Target cppstub::cppstub not found"

This is normal if cppstub is not available. The if(TARGET ...) check prevents build failures.

References

• cppstub README
• cppstub SUMMARY
• Conan CMakeDeps Generator
• CMake target_link_libraries

Related Files

• conan/cppstub/conanfile.py - Conan recipe
• cmake/conan.cmake - CMake integration
• source/util/test/CMakeLists.txt - Example test target
• source/util/test/memPoolTest.cpp - Example test file using addr_any.h