[CMake] Improve FetchContent compatibility: include path consistency and option naming

[hn-sl]

Summary

I'd like to propose two improvements to make isa-l_crypto more friendly for modern CMake consumption patterns (FetchContent, add_subdirectory, package managers like Conan/vcpkg).

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Issue 1: Include Path Inconsistency

Current Behavior:

Usage	Include Path	Usage
After make install	include/isa-l_crypto/*.h	#include <isa-l_crypto/md5_mb.h>
Via FetchContent	include/*.h	#include <md5_mb.h>

This inconsistency makes it difficult to write portable code that works with both consumption methods.

Proposed Solution:

Rename include/ directory to isa-l_crypto/ and adjust CMake paths:

target_include_directories(isal_crypto PUBLIC
    $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}>
    $<INSTALL_INTERFACE:include>)

This is a minimal change (directory rename only, no file content changes) that enables consistent usage:

#include <isa-l_crypto/md5_mb.h>  // Works for all consumption methods

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Issue 2: Generic Option Names

Current:

option(BUILD_TESTS "Build test applications" ON)
option(BUILD_PERF "Build performance applications" ON)

Problem: These generic names can conflict with parent project options when used via FetchContent/add_subdirectory.

Proposed:

option(ISAL_CRYPTO_BUILD_TESTS "Build test applications" ON)
option(ISAL_CRYPTO_BUILD_PERF "Build performance applications" ON)

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Offer

If these proposals are acceptable, I'm happy to submit PRs for both changes.

Related PR: #170 (CMAKE_SOURCE_DIR fix for FetchContent compatibility)

[pablodelara]

Thanks for your PR and suggestions, @hn-sl. About the first issue, renaming "include", it looks strange to rename to isa-l_crypto... Generally "include" is the accepted folder where the header files are stored, right?

[hn-sl]

Sorry, my mistake in the original proposal!

What I actually intended was creating a subdirectory inside include/:

include/
└── isa-l_crypto/
    ├── md5_mb.h
    ├── sha256_mb.h
    └── ...

This keeps the standard include/ convention while enabling consistent namespaced includes (#include <isa-l_crypto/md5_mb.h>) for both installed and FetchContent usage.

Would this approach be acceptable?

[pablodelara]

Sorry, my mistake in the original proposal!

What I actually intended was creating a subdirectory inside include/:

include/
└── isa-l_crypto/
    ├── md5_mb.h
    ├── sha256_mb.h
    └── ...

This keeps the standard include/ convention while enabling consistent namespaced includes (#include <isa-l_crypto/md5_mb.h>) for both installed and FetchContent usage.

Would this approach be acceptable?

Sounds good

[hn-sl]

Update: Issue 1 Implemented

I've implemented the include path restructuring:

• Moved all headers to include/isa-l_crypto/ subdirectory
• Updated CMakeLists.txt and all cmake modules
• Both FetchContent and installed versions now use: #include <isa-l_crypto/md5_mb.h>

PR will be submitted shortly.

Issue 2: Option Names

Will address this in a separate PR to keep changes focused and easier to review.

Proposed changes:

• BUILD_TESTS → ISAL_CRYPTO_BUILD_TESTS
• BUILD_PERF → ISAL_CRYPTO_BUILD_PERF
• SAFE_DATA → ISAL_CRYPTO_SAFE_DATA
• SAFE_PARAM → ISAL_CRYPTO_SAFE_PARAM
• FIPS_MODE → ISAL_CRYPTO_FIPS_MODE

Note: BUILD_SHARED_LIBS will remain unchanged as it's a CMake standard variable.