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Build contracts with -Os whatever CMAKE_BUILD_TYPE the environment sets - #668
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…ment sets The CDT toolchain compiles contracts with -Os. `contracts_target()` passed the contract projects no build type, so CMake 3.22+ took a `CMAKE_BUILD_TYPE` environment variable as the default for their caches, and a Release type appended `-O3 -DNDEBUG`. The Bazel platform wrapper exports that variable, so its Release builds produced contracts 17-37% larger than every other build, with the same ABIs. Pass an explicit empty build type, which overrides the environment, so every contract build gets the toolchain's -Os.
huangminghuang
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Oct 7, 2026
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Reviewed bb04945. No actionable findings. Verified all four contracts_target() callers and the CDT toolchain interaction. Focused CMake/CDT checks passed with Release, Debug, and unset build-type environments, including automatic correction of an existing Release cache. PR CI passed; the full project was not rebuilt locally.
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Summary
Contracts always compile with the CDT toolchain's
-Os.contracts_target()now passes every contract project (the system contracts, the testing contracts and both test-contract sets) an explicit emptyCMAKE_BUILD_TYPE.Why
The contract projects are ExternalProjects and never received a build type, so a plain
cmake -DCMAKE_BUILD_TYPE=Releasetop-level build, and CI's release build, already produced-Oscontracts. But CMake 3.22+ uses aCMAKE_BUILD_TYPEenvironment variable as the default for a new cache, and the Bazel platform wrapper (wire-platform-build-systembuild_defs.bzl) exports it fromWIRE_BUILD_TYPE. A Release type appends-O3 -DNDEBUGafter the toolchain's-Os, so those builds made contracts 17-37% larger than everyone else's, with identical ABIs. Nine of the contract binaries committed in #662 came out that way (sysio.system 277,605 bytes against 202,678), and they cannot be reproduced from the standard build.An explicit
-DCMAKE_BUILD_TYPE=overrides the environment variable. WithCMAKE_BUILD_TYPE=Releaseexported, every contract project now configures with an empty build type, the system contracts rebuild byte-identical to master's, and the test contracts come out identical to a build without the variable. An existing build tree picks this up on its next build, since the changed arguments re-run the contract projects' configure.