Link duckdb_generated_extension_loader when linking duckdb statically - #63
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Homebrew's libduckdb_static.a requires the companion
libduckdb_generated_extension_loader.a archive, which provides the init
hooks for duckdb's own statically-bundled extensions (json, parquet,
icu, autocomplete, core_functions). Without it, statically linking the
duckdb extension fails with undefined symbols like
duckdb::DuckDB::LoadStaticExtension<duckdb::ParquetExtension>().
Link the exported duckdb_generated_extension_loader target after
${DuckDB_LIBRARIES} whenever DuckDB_USE_STATIC_LIBS is set, followed by
each bundled extension archive listed in DuckDB_EXTENSIONS (order
matters: the loader references symbols from both).
adsharma
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Aug 22, 2026
Both ladybug's third_party/mbedtls and a statically-linked duckdb (libduckdb_static.a) bundle mbedtls with plain, unprefixed mbedtls_* symbols. When both end up on one link line (e.g. GEN=Ninja make shell EXTENSION_STATIC_LINK_LIST='httpfs'), the linker reports ~19 duplicate symbol errors for _mbedtls_cipher_*. Fix by wrapping our vendored copy in namespace lbug_mbedtls: - third_party/ports/mbedtls/do-patch.py (new): port patch script, following the zstd port pattern. It renames .c -> .cpp, strips the now-dead extern "C" guards (the copy is compiled as C++ everywhere), and wraps top-level code segments in balanced namespace pairs. Segmentation tracks preprocessor conditional context and brace depth per line, so sibling conditional branches (MBEDTLS_AES_ALT vs MBEDTLS_SELF_TEST) and mid-declaration conditionals (lone 'static' followed by a conditional attribute block) stay balanced. It also absorbs the previously-missing format_c_to_cpp.py step, making the port runnable again. - ports/mbedtls/Makefile: invoke do-patch.py during build. - third_party/mbedtls: vendored sources regenerated via the script (57 files; only namespace pairs and extern "C" removals). Public headers re-expose names via 'using namespace lbug_mbedtls', so in-tree consumers (src/common/sha256.cpp, extension/httpfs/src/crypto.cpp) are unchanged. Requires LadybugDB/extensions#63 (submodule bump included here). Verified with GEN=Ninja make shell EXTENSION_STATIC_LINK_LIST='httpfs': the link succeeds, libmbedtls.a exports zero plain _mbedtls_* symbols, and the shell passes a smoke query.
adsharma
added a commit
to LadybugDB/ladybug
that referenced
this pull request
Aug 22, 2026
Both ladybug's third_party/mbedtls and a statically-linked duckdb (libduckdb_static.a) bundle mbedtls with plain, unprefixed mbedtls_* symbols. When both end up on one link line (e.g. GEN=Ninja make shell EXTENSION_STATIC_LINK_LIST='httpfs'), the linker reports ~19 duplicate symbol errors for _mbedtls_cipher_*. Fix by wrapping our vendored copy in namespace lbug_mbedtls: - third_party/ports/mbedtls/do-patch.py (new): port patch script, following the zstd port pattern. It renames .c -> .cpp, strips the now-dead extern "C" guards (the copy is compiled as C++ everywhere), and wraps top-level code segments in balanced namespace pairs. Segmentation tracks preprocessor conditional context and brace depth per line, so sibling conditional branches (MBEDTLS_AES_ALT vs MBEDTLS_SELF_TEST) and mid-declaration conditionals (lone 'static' followed by a conditional attribute block) stay balanced. It also absorbs the previously-missing format_c_to_cpp.py step, making the port runnable again. - ports/mbedtls/Makefile: invoke do-patch.py during build. - third_party/mbedtls: vendored sources regenerated via the script (57 files; only namespace pairs and extern "C" removals). Public headers re-expose names via 'using namespace lbug_mbedtls', so in-tree consumers (src/common/sha256.cpp, extension/httpfs/src/crypto.cpp) are unchanged. Requires LadybugDB/extensions#63 (submodule bump included here). Verified with GEN=Ninja make shell EXTENSION_STATIC_LINK_LIST='httpfs': the link succeeds, libmbedtls.a exports zero plain _mbedtls_* symbols, and the shell passes a smoke query.
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Problem
Building with
GEN=Ninja make shell EXTENSION_STATIC_LINK_LIST='httpfs'(which flips all extensions to static linking) failed at the final link with undefined symbols:Root cause
When
DuckDB_USE_STATIC_LIBS=ON,find_package(DuckDB)resolvesDuckDB_LIBRARIESto justduckdb_static. But a statically-linked duckdb requires its companionlibduckdb_generated_extension_loader.aarchive (which providesDuckDB::LoadStaticExtension<T>hooks for duckdb's own bundled extensions), and the loader in turn references the bundled extension archives (json,parquet,icu,autocomplete,core_functions), all exported by the DuckDB CMake package.Fix
When
DuckDB_USE_STATIC_LIBSis set, linkduckdb_generated_extension_loaderafter${DuckDB_LIBRARIES}, followed by every${ext}_extensiontarget listed inDuckDB_EXTENSIONS. Order matters: the loader references symbols from bothduckdb_staticand the extension archives.Verified with
GEN=Ninja make shell EXTENSION_STATIC_LINK_LIST='httpfs'against Homebrew duckdb 1.5.1.