mold 2.37.0 is a new release of the high-speed linker. It includes the following new features and bug fixes.
New Features
- If an undefined weak symbol is not resolved to a defined symbol at link time, the linker can choose whether to promote the symbol to a dynamic symbol or not. If promoted, the weak symbol has another chance to be resolved to a defined symbol at load time. Otherwise, it is resolved to address 0 at link time. Previously, mold always resolved remaining undefined weak symbols in an executable to address 0 at link time. Now, you can instruct the linker to promote them to dynamic symbols using
-z dynamic-undefined-weak. (1822e47)
Bug Fixes and Compatibility Improvements
-
[x86-64] The relocation types
R_X86_64_CODE_4_{GOTPCRELX,GOTTPOFF,GOTPC32_TLSDESC}andR_X86_64_CODE_6_GOTTPOFFare now supported. These relocations are for Intel APX (Advanced Performance Extensions), which extends the number of general-purpose registers from 16 to 32. (83152ac, a17202d) -
[ARM32] The
R_ARM_THM_JUMP8relocation type is now supported. (1fbbcec) -
[ARM32] Previously, the
.ARM.exidxsection (which contains exception-handling records) was not subject to garbage collection, even when--gc-sectionswas specified. This prevented all functions from being garbage-collected, as they were referenced by exception-handling records. Now, mold correctly garbage-collects unused.ARM.exidxrecords and functions. (16f7599) -
Previously,
--compress-debug-sectionswas ignored if--separate-debug-filewas specified. Now, mold compresses debug information sections even when they are in a separate debug file. (bab7dd1)
Acknowledgements
mold is an open-source project, and we accept donations via GitHub Sponsors and OpenCollective. We thank everyone who sponsors our project. In particular, we would like to acknowledge the following organizations and people who have sponsored $32/month or more during this release cycle: