[3.6] bpo-28015: Support LTO build with clang (GH-9908) by stratakis · Pull Request #10922 · python/cpython (original) (raw)

.o generated by clang in LTO mode actually are LLVM bitcode files, which leads to a few errors during configure/build step:

• add lto flags to the BASECFLAGS instead of CFLAGS, as CFLAGS are used to build autoconf test case, and some are not compatible with clang LTO (they assume binary in the .o, not bitcode)
• force llvm-ar instead of ar, as ar is not aware of .o files generated by clang -flto (cherry picked from commit 5ad36f9)

Co-authored-by: serge-sans-paille serge.guelton@telecom-bretagne.eu