[compiler-rt] [build_symbolizer] Introduce ZLIB_SRC to specify an on-disk location for (PR #70994)

[Hongtao Yu via llvm-commits]

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@@ -63,7 +71,15 @@ FLAGS+=" -include ${SRC_DIR}/../sanitizer_redefine_builtins.h -DSANITIZER_COMMON
 LINKFLAGS="-fuse-ld=lld -target $TARGET_TRIPLE"
 
 # Build zlib.
-[[ -d ${ZLIB_BUILD} ]] || git clone https://github.com/madler/zlib ${ZLIB_BUILD}
+if [[ -d ${ZLIB_BUILD} ]]; then
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htyu wrote:

Should this be `if [[ ! -d ${ZLIB_BUILD} ]]` ?

https://github.com/llvm/llvm-project/pull/70994