[clang] [compiler-rt] [llvm] [dfsan] Add dataflow sanitizer support for SystemZ (PR #168991)

[Andrew Browne via cfe-commits]

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@@ -10,6 +10,8 @@
 
 # Setup default compiler flags used with -fsanitize=dataflow option.
 clang_dfsan_cflags = ["-fsanitize=dataflow"] + [config.target_cflags]
+if config.target_arch == "s390x":
+    clang_dfsan_cflags.append("-mbackchain")
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browneee wrote:

nit: Please phrase it a bit more explicitly:

# s390x arch needs -mbackchain to print stack backtrace of origin.

https://github.com/llvm/llvm-project/pull/168991