SERVER-50125 Add sanitizer blacklist files to CCACHE_EXTRAFILES

Some versions of ccache do not know how to handle clang's
-fsanitizer-blacklist flags. Some versions don't handle it at all, while
others only handle one instance, even though it can appear multiple
times on the command line. Because the argument can change the resulting
compiled object, not taking the flags into account properly can cause
ccache to pull an incorrect object file from its cache. The exact
behavior depends on the ccache version and how the arguments are changed
on the command line. We implement a workaround suggested by the ccache
developers until a newer version of ccache with all the required fixes
is in common use.

    * Workaround ref: https://github.com/ccache/ccache/issues/174

1 files changed, 10 insertions, 0 deletions

diff --git a/site_scons/site_tools/next/ccache.py b/site_scons/site_tools/next/ccache.py
index d96dd848771..2a894919f8d 100644
--- a/site_scons/site_tools/next/ccache.py
+++ b/site_scons/site_tools/next/ccache.py
@@ -138,6 +138,16 @@ def generate(env):
             env["ENV"]["CCACHE_CPP2"] = "1"
             env.AppendUnique(CCFLAGS=["-fdirectives-only"])
 
+    # Ensure ccache accounts for any extra files in use that affects the generated object
+    # file. This can be used for situations where a file is passed as an argument to a
+    # compiler parameter and differences in the file need to be accounted for in the
+    # hash result to prevent erroneous cache hits.
+    if "CCACHE_EXTRAFILES" in env and env["CCACHE_EXTRAFILES"]:
+        env["ENV"]["CCACHE_EXTRAFILES"] = ":".join([
+            blackfile.path
+            for blackfile in env["CCACHE_EXTRAFILES"]
+        ])
+
     # Make a generator to expand to CCACHE in the case where we are
     # not a conftest. We don't want to use ccache for configure tests
     # because we don't want to use icecream for configure tests, but