SERVER-125835 Simplify Fuzzer build options (#53552)

GitOrigin-RevId: f55bc770d4562167414322841a5af2b443a55baf

.bazelrc

@@ -634,6 +634,11 @@ common:fission --remote_download_regex=.*\.dwo$
 --config=fuzztest
 common:fuzztest --no@fuzztest//fuzztest:use_riegeli
 common:fuzztest --@fuzztest//fuzztest:centipede_integration=True
+common:fuzztest --//bazel/config:fsan=True
+common:fuzztest --//bazel/config:ubsan=True
+common:fuzztest --//bazel/config:opt=debug
+common:fuzztest --//bazel/config:allocator=system
+common:fuzztest --compiler_type=clang
 
 # Avoid failing builds when BES metadata fails to upload.
 common --bes_upload_mode=fully_async

bazel/toolchains/cc/mongo_linux/mongo_linux_cc_toolchain_config.bzl

@@ -1766,11 +1766,6 @@ def _impl(ctx):
         ],
     )
 
-    # By default, undefined behavior sanitizer doesn't stop on the first error. Make
-    # it so. Newer versions of clang have renamed the flag. However, this flag
-    # cannot be included when using the fuzzer sanitizer if we want to suppress
-    # errors to uncover new ones.
-
     # In dynamic builds, the `vptr` sanitizer check can require additional
     # dependency edges. That is very inconvenient, because such builds can't use
     # z,defs. The result is a very fragile link graph, where refactoring the link
@@ -1779,9 +1774,7 @@ def _impl(ctx):
     # approaches in SERVER-49798 of adding a new descriptor type, but that didn't
     # address the fundamental issue that the correct link graph for a dynamic+ubsan
     # build isn't the same as the correct link graph for a regular dynamic build.
-    ubsan_compile_flags = []
-    if not ctx.attr.fsan_enabled:
-        ubsan_compile_flags += ["-fno-sanitize-recover"]
+    ubsan_compile_flags = ["-fno-sanitize-recover"]
     if not ctx.attr.linkstatic:
         ubsan_compile_flags += ["-fno-sanitize=vptr"]
     ubsan_feature = feature(

etc/ubsan.denylist

@@ -9,10 +9,13 @@ fun:_ZN8S2CellId14FromFaceIJWrapEiii
 
 src:src/third_party/abseil-cpp/dist/absl/numeric/int128_have_intrinsic.inc
 
+# fuzztest calls memcpy with a null dst when deserializing empty byte-vector corpus entries.
+src:external/fuzztest~/*
+
 # SERVER-62972
 # libunwind has some UB when doing stack unwinding
 [alignment]
 fun:access_mem
 
 # TODO SERVER-102630 warns of unaligned access on code whose purpose is to prevent unaligned access.
-src:src/third_party/gperftools/dist/src/base/basictypes.h
+src:src/third_party/gperftools/dist/src/base/basictypes.h