WIP: Support for sanitizers

This works fine when composing, but for some reason the client
side apparently infinite loops inside libsolv:

```
(lldb) thread backtrace
* thread #4, name = 'pool-/usr/bin/r'
  * frame #0: 0x00007fd61b97200f libc.so.6`__memcpy_sse2_unaligned_erms + 623
    frame #1: 0x00007fd61cbc88e6 libasan.so.6`__asan::asan_realloc(void*, unsigned long, __sanitizer::BufferedStackTrace*) + 214
    frame #2: 0x00007fd61cc4b725 libasan.so.6`__interceptor_realloc + 245
    frame #3: 0x00007fd61baec43e libsolv.so.1`solv_realloc + 30
    frame #4: 0x00007fd61baf0414 libsolv.so.1`repodata_add_dirstr + 276
    frame #5: 0x00007fd61bb6f755 libsolvext.so.1`end_element + 53
    frame #6: 0x00007fd61b05855d libxml2.so.2`xmlParseEndTag1.constprop.0 + 317
    frame #7: 0x00007fd61b063548 libxml2.so.2`xmlParseTryOrFinish.isra.0 + 888
    frame #8: 0x00007fd61af7ed20 libxml2.so.2`xmlParseChunk + 560
    frame #9: 0x00007fd61bb727e7 libsolvext.so.1`solv_xmlparser_parse + 183
    frame #10: 0x00007fd61bb5ea0e libsolvext.so.1`repo_add_rpmmd + 254
    frame #11: 0x000055a4fce7a5f5 rpm-ostree`::load_filelists_cb(repo=<unavailable>, fp=<unavailable>) at dnf-sack.cpp:444:23
    frame #12: 0x000055a4fce7cad6 rpm-ostree`load_ext(_DnfSack*, libdnf::Repo*, _hy_repo_repodata, char const*, char const*, int (*)(s_Repo*, _IO_FILE*), _GError**) at dnf-sack.cpp:430:13
    frame #13: 0x000055a4fce7df60 rpm-ostree`dnf_sack_load_repo at dnf-sack.cpp:1789:26
    frame #14: 0x000055a4fce7eee9 rpm-ostree`dnf_sack_add_repo at dnf-sack.cpp:2217:28
    frame #15: 0x000055a4fce7f0fb rpm-ostree`dnf_sack_add_repos at dnf-sack.cpp:2271:32
    frame #16: 0x000055a4fce870ee rpm-ostree`dnf_context_setup_sack_with_flags at dnf-context.cpp:1796:29
    frame #17: 0x000055a4fcdf757f rpm-ostree`rpmostree_context_download_metadata at rpmostree-core.cxx:1206:44
    frame #18: 0x000055a4fcdf95c3 rpm-ostree`rpmostree_context_prepare at rpmostree-core.cxx:2001:48
    frame #19: 0x000055a4fce54ab7 rpm-ostree`rpmostree_sysroot_upgrader_prep_layering at rpmostree-sysroot-upgrader.cxx:1018:38
    frame #20: 0x000055a4fcdcb143 rpm-ostree`deploy_transaction_execute(_RpmostreedTransaction*, _GCancellable*, _GError**) at rpmostreed-transaction-types.cxx:1445:49
    frame #21: 0x000055a4fcdba4cd rpm-ostree`transaction_execute_thread(_GTask*, void*, void*, _GCancellable*) at rpmostreed-transaction.cxx:340:34
    frame #22: 0x00007fd61c58f7e2 libgio-2.0.so.0`g_task_thread_pool_thread + 114
    frame #23: 0x00007fd61c3d7e54 libglib-2.0.so.0`g_thread_pool_thread_proxy.lto_priv.0 + 116
    frame #24: 0x00007fd61c3d52b2 libglib-2.0.so.0`g_thread_proxy + 82
    frame #25: 0x00007fd61b8af3f9 libpthread.so.0`start_thread + 233
    frame #26: 0x00007fd61b9c9903 libc.so.6`__clone + 67
(lldb)
```

Cargo.toml

@@ -87,5 +87,7 @@ lto = true
 [features]
 sqlite-rpmdb-default = []
 fedora-integration = []
+# ASAN+UBSAN
+sanitizers = []
 
 default = []

Makefile-rpm-ostree.am

@@ -86,7 +86,7 @@ rpmostree_common_libs = libglnx.la librpmostree-1.la librpmostreecxxrs.la
 
 rpmostree_bin_common_libs = librpmostreeinternals.la $(rpmostree_common_libs)
 librpmostreeinternals_la_CFLAGS = $(AM_CFLAGS) $(rpmostree_common_cflags)
-librpmostreeinternals_la_CXXFLAGS = $(AM_CXXFLAGS) $(rpmostree_common_cflags)
+librpmostreeinternals_la_CXXFLAGS = $(AM_CXXFLAGS) $(SANITIZER_FLAGS) $(rpmostree_common_cflags)
 librpmostreeinternals_la_LIBADD = $(rpmostree_common_libs)
 
 privdatadir=$(pkglibdir)
@@ -101,6 +101,9 @@ endif
 if BUILDOPT_ENABLE_SQLITE_RPMDB_DEFAULT
 cargo_build += --features sqlite-rpmdb-default
 endif
+if BUILDOPT_ASAN
+cargo_build += --features sanitizers
+endif
 
 if RUST_DEBUG
 cargo_target_dir=debug
@@ -136,7 +139,7 @@ endif
 noinst_LTLIBRARIES += librpmostreecxxrs.la
 librpmostreecxxrs_la_SOURCES = rpmostree-cxxrs.h rpmostree-cxxrs.cxx
 # Suppress missing-declarations because https://github.com/dtolnay/cxx/issues/590
-librpmostreecxxrs_la_CXXFLAGS = $(AM_CXXFLAGS) $(rpmostree_common_cflags) -Wno-missing-declarations
+librpmostreecxxrs_la_CXXFLAGS = $(AM_CXXFLAGS) $(SANITIZER_FLAGS) $(rpmostree_common_cflags) -Wno-missing-declarations
 librpmostreecxxrs_la_LIBADD = -lstdc++
 GITIGNOREFILES += $(binding_generated_sources)
 BUILT_SOURCES += $(binding_generated_sources)

build.rs

@@ -16,6 +16,11 @@ fn detect_fedora_feature() -> Result<()> {
 }
 
 fn main() -> Result<()> {
+    if std::env::var("CARGO_FEATURE_SANITIZERS").is_ok() {
+        // Force these on
+        println!("cargo:rustc-link-lib=ubsan");
+        println!("cargo:rustc-link-lib=asan");
+    }
     let cwd = std::env::current_dir()?;
     let cwd = cwd.to_str().expect("utf8 pwd");
     println!("cargo:rustc-link-search={}/.libs", cwd);

configure.ac

@@ -47,14 +47,15 @@ CC_CHECK_FLAGS_APPEND([WARN_CFLAGS], [CFLAGS], [\
 ])])
 AC_SUBST(WARN_CFLAGS)
 
-AC_MSG_CHECKING([for -fsanitize=address in CFLAGS])
-if echo $CFLAGS | grep -q -e -fsanitize=address; then
-AC_MSG_RESULT([yes])
-using_asan=yes
-else
-AC_MSG_RESULT([no])
-fi
-AM_CONDITIONAL(BUILDOPT_ASAN, [test x$using_asan = xyes])
+AC_ARG_ENABLE(sanitizers,
+              AS_HELP_STRING([--enable-sanitizers],
+                             [Enable ASAN and UBSAN (default: no)]),,
+              [enable_sanitizers=no])
+AM_CONDITIONAL(BUILDOPT_ASAN, [test x$enable_sanitizers != xno])
+AM_COND_IF([BUILDOPT_ASAN], [
+  SANITIZER_FLAGS="-fsanitize=address -fsanitize=undefined -fsanitize-undefined-trap-on-error"
+  AC_SUBST([SANITIZER_FLAGS])
+])
 
 # Initialize libtool
 LT_PREREQ([2.2.4])
@@ -164,6 +165,7 @@ echo "
 
     introspection:                           $found_introspection
     rojig:                                   ${enable_rojig:-no}
+    ASAN + UBSAN:                            ${enable_sanitizers:-no}
     gtk-doc:                                 $enable_gtk_doc
     rust:                                    $rust_debug_release
     cbindgen:                                ${cbindgen:-external}

packaging/rpm-ostree.spec.in

@@ -22,6 +22,12 @@ BuildRequires: cargo
 BuildRequires: rust
 %endif
 
+# Enable ASAN + UBSAN
+%bcond_with sanitizers
+%if %{with sanitizers}
+%define sanitizer_flag "--enable-sanitizers"
+%endif
+
 # RHEL8 doesn't ship zchunk today.  See also the comments
 # in configure.ac around this as libdnf/librepo need to be in
 # sync, and today we bundle libdnf but not librepo.
@@ -131,7 +137,8 @@ env NOCONFIGURE=1 ./autogen.sh
 # the %%configure macro today assumes (reasonably) that one is building
 # C/C++ and sets C{,XX}FLAGS
 export RUSTFLAGS="%{build_rustflags}"
-%configure --disable-silent-rules --enable-gtk-doc %{?sqlite_rpmdb_default}
+%configure --disable-silent-rules --enable-gtk-doc %{?sqlite_rpmdb_default} %{?sanitizer_flag} 
+
 %make_build
 
 %install