Don't try to link C from rust doctests for nss detection

This is really annoying, since we can't use cfg(test) for doctests.

2 files changed, 17 insertions, 3 deletions

diff --git a/src/rust/protover/Cargo.toml b/src/rust/protover/Cargo.toml
index a8480e142a..2f7783e76c 100644
--- a/src/rust/protover/Cargo.toml
+++ b/src/rust/protover/Cargo.toml
@@ -4,6 +4,11 @@ version = "0.0.1"
 name = "protover"
 
 [features]
+# We have to define a feature here because doctests don't get cfg(test),
+# and we need to disable some C dependencies when running the doctests
+# because of the various linker issues.  See
+# https://github.com/rust-lang/rust/issues/45599
+test_linking_hack = []
 
 [dependencies]
 libc = "=0.2.39"
@@ -27,4 +32,3 @@ path = "../tor_log"
 name = "protover"
 path = "lib.rs"
 crate_type = ["rlib", "staticlib"]
-
diff --git a/src/rust/protover/protover.rs b/src/rust/protover/protover.rs
index 7b3f808cb2..8417d85959 100644
--- a/src/rust/protover/protover.rs
+++ b/src/rust/protover/protover.rs
@@ -10,7 +10,6 @@ use std::str::FromStr;
 use std::string::String;
 
 use external::c_tor_version_as_new_as;
-use external::c_tor_is_using_nss;
 
 use errors::ProtoverError;
 use protoset::ProtoSet;
@@ -125,6 +124,17 @@ impl From<Protocol> for UnknownProtocol {
     }
 }
 
+#[cfg(feature="test_linking_hack")]
+fn have_linkauth_v1() -> bool {
+    true
+}
+
+#[cfg(not(feature="test_linking_hack"))]
+fn have_linkauth_v1() -> bool {
+    use external::c_tor_is_using_nss;
+    ! c_tor_is_using_nss()
+}
+
 /// Get a CStr representation of current supported protocols, for
 /// passing to C, or for converting to a `&str` for Rust.
 ///
@@ -142,7 +152,7 @@ impl From<Protocol> for UnknownProtocol {
 ///
 //  C_RUST_COUPLED: protover.c `protover_get_supported_protocols`
 pub(crate) fn get_supported_protocols_cstr() -> &'static CStr {
-    if c_tor_is_using_nss() {
+    if ! have_linkauth_v1() {
         cstr!("Cons=1-2 \
                Desc=1-2 \
                DirCache=1-2 \