testing: export CC based on .cargo/config contents

We already need to test cargo about gcc locations so it can perfom
linking -- we just parse this information out to tell rust where
gcc is for complation (nix-test compiles some C code for testing).

Signed-off-by: Paul Osborne <[email protected]>

Author: posborne

ci/cargo-config

@@ -1,13 +1,25 @@
 # Configuration of which linkers to call on Travis for various architectures
 
+[target.x86_64-unknown-linux-gnu]
+linker = "gcc"
+
+[target.x86_64-unknown-linux-musl]
+linker = "gcc"
+
+[target.i686-unknown-linux-gnu]
+linker = "gcc"
+
+[target.i686-unknown-linux-musl]
+linker = "gcc"
+
 [target.arm-linux-androideabi]
 linker = "arm-linux-androideabi-gcc"
 
 [target.arm-unknown-linux-gnueabihf]
-linker = "arm-linux-gnueabihf-gcc-4.7"
+linker = "arm-linux-gnueabihf-gcc"
 
 [target.mips-unknown-linux-gnu]
-linker = "mips-linux-gnu-gcc-5"
+linker = "mips-linux-gnu-gcc"
 
 [target.aarch64-unknown-linux-gnu]
 linker = "aarch64-linux-gnu-gcc"

ci/run.sh

@@ -27,6 +27,17 @@ configure_cargo() {
   cp "${BASE_DIR}/ci/cargo-config" .cargo/config
 }
 
+#
+# We need to export CC for the tests to build properly (some C code is
+# compiled) to work.  We already tell Cargo about the compiler in the
+# cargo config, so we just parse that info out of the cargo config
+#
+cc_for_target() {
+  awk "/\[target\.${TARGET}\]/{getline; print}" .cargo/config |
+      cut -d '=' -f2 | \
+      tr -d '"' | tr -d ' '
+}
+
 cross_compile_tests() {
   case "$TARGET" in
     *-apple-ios)
@@ -99,6 +110,8 @@ test_binary() {
 
 configure_cargo
 
+export CC="$(cc_for_target)"
+
 # select the proper version
 multirust override ${VERSION}