Remove with-clang feature in favor of using $CC

Signed-off-by: Victor Porof <victor.porof@gmail.com>

.travis.yml

@@ -32,13 +32,12 @@ before_script:
 
 script:
   - cargo +nightly-2019-09-11 fmt --all -- --check
-  - cargo +nightly-2019-09-11 clippy --all-features -- -D warnings -A clippy::match-ref-pats -A clippy::needless-lifetimes
-  - cargo build --features with-clang --verbose
-  - cargo build --features with-asan --verbose
-  - cargo build --features with-fuzzer --verbose
-  - cargo build --features with-fuzzer-no-link --verbose
-  - cargo build --features with-asan,with-fuzzer --verbose
-  - cargo build --features with-asan,with-fuzzer-no-link --verbose
+  - CC="clang" cargo +nightly-2019-09-11 clippy --all-features -- -D warnings -A clippy::match-ref-pats -A clippy::needless-lifetimes
+  - CC="clang" cargo build --features with-asan --verbose
+  - CC="clang" cargo build --features with-fuzzer --verbose
+  - CC="clang" cargo build --features with-fuzzer-no-link --verbose
+  - CC="clang" cargo build --features with-asan,with-fuzzer --verbose
+  - CC="clang" cargo build --features with-asan,with-fuzzer-no-link --verbose
   - cargo build --verbose
   - export RUST_BACKTRACE=1
   - cargo test --all --verbose

Cargo.toml

@@ -53,7 +53,6 @@ tempdir = "0.3"
 
 [features]
 default = []
-with-clang = ["lmdb-rkv-sys/with-clang"]
 with-asan = ["lmdb-rkv-sys/with-asan"]
 with-fuzzer = ["lmdb-rkv-sys/with-fuzzer"]
 with-fuzzer-no-link = ["lmdb-rkv-sys/with-fuzzer-no-link"]

lmdb-sys/Cargo.toml

@@ -33,10 +33,9 @@ bindgen = "0.51"
 
 [features]
 default = []
-with-clang = []
-with-asan = ["with-clang"]
-with-fuzzer = ["with-clang"]
-with-fuzzer-no-link = ["with-clang"]
+with-asan = []
+with-fuzzer = []
+with-fuzzer-no-link = []
 
 # These features configure the MDB_IDL_LOGN macro, which determines
 # the size of the free and dirty page lists (and thus the amount of memory

lmdb-sys/build.rs

@@ -61,10 +61,6 @@ fn main() {
             .flag_if_supported("-Wbad-function-cast")
             .flag_if_supported("-Wuninitialized");
 
-        if env::var("CARGO_FEATURE_WITH_CLANG").is_ok() {
-            builder.compiler("clang");
-        }
-
         if env::var("CARGO_FEATURE_WITH_ASAN").is_ok() {
             builder.flag("-fsanitize=address");
         }