replace opam variable with environment variables

CHANGES.md

@@ -1,3 +1,8 @@
+(trunk):
+* Avoid including intrinsics-related headers if SSE/AES-NI is disabled
+* Replace opam variable `nocrypto-inhibit-modernity` with `$NOCRYPTO_NO_ACCEL`
+* Remove cstruct equality
+
 0.5.1 (2015-07-07):
 * Disable AES-NI if not supported in the `./configure` step.
 * Support the global opam variable `nocrypto-inhibit-modernity`.

README.md

@@ -36,27 +36,11 @@ compiled the library with acceleration, but you are using it on a machine that d
 
 `./configure --enable-modernity` enables non-portable code if the build machine supports it.
 
-It defaults to `enable`, but the `opam` file disables it if global opam variable
-`nocrypto-inhibit-modernity` is `true`. You can do something like:
-
-```
-switch=$(opam config var switch)
-echo 'nocrypto-inhibit-modernity: true' >> ~/.opam/${switch}/config/global-config.config
-```
-
-#### Opam woes
-
-Opam dies:
-
-```
-[ERROR] nocrypto-inhibit-modernity is not a valid variable.
-[WARNING] Invalid variable nocrypto-inhibit-modernity in filter
-[ERROR] 'nocrypto-inhibit-modernity' has type string, but a env element of type bool was expected.
-[ERROR] The compilation of nocrypto.XXX failed.
-```
-
-Either upgrade opam, or set the variable, as above.
+The flag defaults to `enable`.
 
+A second way to disable this feature is by exporting `$NOCRYPTO_NO_ACCEL`
+environment variable during build. This is desirable, for example, when building
+via `opam`.
 
 [docs]: http://mirleft.github.io/ocaml-nocrypto
 [nocrypto-mli]: https://github.com/mirleft/ocaml-nocrypto/blob/master/src/nocrypto.mli

opam

@@ -8,7 +8,6 @@ license:      "BSD2"
 
 build: [
   [ "./configure" "--prefix" prefix
-     "--disable-modernity" {nocrypto-inhibit-modernity}
      "--%{lwt:enable}%-lwt"
      "--%{mirage-xen+mirage-entropy-xen:enable}%-xen" ]
   [ make ]

postconf

@@ -8,11 +8,18 @@ XEN_CFLAGS="disabled"
 grep -q '^xen="true"' setup.data && XEN_CFLAGS="$(pkg-config --static mirage-xen --cflags)"
 echo "XEN_CFLAGS=\"${XEN_CFLAGS}\"" >> setup.data
 
-# Kill CPU acceleration if requested but unsupported by the current host.
+# Kill CPU acceleration if requested in ./configure, but:
+# * unsupported by the current host CPU;
+# * unsupported by the current toolchain; or
+# * disabled via NOCRYPTO_NO_ACCEL env var.
 #
-if grep -q '^modernity="true"' setup.data; then
+function test_platform {
   CPUDETECT=$(mktemp -t nocrypto.XXXXXX)
-  ( cc src/native/cpudetect_static.c -o ${CPUDETECT} > /dev/null 2>&1 \
-      && ${CPUDETECT} ) || echo "modernity=\"false\"" >> setup.data
+  (cc src/native/cpudetect_static.c -o ${CPUDETECT} > /dev/null 2>&1 && ${CPUDETECT})
+  ok=$?
   rm -f ${CPUDETECT}
+  return $ok
+}
+if grep -q '^modernity="true"' setup.data; then
+  [[ -z $NOCRYPTO_NO_ACCEL ]] && test_platform || echo "modernity=\"false\"" >> setup.data
 fi