Makefile.am (bench): New target

The configure script will determine if nightly is required for running
benchmarks, because `test` is currently an unstable feature.

5 files changed, 59 insertions, 1 deletions

diff --git a/tamer/Cargo.toml b/tamer/Cargo.toml
index 9880167..406afcb 100644
--- a/tamer/Cargo.toml
+++ b/tamer/Cargo.toml
@@ -17,6 +17,11 @@ opt-level = 3
 [profile.release]
 lto = true
 
+[profile.bench]
+# We want our benchmarks to be representative of how well TAME will perform
+# in a release.
+lto = true
+
 [dependencies]
 quick-xml = ">= 0.17.0"
 petgraph = ">= 0.4.13"
diff --git a/tamer/Makefile.am b/tamer/Makefile.am
index 3248bc6..8e78117 100644
--- a/tamer/Makefile.am
+++ b/tamer/Makefile.am
@@ -18,7 +18,7 @@
 
 .DELETE_ON_ERROR:
 
-.PHONY: all fix fmt
+.PHONY: all fix fmt check-fmt bench
 
 CARGO_BUILD_FLAGS=@CARGO_BUILD_FLAGS@
 
@@ -37,6 +37,9 @@ check-am: check-fmt
 check-fmt:
 	@CARGO@ fmt -- --check
 
+bench:
+	@CARGO@ @CARGO_BENCH_FLAGS@ bench
+
 fix: fmt
 fmt:
 	@CARGO@ fmt
diff --git a/tamer/README.md b/tamer/README.md
index 2d14ef4..4f602f0 100644
--- a/tamer/README.md
+++ b/tamer/README.md
@@ -78,3 +78,20 @@ If you want to automatically fix formatting errors and then run tests:
 ```sh
 $ make fmt check
 ```
+
+
+## Benchmarking
+Benchmarks serve two purposes: external integration tests (which are subject
+to module visibility constraints) and actual benchmarking.  To run
+benchmarks, invoke `make bench`.
+
+Note that link-time optimizations (LTO) are performed on the binary for
+benchmarking so that its performance reflects release builds that will be
+used in production.
+
+The `configure` script will automatically detect whether the `test` feature
+is unstable (as it was as of the time of writing) and, if so, will
+automatically fall back to invoking nightly (by running `cargo +nightly
+bench`).
+
+If you do not have nightly, run you install it via `rustup install nightly`.
diff --git a/tamer/build-aux/bench_check.rs b/tamer/build-aux/bench_check.rs
new file mode 100644
index 0000000..ac3d8e6
--- /dev/null
+++ b/tamer/build-aux/bench_check.rs
@@ -0,0 +1,23 @@
+// Feature check for `test`
+//
+//  Copyright (C) 2014-2019 Ryan Specialty Group, LLC.
+//
+//  This program is free software: you can redistribute it and/or modify
+//  it under the terms of the GNU General Public License as published by
+//  the Free Software Foundation, either version 3 of the License, or
+//  (at your option) any later version.
+//
+//  This program is distributed in the hope that it will be useful,
+//  but WITHOUT ANY WARRANTY; without even the implied warranty of
+//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+//  GNU General Public License for more details.
+//
+//  You should have received a copy of the GNU General Public License
+//  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+// As of the time of writing, this feature is unstable and can only be
+// enabled in nightly.  This file is intended to be used in the `configure`
+// script to determine whether a nightly version of Rust must be used to
+// invoke benchmarks.
+#![feature(test)]
+
diff --git a/tamer/configure.ac b/tamer/configure.ac
index 350b77b..f2a1bff 100644
--- a/tamer/configure.ac
+++ b/tamer/configure.ac
@@ -55,6 +55,16 @@ AX_COMPARE_VERSION([$rustc_version], [ge], [$rustc_ver_req],
 AC_ARG_VAR([CARGO_BUILD_FLAGS],
            [Flags to be passed to `cargo build' when invoked via Make])
 
+# The `test` feature is required for benchmarking.  If unavailable, then
+# it's still an unstable feature and we'll need to use nightly.  We don't
+# check for nightly here, though---if it's missing, then cargo will tell the
+# user what to do.
+AC_MSG_CHECKING([`test` feature support])
+AS_IF(["$RUSTC" --crate-type lib build_aux/bench_check.rs &>/dev/null],
+      [AC_MSG_RESULT(available)],
+      [AC_MSG_RESULT([no (nightly required)])
+       AC_SUBST([CARGO_BENCH_FLAGS], [+nightly])])
+
 # Cargo commands may be available but not necessarily installed for the
 # active toolchain.  Let's check that.
 AC_MSG_CHECKING([whether cargo-fmt is available for active toolchain])