Add cargo-kconv to travis config

- Use cargo-kconv to install kconv, upload to coveralls
- Add script to workaround ICE in rustc when building proptest with
'-C link-dead-code'

.travis.yml

@@ -3,3 +3,30 @@ cache: cargo
 rust:
   - stable
   - beta
+addons:
+  apt:
+    packages:
+      # for kcov build
+      - binutils-dev
+      - libcurl4-openssl-dev
+      - zlib1g-dev
+      - libdw-dev
+      - libiberty-dev
+      - libelf-dev
+      - cmake
+      - gcc
+      - pkg-config
+      - jq
+
+jobs:
+  include:
+    - stage: "Coverage"
+      name: "cargo-kcov"
+      script:
+        - cargo kcov --version || cargo install cargo-kcov
+        - |
+            [[ -x $HOME/.cargo/bin/kcov ]] && echo "kcov bin found in cache" || cargo kcov --print-install-kcov-sh | sh
+        # FIXME: When rust-lang/rust#52478 is fixed, we can remove the rustc shim script
+        # but also cargo kcov seems to fail with a different error when doing the build by itself.
+        - RUSTC="./rustc_ice_proptest_fix.sh" cargo test --no-run
+        - cargo kcov --verbose --no-clean-rebuild --coveralls

rustc_ice_proptest_fix.sh

@@ -0,0 +1,28 @@
+#!/usr/bin/env python3
+#
+# This script modifies calls to rustc such that the '-C link-dead-code'
+# compiler option is not passed only when building the proptest crate.
+# The link-dead-code option is necessary for accurate code coverage.
+# When https://github.com/rust-lang/rust/issues/52478 is fixed, or proptest is
+# modified to somehow not trigger the bug, this script can be deleted, and the
+# travis config updated.
+
+import os
+import sys
+
+argv = sys.argv[1:]
+
+try:
+    pkg_name = os.environ['CARGO_PKG_NAME']
+except KeyError:
+    pass
+else:
+    if pkg_name == 'proptest':
+        try:
+            pos = list(zip(argv, argv[1:])).index(('-C', 'link-dead-code'))
+        except ValueError:
+            pass
+        else:
+            argv[pos:pos + 2] = []
+
+os.execv('/usr/bin/env', ['env', 'rustc'] + argv)