Enable Kcov on macOS builds.

I agree to license my contributions to each file under the terms given
at the top of each file I changed.

.travis.yml

@@ -1,8 +1,7 @@
 language: rust
 cache:
   directories:
-    - $HOME/kcov-i686-unknown-linux-gnu
-    - $HOME/kcov-x86_64-unknown-linux-gnu
+    - $HOME/kcov
     - $HOME/android/android-sdk-linux
     - $HOME/android/armv7a-linux-androideabi26
 matrix:
@@ -17,10 +16,18 @@ matrix:
     #
     # BEGIN GENERATED
 
-    - env: TARGET_X=x86_64-apple-darwin  FEATURES_X= MODE_X=DEBUG KCOV=0
+    - env: TARGET_X=x86_64-apple-darwin  FEATURES_X= MODE_X=DEBUG KCOV=1
       rust: stable
       os: osx
       osx_image: xcode10.1
+      addons:
+        homebrew:
+          packages:
+            - bash
+            - cmake
+            - findutils
+            - pkgconfig
+            - zlib
 
     - env: TARGET_X=x86_64-apple-darwin  FEATURES_X= MODE_X=RELWITHDEBINFO KCOV=0
       rust: stable

mk/travis-install-kcov.sh

@@ -24,9 +24,10 @@ set -ex
 
 # kcov 26 or newer is needed when getting coverage information for Rust.
 # kcov 31 is needed so `kcov --version` doesn't exit with status 1.
+# kcov 36 is needed for accurate coverage on macOS.
 KCOV_VERSION=${KCOV_VERSION:-36}
 
-KCOV_INSTALL_PREFIX="${HOME}/kcov-${TARGET_X}"
+KCOV_INSTALL_PREFIX="${HOME}/kcov"
 
 # Check if kcov has been cached on travis.
 if [[ -f "$KCOV_INSTALL_PREFIX/bin/kcov" ]]; then

mk/travis.sh

@@ -153,8 +153,17 @@ if [[ "$KCOV" == "1" ]]; then
   RUSTFLAGS="-C link-dead-code" \
     cargo test -vv --no-run -j2  ${mode-} ${FEATURES_X-} --target=$TARGET_X
   mk/travis-install-kcov.sh
+
+  if [[ "$TARGET_X"  =~ "apple" ]]; then
+    # Add `/usr/bin` to the front of PATH to use the system python.
+    PATH="/usr/bin:$PATH"
+
+    # Add GNU find(1) from homebrew to PATH.
+    PATH="/usr/local/opt/findutils/libexec/gnubin:$PATH"
+  fi
+
   for test_exe in `find target/$TARGET_X/debug -maxdepth 1 -executable -type f`; do
-    ${HOME}/kcov-${TARGET_X}/bin/kcov \
+    ${HOME}/kcov/bin/kcov \
       --verify \
       --coveralls-id=$TRAVIS_JOB_ID \
       --exclude-path=/usr/include \

mk/update-travis-yml.py

@@ -100,12 +100,18 @@ entry_template = """
 
 entry_indent = "      "
 
-entry_packages_template = """
+entry_linux_packages_template = """
       addons:
         apt:
           packages:
             %(packages)s"""
 
+entry_macos_packages_template = """
+      addons:
+        homebrew:
+          packages:
+            %(packages)s"""
+
 entry_sources_template = """
           sources:
             %(sources)s"""
@@ -116,15 +122,15 @@ def format_entry(os, target, compiler, rust, mode, features):
     vendor = target_words[1]
     sys = target_words[2]
 
-    # Currently kcov only runs on Linux.
+    # Currently kcov only runs on Linux and macOS.
     #
     # GCC 7 was picked arbitrarily to restrict coverage report to one build for
     # efficiency reasons.
     #
     # DEBUG mode is needed because debug symbols are needed for coverage
     # tracking.
-    kcov = (os == "linux" and compiler == gcc and rust == "stable" and
-            mode == "DEBUG")
+    kcov = (((os == "linux" and compiler == gcc) or os == "osx")
+            and rust == "stable" and mode == "DEBUG")
 
     if sys == "darwin":
         abi = sys
@@ -139,28 +145,26 @@ def format_entry(os, target, compiler, rust, mode, features):
         return [prefix + x for x in xs]
 
     template = entry_template
+    packages = []
+    sources = []
 
     if sys == "linux":
+        template += """
+      dist: trusty"""
         packages = sorted(get_linux_packages_to_install(target, compiler, arch, kcov))
         sources_with_dups = sum([get_sources_for_package(p) for p in packages],[])
         sources = sorted(list(set(sources_with_dups)))
-        template += """
-      dist: trusty"""
-
-    if sys == "linux":
         if packages:
-            template += entry_packages_template
+            template += entry_linux_packages_template
         if sources:
             template += entry_sources_template
-    else:
-        packages = []
-        sources = []
+    elif sys == "macos":
+        os += "\n" + entry_indent + "osx_image: xcode10.1"
+        packages = sorted(get_macos_packages_to_install(target, compiler, arch, kcov))
+        if packages:
+            template += entry_macos_packages_template
 
     cc = compiler
-
-    if os == "osx":
-        os += "\n" + entry_indent + "osx_image: xcode10.1"
-
     compilers = []
     if cc != "":
         compilers += ["CC_X=" + cc]
@@ -178,6 +182,17 @@ def format_entry(os, target, compiler, rust, mode, features):
             "os" : os,
             }
 
+def get_macos_packages_to_install(target, compiler, arch, kcov):
+    packages = []
+
+    if kcov == True:
+        packages = ["bash",
+                    "cmake",
+                    "findutils",
+                    "pkgconfig",
+                    "zlib"]
+    return packages
+
 def get_linux_packages_to_install(target, compiler, arch, kcov):
     if compiler.startswith("clang-") or compiler.startswith("gcc-"):
         packages = [compiler]