Add gcov flags for build (#146)

* ENH: Added gcov flags for build

* MAINT: Changed build flag name to `gcov`

* TST: Added tests for `gcov` flag

* ENH: Added `perror` and few visual changes

* DOC: Added details on generating coverage reports

* Expand gcov documentation

* Minor tidy-up of meson_args list conversion

---------

Co-authored-by: Stefan van der Walt <stefanv@berkeley.edu>

.github/workflows/test.sh

@@ -3,11 +3,13 @@ set -e
 PLATFORM=$(python -c 'import sys; print(sys.platform)')
 
 RED="\033[31;1m"
+BLUE="\033[34m"
 MAGENTA="\033[35m"
 NORMAL="\033[0m"
 
 ptest() { echo -e "\n${MAGENTA}[TEST] $@${NORMAL}\n" ; }
-prun() { echo -e "$RED\$ $@ $NORMAL" ; "$@" ; }
+perror() { echo -e "\n${RED}[ERROR] $@${NORMAL}\n" ; }
+prun() { echo -e "${BLUE}\$ $@ ${NORMAL}" ; "$@" ; }
 
 prun cd example_pkg
 
@@ -16,13 +18,32 @@ prun spin --version
 
 ptest build command runs
 pip install meson-python ninja
-prun spin build
+
+
+# Test spin build + debug builds
+echo "Creating debug builds"
+prun spin build --gcov
+ptest Did the build folder get generated?
+if [ ! -d "build" ] || [ ! -d "build-install" ]; then
+    perror build and/or build-install folders did not get generated
+    exit 1
+else
+    echo "Yes"
+fi
+ptest Does the debug build contain gcov files?
+matching_files=$(find . -type f -name "*.gc*")
+if [ -z "$matching_files" ]; then
+    perror Debug files did not get generated
+    exit 1
+else
+    echo "Yes"
+fi
 
 ptest Does spin expand \$PYTHONPATH?
 SPIN_PYTHONPATH=$(spin run 'echo $PYTHONPATH')
 echo spin sees PYTHONPATH=\"${SPIN_PYTHONPATH}\"
 if [[ ${SPIN_PYTHONPATH} == "\$PYTHONPATH" ]]; then
-    echo "Expected Python path, but got $SPIN_PYTHONPATH instead"
+    perror Expected Python path, but got $SPIN_PYTHONPATH instead
     exit 1
 fi
 
@@ -39,7 +60,7 @@ VERSION=$(spin run python -c 'import sys; del sys.path[0]; import example_pkg; p
 if [[ $VERSION == "0.0.0dev0" ]]; then
     echo "Yes"
 else
-    echo "No, output is $VERSION"
+    perror No, output is $VERSION
     exit 1
 fi
 
@@ -49,7 +70,7 @@ OUT=$(spin run ls)
 if [[ $OUT == *"Warning! An editable installation"* ]]; then
     echo "Yes"
 else
-    echo "No"
+    perror No
     exit 1
 fi
 prun pip uninstall --quiet -y example_pkg
@@ -63,7 +84,7 @@ if [[ $PLATFORM == linux || $PLATFORM == darwin ]]; then
     if [[ $OUT == *"Did you mean to call"* ]]; then
         echo "Yes"
     else
-        echo "No, output is: $OUT"
+        perror No, output is: $OUT
         exit 1
     fi
 fi

spin/cmds/meson.py

@@ -130,8 +130,24 @@ def _meson_version_configured():
 @click.option(
     "-v", "--verbose", is_flag=True, help="Print detailed build and installation output"
 )
+@click.option(
+    "--gcov",
+    is_flag=True,
+    help="""Enable C code coverage via `gcov`.
+
+    The meson-generated `build/build.ninja` has targets for compiling
+    coverage reports.
+
+    E.g., to build an HTML report, in the `build` directory run
+     `ninja coverage-html`.
+
+    To see a list all supported formats, run
+    `ninja -t targets | grep coverage-`.
+
+    Also see https://mesonbuild.com/howtox.html#producing-a-coverage-report.""",
+)
 @click.argument("meson_args", nargs=-1)
-def build(meson_args, jobs=None, clean=False, verbose=False, quiet=False):
+def build(meson_args, jobs=None, clean=False, verbose=False, gcov=False, quiet=False):
     """🔧 Build package with Meson/ninja and install
 
     MESON_ARGS are passed through e.g.:
@@ -150,7 +166,12 @@ def build(meson_args, jobs=None, clean=False, verbose=False, quiet=False):
       CFLAGS="-O0 -g" spin build
     """
     build_dir = "build"
-    setup_cmd = _meson_cli() + ["setup", build_dir, "--prefix=/usr"] + list(meson_args)
+    meson_args = list(meson_args)
+
+    if gcov:
+        meson_args = meson_args + ["-Db_coverage=true"]
+
+    setup_cmd = _meson_cli() + ["setup", build_dir, "--prefix=/usr"] + meson_args
 
     if clean:
         print(f"Removing `{build_dir}`")
@@ -236,8 +257,15 @@ def _get_configured_command(command_name):
     is_flag=True,
     help="Generate a coverage report of executed tests. An HTML copy of the report is written to `build/coverage`.",
 )
+@click.option(
+    "--gcov",
+    is_flag=True,
+    help="Enable C code coverage via `gcov`. `gcov` output goes to `build/**/*.gc*`. "
+    "Reports can be generated using `ninja coverage*` commands. "
+    "See https://mesonbuild.com/howtox.html#producing-a-coverage-report",
+)
 @click.pass_context
-def test(ctx, pytest_args, n_jobs, tests, verbose, coverage=False):
+def test(ctx, pytest_args, n_jobs, tests, verbose, coverage=False, gcov=False):
     """🔧 Run tests
 
     PYTEST_ARGS are passed through directly to pytest, e.g.:
@@ -283,7 +311,7 @@ def test(ctx, pytest_args, n_jobs, tests, verbose, coverage=False):
         click.secho(
             "Invoking `build` prior to running tests:", bold=True, fg="bright_green"
         )
-        ctx.invoke(build_cmd)
+        ctx.invoke(build_cmd, gcov=gcov)
 
     package = cfg.get("tool.spin.package", None)
     if (not pytest_args) and (not tests):