Introduce test coverage.

.gitignore

@@ -1,3 +1,4 @@
+Makefile.local
 # files generated by configure
 Makefile.configure
 config.h
@@ -15,5 +16,10 @@ lowdown-diff
 lowdown.pc
 lowdown.tar.gz
 lowdown.tar.gz.sha512
+# files for valgrind
 *.valgrind
 *.diff-valgrind
+# files for gcov
+*.gcno
+*.gcov
+*.gcda

Makefile

@@ -2,6 +2,8 @@
 .SUFFIXES: .xml .md .html .pdf .1 .1.html .3 .3.html .5 .5.html .thumb.jpg .png .in.pc .pc .valgrind .old.md .diff-valgrind
 
 include Makefile.configure
+WWWDIR		 = /var/www/vhosts/kristaps.bsd.lv/htdocs/lowdown
+sinclude Makefile.local
 
 # Follows semver.
 # This is complex because lowdown is both a program and a library; and
@@ -30,7 +32,6 @@ OBJS		 = autolink.o \
 		   tree.o \
 		   util.o
 COMPAT_OBJS	 = compats.o
-WWWDIR		 = /var/www/vhosts/kristaps.bsd.lv/htdocs/lowdown
 HTMLS		 = archive.html \
 		   atom.xml \
 		   diff.html \
@@ -326,6 +327,14 @@ $(HTMLS): versions.xml lowdown
 	  ./lowdown $< ; \
 	  echo "</article>" ; ) >$@
 
+index.xml: index.md coverage.md coverage-table.md lowdown
+	( echo "<?xml version=\"1.0\" encoding=\"UTF-8\" ?>" ; \
+	  echo "<article data-sblg-article=\"1\">" ; \
+	  ./lowdown index.md ; \
+	  ./lowdown coverage.md ; \
+	  ./lowdown coverage-table.md ; \
+	  echo "</article>" ; ) >$@
+
 .1.1.html .3.3.html .5.5.html:
 	mandoc -Thtml -Ostyle=https://bsd.lv/css/mandoc.css $< >$@
 
@@ -372,6 +381,20 @@ clean:
 distclean: clean
 	rm -f Makefile.configure config.h config.log config.h.old config.log.old
 
+coverage-table.md:
+	$(MAKE) clean
+	CC=gcc CFLAGS="--coverage" ./configure LDFLAGS="--coverage"
+	$(MAKE) regress
+	( echo "| Files | Coverage |" ; \
+	  echo "|-------|----------|" ; \
+	  for f in $(OBJS) ; do \
+	  	src=$$(basename $$f .o).c ; \
+		pct=$$(gcov -H $$src | grep 'Lines executed' | head -n1 | \
+			cut -d ":" -f 2 | cut -d "%" -f 1) ; \
+	  	echo "| $$src | $$pct% | " ; \
+	  done ; \
+	) >coverage-table.md
+
 regen_regress: bins
 	@tmp1=`mktemp` ; \
 	tmp2=`mktemp` ; \

coverage-table.md

@@ -0,0 +1,19 @@
+| Files | Coverage |
+|-------|----------|
+| autolink.c | 65.73% | 
+| buffer.c | 71.91% | 
+| diff.c | 79.40% | 
+| document.c | 74.01% | 
+| entity.c | 40.74% | 
+| gemini.c | 65.91% | 
+| html.c | 66.51% | 
+| html_escape.c | 87.65% | 
+| latex.c | 64.08% | 
+| library.c | 80.14% | 
+| libdiff.c | 94.05% | 
+| nroff.c | 71.38% | 
+| odt.c | 63.64% | 
+| smartypants.c | 83.89% | 
+| term.c | 67.54% | 
+| tree.c | 34.84% | 
+| util.c | 6.38% | 

coverage.md

@@ -0,0 +1,7 @@
+## Coverage
+
+The regression suite executes the *lowdown* code in many ways.  It's
+easy to track this by examining run-time coverage using
+[gcov](https://gcc.gnu.org/onlinedocs/gcc/Gcov.html) (or the clang
+alternative).  To examine how the regression suite covers the sources,
+run `make coverage`.  The current coverage is as follows: