From 2bb11bb176b8feec6ea06af157bcede1de30bd1f Mon Sep 17 00:00:00 2001
From: Peter Eisentraut <peter_e@gmx.net>
Date: Thu, 10 Aug 2017 23:33:47 -0400
Subject: [PATCH v2 3/9] Add lcov --initial

By just running lcov on the produced .gcda data files, we don't account
for source files that are not touched by tests at all.  To fix that, run
lcov --initial to create a base line info file with all zero counters,
and merge that with the actual counters when creating the final report.
---
 .gitignore             |  2 +-
 src/Makefile.global.in | 25 +++++++++++++++++++------
 2 files changed, 20 insertions(+), 7 deletions(-)

diff --git a/.gitignore b/.gitignore
index 2052f719d1..de6365cb4f 100644
--- a/.gitignore
+++ b/.gitignore
@@ -19,7 +19,7 @@ objfiles.txt
 .deps/
 *.gcno
 *.gcda
-lcov.info
+lcov*.info
 coverage/
 coverage-stamp
 *.vcproj
diff --git a/src/Makefile.global.in b/src/Makefile.global.in
index 7d8f3dd33d..c95cff543b 100644
--- a/src/Makefile.global.in
+++ b/src/Makefile.global.in
@@ -863,19 +863,32 @@ endif # enable_nls
 #		(by gcc -ftest-coverage)
 #   foo.gcda	gcov data file, created when the program is run (for
 #		programs compiled with gcc -fprofile-arcs)
-#   lcov.info	lcov tracefile, built from gcda files in one directory,
+#   lcov_test.info
+#		lcov tracefile, built from gcda files in one directory,
 #		later collected by "make coverage-html"
+#   lcov_base.info
+#		tracefile for zero counters for every file, so that
+#		even files that are not touched by tests are counted
+#		for the overall coverage rate
 
 ifeq ($(enable_coverage), yes)
 
+LCOV += --gcov-tool $(GCOV)
+LCOVFLAGS = --no-external
+
+gcno_files = $(shell find . -name '*.gcno' -print)
+
+lcov_base.info: $(gcno_files)
+	$(LCOV) $(LCOVFLAGS) -c -i -d . -o $@
+
 gcda_files = $(shell find . -name '*.gcda' -print)
 
-lcov.info: $(gcda_files)
-	$(LCOV) -d . -c -o $@ $(LCOVFLAGS) --gcov-tool $(GCOV) --no-external
+lcov_test.info: $(gcda_files)
+	$(LCOV) $(LCOVFLAGS) -c -d . -o $@
 
-coverage-stamp: lcov.info
+coverage-stamp: lcov_base.info lcov_test.info
 	rm -rf coverage
-	$(GENHTML) --show-details --legend --output-directory=coverage --title=PostgreSQL --num-spaces=4 --prefix=$(abs_top_srcdir) $<
+	$(GENHTML) --show-details --legend --output-directory=coverage --title=PostgreSQL --num-spaces=4 --prefix=$(abs_top_srcdir) $^
 	touch $@
 
 .PHONY: coverage coverage-html
@@ -888,7 +901,7 @@ clean distclean maintainer-clean: clean-coverage
 .PHONY: clean-coverage
 clean-coverage:
 	rm -rf coverage/ coverage-stamp
-	rm -f *.gcda *.gcno lcov.info
+	rm -f *.gcda *.gcno lcov*.info
 
 
 # User-callable target to reset counts between test runs
-- 
2.14.1