do coverage test without install lcov

From 3cd9b06134a7503f6cfbb7b8c1847aac026e7280 Mon Sep 17 00:00:00 2001
From: Shenhao Wang <wangsh.fnst@cn.fujitsu.com>
Date: Mon, 22 Feb 2021 16:10:17 +0800
Subject: [PATCH] make --enable-coverage success without lcov

---
 configure              | 10 ++++++++--
 configure.ac           |  6 ++++--
 src/Makefile.global.in |  7 +++++--
 3 files changed, 17 insertions(+), 6 deletions(-)

diff --git a/configure b/configure
index ce9ea36999..aceadaf7f6 100755
--- a/configure
+++ b/configure
@@ -3476,7 +3476,10 @@ $as_echo "$LCOV" >&6; }
 fi
 
 if test -z "$LCOV"; then
-  as_fn_error $? "lcov not found" "$LINENO" 5
+  { $as_echo "$as_me:${as_lineno-$LINENO}: WARNING:
+*** Without lcov you will not be able to generate HTML format report." >&5
+$as_echo "$as_me: WARNING:
+*** Without lcov you will not be able to generate HTML format report." >&2;}
 fi
 if test -z "$GENHTML"; then
   for ac_prog in genhtml
@@ -3533,7 +3536,10 @@ $as_echo "$GENHTML" >&6; }
 fi
 
 if test -z "$GENHTML"; then
-  as_fn_error $? "genhtml not found" "$LINENO" 5
+  { $as_echo "$as_me:${as_lineno-$LINENO}: WARNING:
+*** Without genhtml you will not be able to generate HTML format report." >&5
+$as_echo "$as_me: WARNING:
+*** Without genhtml you will not be able to generate HTML format report." >&2;}
 fi
       ;;
     no)
diff --git a/configure.ac b/configure.ac
index f54f65febe..459b90474b 100644
--- a/configure.ac
+++ b/configure.ac
@@ -221,11 +221,13 @@ if test -z "$GCOV"; then
 fi
 PGAC_PATH_PROGS(LCOV, lcov)
 if test -z "$LCOV"; then
-  AC_MSG_ERROR([lcov not found])
+  AC_MSG_WARN([
+*** Without lcov you will not be able to generate HTML format report.])
 fi
 PGAC_PATH_PROGS(GENHTML, genhtml)
 if test -z "$GENHTML"; then
-  AC_MSG_ERROR([genhtml not found])
+  AC_MSG_WARN([
+*** Without genhtml you will not be able to generate HTML format report.])
 fi])
 AC_SUBST(enable_coverage)
 
diff --git a/src/Makefile.global.in b/src/Makefile.global.in
index 74b3a6acd2..3286368408 100644
--- a/src/Makefile.global.in
+++ b/src/Makefile.global.in
@@ -1003,12 +1003,15 @@ coverage-html-stamp: lcov_base.info lcov_test.info
 	$(GENHTML) $(GENHTML_FLAGS) -o coverage --title='$(GENHTML_TITLE)' --num-spaces=4 $(if $(filter no,$(vpath_build)),--prefix='$(abs_top_srcdir)') $^
 	touch $@
 
-LCOV += --gcov-tool $(GCOV)
-LCOVFLAGS = -q --no-external
+LCOVFLAGS = --gcov-tool $(GCOV) -q --no-external
 
 all_gcno_files = $(shell find . -name '*.gcno' -print)
 
 lcov_base.info: $(all_gcno_files)
+ifeq ($(LCOV),)
+	@echo "please install lcov and re-configure"; \
+	false;
+endif
 	$(LCOV) $(LCOVFLAGS) -c -i -d . -d $(srcdir) -o $@
 
 all_gcda_files = $(shell find . -name '*.gcda' -print)
-- 
2.26.2