scripts, Makefile: move static_analysis_tests to a Makefile target

To further trim down run_tests.sh, move the code that runs the clang
static analyzer into a 'make' target.

.travis.yml

@@ -22,7 +22,8 @@ matrix:
         - sudo apt-get install -y libz-dev gcc-multilib libz-dev:i386
           libc6-dev-i386 clang
       script:
-        - scripts/run_tests.sh checksum_benchmarks static_analysis
+        - scripts/run_tests.sh checksum_benchmarks
+        - make scan-build
 
     - name: Native tests (Linux aarch64)
       os: linux
@@ -40,7 +41,8 @@ matrix:
       before_install:
         - sudo apt-get install -y libz-dev clang
       script:
-        - scripts/run_tests.sh checksum_benchmarks static_analysis
+        - scripts/run_tests.sh checksum_benchmarks
+        - make scan-build
 
     - name: gzip and cross-compile-for-Windows tests (Linux)
       os: linux

Makefile

@@ -324,6 +324,10 @@ check:test_programs
 		./$$prog || exit 1;	\
 	done
 
+# Run the clang static analyzer.
+scan-build:
+	scan-build --status-bugs make all test_programs
+
 help:
 	@echo "Available targets:"
 	@echo "------------------"
@@ -346,6 +350,7 @@ realclean: clean
 
 FORCE:
 
-.PHONY: all install uninstall test_programs help clean realclean
+.PHONY: all install uninstall test_programs check scan-build help \
+	clean realclean
 
 .DEFAULT_GOAL = all

scripts/run_tests.sh

@@ -239,17 +239,6 @@ windows_tests() {
 
 ###############################################################################
 
-static_analysis_tests() {
-	test_group_included static_analysis || return 0
-	if ! type -P scan-build > /dev/null; then
-		log_skip "clang static analyzer (scan-build) not found"
-		return 0
-	fi
-	run_cmd scan-build --status-bugs make -j$NPROC all test_programs
-}
-
-###############################################################################
-
 gzip_tests() {
 	test_group_included gzip || return 0
 
@@ -288,7 +277,6 @@ native_tests
 freestanding_tests
 checksum_benchmarks
 windows_tests
-static_analysis_tests
 gzip_tests
 
 if (( TESTS_SKIPPED )); then