kconfig: add CONFIG_CC_COVERAGE

Make it possible to use gcc code coverage analysis.

v1 -> v2:
 - Kconfig: remove not needed 'default n'
 - Makefile: use consistent spacing

Signed-off-by: Christian Gmeiner <christian.gmeiner@gmail.com>
Reviewed-by: Tom Rini <trini@konsulko.com>

.gitignore

@@ -85,3 +85,7 @@ GTAGS
 *.orig
 *~
 \#*#
+
+# gcc code coverage files
+*.gcda
+*.gcno

Kconfig

@@ -59,6 +59,13 @@ config CC_OPTIMIZE_FOR_SIZE
 
 	  This option is enabled by default for U-Boot.
 
+config CC_COVERAGE
+	bool "Enable code coverage analysis"
+	depends on SANDBOX
+	help
+	  Enabling this option will pass "--coverage" to gcc to compile
+	  and link code instrumented for coverage analysis.
+
 config DISTRO_DEFAULTS
 	bool "Select defaults suitable for booting general purpose Linux distributions"
 	default y if ARCH_SUNXI || TEGRA

Makefile

@@ -725,6 +725,12 @@ else
 PLATFORM_LIBGCC := -L $(shell dirname `$(CC) $(c_flags) -print-libgcc-file-name`) -lgcc
 endif
 PLATFORM_LIBS += $(PLATFORM_LIBGCC)
+
+ifdef CONFIG_CC_COVERAGE
+KBUILD_CFLAGS += --coverage
+PLATFORM_LIBGCC += -lgcov
+endif
+
 export PLATFORM_LIBS
 export PLATFORM_LIBGCC