build: Add build flag to enable sparse checking of C source files

Similar to the 'make C=1' for the Linux kernel, wire up the sparse
command for our build system in a similar fashion. Use 'make C=1 [tool]'
to check the source files using sparse. Of course, the sparse tool needs
to be installed and available in your $PATH for this to work.

Signed-off-by: Tobias Klauser <tklauser@distanz.ch>

5 files changed, 13 insertions, 0 deletions

diff --git a/Cmds b/Cmds
index 9d2675f..247a972 100644
--- a/Cmds
+++ b/Cmds
@@ -14,6 +14,13 @@ else
   STRIP = $(Q)echo -e "  STRIP\t$@" && $(CROSS_COMPILE)strip
 endif
 
+# sparse related
+ifeq ($(C), 1)
+  CHECK = $(Q)echo -e "  CHECK\t$<" && sparse
+else
+  CHECK = $(Q)true
+endif
+
 # Flex/bison related
 LEX = $(Q)echo -e "  LEX\t$<" && flex
 YAAC = $(Q)echo -e "  YAAC\t$<" && bison
diff --git a/INSTALL b/INSTALL
index 830f6a1..ee0a562 100644
--- a/INSTALL
+++ b/INSTALL
@@ -13,6 +13,7 @@ What additional tools next to your build-chain are required?
 
  - ccache (optional)
  - gpg (optional)
+ - sparse (optional)
 
  - pkg-config:		   all
  - flex, bison:		   bpfc, trafgen
diff --git a/Makefile b/Makefile
index 03eaa61..c2735fa 100644
--- a/Makefile
+++ b/Makefile
@@ -107,6 +107,9 @@ ifeq ("$(origin CROSS_LD_LIBRARY_PATH)", "command line")
   LDFLAGS += -L$(CROSS_LD_LIBRARY_PATH)
 endif
 
+CHECKFLAGS = -D__linux__ -Dlinux -D__STDC__ -Dunix -D__unix \
+	     -Wbitwise -Wnoreturn-void
+
 VERSION_SHORT  =  $(VERSION).$(PATCHLEVEL).$(SUBLEVEL)$(EXTRAVERSION)
 VERSION_STRING = "$(VERSION_SHORT)$(CONFIG_RC)"
 VERSION_LONG   = "$(VERSION_SHORT)$(CONFIG_RC) ($(NAME))"
diff --git a/Misc b/Misc
index 8c826ed..a56a0b1 100644
--- a/Misc
+++ b/Misc
@@ -114,4 +114,5 @@ help:
 	$(Q)echo " CPPFLAGS=\"-I <path> ...\"     - Additional CFLAGS for compilation"
 	$(Q)echo " LDFLAGS=\"-L <path> ...\"      - Additional LDFLAGS for compilation"
 	$(Q)echo " CCACHE=                      - Do not use ccache for compilation"
+	$(Q)echo " C=1                          - Check all C source files with sparse"
 	$(Q)echo " Q=                           - Show verbose garbage"
diff --git a/Template b/Template
index e3093ea..4978eed 100644
--- a/Template
+++ b/Template
@@ -21,5 +21,6 @@ define TOOL_templ
   $(1)/%.tab.o: $(1)/%.tab.c
 	$$(CC) $$(CFLAGS) -o $$@ -c $$<
   $(1)/%.o: %.c
+	$$(CHECK) $$(CFLAGS) $$(CHECKFLAGS) $$<
 	$$(CC) $$(CFLAGS) -o $(1)/$$(shell basename $$@) -c $$<
 endef