Add extract-gcov utility for extracting gcda from skiboot dump

If you dump the (relocated) skiboot memory (2MB, from 0x30000000)
and point extract-gcov at it, you'll get a bunch of gcda files
extracted in pwd that you can then feed to gcov to get real usage
data.

This is a different approach than, say, the linux kernel, which when
built with gcov provides a debugfs interface to the gcda files that
you can just copy with normal userspace utilities.

For skiboot, I have no desire to add a VFS style interface and since
if you're dealing with GCOV+skiboot you should probably pretty well
know what you're doing, parsing the gcov data structures in userspace
from a dump of memory is actually not too bad.

You can grab this memory from linux, FSP, mambo or any debug mechanism that
lets you dump out a section of physical memory.

Signed-off-by: Stewart Smith <stewart@linux.vnet.ibm.com>

1 files changed, 4 insertions, 1 deletions

diff --git a/Makefile.main b/Makefile.main
index c01b16b..310601d 100644
--- a/Makefile.main
+++ b/Makefile.main
@@ -119,7 +119,7 @@ include $(SRC)/libc/Makefile.inc
 include $(SRC)/ccan/Makefile.inc
 include $(SRC)/$(DEVSRC)/Makefile.inc
 
-all: $(SUBDIRS) $(TARGET).lid $(TARGET).map
+all: $(SUBDIRS) $(TARGET).lid $(TARGET).map extract-gcov
 
 OBJS := $(ASM) $(CORE) $(HW) $(PLATFORMS) $(LIBFDT) $(LIBFLASH)
 ifeq ($(PORE),1)
@@ -171,6 +171,9 @@ version.c: $(SRC)/make_version.sh $(OBJS_NO_VER) .version
 .PHONY: coverage
 include $(shell find $(SRC)/* -name Makefile.check)
 
+extract-gcov: extract-gcov.c
+	$(call Q, HOSTCC ,$(HOSTCC) $(HOSTCFLAGS) -O0 -g -I . -o $@ $<,$<)
+
 coverage-report: skiboot.info
 	genhtml -q -o $@ $<