trace: fix tcg tracing build breakage

Commit 0ab8ed18 ("trace: switch to
modular code generation for sub-directories") forgot to convert "tcg"
trace events to the modular code generation approach where each
sub-directory has its own trace-events file.

This patch fixes compilation for "tcg" trace events.  Currently they are
only used in the root ./trace-events file.

"tcg" trace events can only be used in the root ./trace-events file for
the time being.

Reported-by: Peter Maydell <peter.maydell@linaro.org>
Tested-by: Emilio G. Cota <cota@braap.org>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 20170327131718.18268-1-stefanha@redhat.com
Suggested-by: Emilio G. Cota <cota@braap.org>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>

docs/tracing.txt

@@ -405,6 +405,9 @@ information. If used together with the "tcg" property, it adds a second
 "TCGv_env" argument that must point to the per-target global TCG register that
 points to the vCPU when guest code is executed (usually the "cpu_env" variable).
 
+The "tcg" and "vcpu" properties are currently only honored in the root
+./trace-events file.
+
 The following example events:
 
     foo(uint32_t a) "a=%x"

scripts/tracetool/format/tcg_h.py

@@ -40,6 +40,7 @@ def generate(events, backend, group):
         '#define TRACE_%s_GENERATED_TCG_TRACERS_H' % group.upper(),
         '',
         '#include "exec/helper-proto.h"',
+        '#include "%s"' % header,
         '',
         )
 

scripts/tracetool/format/tcg_helper_c.py

@@ -55,6 +55,7 @@ def generate(events, backend, group):
         '#include "qemu-common.h"',
         '#include "cpu.h"',
         '#include "exec/helper-proto.h"',
+        '#include "%s"' % header,
         '',
         )
 

trace/Makefile.objs

@@ -9,27 +9,27 @@ $(BUILD_DIR)/trace-events-all: $(trace-events-files)
 
 $(obj)/generated-helpers-wrappers.h: $(obj)/generated-helpers-wrappers.h-timestamp
 	@cmp $< $@ >/dev/null 2>&1 || cp $< $@
-$(obj)/generated-helpers-wrappers.h-timestamp: $(trace-events-files) $(BUILD_DIR)/config-host.mak $(tracetool-y)
+$(obj)/generated-helpers-wrappers.h-timestamp: $(SRC_PATH)/trace-events $(BUILD_DIR)/config-host.mak $(tracetool-y)
 	$(call quiet-command,$(TRACETOOL) \
-		--group=all \
+		--group=root \
 		--format=tcg-helper-wrapper-h \
 		--backend=$(TRACE_BACKENDS) \
 		$< > $@,"GEN","$(patsubst %-timestamp,%,$@)")
 
 $(obj)/generated-helpers.h: $(obj)/generated-helpers.h-timestamp
 	@cmp $< $@ >/dev/null 2>&1 || cp $< $@
-$(obj)/generated-helpers.h-timestamp: $(trace-events-files) $(BUILD_DIR)/config-host.mak $(tracetool-y)
+$(obj)/generated-helpers.h-timestamp: $(SRC_PATH)/trace-events $(BUILD_DIR)/config-host.mak $(tracetool-y)
 	$(call quiet-command,$(TRACETOOL) \
-		--group=all \
+		--group=root \
 		--format=tcg-helper-h \
 		--backend=$(TRACE_BACKENDS) \
 		$< > $@,"GEN","$(patsubst %-timestamp,%,$@)")
 
 $(obj)/generated-helpers.c: $(obj)/generated-helpers.c-timestamp
 	@cmp $< $@ >/dev/null 2>&1 || cp $< $@
-$(obj)/generated-helpers.c-timestamp: $(trace-events-files) $(BUILD_DIR)/config-host.mak $(tracetool-y)
+$(obj)/generated-helpers.c-timestamp: $(SRC_PATH)/trace-events $(BUILD_DIR)/config-host.mak $(tracetool-y)
 	$(call quiet-command,$(TRACETOOL) \
-		--group=all \
+		--group=root \
 		--format=tcg-helper-c \
 		--backend=$(TRACE_BACKENDS) \
 		$< > $@,"GEN","$(patsubst %-timestamp,%,$@)")
@@ -41,9 +41,9 @@ target-obj-y += generated-helpers.o
 
 $(obj)/generated-tcg-tracers.h: $(obj)/generated-tcg-tracers.h-timestamp
 	@cmp $< $@ >/dev/null 2>&1 || cp $< $@
-$(obj)/generated-tcg-tracers.h-timestamp: $(trace-events-files) $(BUILD_DIR)/config-host.mak $(tracetool-y)
+$(obj)/generated-tcg-tracers.h-timestamp: $(SRC_PATH)/trace-events $(BUILD_DIR)/config-host.mak $(tracetool-y)
 	$(call quiet-command,$(TRACETOOL) \
-		--group=all \
+		--group=root \
 		--format=tcg-h \
 		--backend=$(TRACE_BACKENDS) \
 		$< > $@,"GEN","$(patsubst %-timestamp,%,$@)")