gcov: clang: move common GCC code into gcc_base.c

Patch series "gcov: add Clang support", v4.

This patch (of 3):

base.c contains a few callbacks specific to GCC's gcov implementation.
Move these into their own module in preparation for Clang support.

Link: http://lkml.kernel.org/r/20190318025411.98014-2-trong@android.comSigned-off-by: Greg Hackmann <ghackmann@android.com>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Tri Vo <trong@android.com>
Tested-by: Trilok Soni <tsoni@quicinc.com>
Tested-by: Prasad Sodagudi <psodagud@quicinc.com>
Tested-by: Tri Vo <trong@android.com>
Reviewed-by: Peter Oberparleiter <oberpar@linux.ibm.com>
Cc: Daniel Mentz <danielmentz@google.com>
Cc: Petri Gynther <pgynther@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

kernel/gcov/Makefile

@@ -2,5 +2,5 @@
 ccflags-y := -DSRCTREE='"$(srctree)"' -DOBJTREE='"$(objtree)"'
 
 obj-y := base.o fs.o
-obj-$(CONFIG_GCOV_FORMAT_3_4) += gcc_3_4.o
-obj-$(CONFIG_GCOV_FORMAT_4_7) += gcc_4_7.o
+obj-$(CONFIG_GCOV_FORMAT_3_4) += gcc_base.o gcc_3_4.o
+obj-$(CONFIG_GCOV_FORMAT_4_7) += gcc_base.o gcc_4_7.o

kernel/gcov/base.c

@@ -22,88 +22,8 @@
 #include <linux/sched.h>
 #include "gcov.h"
 
-static int gcov_events_enabled;
-static DEFINE_MUTEX(gcov_lock);
-
-/*
- * __gcov_init is called by gcc-generated constructor code for each object
- * file compiled with -fprofile-arcs.
- */
-void __gcov_init(struct gcov_info *info)
-{
-	static unsigned int gcov_version;
-
-	mutex_lock(&gcov_lock);
-	if (gcov_version == 0) {
-		gcov_version = gcov_info_version(info);
-		/*
-		 * Printing gcc's version magic may prove useful for debugging
-		 * incompatibility reports.
-		 */
-		pr_info("version magic: 0x%x\n", gcov_version);
-	}
-	/*
-	 * Add new profiling data structure to list and inform event
-	 * listener.
-	 */
-	gcov_info_link(info);
-	if (gcov_events_enabled)
-		gcov_event(GCOV_ADD, info);
-	mutex_unlock(&gcov_lock);
-}
-EXPORT_SYMBOL(__gcov_init);
-
-/*
- * These functions may be referenced by gcc-generated profiling code but serve
- * no function for kernel profiling.
- */
-void __gcov_flush(void)
-{
-	/* Unused. */
-}
-EXPORT_SYMBOL(__gcov_flush);
-
-void __gcov_merge_add(gcov_type *counters, unsigned int n_counters)
-{
-	/* Unused. */
-}
-EXPORT_SYMBOL(__gcov_merge_add);
-
-void __gcov_merge_single(gcov_type *counters, unsigned int n_counters)
-{
-	/* Unused. */
-}
-EXPORT_SYMBOL(__gcov_merge_single);
-
-void __gcov_merge_delta(gcov_type *counters, unsigned int n_counters)
-{
-	/* Unused. */
-}
-EXPORT_SYMBOL(__gcov_merge_delta);
-
-void __gcov_merge_ior(gcov_type *counters, unsigned int n_counters)
-{
-	/* Unused. */
-}
-EXPORT_SYMBOL(__gcov_merge_ior);
-
-void __gcov_merge_time_profile(gcov_type *counters, unsigned int n_counters)
-{
-	/* Unused. */
-}
-EXPORT_SYMBOL(__gcov_merge_time_profile);
-
-void __gcov_merge_icall_topn(gcov_type *counters, unsigned int n_counters)
-{
-	/* Unused. */
-}
-EXPORT_SYMBOL(__gcov_merge_icall_topn);
-
-void __gcov_exit(void)
-{
-	/* Unused. */
-}
-EXPORT_SYMBOL(__gcov_exit);
+int gcov_events_enabled;
+DEFINE_MUTEX(gcov_lock);
 
 /**
  * gcov_enable_events - enable event reporting through gcov_event()

kernel/gcov/gcc_base.c

+// SPDX-License-Identifier: GPL-2.0
+
+#include <linux/export.h>
+#include <linux/kernel.h>
+#include <linux/mutex.h>
+#include "gcov.h"
+
+/*
+ * __gcov_init is called by gcc-generated constructor code for each object
+ * file compiled with -fprofile-arcs.
+ */
+void __gcov_init(struct gcov_info *info)
+{
+	static unsigned int gcov_version;
+
+	mutex_lock(&gcov_lock);
+	if (gcov_version == 0) {
+		gcov_version = gcov_info_version(info);
+		/*
+		 * Printing gcc's version magic may prove useful for debugging
+		 * incompatibility reports.
+		 */
+		pr_info("version magic: 0x%x\n", gcov_version);
+	}
+	/*
+	 * Add new profiling data structure to list and inform event
+	 * listener.
+	 */
+	gcov_info_link(info);
+	if (gcov_events_enabled)
+		gcov_event(GCOV_ADD, info);
+	mutex_unlock(&gcov_lock);
+}
+EXPORT_SYMBOL(__gcov_init);
+
+/*
+ * These functions may be referenced by gcc-generated profiling code but serve
+ * no function for kernel profiling.
+ */
+void __gcov_flush(void)
+{
+	/* Unused. */
+}
+EXPORT_SYMBOL(__gcov_flush);
+
+void __gcov_merge_add(gcov_type *counters, unsigned int n_counters)
+{
+	/* Unused. */
+}
+EXPORT_SYMBOL(__gcov_merge_add);
+
+void __gcov_merge_single(gcov_type *counters, unsigned int n_counters)
+{
+	/* Unused. */
+}
+EXPORT_SYMBOL(__gcov_merge_single);
+
+void __gcov_merge_delta(gcov_type *counters, unsigned int n_counters)
+{
+	/* Unused. */
+}
+EXPORT_SYMBOL(__gcov_merge_delta);
+
+void __gcov_merge_ior(gcov_type *counters, unsigned int n_counters)
+{
+	/* Unused. */
+}
+EXPORT_SYMBOL(__gcov_merge_ior);
+
+void __gcov_merge_time_profile(gcov_type *counters, unsigned int n_counters)
+{
+	/* Unused. */
+}
+EXPORT_SYMBOL(__gcov_merge_time_profile);
+
+void __gcov_merge_icall_topn(gcov_type *counters, unsigned int n_counters)
+{
+	/* Unused. */
+}
+EXPORT_SYMBOL(__gcov_merge_icall_topn);
+
+void __gcov_exit(void)
+{
+	/* Unused. */
+}
+EXPORT_SYMBOL(__gcov_exit);

kernel/gcov/gcov.h

@@ -83,4 +83,7 @@ struct gcov_link {
 };
 extern const struct gcov_link gcov_link[];
 
+extern int gcov_events_enabled;
+extern struct mutex gcov_lock;
+
 #endif /* GCOV_H */