testsuite: optional limiting of coverage dumps

Add an option that limits the generation of `.gcda` files when running
coverage testing. This can be useful when running testing coverage on
downstream repos, which would otherwise result in large `.gcda` files
for paths we don't care about filling up the disk.

Signed-off-by: Jordan Yates <[email protected]>

Author: JordanYates

subsys/testsuite/Kconfig

@@ -72,9 +72,10 @@ config COVERAGE_GCOV
 
 endchoice
 
+if COVERAGE_GCOV
+
 config COVERAGE_GCOV_HEAP_SIZE
 	int "Size of heap allocated for gcov coverage data dump"
-	depends on COVERAGE_GCOV
 	default 32768 if X86 || SOC_SERIES_MPS2
 	default 16384
 	help
@@ -84,10 +85,20 @@ config COVERAGE_GCOV_HEAP_SIZE
 
 config COVERAGE_DUMP
 	bool "Dump coverage data on exit"
-	depends on COVERAGE_GCOV
 	help
 	  Dump collected coverage information to console on exit.
 
+config COVERAGE_DUMP_PATH_EXCLUSIVE
+	string "Only files matching this pattern are dumped in coverage data"
+	default ""
+	help
+	  Filenames are matched against the pattern using the posix fnmatch
+	  function. Filenames are based on their path in the build folder, not the
+	  original source tree. To only include files in a given west module, use
+	  the module name from `module.yml`.
+
+endif # COVERAGE_GCOV
+
 config FORCE_COVERAGE
 	bool "Force coverage"
 	select HAS_COVERAGE_SUPPORT

subsys/testsuite/coverage/coverage.c

@@ -9,6 +9,7 @@
 #include <stdint.h>
 #include <errno.h>
 #include <string.h>
+#include <fnmatch.h>
 #include "coverage.h"
 
 K_HEAP_DEFINE(gcov_heap, CONFIG_COVERAGE_GCOV_HEAP_SIZE);
@@ -315,6 +316,11 @@ void gcov_coverage_dump(void)
 	}
 	printk("\nGCOV_COVERAGE_DUMP_START");
 	while (gcov_list) {
+		if ((strlen(CONFIG_COVERAGE_DUMP_PATH_EXCLUSIVE) > 0) &&
+		    (fnmatch(CONFIG_COVERAGE_DUMP_PATH_EXCLUSIVE, gcov_list->filename, 0) != 0)) {
+			/* Don't print a note here, it would be interpreted as dump data */
+			goto file_dump_end;
+		}
 
 		dump_on_console_start(gcov_list->filename);
 		size = gcov_calculate_buff_size(gcov_list);
@@ -334,6 +340,7 @@ void gcov_coverage_dump(void)
 		dump_on_console_data(buffer, size);
 
 		k_heap_free(&gcov_heap, buffer);
+file_dump_end:
 		gcov_list = gcov_list->next;
 		if (gcov_list_first == gcov_list) {
 			goto coverage_dump_end;