[PATCH 1/2] gcov: test switch/break line counts

["Jørgen Kvalsvik" <jorgen.kvalsvik@woven-planet.global>]

The coverage support will under some conditions decide to split edges to
accurately report coverage. By running the test suite with/without this
edge splitting a small diff shows up, addressed by this patch, which
should catch future regressions.

Removing the edge splitting:

    $ diff --git a/gcc/profile.cc b/gcc/profile.cc
    --- a/gcc/profile.cc
    +++ b/gcc/profile.cc
    @@ -1244,19 +1244,7 @@ branch_prob (bool thunk)
                    Don't do that when the locuses match, so
                    if (blah) goto something;
                    is not computed twice.  */
    -             if (last
    -                 && gimple_has_location (last)
    -                 && !RESERVED_LOCATION_P (e->goto_locus)
    -                 && !single_succ_p (bb)
    -                 && (LOCATION_FILE (e->goto_locus)
    -                     != LOCATION_FILE (gimple_location (last))
    -                     || (LOCATION_LINE (e->goto_locus)
    -                         != LOCATION_LINE (gimple_location (last)))))
    -               {
    -                 basic_block new_bb = split_edge (e);
    -                 edge ne = single_succ_edge (new_bb);
    -                 ne->goto_locus = e->goto_locus;
    -               }
    +
            if ((e->flags & (EDGE_ABNORMAL | EDGE_ABNORMAL_CALL))
                    && e->dest != EXIT_BLOCK_PTR_FOR_FN (cfun))
                    need_exit_edge = 1;

Assuming the .gcov files from make chec-gcc RUNTESTFLAGS=gcov.exp are
kept:

    $ diff -r no-split-edge with-split-edge | grep -C 2 -E "^[<>]\s\s"
    diff -r sans-split-edge/gcc/gcov-4.c.gcov with-split-edge/gcc/gcov-4.c.gcov
    228c228
    <         -:  224:        break;
    ---
    >         1:  224:        break;
    231c231
    <         -:  227:        break;
    ---
    >     #####:  227:        break;
    237c237
    <         -:  233:        break;
    ---
    >         2:  233:        break;

gcc/testsuite/ChangeLog:

	* g++.dg/gcov/gcov-1.C: Add line count check.
	* gcc.misc-tests/gcov-4.c: Likewise.
---
 gcc/testsuite/g++.dg/gcov/gcov-1.C    | 8 ++++----
 gcc/testsuite/gcc.misc-tests/gcov-4.c | 4 ++--
 2 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/gcc/testsuite/g++.dg/gcov/gcov-1.C b/gcc/testsuite/g++.dg/gcov/gcov-1.C
index 9018b9a3a73..ee383b480a8 100644
--- a/gcc/testsuite/g++.dg/gcov/gcov-1.C
+++ b/gcc/testsuite/g++.dg/gcov/gcov-1.C
@@ -257,20 +257,20 @@ test_switch (int i, int j)
   switch (i)				/* count(5) */
 					/* branch(end) */
     {
-      case 1:
+      case 1:				/* count(1) */
         result = do_something (2);	/* count(1) */
-        break;
+        break;				/* count(1) */
       case 2:
         result = do_something (1024);
         break;
-      case 3:
+      case 3:				/* count(3) */
       case 4:
 					/* branch(67) */
         if (j == 2)			/* count(3) */
 					/* branch(end) */
           return do_something (4);	/* count(1) */
         result = do_something (8);	/* count(2) */
-        break;
+        break;				/* count(2) */
       default:
 	result = do_something (32);	/* count(1) */
 	switch_m++;			/* count(1) */
diff --git a/gcc/testsuite/gcc.misc-tests/gcov-4.c b/gcc/testsuite/gcc.misc-tests/gcov-4.c
index 9d8ab1c1097..498d299b66b 100644
--- a/gcc/testsuite/gcc.misc-tests/gcov-4.c
+++ b/gcc/testsuite/gcc.misc-tests/gcov-4.c
@@ -221,7 +221,7 @@ test_switch (int i, int j)
     {
       case 1:
         result = do_something (2);	/* count(1) */
-        break;
+        break;				/* count(1) */
       case 2:
         result = do_something (1024);
         break;
@@ -230,7 +230,7 @@ test_switch (int i, int j)
         if (j == 2)			/* count(3) */
           return do_something (4);	/* count(1) */
         result = do_something (8);	/* count(2) */
-        break;
+        break;				/* count(2) */
       default:
 	result = do_something (32);	/* count(1) */
 	switch_m++;			/* count(1) */
-- 
2.34.0