[binutils-gdb] gdb.base/skip.exp: Use finish to exit functions

[Bruno Larsen <blarsen@sourceware.org>]

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=7e1cd467b5c12b719c764fe219c7f6736ccf8c31

commit 7e1cd467b5c12b719c764fe219c7f6736ccf8c31
Author: Bruno Larsen <blarsen@redhat.com>
Date:   Wed Jul 20 16:44:40 2022 -0300

    gdb.base/skip.exp: Use finish to exit functions
    
    gdb.base/skip.exp was making use of a fixed number of step commands to
    exit some functions.  This caused some problems when using clang to test
    GDB, as GDB would need fewer steps to reach the desired spots.  For
    instance, when testing in the section "step after disabling 3", the log
    looks like this:
    
        Breakpoint 4, main () at binutils-gdb/gdb/testsuite/gdb.base/skip.c:32
        32        x = baz ((bar (), foo ()));
        (gdb) step
        bar () at binutils-gdb/gdb/testsuite/gdb.base/skip1.c:21
        21        return 1;
        (gdb) PASS: gdb.base/skip.exp: step after disabling 3: step 1
        step
        foo () at binutils-gdb/gdb/testsuite/gdb.base/skip.c:42
        42        return 0;
        (gdb) PASS: gdb.base/skip.exp: step after disabling 3: step 2
        step
        main () at binutils-gdb/gdb/testsuite/gdb.base/skip.c:34
        34        test_skip_file_and_function ();
        (gdb) step
        test_skip_file_and_function () at binutils-gdb/gdb/testsuite/gdb.base/skip.c:59
        59        test_skip ();
        (gdb) FAIL: gdb.base/skip.exp: step after disabling 3: step 3
        step
        test_skip () at binutils-gdb/gdb/testsuite/gdb.base/skip.c:48
        48      }
        (gdb) PASS: gdb.base/skip.exp: step after disabling 3: step 4
        step
        test_skip_file_and_function () at binutils-gdb/gdb/testsuite/gdb.base/skip.c:60
        60        skip1_test_skip_file_and_function ();
        (gdb) FAIL: gdb.base/skip.exp: step after disabling 3: step 5
    
    This shows that the feature is working but because the inferior lands in
    a different location, it registers as a failure.  Seeing as along with
    this difference, there are also some differences that depend on gcc
    versions (where gdb might stop back at line 32 before entering foo), it
    would not be easy to test for this behavior using steps and analzing
    where the inferior stops at each point. On the other hand, using
    gdb_step_until is not feasible because we'd possibly gloss over stepping
    into baz and rendering the whole test useless.  Instead, skip.exp now
    uses finish to leave functions, synchronizing through compilers and
    compiler versions.  Some test names were also changed to be a bit more
    descriptive.  The new log looks like this, independently of compiler used:
    
        Breakpoint 4, main () at binutils-gdb/gdb/testsuite/gdb.base/skip.c:32
        32        x = baz ((bar (), foo ()));
        (gdb) step
        bar () at binutils-gdb/gdb/testsuite/gdb.base/skip1.c:21
        21        return 1;
        (gdb) PASS: gdb.base/skip.exp: step after disabling 3: step into bar
        finish
        Run till exit from #0  bar () at binutils-gdb/gdb/testsuite/gdb.base/skip1.c:21
        main () at binutils-gdb/gdb/testsuite/gdb.base/skip.c:32
        32        x = baz ((bar (), foo ()));
        Value returned is $2 = 1
        (gdb) PASS: gdb.base/skip.exp: step after disabling 3: return from bar
        step
        foo () at binutils-gdb/gdb/testsuite/gdb.base/skip.c:42
        42        return 0;
        (gdb) PASS: gdb.base/skip.exp: step after disabling 3: step into foo
        finish
        Run till exit from #0  foo () at binutils-gdb/gdb/testsuite/gdb.base/skip.c:42
        main () at binutils-gdb/gdb/testsuite/gdb.base/skip.c:32
        32        x = baz ((bar (), foo ()));
        Value returned is $3 = 0
        (gdb) PASS: gdb.base/skip.exp: step after disabling 3: Return from foo
        step
        34        test_skip_file_and_function ();
        (gdb) PASS: gdb.base/skip.exp: step after disabling 3: step and skip baz

Diff:
---
 gdb/testsuite/gdb.base/skip.exp | 34 +++++++++++++++++-----------------
 1 file changed, 17 insertions(+), 17 deletions(-)

diff --git a/gdb/testsuite/gdb.base/skip.exp b/gdb/testsuite/gdb.base/skip.exp
index e6b660004d9..0864e445f13 100644
--- a/gdb/testsuite/gdb.base/skip.exp
+++ b/gdb/testsuite/gdb.base/skip.exp
@@ -100,6 +100,14 @@ if ![runto_main] {
 gdb_test "step" ".*" "step in the main"
 gdb_test "bt" "\\s*\\#0\\s+main.*" "step after all ignored"
 
+# This proc tests that GDB can step into the function foo, exit it
+# and skip the functions bar and baz.
+proc step_foo_skip_bar_baz {} {
+    gdb_test "step" "foo \\(\\) at.*" "step and skip bar"
+    gdb_test "finish" ".*" "return from bar"
+    gdb_test "step" ".*test_skip_file_and_function.*" "step and skip baz"
+}
+
 # Now remove skip.c from the skiplist.  Our first step should take us
 # into foo(), and our second step should take us to the next line in main().
 
@@ -117,21 +125,19 @@ with_test_prefix "step after deleting 1" {
 	return
     }
 
-    gdb_test "step" "foo \\(\\) at.*" "step 1"
-    gdb_test "step" ".*" "step 2" ; # Return from foo()
-    gdb_test "step" "main \\(\\) at.*" "step 3"
+    step_foo_skip_bar_baz
 }
 
 # Test that we step into foo(), then into bar(), but not into baz().
 proc step_bar_foo_skip_baz {} {
-    gdb_test "step" "bar \\(\\) at.*" "step 1"
-    gdb_test "step" ".*" "step 2"; # Return from bar()
+    gdb_test "step" "bar \\(\\) at.*" "step into bar"
+    gdb_test "finish" ".*" "return from bar"
 
     # With at least gcc 6.5.0 and 9.2.0, we jump once back to main
     # before entering foo here.  If that happens try to step a second
     # time.
     set stepped_again 0
-    gdb_test_multiple "step" "step 3" {
+    gdb_test_multiple "step" "step into foo" {
 	-re -wrap "foo \\(\\) at.*" {
 	    pass $gdb_test_name
 	}
@@ -144,8 +150,8 @@ proc step_bar_foo_skip_baz {} {
 	}
     }
 
-    gdb_test "step" ".*" "step 4"; # Return from foo()
-    gdb_test "step" "main \\(\\) at.*" "step 5"
+    gdb_test "finish" ".*" "Return from foo"
+    gdb_test "step" ".*test_skip_file_and_function.*" "step and skip baz"
 }
 
 # Now disable the skiplist entry for  skip1.c.  We should now
@@ -178,9 +184,7 @@ with_test_prefix "step after enable 3" {
 	return
     }
 
-    gdb_test "step" "foo \\(\\) at.*" "step 1"
-    gdb_test "step" ".*" "step 2"; # Return from foo()
-    gdb_test "step" "main \\(\\) at.*" "step 3"
+    step_foo_skip_bar_baz
 }
 
 # Admin tests (disable,enable,delete).
@@ -249,9 +253,7 @@ with_test_prefix "step using -fi" {
 
     gdb_test_no_output "skip disable"
     gdb_test_no_output "skip enable 5"
-    gdb_test "step" "foo \\(\\) at.*" "step 1"
-    gdb_test "step" ".*" "step 2"; # Return from foo()
-    gdb_test "step" "main \\(\\) at.*" "step 3"
+    step_foo_skip_bar_baz
 }
 
 with_test_prefix "step using -gfi" {
@@ -261,9 +263,7 @@ with_test_prefix "step using -gfi" {
 
     gdb_test_no_output "skip disable"
     gdb_test_no_output "skip enable 6"
-    gdb_test "step" "foo \\(\\) at.*" "step 1"
-    gdb_test "step" ".*" "step 2"; # Return from foo()
-    gdb_test "step" "main \\(\\) at.*" "step 3"
+    step_foo_skip_bar_baz
 }
 
 with_test_prefix "step using -fu for baz" {