[gdb/testsuite] Ignore pass in gdb_caching_proc

Before commit d4295de4f3 "[gdb/testsuite] Handle missing gnatmake in
gnat_runtime_has_debug_info", calling the gdb_caching_proc
gnat_runtime_has_debug_info could generate a pass because of using
gdb_compile_ada.

This has been fixed in that commit by using a factored out variant
gdb_compile_ada_1, which does not call pass.

Additionally, fix cases like this in more generic way: by ignoring pass calls
during execution of a gdb_caching_proc.

Build and reg-tested on x86_64-linux.

gdb/testsuite/ChangeLog:

2020-02-19  Tom de Vries  <tdevries@suse.de>

	* lib/cache.exp (ignore_pass, gdb_do_cache_wrap): New proc.
	(gdb_do_cache): Use gdb_do_cache_wrap.
	* gdb.base/gdb-caching-proc.exp (test_proc): Use gdb_do_cache_wrap.

3 files changed, 38 insertions, 3 deletions

diff --git a/gdb/testsuite/ChangeLog b/gdb/testsuite/ChangeLog
index fb733dfec04..897861766d2 100644
--- a/gdb/testsuite/ChangeLog
+++ b/gdb/testsuite/ChangeLog
@@ -1,5 +1,11 @@
 2020-02-19  Tom de Vries  <tdevries@suse.de>
 
+	* lib/cache.exp (ignore_pass, gdb_do_cache_wrap): New proc.
+	(gdb_do_cache): Use gdb_do_cache_wrap.
+	* gdb.base/gdb-caching-proc.exp (test_proc): Use gdb_do_cache_wrap.
+
+2020-02-19  Tom de Vries  <tdevries@suse.de>
+
 	* lib/dtrace.exp (dtrace_build_usdt_test_program): Use quiet as
 	gdb_compile option.
 
diff --git a/gdb/testsuite/gdb.base/gdb-caching-proc.exp b/gdb/testsuite/gdb.base/gdb-caching-proc.exp
index b2d71a5e7d9..3810347a652 100644
--- a/gdb/testsuite/gdb.base/gdb-caching-proc.exp
+++ b/gdb/testsuite/gdb.base/gdb-caching-proc.exp
@@ -28,7 +28,7 @@ proc test_proc { name } {
 
     set resultlist [list]
 
-    set first [$real_name]
+    set first [gdb_do_cache_wrap $real_name]
     lappend resultlist $first
 
     # Ten repetitions was enough to trigger target_supports_scheduler_locking,
@@ -37,7 +37,7 @@ proc test_proc { name } {
 
     set racy 0
     for {set i 0} {$i < $repeat} {incr i} {
-	set rerun [$real_name]
+	set rerun [gdb_do_cache_wrap $real_name]
 	lappend resultlist $rerun
 	if { $rerun != $first } {
 	    set racy 1
diff --git a/gdb/testsuite/lib/cache.exp b/gdb/testsuite/lib/cache.exp
index dc57cab964c..25bfe025109 100644
--- a/gdb/testsuite/lib/cache.exp
+++ b/gdb/testsuite/lib/cache.exp
@@ -17,6 +17,35 @@
 # The in-memory cache.
 array set gdb_data_cache {}
 
+# Print pass message msg into gdb.log
+proc ignore_pass { msg } {
+    verbose -log "gdb_do_cache_wrap ignoring pass: $msg"
+}
+
+# Call proc real_name and return the result, while ignoring calls to pass.
+proc gdb_do_cache_wrap {real_name} {
+    if { [info procs save_pass] != "" } {
+	return [uplevel 2 $real_name]
+    }
+
+    rename pass save_pass
+    rename ignore_pass pass
+
+    set code [catch {uplevel 2 $real_name} result]
+
+    rename pass ignore_pass
+    rename save_pass pass
+
+    if {$code == 1} {
+	global errorInfo errorCode
+	return -code error -errorinfo $errorInfo -errorcode $errorCode $result
+    } elseif {$code > 1} {
+	return -code $code $result
+    }
+
+    return $result
+}
+
 # A helper for gdb_caching_proc that handles the caching.
 
 proc gdb_do_cache {name} {
@@ -46,7 +75,7 @@ proc gdb_do_cache {name} {
     }
 
     set real_name gdb_real__$name
-    set gdb_data_cache($cache_name) [uplevel 1 $real_name]
+    set gdb_data_cache($cache_name) [gdb_do_cache_wrap $real_name]
 
     if {[info exists GDB_PARALLEL]} {
 	verbose "$name: returning '$gdb_data_cache($cache_name)' and writing file" 2