[gdb/testsuite] Fix gdb.base/consecutive.exp with gcc-8

When running test-case gdb.base/consecutive.exp with gcc-8 instead of gcc-7,
we get:
...
 (gdb) step^M
 ^M
-Breakpoint 3, 0x00000000004004b1 in foo () at consecutive.c:10^M
+Breakpoint 3, foo () at consecutive.c:10^M
 10        return a[0] + a[1] + a[2] + a[3] + a[4] + a[5] + a[6];^M
-(gdb) PASS: gdb.base/consecutive.exp: stopped at bp, 2nd instr
+(gdb) FAIL: gdb.base/consecutive.exp: stopped at bp, 2nd instr
...

This is due to the fact that gcc-8 generates more precise line info, making
the breakpoint address a "recommended breakpoint location", and consequently
gdb doesn't print the address prefix anymore.

Fix the FAIL by checking in the test-case whether the breakpoint address is at
"recommended breakpoint location" or not.

gdb/testsuite/ChangeLog:

2020-05-06  Tom de Vries  <tdevries@suse.de>

	* lib/gdb.exp (is_stmt_addresses, hex_in_list): New proc, factored out
	of ...
	* gdb.base/async.exp: ... here.
	* gdb.base/consecutive.exp: Handle if 2nd breakpoint is at a
	"recommended breakpoint location".

4 files changed, 56 insertions, 13 deletions

diff --git a/gdb/testsuite/ChangeLog b/gdb/testsuite/ChangeLog
index 7b88b3a469c..4ffff5dcbe5 100644
--- a/gdb/testsuite/ChangeLog
+++ b/gdb/testsuite/ChangeLog
@@ -1,5 +1,13 @@
 2020-05-06  Tom de Vries  <tdevries@suse.de>
 
+	* lib/gdb.exp (is_stmt_addresses, hex_in_list): New proc, factored out
+	of ...
+	* gdb.base/async.exp: ... here.
+	* gdb.base/consecutive.exp: Handle if 2nd breakpoint is at a
+	"recommended breakpoint location".
+
+2020-05-06  Tom de Vries  <tdevries@suse.de>
+
 	* gdb.compile/compile-ifunc.exp: Use -Wno-attribute-alias.
 
 2020-05-04  Tom de Vries  <tdevries@suse.de>
diff --git a/gdb/testsuite/gdb.base/async.exp b/gdb/testsuite/gdb.base/async.exp
index bf124ca56a9..1a4d3fbee83 100644
--- a/gdb/testsuite/gdb.base/async.exp
+++ b/gdb/testsuite/gdb.base/async.exp
@@ -79,16 +79,7 @@ test_background "step&" "" ".*y = foo \\(\\).*" "step& #1"
 
 test_background "step&" "" " foo \\(\\) at .*async.c.*x = 5.*" "step& #2"
 
-set is_stmt [list]
-gdb_test_multiple "maint info line-table async.c" "" {
-    -re "\r\n$decimal\[ \t\]+$decimal\[ \t\]+($hex)\[ \t\]+Y\[^\r\n\]*" {
-	lappend is_stmt $expect_out(1,string)
-	exp_continue
-    }
-    -re -wrap "" {
-	pass $gdb_test_name
-    }
-}
+set is_stmt [is_stmt_addresses $srcfile]
 
 # Get the next instruction address.
 set next_insn_addr ""
@@ -99,8 +90,7 @@ gdb_test_multiple {x/2i $pc} "$test" {
 	pass "$test"
     }
 }
-set next_insn_is_stmt \
-    [expr [lsearch -regexp $is_stmt 0x0*$next_insn_addr] != -1]
+set next_insn_is_stmt [hex_in_list $next_insn_addr $is_stmt]
 
 if { $next_insn_is_stmt } {
     set prefix ""
diff --git a/gdb/testsuite/gdb.base/consecutive.exp b/gdb/testsuite/gdb.base/consecutive.exp
index afbe335efc6..d0f541f1a25 100644
--- a/gdb/testsuite/gdb.base/consecutive.exp
+++ b/gdb/testsuite/gdb.base/consecutive.exp
@@ -35,6 +35,8 @@ if ![runto_main] then {
     continue
 }
 
+set is_stmt [is_stmt_addresses $srcfile]
+
 set nl "\[\r\n\]+"
 
 gdb_breakpoint foo
@@ -55,7 +57,7 @@ gdb_test "break \*$bp_addr" "Breakpoint $decimal at $bp_addr: file .*" \
 	"set bp, 2nd instr"
 
 gdb_test_multiple "step" "stopped at bp, 2nd instr" {
-    -re "Breakpoint $decimal, ($hex) in foo.*$gdb_prompt $" {
+    -re -wrap "Breakpoint $decimal, ($hex) in foo.*" {
 	set stop_addr $expect_out(1,string)
 	if [eval expr "$bp_addr == $stop_addr"] then {
 	    pass "stopped at bp, 2nd instr"
@@ -63,5 +65,16 @@ gdb_test_multiple "step" "stopped at bp, 2nd instr" {
 	    fail "stopped at bp, 2nd instr (wrong address)"
 	}
     }
+    -re -wrap "Breakpoint $decimal, foo.*" {
+	set stop_addr [get_valueof "/x" "\$pc" "" "value of pc"]
+	set stop_addr_is_stmt [hex_in_list $stop_addr $is_stmt]
+	if { ! $stop_addr_is_stmt } {
+	    fail "stopped at bp, 2nd instr (missing hex prefix)"
+	} elseif [eval expr "$bp_addr == $stop_addr"] then {
+	    pass "stopped at bp, 2nd instr"
+	} else {
+	    fail "stopped at bp, 2nd instr (wrong address)"
+	}
+    }
 }
 
diff --git a/gdb/testsuite/lib/gdb.exp b/gdb/testsuite/lib/gdb.exp
index 37326144141..239871114d2 100644
--- a/gdb/testsuite/lib/gdb.exp
+++ b/gdb/testsuite/lib/gdb.exp
@@ -7136,5 +7136,37 @@ proc debug_types { } {
     return 0
 }
 
+# Return the addresses in the line table for FILE for which is_stmt is true.
+
+proc is_stmt_addresses { file } {
+    global decimal
+    global hex
+
+    set is_stmt [list]
+
+    gdb_test_multiple "maint info line-table $file" "" {
+	-re "\r\n$decimal\[ \t\]+$decimal\[ \t\]+($hex)\[ \t\]+Y\[^\r\n\]*" {
+	    lappend is_stmt $expect_out(1,string)
+	    exp_continue
+	}
+	-re -wrap "" {
+	}
+    }
+
+    return $is_stmt
+}
+
+# Return 1 if hex number VAL is an element of HEXLIST.
+
+proc hex_in_list { val hexlist } {
+    # Normalize val by removing 0x prefix, and leading zeros.
+    set val [regsub ^0x $val ""]
+    set val [regsub ^0+ $val "0"]
+
+    set re 0x0*$val
+    set index [lsearch -regexp $hexlist $re]
+    return [expr $index != -1]
+}
+
 # Always load compatibility stuff.
 load_lib future.exp