gdb: Add maint set ignore-prologue-end-flag

The previous patch added support for the DWARF prologue-end flag in line
table. This flag can be used by DWARF producers to indicate where to
place breakpoints past a function prologue.  However, this takes
precedence over prologue analyzers. So if we have to debug a program
with erroneous debug information, the overall debugging experience will
be degraded.

This commit proposes to add a maintenance command to instruct GDB to
ignore the prologue_end flag.

Tested on x86_64-gnu-linux.

Change-Id: Idda6d1b96ba887f4af555b43d9923261b9cc6f82

1 files changed, 14 insertions, 0 deletions

diff --git a/gdb/testsuite/gdb.dwarf2/dw2-prologue-end.exp b/gdb/testsuite/gdb.dwarf2/dw2-prologue-end.exp
index 0de13ae..b5f8bcc 100644
--- a/gdb/testsuite/gdb.dwarf2/dw2-prologue-end.exp
+++ b/gdb/testsuite/gdb.dwarf2/dw2-prologue-end.exp
@@ -89,3 +89,17 @@ if ![runto_main] {
 
 set prologue_end_line [gdb_get_line_number "main assign o"]
 gdb_test "frame" ".*main \\\(\\\) at \[^\r\n\]*:$prologue_end_line\r\n.*"
+
+with_test_prefix "ignore-prologue-end" {
+    clean_restart $binfile
+    gdb_test_no_output "maintenance set ignore-prologue-end-flag on"
+
+    if ![runto_main] {
+	return -1
+    }
+
+    # If we ignore the prologue-end flag, we should stop at the first statement
+    # of main which assigns m.
+    set prologue_end_line [gdb_get_line_number "main assign m"]
+    gdb_test "frame" ".*main \\\(\\\) at \[^\r\n\]*:$prologue_end_line\r\n.*"
+}