Allow for different method prologues in debuginfotest.

substratevm/mx.substratevm/testhello.py

@@ -159,9 +159,7 @@ def test():
 
     musl = os.environ.get('debuginfotest_musl', 'no') == 'yes'
 
-    isolates = False
-    if os.environ.get('debuginfotest_isolates', 'no') == 'yes':
-        isolates = True
+    isolates = os.environ.get('debuginfotest_isolates', 'no') == 'yes'
 
     arch = os.environ.get('debuginfotest_arch', 'amd64')
 
@@ -781,30 +779,27 @@ def test():
            r"f11 = 12.375"]
     checker = Checker('info args', rexp)
     checker.check(exec_string)
-
-    exec_string = execute("x/i $pc")
-    if arch == 'aarch64':
-        rexp = r"%ssub%ssp, sp, #0x%s"%(wildcard_pattern, spaces_pattern, hex_digits_pattern)
-    else:
-        rexp = r"%ssub %s\$0x%s,%%rsp"%(wildcard_pattern, spaces_pattern, hex_digits_pattern)
-    checker = Checker('x/i $pc', rexp)
-    checker.check(exec_string)
 
-    if arch == 'aarch64':
-        exec_string = execute("stepi")
-        print(exec_string)
-        # n.b. stack param offsets will be wrong here because
-        # aarch64 creates the frame in two steps, a sub of
-        # the frame size followed by a stack push of [lr,sp]
-        # (needs fixing in the initial frame location info split
-        # in the generator not here)
+    # proceed to the next infopoint, which is at the end of the method prologue.
+    # since the compiler may emit different instruction sequences, we step
+    # through the instructions until we find and execute the first instruction
+    # that adjusts the stack pointer register, which concludes the prologue.
+    sp_register = 'sp' if arch == 'aarch64' else 'rsp'
+    instruction_adjusts_sp_register_pattern = re.compile(r"%s,%%%s"%(wildcard_pattern,sp_register))
+    max_num_stepis = 6
+    num_stepis = 0
+    while True:
         exec_string = execute("x/i $pc")
         print(exec_string)
-        exec_string = execute("stepi")
-        print(exec_string)
-    else:
-        exec_string = execute("stepi")
-
+        execute("stepi")
+        num_stepis += 1
+        if instruction_adjusts_sp_register_pattern.match(exec_string):
+            print("method prologue reached successfully")
+            break
+        if num_stepis >= max_num_stepis:
+            print("method prologue is unexpectedly long, did not reach end after %s stepis" % num_stepis)
+            sys.exit(1)
+
     exec_string = execute("info args")
     rexp =[r"i0 = 0",
            r"i1 = 1",