[lldb] Fix nondeterminism in TestCppBitfields

labath · zmodem · commit 54b022d34441 · 2020-01-28T14:24:36.000+01:00
The test was printing a char[3] variable without a terminating nul. The memory after that variable (an unnamed bitfield) was not initialized. If the memory happened to be nonzero, the summary provider for the variable would run off into the next field. This is probably not the right behavior (it should stop at the end of the array), but this is not the purpose of this test. I have filed pr44649 for this bug, and fixed the test to not depend on this behavior. (cherry picked from commit 77cedb0)
diff --git a/lldb/packages/Python/lldbsuite/test/lang/cpp/bitfields/TestCppBitfields.py b/lldb/packages/Python/lldbsuite/test/lang/cpp/bitfields/TestCppBitfields.py
@@ -80,7 +80,7 @@ def test_and_run_command(self):
             "frame variable --show-types lbd",
             VARIABLES_DISPLAYED_CORRECTLY,
             substrs=[
-                '(char [3]) arr = "abc"',
+                '(char [3]) arr = "ab"',
                 '(int:32)  =',
                 '(unsigned int:20) a = 5',
                 ])
diff --git a/lldb/packages/Python/lldbsuite/test/lang/cpp/bitfields/main.cpp b/lldb/packages/Python/lldbsuite/test/lang/cpp/bitfields/main.cpp
@@ -73,7 +73,7 @@ int main(int argc, char const *argv[]) {
 
   lbd.arr[0] = 'a';
   lbd.arr[1] = 'b';
-  lbd.arr[2] = 'c';
+  lbd.arr[2] = '\0';
   lbd.a = 5;
 
 
