Restore code size tracking support in Darwin

[paquette]

Summary

D109576 broke code size metric collection on Darwin platforms.

This patch restores support in Darwin.

The reason support was broken is that llvm-size outputs text section size with leading underscores, while on other platforms, it leads with periods.

[fhahn]

LGTM, thanks for fixing this!

[azharudd]

lnt/tests/test_suite.py

83

In light of the comment below, this could become:

{{ test.metrics['size..text'] or test.metrics['size.__text'] if test.metrics }};\

or, better yet

{{ test.metrics.get('size..text') or test.metrics.get('size.__text') if test.metrics }};\

716

Wouldn't it be a more clear/straightforward solution to just add another line here for 'size.__text' (similar to what we are doing for mem right below)?

'size..text': 'code_size',
# On Darwin, the section name is reported as `__text`.
'size.__text': 'code_size',

Only one of 'size..text' or 'size.__text' would exist in the lit output, and whichever exists would correspond to the 'code_size'. This way, we would also not need https://reviews.llvm.org/D146260, and the lit output will continue to have the exact section name.

726

and another corresponding 'size.__text': float, line right below this too.

[paquette]

lnt/tests/test_suite.py

716

Sure, that sounds good to me.

[paquette]

Address review feedback

[azharudd]

LGTM.

lnt/tests/test_suite.py

 Program;CC;CC_Time;Code_Size;CC_Hash;Exec;Exec_Time;Score
 {%- for suite in suites -%}
     {%- for test in suite.tests %}
 {{ suite.name }}/{{ test.path }}/{{ test.name }};
         {%- if test.code == "NOEXE" -%}
             fail;*;*;*;
         {%- else -%}
             pass;{{ test.metrics.compile_time if test.metrics }};\
-{{ test.metrics['size..text'] if test.metrics }};\
+{{ test.metrics.get('size..text') or test.metrics.get('size.__text') if test.metrics }};\
 {{ test.metrics.hash if test.metrics }};
         {%- endif -%}
         {%- if test.code == "FAIL" or test.code == "NOEXE" -%}
             fail;*;*;
         {%- else -%}
             pass;{{ test.metrics.exec_time if test.metrics }};\
 {{ test.metrics.score if test.metrics }};
         {%- endif -%}
class TestSuiteTest(BuiltinTest):
 
     def _parse_lit_output(self, path, data, cmake_vars, only_test=False):
         LIT_METRIC_TO_LNT = {
             'compile_time': 'compile',
             'exec_time': 'exec',
             'score': 'score',
             'hash': 'hash',
             'link_time': 'compile',
             'size..text': 'code_size',
+            # On Darwin, the section name is reported as `__text`.
+            'size.__text': 'code_size',
             'mem_bytes': 'mem',
             'link_mem_bytes': 'mem'
         }
         LIT_METRIC_CONV_FN = {
             'compile_time': float,
             'exec_time': float,
             'score': float,
             'hash': str,
             'link_time': float,
             'size..text': float,
+            # On Darwin, the section name is reported as `__text`.
+            'size.__text': float,
             'mem_bytes': float,
             'link_mem_bytes': float
         }
 
         # We don't use the test info, currently.
         test_info = {}
         test_samples = []