[debuginfo-tests][dexter] Add --builder gcc support for POSIX

[Pierre-vh]

Summary

During our tests, we found that Dexter lacked GCC support, so we added --builder GCC support and we now propose to upstream it.
We think that having GCC support in Dexter is a great idea as it allows us to make comparisons between Clang and GCC.

This is a rather trivial change:

• Added a gcc.sh script (for POSIX systems) that invokes GCC instead of clang. The script is very similar to the clang.sh script in the same folder.
• Added an implementation of _verify_options in the clang_opt_bisect tool so it'll refuse to run when the builder is GCC

[jmorse]

Would it not be possible to override handle_options in the tool class, put the logic from _verify_options there (raising an Error if there's a problem), and then call super(Tool,self).handle_options() if there's no error? This would avoid the need to add a new method / code path.

Otherwise, adding a gcc builder sounds great!

[Pierre-vh]

In D75339#1901101, @jmorse wrote:

Would it not be possible to override handle_options in the tool class, put the logic from _verify_options there (raising an Error if there's a problem), and then call super(Tool,self).handle_options() if there's no error? This would avoid the need to add a new method / code path.

Otherwise, adding a gcc builder sounds great!

This is definitely possible, but I did it that way because my other change (the gen tool RFC) also needs a similar feature (see the parent diff: D75337)
If you prefer, I can change both this diff and D75343 to do what you suggested, then I can simply delete the parent revision (D75337).

[Pierre-vh]

Here is the updated revision with _verify_options removed.
Note that it also contains 2 minor formatting fixes, but if you want I can remove them.

[jmorse]

LGTM

debuginfo-tests/dexter/dex/builder/scripts/posix/gcc.sh

+#!/usr/bin/env bash
+set -e
+
+if test -z "$PATHTOGCC"; then
+  PATHTOGCC=gcc
+fi
+
+for INDEX in $SOURCE_INDEXES
+do
+  CFLAGS=$(eval echo "\$COMPILER_OPTIONS_$INDEX")
+  SRCFILE=$(eval echo "\$SOURCE_FILE_$INDEX")
+  OBJFILE=$(eval echo "\$OBJECT_FILE_$INDEX")
+  $PATHTOGCC -std=gnu++11 -c $CFLAGS $SRCFILE -o $OBJFILE
+done
+
+$PATHTOGCC $LINKER_OPTIONS $OBJECT_FILES -o $EXECUTABLE_FILE

debuginfo-tests/dexter/dex/tools/clang_opt_bisect/Tool.py

def _get_bisect_limits(self):
             options.source_files), (results, options.source_files)
 
         limits = [
             int(Tool._re_running_pass.match(r).group(1)) for r in results
         ]
 
         return limits
 
+    def handle_options(self, defaults):
+        options = self.context.options
+        if "clang" not in options.builder.lower():
+            raise Error("--builder %s is not supported by the clang-opt-bisect tool - only 'clang' is "
+                        "supported " % options.builder)
+        super(Tool, self).handle_options(defaults)
+
     def _run_test(self, test_name):  # noqa
         options = self.context.options
 
         per_pass_score = []
         current_bisect_pass_summary = defaultdict(list)
 
         max_limits = self._get_bisect_limits()
         overall_limit = sum(max_limits)
def _run_test(self, test_name):  # noqa
                             len(str(overall_limit))).format(current_limit),
                         '{:.4f}'.format(heuristic.score).replace(
                             '.', '_'), pass_info[1]
                     ] if s is not None)
 
                 file_name = ''.join(
                     c for c in file_name
                     if c.isalnum() or c in '()-_./ ').strip().replace(
-                        ' ', '_').replace('/', '_')
 
                 output_text_path = os.path.join(options.results_directory,
                                                 '{}.txt'.format(file_name))
                 with open(output_text_path, 'w') as fp:
                     self.context.o.auto(summary + '\n', stream=Stream(fp))
                     self.context.o.auto(str(steps) + '\n', stream=Stream(fp))
                     self.context.o.auto(
                         heuristic_verbose_output + '\n', stream=Stream(fp))
 
                 output_dextIR_path = os.path.join(options.results_directory,
                                                   '{}.dextIR'.format(file_name))
                 with open(output_dextIR_path, 'wb') as fp:
                     pickle.dump(steps, fp, protocol=pickle.HIGHEST_PROTOCOL)
 
             per_pass_score.append((test_name, pass_text,
                                    heuristic.score))
 
             if pass_info[1]:
                 self._all_bisect_pass_summary[pass_info[1]].append(
def _handle_results(self) -> ReturnCode:
         options = self.context.options
         pass_summary_path = os.path.join(options.results_directory,
                                          'overall-pass-summary.csv')
 
         self._write_pass_summary(pass_summary_path,
                                  self._all_bisect_pass_summary)
         return ReturnCode.OK
 
-
     def _clang_opt_bisect_build(self, opt_bisect_limits):
         options = self.context.options
         compiler_options = [
             '{} -mllvm -opt-bisect-limit={}'.format(options.cflags,
                                                     opt_bisect_limit)
             for opt_bisect_limit in opt_bisect_limits
         ]
         linker_options = options.ldflags