Subzero: Change the szbuild.py --force default.

With the --force option, the behavior of its default setting is dangerous. Specifically, it doesn't retranslate by default when you change the szbuild command-line arguments. This leads to debugging frustration. Therefore, we change the default setting to be "dumb" and always retranslate. For bisection debugging, the user will quickly realize that they want to add "--force=0". BUG= none R=jpp@chromium.org Review URL: https://codereview.chromium.org/1608323002 .

Subzero: Change the szbuild.py --force default.
bc3bd502 · Jim Stichnoth · 4ab4fbed · bc3bd502 · bc3bd502
Commit bc3bd502 authored Jan 20, 2016 by Jim Stichnoth
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Showing with 10 additions and 8 deletions

Makefile.standalone Makefile.standalone +1 -1

szbuild.py pydir/szbuild.py +9 -7

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--- a/Makefile.standalone
+++ b/Makefile.standalone
@@ -473,7 +473,7 @@ endif
 SPECFLAGS :=
 SPECBUILDONLY := false
 %.spec2k: % $(OBJDIR)/pnacl-sz make_symlink runtime
-	./pydir/szbuild_spec2k.py -v --force \
+	./pydir/szbuild_spec2k.py -v \
          $(SPECFLAGS) --target=$(TARGETFLAG) $(SPEC) $<
 	$(SPECBUILDONLY) || ( cd ../../../tests/spec2k; \
 	 ./run_all.sh RunTimedBenchmarks $(SETUP) train $< )

--- a/pydir/szbuild.py
+++ b/pydir/szbuild.py
@@ -61,8 +61,10 @@ def MatchSymbol(sym, re_include, re_exclude, default_match):
    return default_match

 def AddOptionalArgs(argparser):
-    argparser.add_argument('--force', dest='force', action='store_true',
-                           help='Force all re-translations of the pexe')
+    argparser.add_argument('--force', dest='force', type=int, choices=[0, 1],
+                           default=1,
+                           help='Force all re-translations of the pexe.' +
+                                ' Default %(default)s.')
    argparser.add_argument('--include', '-i', default=[], dest='include',
                           action='append',
                           help='Subzero symbols to include ' +
@@ -240,11 +242,11 @@ def main():
    If no --include or --exclude arguments are given, the executable is produced
    entirely using Subzero, without using llc or linker tricks.

-    This script uses file modification timestamps to determine whether llc and
-    Subzero re-translation are needed.  It checks timestamps of llc, pnacl-sz,
-    and the pexe against the translated object files to determine the minimal
-    work necessary.  The --force option suppresses those checks and
-    re-translates everything.
+    When using the --force=0 option, this script uses file modification
+    timestamps to determine whether llc and Subzero re-translation are needed.
+    It checks timestamps of llc, pnacl-sz, and the pexe against the translated
+    object files to determine the minimal work necessary.  The --force=1 option
+    (default) suppresses those checks and re-translates everything.

    This script expects various PNaCl and LLVM tools to be found within the
    native_client tree.  When changes are made to these tools, copy them this