-Advice for using bugpoint
+The miscompilation debugger works similarly to the code generator debugger. +It works by splitting the test program into two pieces, running the +optimizations specified on one piece, linking the two pieces back together, and +then executing the result. It attempts to narrow down the list of passes to +the one (or few) which are causing the miscompilation, then reduce the portion +of the test program which is being miscompiled. The miscompilation debugger +assumes that the selected code generator is working properly.
+ +@@ -131,10 +180,10 @@ non-obvious ways. Here are some hints and tips:
- In the code generator and miscompilation debuggers, bugpoint only works with programs that have deterministic output. Thus, if the program - outputs argv[0], the date, time, or any other "random" data, bugpoint may - misinterpret differences in these data, when output, as the result of a - miscompilation. Programs should be temporarily modified to disable - outputs that are likely to vary from run to run. + outputs argv[0], the date, time, or any other "random" data, + bugpoint may misinterpret differences in these data, when output, + as the result of a miscompilation. Programs should be temporarily modified + to disable outputs that are likely to vary from run to run.
- In the code generator and miscompilation debuggers, debugging will go
faster if you manually modify the program or its inputs to reduce the
@@ -143,15 +192,19 @@ non-obvious ways. Here are some hints and tips:
- bugpoint is extremely useful when working on a new optimization: it helps track down regressions quickly. To avoid having to relink bugpoint every time you change your optimization however, have - bugpoint dynamically load your optimization with the -load option. + bugpoint dynamically load your optimization with the + -load option. -
- bugpoint can generate a lot of output and run for a long period of
- time. It is often useful to capture the output of the program to file. For
- example, in the C shell, you can type:
- bugpoint ..... |& tee bugpoint.log -
to get a copy of bugpoint's output in the file - bugpoint.log, as well as on your terminal. + bugpoint can generate a lot of output and run for a long period + of time. It is often useful to capture the output of the program to file. + For example, in the C shell, you can run:
+ +++ +bugpoint ... |& tee bugpoint.log
+to get a copy of bugpoint's output in the file + bugpoint.log, as well as on your terminal.
- bugpoint cannot debug problems with the LLVM linker. If
bugpoint crashes before you see its "All input ok" message,
@@ -165,89 +218,21 @@ non-obvious ways. Here are some hints and tips:
OPTIONS
+-
-
- -additional-so <library>
- Load <library> into the test program whenever it is run. - This is useful if you are debugging programs which depend on non-LLVM - libraries (such as the X or curses libraries) to run.+ -
- -args <program args>
- Pass all arguments specified after -args to the - test program whenever it runs. Note that if any of - the <program args> start with a '-', you should use: -- bugpoint <bugpoint args> -args -- <program args> -
- The "--" right after the -args option tells - bugpoint to consider any options starting with - to be - part of the -args option, not as options to bugpoint - itself.
+
+ ++
-
- -tool-args <tool args>
- Pass all arguments specified after -tool-args to the - LLVM tool under test (llc, lli, etc.) whenever it runs. - You should use this option in the following way: -- bugpoint <bugpoint args> -tool-args -- <tool args> -
- The "--" right after the -tool-args option tells - bugpoint to consider any options starting with - to be - part of the -tool-args option, not as options to - bugpoint itself. (See -args, above.)
+ Chris Lattner
+ LLVM Compiler Infrastructure
+ Last modified: $Date$ + - - -check-exit-code={true,false}
- Assume a non-zero exit code or core dump from the test program is - a failure. Defaults to true.- -
- -disable-{dce,simplifycfg}
- Do not run the specified passes to clean up and reduce the size of the - test program. By default, bugpoint uses these passes internally - when attempting to reduce test programs. If you're trying to find - a bug in one of these passes, bugpoint may crash.- -
- -help
- Print a summary of command line options.- -
- -input <filename>
- Open <filename> and redirect the standard input of the - test program, whenever it runs, to come from that file. -- -
- -load <plugin>
- Load the dynamic object <plugin> into bugpoint - itself. This object should register new - optimization passes. Once loaded, the object will add new command line - options to enable various optimizations. To see the new complete list - of optimizations, use the -help and -load options together: -- bugpoint -load <plugin> -help -
- -input <filename>
EXIT STATUS
- -If bugpoint succeeds in finding a problem, it will exit with 0. -Otherwise, if an error occurs, it will exit with a non-zero value. - --Maintained by the