Commit Graph

5 Commits

Author SHA1 Message Date
Adrian Prantl a8b2ddbde4 Move the stripping of invalid debug info from the Verifier to AutoUpgrade.
This came out of a recent discussion on llvm-dev
(https://reviews.llvm.org/D38042). Currently the Verifier will strip
the debug info metadata from a module if it finds the dbeug info to be
malformed. This feature is very valuable since it allows us to improve
the Verifier by making it stricter without breaking bcompatibility,
but arguable the Verifier pass should not be modifying the IR. This
patch moves the stripping of broken debug info into AutoUpgrade
(UpgradeDebugInfo to be precise), which is a much better location for
this since the stripping of malformed (i.e., produced by older, buggy
versions of Clang) is a (harsh) form of AutoUpgrade.

This change is mostly NFC in nature, the one big difference is the
behavior when LLVM module passes are introducing malformed debug
info. Prior to this patch, a NoAsserts build would have printed a
warning and stripped the debug info, after this patch the Verifier
will report a fatal error. I believe this behavior is actually more
desirable anyway.

Differential Revision: https://reviews.llvm.org/D38184

llvm-svn: 314699
2017-10-02 18:31:29 +00:00
Davide Italiano 2122119150 [Verifier] Stop accepting broken DIGlobalVariable(s).
The code wasn't yelling at the user when there's a reference
from a DIGlobalVariableExpression. Thanks to Adrian for the
reduced testcase. Fixes PR34672.

llvm-svn: 314069
2017-09-24 01:06:35 +00:00
Adrian Prantl 05782218ab Canonicalize the representation of empty an expression in DIGlobalVariableExpression
This change simplifies code that has to deal with
DIGlobalVariableExpression and mirrors how we treat DIExpressions in
debug info intrinsics. Before this change there were two ways of
representing empty expressions on globals, a nullptr and an empty
!DIExpression().

If someone needs to upgrade out-of-tree testcases:
  perl -pi -e 's/(!DIGlobalVariableExpression\(var: ![0-9]*)\)/\1, expr: !DIExpression())/g' <MYTEST.ll>
will catch 95%.

llvm-svn: 312144
2017-08-30 18:06:51 +00:00
Davide Italiano 903fd3ea4e [Verifier] Avoid visiting DIGlobalVariables twice.
We currently visit them twice.
Once, through `visitMDNode()` -> (the code generated by)
  `../include/llvm/IR/Metadata.def:109` -> `visitDIGlobalVariable()`
Then, through `visitMDNode()` -> `visitDIGlobalVariableExpression()`
  -> `visitDIGlobalVariable()`

This results in verification failures printed twice, e.g.:

  $ ./opt -verify ../../test/DebugInfo/pr34186.ll
  missing global variable type
  !4 = distinct !DIGlobalVariable(name: "pat", scope: !0,
    file: !1, line: 27, isLocal: true, isDefinition: true)
  missing global variable type
  !4 = distinct !DIGlobalVariable(name: "pat", scope: !0,
    file: !1, line: 27, isLocal: true, isDefinition: true)
  ./opt: ../../test/DebugInfo/pr34186.ll: error: input module is broken!

The patch removes one call so we ensure each GV is visited exactly once.

Differential Revision:  https://reviews.llvm.org/D36797

llvm-svn: 311081
2017-08-17 11:32:21 +00:00
Davide Italiano cd21378ff6 [Verifier] Reject globals without a type associated.
llvm-svn: 311012
2017-08-16 15:16:33 +00:00