Commit Graph

9 Commits

Author SHA1 Message Date
Nikita Popov 90ec6dff86 [OpaquePtr] Forbid mixing typed and opaque pointers
Currently, opaque pointers are supported in two forms: The
-force-opaque-pointers mode, where all pointers are opaque and
typed pointers do not exist. And as a simple ptr type that can
coexist with typed pointers.

This patch removes support for the mixed mode. You either get
typed pointers, or you get opaque pointers, but not both. In the
(current) default mode, using ptr is forbidden. In -opaque-pointers
mode, all pointers are opaque.

The motivation here is that the mixed mode introduces additional
issues that don't exist in fully opaque mode. D105155 is an example
of a design problem. Looking at D109259, it would probably need
additional work to support mixed mode (e.g. to generate GEPs for
typed base but opaque result). Mixed mode will also end up
inserting many casts between i8* and ptr, which would require
significant additional work to consistently avoid.

I don't think the mixed mode is particularly valuable, as it
doesn't align with our end goal. The only thing I've found it to
be moderately useful for is adding some opaque pointer tests in
between typed pointer tests, but I think we can live without that.

Differential Revision: https://reviews.llvm.org/D109290
2021-09-10 15:18:23 +02:00
Arthur Eubanks 86d1a0b306 [test] Remove some legacy PM tests in llvm/test/Instrumentation 2021-09-05 11:51:19 -07:00
Nikita Popov c4de78e91c [SanitizerCoverage] Fix global type check with opaque pointers
The code was previously relying on the fact that an incorrectly
typed global would result in the insertion of a BitCast constant
expression. With opaque pointers, this is no longer the case, so
we should check the type explicitly.
2021-06-29 20:32:14 +02:00
Arthur Eubanks 9b1539be40 [NewPM][Sancov] Pin RUN lines with -sancov to legacy PM
Since the NPM pass is named sancov-module, not sancov.
This makes all tests under Instrumentation/SanitizerCoverage pass when
-enable-new-pm is on by default.

Reviewed By: vitalybuka

Differential Revision: https://reviews.llvm.org/D84687
2020-07-28 09:10:01 -07:00
Leonard Chan eca01b031d [NewPM][Sancov] Make Sancov a Module Pass instead of 2 Passes
This patch merges the sancov module and funciton passes into one module pass.

The reason for this is because we ran into an out of memory error when
attempting to run asan fuzzer on some protobufs (pc.cc files). I traced the OOM
error to the destructor of SanitizerCoverage where we only call
appendTo[Compiler]Used which calls appendToUsedList. I'm not sure where precisely
in appendToUsedList causes the OOM, but I am able to confirm that it's calling
this function *repeatedly* that causes the OOM. (I hacked sancov a bit such that
I can still create and destroy a new sancov on every function run, but only call
appendToUsedList after all functions in the module have finished. This passes, but
when I make it such that appendToUsedList is called on every sancov destruction,
we hit OOM.)

I don't think the OOM is from just adding to the SmallSet and SmallVector inside
appendToUsedList since in either case for a given module, they'll have the same
max size. I suspect that when the existing llvm.compiler.used global is erased,
the memory behind it isn't freed. I could be wrong on this though.

This patch works around the OOM issue by just calling appendToUsedList at the
end of every module run instead of function run. The same amount of constants
still get added to llvm.compiler.used, abd we make the pass usage and logic
simpler by not having any inter-pass dependencies.

Differential Revision: https://reviews.llvm.org/D66988

llvm-svn: 370971
2019-09-04 20:30:29 +00:00
Leonard Chan 007f674c6a Reland the "[NewPM] Port Sancov" patch from rL365838. No functional
changes were made to the patch since then.

--------

[NewPM] Port Sancov

This patch contains a port of SanitizerCoverage to the new pass manager. This one's a bit hefty.

Changes:

- Split SanitizerCoverageModule into 2 SanitizerCoverage for passing over
  functions and ModuleSanitizerCoverage for passing over modules.
- ModuleSanitizerCoverage exists for adding 2 module level calls to initialization
  functions but only if there's a function that was instrumented by sancov.
- Added legacy and new PM wrapper classes that own instances of the 2 new classes.
- Update llvm tests and add clang tests.

llvm-svn: 367053
2019-07-25 20:53:15 +00:00
Leonard Chan bb147aabc6 Revert "[NewPM] Port Sancov"
This reverts commit 5652f35817.

llvm-svn: 366153
2019-07-15 23:18:31 +00:00
Leonard Chan 5652f35817 [NewPM] Port Sancov
This patch contains a port of SanitizerCoverage to the new pass manager. This one's a bit hefty.

Changes:

- Split SanitizerCoverageModule into 2 SanitizerCoverage for passing over
  functions and ModuleSanitizerCoverage for passing over modules.
- ModuleSanitizerCoverage exists for adding 2 module level calls to initialization
  functions but only if there's a function that was instrumented by sancov.
- Added legacy and new PM wrapper classes that own instances of the 2 new classes.
- Update llvm tests and add clang tests.

Differential Revision: https://reviews.llvm.org/D62888

llvm-svn: 365838
2019-07-11 22:35:40 +00:00
Julian Lettner 29ac3a5b82 [SanitizerCoverage] Clang crashes if user declares `__sancov_lowest_stack` variable
Summary:
If the user declares or defines `__sancov_lowest_stack` with an
unexpected type, then `getOrInsertGlobal` inserts a bitcast and the
following cast fails:
```
Constant *SanCovLowestStackConstant =
       M.getOrInsertGlobal(SanCovLowestStackName, IntptrTy);
SanCovLowestStack = cast<GlobalVariable>(SanCovLowestStackConstant);
```

This variable is a SanitizerCoverage implementation detail and the user
should generally never have a need to access it, so we emit an error
now.

rdar://problem/44143130

Reviewers: morehouse

Differential Revision: https://reviews.llvm.org/D57633

llvm-svn: 353100
2019-02-04 22:06:30 +00:00