Under NPM, the asan-globals-md analysis is required but cannot be run
within the asan function pass due to module analyses not being able to
run from a function pass. So this pins all tests using "-asan" to the
legacy PM and adds a corresponding RUN line with
-passes='require<asan-globals-md>,function(asan)'.
Now all tests in Instrumentation/AddressSanitizer pass when
-enable-new-pm is by default on.
Tests were automatically converted using the following python script and
failures were manually fixed up.
import sys
for i in sys.argv:
with open(i, 'r') as f:
s = f.read()
with open(i, 'w') as f:
for l in s.splitlines():
if "RUN:" in l and ' -asan -asan-module ' in l and '\\' not in l:
f.write(l.replace(' -asan -asan-module ', ' -asan -asan-module -enable-new-pm=0 '))
f.write('\n')
f.write(l.replace(' -asan -asan-module ', " -passes='require<asan-globals-md>,function(asan),module(asan-module)' "))
f.write('\n')
elif "RUN:" in l and ' -asan ' in l and '\\' not in l:
f.write(l.replace(' -asan ', ' -asan -enable-new-pm=0 '))
f.write('\n')
f.write(l.replace(' -asan ', " -passes='require<asan-globals-md>,function(asan)' "))
f.write('\n')
else:
f.write(l)
f.write('\n')
See https://bugs.llvm.org/show_bug.cgi?id=46611.
Reviewed By: vitalybuka
Differential Revision: https://reviews.llvm.org/D83921
Summary:
In some cases, ASan may insert instrumentation before function arguments
have been stored into their allocas. This causes two issues:
1) The argument value must be spilled until it can be stored into the
reserved alloca, wasting a stack slot.
2) Until the store occurs in a later basic block, the debug location
will point to the wrong frame offset, and backtraces will show an
uninitialized value.
The proposed solution is to move instructions which initialize allocas
for arguments up into the entry block, before the position where ASan
starts inserting its instrumentation.
For the motivating test case, before the patch we see:
```
| 0033: movq %rdi, 0x68(%rbx) | | DW_TAG_formal_parameter |
| ... | | DW_AT_name ("a") |
| 00d1: movq 0x68(%rbx), %rsi | | DW_AT_location (RBX+0x90) |
| 00d5: movq %rsi, 0x90(%rbx) | | ^ not correct ... |
```
and after the patch we see:
```
| 002f: movq %rdi, 0x70(%rbx) | | DW_TAG_formal_parameter |
| | | DW_AT_name ("a") |
| | | DW_AT_location (RBX+0x70) |
```
rdar://61122691
Reviewers: aprantl, eugenis
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D77182
Arthur Eubanks