Clang 10 “#include_next” problem #2
Comments
sbingner
pushed a commit
that referenced
this issue
Jan 18, 2021
…itions This is a revert-of-revert (i.e. this reverts commit 802bec8, which itself reverted fa4701e and 79daafc) with a fix folded in. The problem was that call site tags weren't emitted properly when LTO was enabled along with split-dwarf. This required a minor fix. I've added a reduced test case in test/DebugInfo/X86/fission-call-site.ll. Original commit message: This allows a call site tag in CU A to reference a callee DIE in CU B without resorting to creating an incomplete duplicate DIE for the callee inside of CU A. We already allow cross-CU references of subprogram declarations, so it doesn't seem like definitions ought to be special. This improves entry value evaluation and tail call frame synthesis in the LTO setting. During LTO, it's common for cross-module inlining to produce a call in some CU A where the callee resides in a different CU, and there is no declaration subprogram for the callee anywhere. In this case llvm would (unnecessarily, I think) emit an empty DW_TAG_subprogram in order to fill in the call site tag. That empty 'definition' defeats entry value evaluation etc., because the debugger can't figure out what it means. As a follow-up, maybe we could add a DWARF verifier check that a DW_TAG_subprogram at least has a DW_AT_name attribute. Update #1: Reland with a fix to create a declaration DIE when the declaration is missing from the CU's retainedTypes list. The declaration is left out of the retainedTypes list in two cases: 1) Re-compiling pre-r266445 bitcode (in which declarations weren't added to the retainedTypes list), and 2) Doing LTO function importing (which doesn't update the retainedTypes list). It's possible to handle (1) and (2) by modifying the retainedTypes list (in AutoUpgrade, or in the LTO importing logic resp.), but I don't see an advantage to doing it this way, as it would cause more DWARF to be emitted compared to creating the declaration DIEs lazily. Update #2: Fold in a fix for call site tag emission in the split-dwarf + LTO case. Tested with a stage2 ThinLTO+RelWithDebInfo build of clang, and with a ReleaseLTO-g build of the test suite. rdar://46577651, rdar://57855316, rdar://57840415, rdar://58888440 Differential Revision: https://reviews.llvm.org/D70350 (cherry picked from commit e08f205)
sbingner
pushed a commit
that referenced
this issue
Jan 18, 2021
Summary: Previously `AtosSymbolizer` would set the PID to examine in the constructor which is called early on during sanitizer init. This can lead to incorrect behaviour in the case of a fork() because if the symbolizer is launched in the child it will be told examine the parent process rather than the child. To fix this the PID is determined just before the symbolizer is launched. A test case is included that triggers the buggy behaviour that existed prior to this patch. The test observes the PID that `atos` was called on. It also examines the symbolized stacktrace. Prior to this patch `atos` failed to symbolize the stacktrace giving output that looked like... ``` #0 0x100fc3bb5 in __sanitizer_print_stack_trace asan_stack.cpp:86 #1 0x10490dd36 in PrintStack+0x56 (/path/to/print-stack-trace-in-code-loaded-after-fork.cpp.tmp_shared_lib.dylib:x86_64+0xd36) #2 0x100f6f986 in main+0x4a6 (/path/to/print-stack-trace-in-code-loaded-after-fork.cpp.tmp_loader:x86_64+0x100001986) #3 0x7fff714f1cc8 in start+0x0 (/usr/lib/system/libdyld.dylib:x86_64+0x1acc8) ``` After this patch stackframes `#1` and `#2` are fully symbolized. This patch is also a pre-requisite refactor for rdar://problem/58789439. Reviewers: kubamracek, yln Subscribers: #sanitizers, llvm-commits Tags: #sanitizers Differential Revision: https://reviews.llvm.org/D77623 (cherry picked from commit 8efc3cc)
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Hi! I’m really impressed with the command line tools available in Cydia. Thank you for your contributions.
I’ve installed the clang package, and attempting to compile a simple program on my iPad, I get this problem:
I’m able to find info on the internet about this issue, but they involve macOS where folks are providing include paths and stuff to the clang-10 to give it paths for where to find the “original” header that string.h line 60 is trying to include. But... on my iPad there is only one string.h, the llvm-10 one... Looks like a catch-22.
The text was updated successfully, but these errors were encountered: