Fix MCCAS after changed made to MC layer upstream #11184
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This reverts commit 1d94ada.
The MCPseudoProbeAddrFragment type has been removed as a type of fragment and has been merged with the MCLEBFragment.
…class The MCSection class has been refactored to no longer have printSwitchToSection, and useCodeAlign function. It also no longer can contain a classof function. This change removes these functions to make it compile properly again.
The create function in the MCFRAGMENT_NODE_REF macro has to take an MCFragment object because of the changes in MCFragment which removed the concept that different fragment types would have their own class.
adrian-prantl
approved these changes
Aug 15, 2025
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The MCAlignFragment class has been removed from MCSection.h and the Align Fragment is now part of the MCFragment class. The Align fragment has also been significantly changed. In the past, the Align fragment would only contain alignment data, however, now it can also contain regular data as well (similar to an MCDataFragment, but with alignment data as well). This patch makes the necessary changes to make MCCAS work properly with the new MCAlignFragment.
Since the create function in MCFRAGMENT_NODE_REF just takes an MCFragment object as an argument, this change just makes the change for MCBoundaryAlignFragmentRef::create.
Since the create function in MCFRAGMENT_NODE_REF just takes an MCFragment object as an argument, this change just makes the change for MCCVInlineLineTableFragmentRef::create.
Since the create function in MCFRAGMENT_NODE_REF just takes an MCFragment object as an argument, this change just makes the necessary changes for MCFillFragmentRef::create.
Since the create function in MCFRAGMENT_NODE_REF just takes an MCFragment object as an argument, this change just makes the change for MCLEBFragmentRef::create.
Since the create function in MCFRAGMENT_NODE_REF just takes an MCFragment object as an argument, this change just makes the necessary changes for MCNopsFragmentRef::create.
Since the create function in MCFRAGMENT_NODE_REF just takes an MCFragment object as an argument, this change just makes the necessary changes for MCOrgFragmentRef::create.
Since the create function in MCFRAGMENT_NODE_REF just takes an MCFragment object as an argument, this change just makes the necessary changes for MCSymbolIdFragmentRef::create.
The MCFragments have been changed, they can now have both a fixed content and a variable content as well. This patch makes the necessary changes to the getFragmentContents() function to make it work properly.
MCCASBuilder::mergeMCFragmentContents merges all content from all the fragments in a section into one buffer. However, since the way content is stored in a fragemnts has changed, this function had to be updated as well.
There is no concept on an EncodedFragment anymore, hence we have to list all fragments that are mergeable.
There is no class called MCDataFragment, it has been folded into the MCFragment class. Change the cast<MCDataFragment> to cast<MCFragment>.
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rastogishubham
commented
Aug 21, 2025
| // CASObjects, one can use a conditional breakpoint to find the Fragment | ||
| // which might have a bug. | ||
| #ifndef NDEBUG | ||
| uint64_t TotalFragmentWithoutAddendsSize = 0; |
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I do get the warning
[236/236] Building CXX object lib/MCCAS/CMakeFiles/LLVMMCCAS.dir/MCCASObjectV1.cpp.o
/Users/shubhamrastogi/Development/llvm-project-cas/llvm-project/llvm/lib/MCCAS/MCCASObjectV1.cpp:3131:14: warning: variable 'TotalFragmentWithoutAddendsSize' set but not used [-Wunused-but-set-variable]
3131 | uint64_t TotalFragmentWithoutAddendsSize = 0;
|
This is because TotalFragmentWithoutAddendsSize is never read from, but this is really useful for debugging MCCAS. Any ideas on what to do?
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I suggest use debug macros: https://llvm.org/docs/ProgrammersManual.html#the-llvm-debug-macro-and-debug-option
For non-assert build just add a reference:
(void) TotalFragmentWithoutAddendsSize;
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You want to add #define DEBUG_TYPE for the file.
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In rare cases (like in the case of armv7-cas.ll), where we still produce DWARF4, we are still trying to read the information from a non-existent DebugStringOffsets section. We do not need the data from that section to partition compile units. That code has been removed
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The MC layer has gone through many changes, which affect MCCAS, especially the changes made to MCFragments.
This PR addresses them all
rdar://156159206