With compilation fix.
Original commit message:
D39788 added a '.stack-size' section containing metadata on function stack sizes
to output ELF files behind the new -stack-size-section flag.
This change does following two things on top:
1) Imagine the case when there are -ffunction-sections flag given and there are text sections in COMDATs.
The patch adds a '.stack-size' section into corresponding COMDAT group, so that linker will be able to
eliminate them fast during resolving the COMDATs.
2) Patch sets a SHF_LINK_ORDER flag and links '.stack-size' with the corresponding .text.
With that linker will be able to do -gc-sections on dead stack sizes sections.
Differential revision: https://reviews.llvm.org/D46874
llvm-svn: 335336
D39788 added a '.stack-size' section containing metadata on function stack sizes
to output ELF files behind the new -stack-size-section flag.
This change does following two things on top:
1) Imagine the case when there are -ffunction-sections flag given and there are text sections in COMDATs.
The patch adds a '.stack-size' section into corresponding COMDAT group, so that linker will be able to
eliminate them fast during resolving the COMDATs.
2) Patch sets a SHF_LINK_ORDER flag and links '.stack-size' with the corresponding .text.
With that linker will be able to do -gc-sections on dead stack sizes sections.
Differential revision: https://reviews.llvm.org/D46874
llvm-svn: 335332
Re applying after fixing issues in the diff, sorry for any painful conflicts/merges!
Original RFC: http://lists.llvm.org/pipermail/llvm-dev/2017-August/117028.html
This change adds a '.stack-size' section containing metadata on function stack sizes to output ELF files behind the new -stack-size-section flag. The section contains pairs of function symbol references (8 byte) and stack sizes (unsigned LEB128).
The contents of this section can be used to measure changes to stack sizes between different versions of the compiler or a source base. The advantage of having a section is that we can extract this information when examining binaries that we didn't build, and it allows users and tools easy access to that information just by referencing the binary.
There is a follow up change to add an option to clang.
Thanks.
Reviewers: hfinkel, MatzeB
Reviewed By: MatzeB
Subscribers: thegameg, asb, llvm-commits
Differential Revision: https://reviews.llvm.org/D39788
llvm-svn: 319430
Summary:
Original RFC: http://lists.llvm.org/pipermail/llvm-dev/2017-August/117028.html
I wasn't sure who to put as reviewers, so please add/remove people as appropriate.
This change adds a '.stack-size' section containing metadata on function stack sizes to output ELF files behind the new -stack-size-section flag. The section contains pairs of function symbol references (8 byte) and stack sizes (unsigned LEB128).
The contents of this section can be used to measure changes to stack sizes between different versions of the compiler or a source base. The advantage of having a section is that we can extract this information when examining binaries that we didn't build, and it allows users and tools easy access to that information just by referencing the binary.
There is a follow up change to add an option to clang.
Thanks.
Reviewers: hfinkel, MatzeB
Reviewed By: MatzeB
Subscribers: thegameg, asb, llvm-commits
Differential Revision: https://reviews.llvm.org/D39788
llvm-svn: 319423
