Author: Martin Storsjö Date: 2022-03-07T14:38:09-08:00 New Revision: 43b4544023b73d334b5f60edaf7e1dcce4c75d3f
URL: https://github.com/llvm/llvm-project/commit/43b4544023b73d334b5f60edaf7e1dcce4c75d3f DIFF: https://github.com/llvm/llvm-project/commit/43b4544023b73d334b5f60edaf7e1dcce4c75d3f.diff LOG: [LLD] [COFF] Order .debug_* sections at the end, to avoid leaving gaps if stripped So far, we sort all discardable sections at the end, with only some extra logic to make sure that the .reloc section is at the start of that group of sections. But if there are other discardable sections, other than .reloc, they must also be ordered before .debug_* sections, to avoid leaving gaps if the executable is stripped. (Stripping executables doesn't remove all discardable sections, only the ones named .debug_*). Rust binaries seem to include a .rmeta section, which is marked discardable. This fixes stripping such binaries if built with dwarf debug info included. This fixes issues observed in MSYS2 in https://github.com/msys2/MINGW-packages/pull/10555. Differential Revision: https://reviews.llvm.org/D120805 (cherry picked from commit 4c3b74b7f5d6192d1731c88f1aeb396bc51d4949) Added: Modified: lld/COFF/Writer.cpp lld/test/COFF/sort-debug.test Removed: ################################################################################ diff --git a/lld/COFF/Writer.cpp b/lld/COFF/Writer.cpp index 12db942f1db55..1ed2327ea630d 100644 --- a/lld/COFF/Writer.cpp +++ b/lld/COFF/Writer.cpp @@ -926,8 +926,14 @@ void Writer::createSections() { // Move DISCARDABLE (or non-memory-mapped) sections to the end of file // because the loader cannot handle holes. Stripping can remove other // discardable ones than .reloc, which is first of them (created early). - if (s->header.Characteristics & IMAGE_SCN_MEM_DISCARDABLE) + if (s->header.Characteristics & IMAGE_SCN_MEM_DISCARDABLE) { + // Move discardable sections named .debug_ to the end, after other + // discardable sections. Stripping only removes the sections named + // .debug_* - thus try to avoid leaving holes after stripping. + if (s->name.startswith(".debug_")) + return 3; return 2; + } // .rsrc should come at the end of the non-discardable sections because its // size may change by the Win32 UpdateResources() function, causing // subsequent sections to move (see https://crbug.com/827082). diff --git a/lld/test/COFF/sort-debug.test b/lld/test/COFF/sort-debug.test index d8fd7ae605645..bbe2ecd0efd8d 100644 --- a/lld/test/COFF/sort-debug.test +++ b/lld/test/COFF/sort-debug.test @@ -10,6 +10,7 @@ # CHECK: Name: .text # CHECK: Name: .reloc +# CHECK: Name: .rmeta # CHECK: Name: .debug_abbrev # CHECK: Name: .debug_info # CHECK: Name: .debug_line @@ -18,6 +19,7 @@ # NODEBUG: Name: .text # NODEBUG: Name: .reloc +# NODEBUG: Name: .rmeta # NODEBUG-NOT: Name: .debug_abbrev # NODEBUG-NOT: Name: .debug_info # NODEBUG-NOT: Name: .debug_line @@ -183,6 +185,10 @@ sections: - VirtualAddress: 43 SymbolName: .text Type: IMAGE_REL_I386_DIR32 + - Name: .rmeta + Characteristics: [ IMAGE_SCN_CNT_INITIALIZED_DATA, IMAGE_SCN_MEM_DISCARDABLE, IMAGE_SCN_MEM_READ ] + Alignment: 1 + SectionData: 00112233 symbols: - Name: .text Value: 0 _______________________________________________ llvm-branch-commits mailing list llvm-branch-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-branch-commits
