From 0a7e7475c3799552b30aca629b87531301da4faf Mon Sep 17 00:00:00 2001 From: Ed Maste Date: Tue, 4 Jul 2017 17:32:51 +0000 Subject: [PATCH] lld: [ELF] Remove unused synthetic sections from script commands Script commands are processed before unused synthetic sections are removed. Therefore, if a linker script matches one of these sections it'll get emitted as an empty output section because the logic for removing unused synthetic sections ignores script commands which could have already matched and captured one of these sections. This patch fixes that by also removing the unused synthetic sections from the script commands. Discussed with: dim Obtained from: LLVM r307037 Sponsored by: The FreeBSD Foundation --- contrib/llvm/tools/lld/ELF/Writer.cpp | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) diff --git a/contrib/llvm/tools/lld/ELF/Writer.cpp b/contrib/llvm/tools/lld/ELF/Writer.cpp index 080d8e787301..551ca260de10 100644 --- a/contrib/llvm/tools/lld/ELF/Writer.cpp +++ b/contrib/llvm/tools/lld/ELF/Writer.cpp @@ -1149,8 +1149,17 @@ static void removeUnusedSyntheticSections(std::vector &V) { SS->Live = false; // If there are no other sections in the output section, remove it from the // output. - if (OS->Sections.empty()) + if (OS->Sections.empty()) { V.erase(std::find(V.begin(), V.end(), OS)); + // Also remove script commands matching the output section. + auto &Cmds = Script->Opt.Commands; + auto I = std::remove_if(Cmds.begin(), Cmds.end(), [&](BaseCommand *Cmd) { + if (auto *OSCmd = dyn_cast(Cmd)) + return OSCmd->Sec == OS; + return false; + }); + Cmds.erase(I, Cmds.end()); + } } }