Remove empty section commands.
We were already not creating them, and with this other parts of the
code don't have to worry about them.
llvm-svn: 281968
diff --git a/lld/ELF/LinkerScript.cpp b/lld/ELF/LinkerScript.cpp
index e4f8378..ea2c14b 100644
--- a/lld/ELF/LinkerScript.cpp
+++ b/lld/ELF/LinkerScript.cpp
@@ -446,6 +446,29 @@
}
template <class ELFT> void LinkerScript<ELFT>::assignAddresses() {
+ // It is common practice to use very generic linker scripts. So for any
+ // given run some of the output sections in the script will be empty.
+ // We could create corresponding empty output sections, but that would
+ // clutter the output.
+ // We instead remove trivially empty sections. The bfd linker seems even
+ // more aggressive at removing them.
+ auto Pos = std::remove_if(
+ Opt.Commands.begin(), Opt.Commands.end(),
+ [&](const std::unique_ptr<BaseCommand> &Base) {
+ auto *Cmd = dyn_cast<OutputSectionCommand>(Base.get());
+ if (!Cmd)
+ return false;
+ std::vector<OutputSectionBase<ELFT> *> Secs =
+ findSections(*Cmd, *OutputSections);
+ if (!Secs.empty())
+ return false;
+ for (const std::unique_ptr<BaseCommand> &I : Cmd->Commands)
+ if (!isa<InputSectionDescription>(I.get()))
+ return false;
+ return true;
+ });
+ Opt.Commands.erase(Pos, Opt.Commands.end());
+
// Orphan sections are sections present in the input files which
// are not explicitly placed into the output file by the linker script.
// We place orphan sections at end of file.
diff --git a/lld/test/ELF/linkerscript/align-empty.s b/lld/test/ELF/linkerscript/align-empty.s
new file mode 100644
index 0000000..4af943f
--- /dev/null
+++ b/lld/test/ELF/linkerscript/align-empty.s
@@ -0,0 +1,14 @@
+# REQUIRES: x86
+# RUN: llvm-mc -filetype=obj -triple=x86_64-unknown-linux %s -o %t
+
+# RUN: echo "SECTIONS { \
+# RUN: abc : { } \
+# RUN: . = ALIGN(0x1000); \
+# RUN: .text : { *(.text) } \
+# RUN: }" > %t.script
+# RUN: ld.lld -o %t1 --script %t.script %t -shared
+# RUN: llvm-objdump -section-headers %t1 | FileCheck %s
+# CHECK: Sections:
+# CHECK-NEXT: Idx Name Size Address
+# CHECK-NEXT: 0 00000000 0000000000000000
+# CHECK-NEXT: 1 .text 00000000 0000000000001000