[LLD][ELF] - Do not remove empty sections referenced in LOADADDR/ADDR commands.

This is https://bugs.llvm.org//show_bug.cgi?id=38750.

If script references empty sections in LOADADDR/ADDR commands

.empty  : { *(.empty ) }
.text   : AT(LOADADDR (.empty) + SIZEOF (.empty)) { *(.text) }
then an empty section will be removed and LOADADDR/ADDR will evaluate to null.
It is not that user may expect from using of the generic script, what is a common case.

Differential revision: https://reviews.llvm.org/D54621

llvm-svn: 359279

1 files changed, 2 insertions, 0 deletions

diff --git a/lld/ELF/ScriptParser.cpp b/lld/ELF/ScriptParser.cpp
index 783d20c2025..741b32ff031 100644
--- a/lld/ELF/ScriptParser.cpp
+++ b/lld/ELF/ScriptParser.cpp
@@ -1154,6 +1154,7 @@ Expr ScriptParser::readPrimary() {
   if (Tok == "ADDR") {
     StringRef Name = readParenLiteral();
     OutputSection *Sec = Script->getOrCreateOutputSection(Name);
+    Sec->UsedInExpression = true;
     return [=]() -> ExprValue {
       checkIfExists(Sec, Location);
       return {Sec, false, 0, Location};
@@ -1230,6 +1231,7 @@ Expr ScriptParser::readPrimary() {
   if (Tok == "LOADADDR") {
     StringRef Name = readParenLiteral();
     OutputSection *Cmd = Script->getOrCreateOutputSection(Name);
+    Cmd->UsedInExpression = true;
     return [=] {
       checkIfExists(Cmd, Location);
       return Cmd->getLMA();