Allow SIZEOF() command on nonexistent section.
Linker script doesn't create a section if it has no content. So the following
script doesn't create .norelocs section if it doesn't have any .rel* sections.
.norelocs : { *(.rel*) }
Later, if you assert that the size of .norelocs is 0, LLD printed out
an error message, because it didn't allow calling SIZEOF() on nonexistent
sections.
This patch allows SIZEOF() on nonexistent sections, so that you can do
something like this.
ASSERT(SIZEOF(.norelocs), "shouldn't contain .rel sections!")
Note that this behavior is compatible with GNU.
Differential Revision: https://reviews.llvm.org/D26810
llvm-svn: 287257
diff --git a/lld/ELF/LinkerScript.cpp b/lld/ELF/LinkerScript.cpp
index 2b7d246..7b18afe 100644
--- a/lld/ELF/LinkerScript.cpp
+++ b/lld/ELF/LinkerScript.cpp
@@ -868,6 +868,20 @@
return &FakeSec;
}
+// This function is essentially the same as getOutputSection(Name)->Size,
+// but it won't print out an error message if a given section is not found.
+//
+// Linker script does not create an output section if its content is empty.
+// We want to allow SIZEOF(.foo) where .foo is a section which happened to
+// be empty. That is why this function is different from getOutputSection().
+template <class ELFT>
+uint64_t LinkerScript<ELFT>::getOutputSectionSize(StringRef Name) {
+ for (OutputSectionBase *Sec : *OutputSections)
+ if (Sec->getName() == Name)
+ return Sec->Size;
+ return 0;
+}
+
template <class ELFT> uint64_t LinkerScript<ELFT>::getHeaderSize() {
return elf::getHeaderSize<ELFT>();
}
@@ -1719,8 +1733,7 @@
}
if (Tok == "SIZEOF") {
StringRef Name = readParenLiteral();
- return
- [=](uint64_t Dot) { return ScriptBase->getOutputSection(Name)->Size; };
+ return [=](uint64_t Dot) { return ScriptBase->getOutputSectionSize(Name); };
}
if (Tok == "ALIGNOF") {
StringRef Name = readParenLiteral();