[lld] r278204 - [ELF] - Linkerscript: implement SIZEOF_HEADERS.
George Rimar via llvm-commits
llvm-commits at lists.llvm.org
Wed Aug 10 00:59:34 PDT 2016
Author: grimar
Date: Wed Aug 10 02:59:34 2016
New Revision: 278204
URL: http://llvm.org/viewvc/llvm-project?rev=278204&view=rev
Log:
[ELF] - Linkerscript: implement SIZEOF_HEADERS.
SIZEOF_HEADERS - Return the size in bytes of the output file’s headers.
It is is a feature used in FreeBsd script, for example.
There is a discussion on PR28688 page about it.
Differential revision: https://reviews.llvm.org/D23165
Added:
lld/trunk/test/ELF/linkerscript/linkerscript-sizeofheaders.s
Modified:
lld/trunk/ELF/LinkerScript.cpp
lld/trunk/ELF/LinkerScript.h
Modified: lld/trunk/ELF/LinkerScript.cpp
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/ELF/LinkerScript.cpp?rev=278204&r1=278203&r2=278204&view=diff
==============================================================================
--- lld/trunk/ELF/LinkerScript.cpp (original)
+++ lld/trunk/ELF/LinkerScript.cpp Wed Aug 10 02:59:34 2016
@@ -238,7 +238,7 @@ template <class ELFT> void LinkerScript<
}
// Assign addresses as instructed by linker script SECTIONS sub-commands.
- Dot = Out<ELFT>::ElfHeader->getSize() + Out<ELFT>::ProgramHeaders->getSize();
+ Dot = getSizeOfHeaders();
uintX_t MinVA = std::numeric_limits<uintX_t>::max();
uintX_t ThreadBssOffset = 0;
@@ -430,6 +430,11 @@ typename ELFT::uint LinkerScript<ELFT>::
return 0;
}
+template <class ELFT>
+typename ELFT::uint LinkerScript<ELFT>::getSizeOfHeaders() {
+ return Out<ELFT>::ElfHeader->getSize() + Out<ELFT>::ProgramHeaders->getSize();
+}
+
// Returns indices of ELF headers containing specific section, identified
// by Name. Each index is a zero based number of ELF header listed within
// PHDRS {} script block.
@@ -915,6 +920,21 @@ static uint64_t getSectionSize(StringRef
}
}
+static uint64_t getSizeOfHeaders() {
+ switch (Config->EKind) {
+ case ELF32LEKind:
+ return Script<ELF32LE>::X->getSizeOfHeaders();
+ case ELF32BEKind:
+ return Script<ELF32BE>::X->getSizeOfHeaders();
+ case ELF64LEKind:
+ return Script<ELF64LE>::X->getSizeOfHeaders();
+ case ELF64BEKind:
+ return Script<ELF64BE>::X->getSizeOfHeaders();
+ default:
+ llvm_unreachable("unsupported target");
+ }
+}
+
SymbolAssignment *ScriptParser::readAssignment(StringRef Name) {
StringRef Op = next();
assert(Op == "=" || Op == "+=");
@@ -1063,6 +1083,8 @@ Expr ScriptParser::readPrimary() {
expect(")");
return [=](uint64_t Dot) { return getSectionSize(Name); };
}
+ if (Tok == "SIZEOF_HEADERS")
+ return [=](uint64_t Dot) { return getSizeOfHeaders(); };
// Parse a symbol name or a number literal.
uint64_t V = 0;
Modified: lld/trunk/ELF/LinkerScript.h
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/ELF/LinkerScript.h?rev=278204&r1=278203&r2=278204&view=diff
==============================================================================
--- lld/trunk/ELF/LinkerScript.h (original)
+++ lld/trunk/ELF/LinkerScript.h Wed Aug 10 02:59:34 2016
@@ -149,6 +149,7 @@ public:
void addScriptedSymbols();
bool hasPhdrsCommands();
uintX_t getOutputSectionSize(StringRef Name);
+ uintX_t getSizeOfHeaders();
std::vector<OutputSectionBase<ELFT> *> *OutputSections;
Added: lld/trunk/test/ELF/linkerscript/linkerscript-sizeofheaders.s
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/test/ELF/linkerscript/linkerscript-sizeofheaders.s?rev=278204&view=auto
==============================================================================
--- lld/trunk/test/ELF/linkerscript/linkerscript-sizeofheaders.s (added)
+++ lld/trunk/test/ELF/linkerscript/linkerscript-sizeofheaders.s Wed Aug 10 02:59:34 2016
@@ -0,0 +1,18 @@
+# REQUIRES: x86
+# RUN: llvm-mc -filetype=obj -triple=x86_64-unknown-linux %s -o %t
+# RUN: echo " SECTIONS { \
+# RUN: . = SIZEOF_HEADERS; \
+# RUN: _size = SIZEOF_HEADERS; \
+# RUN: .text : {*(.text.*)} \
+# RUN: }" > %t.script
+# RUN: ld.lld -o %t1 --script %t.script %t
+# RUN: llvm-objdump -t %t1 | FileCheck %s
+
+#CHECK: SYMBOL TABLE:
+#CHECK-NEXT: 0000000000000000 *UND* 00000000
+#CHECK-NEXT: 0000000000000120 .text 00000000 _start
+#CHECK-NEXT: 0000000000000120 *ABS* 00000000 _size
+
+.global _start
+_start:
+ nop
More information about the llvm-commits
mailing list