Correct ALIGN expression when inside a section.

[• rafael]

Summary

When given

foobar = ALIGN(., 0x100);

my expectation from what the manual says is that the final address of foobar will be aligned. It seems that bfd aligns the offset in the section, which causes some odd results if the section is not 0x100 aligned. Gold algins the address.

This changes lld to align the final address.

[ruiu]

LGTM

[• espindola]

312979

ELF/LinkerScript.cpp

if (!Cmd->Sym)
     return;
 
   auto *Sym = cast<DefinedRegular>(Cmd->Sym);
   ExprValue V = Cmd->Expression();
   if (V.isAbsolute()) {
     Sym->Value = V.getValue();
   } else {
     Sym->Section = V.Sec;
-    Sym->Value = alignTo(V.Val, V.Alignment);
+    Sym->Value = V.getValue() - V.getSecAddr();
   }
 }
 
 void LinkerScript::addSymbol(SymbolAssignment *Cmd) {
   if (Cmd->Name == ".")
     return;
 
   // If a symbol was in PROVIDE(), we need to define it only when

test/ELF/linkerscript/align.s

 # ZERO-NEXT:   0               00000000 0000000000000000
 # ZERO-NEXT:   1 .aaa          00000008 0000000000000123 DATA
 
 ## Check that ALIGN zero do nothing and does not crash #2.
 # RUN: echo "SECTIONS { . = 0x123; . = ALIGN(0); .aaa : { *(.aaa) } }" > %t.script
 # RUN: ld.lld -o %t5 --script %t.script %t
 # RUN: llvm-objdump -section-headers %t5 | FileCheck %s -check-prefix=ZERO
 
+
+# RUN: echo "SECTIONS {                              \
+# RUN:  . = 0xff8;                                   \
+# RUN:  .aaa : { *(.aaa) foo = ALIGN(., 0x100); bar = .; } \
+# RUN:  .bbb : { *(.bbb); } \
+# RUN:  .ccc : { *(.ccc); } \
+# RUN:  .text : { *(.text); } \
+# RUN: }" > %t.script
+# RUN: ld.lld -o %t1 --script %t.script %t
+# RUN: llvm-objdump -t %t1 | FileCheck --check-prefix=OFFSET %s
+
+# OFFSET: 0000000000001000         .aaa            00000000 foo
+# OFFSET: 0000000000001000         .aaa            00000000 bar
+
 .global _start
 _start:
  nop
 
 .section .aaa, "a"
 .quad 0
 
 .section .bbb, "a"
 .quad 0
 
 .section .ccc, "a"
 .quad 0