[ELF] - Linkerscript: Implement two argument version of ALIGN()

[arichardson]

Summary

Fixes http://llvm.org/PR31129

[grimar]

ELF/LinkerScript.cpp

1753

You do not need else after return:

if (consume(",")) {
  Expr E2 = readExpr();
  expect(")");
  return [=](uint64_t Dot) { return alignTo(E(Dot), E2(Dot)); };
}

expect(")");
return [=](uint64_t Dot) { return alignTo(Dot, E(Dot)); };

[arichardson]

address comment

[grimar]

This looks good to me, but please wait for Rui's opinion.

[ruiu]

LGTM

[arichardson]

I don't have commit access, can someone commit for me please?

ELF/LinkerScript.cpp

if (Tok == "LOADADDR") {
     StringRef Name = readParenLiteral();
     return [=](uint64_t Dot) {
       return ScriptBase->getOutputSection(Location, Name)->getLMA();
     };
   }
   if (Tok == "ASSERT")
     return readAssert();
   if (Tok == "ALIGN") {
-    Expr E = readParenExpr();
+    expect("(");
+    Expr E = readExpr();
+    if (consume(",")) {
+      Expr E2 = readExpr();
+      expect(")");
+      return [=](uint64_t Dot) { return alignTo(E(Dot), E2(Dot)); };
+    }
+    expect(")");
     return [=](uint64_t Dot) { return alignTo(Dot, E(Dot)); };
   }
   if (Tok == "CONSTANT") {
     StringRef Name = readParenLiteral();
     return [=](uint64_t Dot) { return getConstant(Name); };
   }
   if (Tok == "DEFINED") {
     StringRef Name = readParenLiteral();
     return [=](uint64_t Dot) { return ScriptBase->isDefined(Name) ? 1 : 0; };
   }
   if (Tok == "SEGMENT_START") {
     expect("(");
     skip();
     expect(",");
     Expr E = readExpr();

test/ELF/linkerscript/align.s

 # RUN:  . = ALIGN(4096 * 4); \
 # RUN:  .ccc : \
 # RUN:  { \
 # RUN:   *(.ccc) \
 # RUN:  } \
 # RUN: }" > %t.script
 # RUN: ld.lld -o %t1 --script %t.script %t
 # RUN: llvm-objdump -section-headers %t1 | FileCheck %s
+
+## Check that the two argument version of ALIGN command works
+# RUN: echo "SECTIONS { \
+# RUN:  . = ALIGN(0x1234, 0x10000); \
+# RUN:  .aaa : \
+# RUN:  { \
+# RUN:   *(.aaa) \
+# RUN:  } \
+# RUN:  . = ALIGN(., 4096); \
+# RUN:  .bbb : \
+# RUN:  { \
+# RUN:   *(.bbb) \
+# RUN:  } \
+# RUN:  . = ALIGN(., 4096 * 4); \
+# RUN:  .ccc : \
+# RUN:  { \
+# RUN:   *(.ccc) \
+# RUN:  } \
+# RUN: }" > %t.script
+# RUN: ld.lld -o %t1 --script %t.script %t
+# RUN: llvm-objdump -section-headers %t1 | FileCheck %s
+
 # CHECK:      Sections:
 # CHECK-NEXT: Idx Name          Size      Address          Type
 # CHECK-NEXT:   0               00000000 0000000000000000
 # CHECK-NEXT:   1 .aaa          00000008 0000000000010000 DATA
 # CHECK-NEXT:   2 .bbb          00000008 0000000000011000 DATA
 # CHECK-NEXT:   3 .ccc          00000008 0000000000014000 DATA
 
 ## Check output sections ALIGN modificator