[ELF] - Implemented linkerscript ALIGN command

George Rimar · George Rimar · commit dffc1410c55f · 2016-04-22T11:40:53.000Z
ALIGN(exp) Return the location counter (.) aligned to the next exp boundary. (https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/4/html/Using_ld_the_GNU_Linker/expressions.html) Patch implements this command. This fixes PR27406. Differential revision: http://reviews.llvm.org/D19364 llvm-svn: 267145
diff --git a/lld/ELF/LinkerScript.cpp b/lld/ELF/LinkerScript.cpp
@@ -94,6 +94,14 @@ uint64_t LinkerScript<ELFT>::parsePrimary(ArrayRef<StringRef> &Tokens) {
       return 0;
     return V;
   }
+  if (Tok == "ALIGN") {
+    if (!expect(Tokens, "("))
+      return 0;
+    uint64_t V = parseExpr(Tokens);
+    if (!expect(Tokens, ")"))
+      return 0;
+    return alignTo(Dot, V);
+  }
   return getInteger(Tok);
 }
 
diff --git a/lld/test/ELF/linkerscript-align.s b/lld/test/ELF/linkerscript-align.s
@@ -0,0 +1,41 @@
+# REQUIRES: x86
+# RUN: llvm-mc -filetype=obj -triple=x86_64-unknown-linux %s -o %t
+
+# RUN: echo "SECTIONS { \
+# RUN:  . = 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
+
+.global _start
+_start:
+ nop
+
+.section .aaa, "a"
+.quad 0
+
+.section .bbb, "a"
+.quad 0
+
+.section .ccc, "a"
+.quad 0

Original file line number	Diff line number	Diff line change
`@@ -94,6 +94,14 @@ uint64_t LinkerScript<ELFT>::parsePrimary(ArrayRef<StringRef> &Tokens) {`
`94`	`94`	`return 0;`
`95`	`95`	`return V;`
`96`	`96`	`}`
	`97`	`+ if (Tok == "ALIGN") {`
	`98`	`+ if (!expect(Tokens, "("))`
	`99`	`+ return 0;`
	`100`	`+ uint64_t V = parseExpr(Tokens);`
	`101`	`+ if (!expect(Tokens, ")"))`
	`102`	`+ return 0;`
	`103`	`+ return alignTo(Dot, V);`
	`104`	`+ }`
`97`	`105`	`return getInteger(Tok);`
`98`	`106`	`}`
`99`	`107`