[lld] r302564 - Add memory ORIGIN and LENGTH expression support

[Rui Ueyama via llvm-commits]

Author: ruiu
Date: Tue May  9 13:24:38 2017
New Revision: 302564

URL: http://llvm.org/viewvc/llvm-project?rev=302564&view=rev
Log:
Add memory ORIGIN and LENGTH expression support

Adds support for the ORIGIN and LENGTH linker script built in functions.

  ORIGIN(memory) Return the origin of the memory region
  LENGTH(memory) Return the length of the memory region

Redo of D29775 for refactored linker script parsing.

Patch by Robert Clarke

Differential Revision: https://reviews.llvm.org/D32934

Added:
    lld/trunk/test/ELF/linkerscript/symbol-memoryexpr.s
Modified:
    lld/trunk/ELF/ScriptParser.cpp

Modified: lld/trunk/ELF/ScriptParser.cpp
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/ELF/ScriptParser.cpp?rev=302564&r1=302563&r2=302564&view=diff
==============================================================================
--- lld/trunk/ELF/ScriptParser.cpp (original)
+++ lld/trunk/ELF/ScriptParser.cpp Tue May  9 13:24:38 2017
@@ -900,10 +900,22 @@ Expr ScriptParser::readPrimary() {
     StringRef Name = readParenLiteral();
     return [=] { return Script->isDefined(Name) ? 1 : 0; };
   }
+  if (Tok == "LENGTH") {
+    StringRef Name = readParenLiteral();
+    if (Script->Opt.MemoryRegions.count(Name) == 0)
+      setError("memory region not defined: " + Name);
+    return [=] { return Script->Opt.MemoryRegions[Name].Length; };
+  }
   if (Tok == "LOADADDR") {
     StringRef Name = readParenLiteral();
     return [=] { return Script->getOutputSection(Location, Name)->getLMA(); };
   }
+  if (Tok == "ORIGIN") {
+    StringRef Name = readParenLiteral();
+    if (Script->Opt.MemoryRegions.count(Name) == 0)
+      setError("memory region not defined: " + Name);
+    return [=] { return Script->Opt.MemoryRegions[Name].Origin; };
+  }
   if (Tok == "SEGMENT_START") {
     expect("(");
     skip();

Added: lld/trunk/test/ELF/linkerscript/symbol-memoryexpr.s
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/test/ELF/linkerscript/symbol-memoryexpr.s?rev=302564&view=auto
==============================================================================
--- lld/trunk/test/ELF/linkerscript/symbol-memoryexpr.s (added)
+++ lld/trunk/test/ELF/linkerscript/symbol-memoryexpr.s Tue May  9 13:24:38 2017
@@ -0,0 +1,33 @@
+# REQUIRES: x86
+# RUN: llvm-mc -filetype=obj -triple=x86_64-unknown-linux %s -o %t
+
+# RUN: echo "MEMORY { \
+# RUN:   ram (rwx)  : ORIGIN = 0x8000, LENGTH = 256K \
+# RUN: } \
+# RUN: SECTIONS { \
+# RUN:         origin = ORIGIN(ram); \
+# RUN:         length = LENGTH(ram); \
+# RUN:         end    = ORIGIN(ram) + LENGTH(ram); \
+# 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: 0000000000008000 .text 00000000 _start
+# CHECK-NEXT: 0000000000008000 *ABS* 00000000 origin
+# CHECK-NEXT: 0000000000040000 *ABS* 00000000 length
+# CHECK-NEXT: 0000000000048000 *ABS* 00000000 end
+
+# RUN: echo "SECTIONS { \
+# RUN:         no_exist_origin = ORIGIN(ram); \
+# RUN:         no_exist_length = LENGTH(ram); \
+# RUN:       }" > %t2.script
+# RUN: not ld.lld -o %t2 --script %t2.script %t 2>&1 \
+# RUN:  | FileCheck -check-prefix=ERR %s
+# ERR: {{.*}}.script:1: memory region not defined: ram
+
+
+.global _start
+_start:
+ nop