Make filler expression compatible with gold.

Previously, a decimal filler expression is interpreted as a byte value.
Gold on the other hand use it as a 32-bit big-endian value.
This patch fixes the compatibility issue.

Differential Revision: https://reviews.llvm.org/D23142

llvm-svn: 277680

2 files changed, 10 insertions, 9 deletions

diff --git a/lld/ELF/LinkerScript.cpp b/lld/ELF/LinkerScript.cpp
index e1342e2527a..808d62433e6 100644
--- a/lld/ELF/LinkerScript.cpp
+++ b/lld/ELF/LinkerScript.cpp
@@ -843,18 +843,19 @@ std::vector<uint8_t> ScriptParser::readOutputSectionFiller() {
   if (!Tok.startswith("="))
     return {};
   next();
+
+  // Read a hexstring of arbitrary length.
   if (Tok.startswith("=0x"))
     return parseHex(Tok.substr(3));
 
-  // This must be a decimal.
-  unsigned int Value;
-  if (Tok.substr(1).getAsInteger(10, Value)) {
-    setError("filler should be a decimal/hexadecimal value");
+  // Read a decimal or octal value as a big-endian 32 bit value.
+  // Why do this? I don't know, but that's what gold does.
+  uint32_t V;
+  if (Tok.substr(1).getAsInteger(0, V)) {
+    setError("invalid filler expression: " + Tok);
     return {};
   }
-  if (Value > 255)
-    setError("only single bytes decimal are supported for the filler now");
-  return {static_cast<unsigned char>(Value)};
+  return { uint8_t(V >> 24), uint8_t(V >> 16), uint8_t(V >> 8), uint8_t(V) };
 }
 
 void ScriptParser::readProvide(bool Hidden) {
diff --git a/lld/test/ELF/linkerscript/linkerscript-sections-padding.s b/lld/test/ELF/linkerscript/linkerscript-sections-padding.s
index aadd5e82976..78d1ffc14f5 100644
--- a/lld/test/ELF/linkerscript/linkerscript-sections-padding.s
+++ b/lld/test/ELF/linkerscript/linkerscript-sections-padding.s
@@ -20,10 +20,10 @@
 # NO: 00000120  66 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 
 ## Decimal value.
-# RUN: echo "SECTIONS { .mysec : { *(.mysec*) } =99 }" > %t.script
+# RUN: echo "SECTIONS { .mysec : { *(.mysec*) } =777 }" > %t.script
 # RUN: ld.lld -o %t.out --script %t.script %t
 # RUN: hexdump -C %t.out | FileCheck -check-prefix=DEC %s
-# DEC: 00000120  66 63 63 63 63 63 63 63  63 63 63 63 63 63 63 63
+# DEC: 00000120  66 00 03 09 00 00 03 09 00 00 03 09 00 00 03 09
 
 ## Invalid hex value:
 # RUN: echo "SECTIONS { .mysec : { *(.mysec*) } =0x99XX }" > %t.script