From 58aa9e8010779cbbfd264a4ebd66aa156643e420 Mon Sep 17 00:00:00 2001
From: Rafael Espindola <rafael.espindola@gmail.com>
Date: Thu, 16 Sep 2010 15:03:59 +0000
Subject: [PATCH] Add support for the .zero directive.

llvm-svn: 114077
---
 lib/MC/MCParser/AsmParser.cpp | 22 ++++++++++++++++++++++
 test/MC/ELF/zero.s            | 15 +++++++++++++++
 2 files changed, 37 insertions(+)
 create mode 100644 test/MC/ELF/zero.s

diff --git a/lib/MC/MCParser/AsmParser.cpp b/lib/MC/MCParser/AsmParser.cpp
index b3ffed846d5..d101ad2c4bf 100644
--- a/lib/MC/MCParser/AsmParser.cpp
+++ b/lib/MC/MCParser/AsmParser.cpp
@@ -180,6 +180,7 @@ private:
   bool ParseDirectiveValue(unsigned Size); // ".byte", ".long", ...
   bool ParseDirectiveFill(); // ".fill"
   bool ParseDirectiveSpace(); // ".space"
+  bool ParseDirectiveZero(); // ".zero"
   bool ParseDirectiveSet(); // ".set"
   bool ParseDirectiveOrg(); // ".org"
   // ".align{,32}", ".p2align{,w,l}"
@@ -871,6 +872,8 @@ bool AsmParser::ParseStatement() {
       return ParseDirectiveFill();
     if (IDVal == ".space")
       return ParseDirectiveSpace();
+    if (IDVal == ".zero")
+      return ParseDirectiveZero();
 
     // Symbol attribute directives
 
@@ -1353,6 +1356,25 @@ bool AsmParser::ParseDirectiveSpace() {
   return false;
 }
 
+/// ParseDirectiveZero
+///  ::= .zero expression
+bool AsmParser::ParseDirectiveZero() {
+  CheckForValidSection();
+
+  int64_t NumBytes;
+  if (ParseAbsoluteExpression(NumBytes))
+    return true;
+
+  if (getLexer().isNot(AsmToken::EndOfStatement))
+    return TokError("unexpected token in '.zero' directive");
+
+  Lex();
+
+  getStreamer().EmitFill(NumBytes, 0, DEFAULT_ADDRSPACE);
+
+  return false;
+}
+
 /// ParseDirectiveFill
 ///  ::= .fill expression , expression , expression
 bool AsmParser::ParseDirectiveFill() {
diff --git a/test/MC/ELF/zero.s b/test/MC/ELF/zero.s
new file mode 100644
index 00000000000..2ad21e60815
--- /dev/null
+++ b/test/MC/ELF/zero.s
@@ -0,0 +1,15 @@
+// RUN: llvm-mc -filetype=obj -triple x86_64-pc-linux-gnu %s -o - | elf-dump  --dump-section-data | FileCheck %s
+
+.zero 4
+
+// CHECK: ('sh_name', 1) # '.text'
+// CHECK: ('sh_type', 1)
+// CHECK: ('sh_flags', 6)
+// CHECK: ('sh_addr', 0)
+// CHECK: ('sh_offset', 64)
+// CHECK: ('sh_size', 4)
+// CHECK: ('sh_link', 0)
+// CHECK: ('sh_info', 0)
+// CHECK: ('sh_addralign', 4)
+// CHECK: ('sh_entsize', 0)
+// CHECK: ('_section_data', '00000000')