From 61716878aec0dd615ce88f2f8283292abd01e133 Mon Sep 17 00:00:00 2001
From: Martin Storsjo <martin@martin.st>
Date: Wed, 15 Nov 2017 08:18:25 +0000
Subject: [PATCH] [COFF] Always include the size of the string table size field

Even if we don't actually write any string table contents, the
4 byte size for the string table will always be written. Make
sure we accommodate for this in the file size. Since this size
is aligned up, this would seldom be an issue in practice.

Differential Revision: https://reviews.llvm.org/D39891

llvm-svn: 318284
---
 lld/COFF/Writer.cpp         |   3 +-
 lld/test/COFF/strtab-size.s | 216 ++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 217 insertions(+), 2 deletions(-)
 create mode 100644 lld/test/COFF/strtab-size.s

diff --git a/lld/COFF/Writer.cpp b/lld/COFF/Writer.cpp
index e22a82a..b398bb6 100644
--- a/lld/COFF/Writer.cpp
+++ b/lld/COFF/Writer.cpp
@@ -564,8 +564,7 @@ void Writer::createSymbolAndStringTable() {
     PointerToSymbolTable = FileOff;
     FileOff += OutputSymtab.size() * sizeof(coff_symbol16);
   }
-  if (!Strtab.empty())
-    FileOff += Strtab.size() + 4;
+  FileOff += Strtab.size() + 4;
   FileSize = alignTo(FileOff, SectorSize);
 }
 
diff --git a/lld/test/COFF/strtab-size.s b/lld/test/COFF/strtab-size.s
new file mode 100644
index 0000000..88294f1
--- /dev/null
+++ b/lld/test/COFF/strtab-size.s
@@ -0,0 +1,216 @@
+# REQEUIRES: x86
+
+# Test that the strtab size is included in the allocation even if the
+# strtab itself is empty. To achieve this, we need a number of symbols N
+# where alignTo(N*18, 512) < alignTo(N*18 + 4, 512), where the first
+# positive N fulfilling that is 199.
+
+# RUN: llvm-mc -triple=x86_64-windows-msvc %s -filetype=obj -o %t.obj
+# RUN: lld-link -out:%t.exe -entry:main %t.obj -debug
+
+# If the size of the strtab isn't allocated for, llvm-readobj would
+# output SymbolCount: 0 (and dumpbin.exe would error out with "invalid file
+# or disk full, cannot seek to 0x1602").
+
+# RUN: llvm-readobj -file-headers %t.exe | FileCheck %s
+# CHECK: SymbolCount: 199
+
+.global main
+.text
+main:
+sym0:
+sym1:
+sym2:
+sym3:
+sym4:
+sym5:
+sym6:
+sym7:
+sym8:
+sym9:
+sym10:
+sym11:
+sym12:
+sym13:
+sym14:
+sym15:
+sym16:
+sym17:
+sym18:
+sym19:
+sym20:
+sym21:
+sym22:
+sym23:
+sym24:
+sym25:
+sym26:
+sym27:
+sym28:
+sym29:
+sym30:
+sym31:
+sym32:
+sym33:
+sym34:
+sym35:
+sym36:
+sym37:
+sym38:
+sym39:
+sym40:
+sym41:
+sym42:
+sym43:
+sym44:
+sym45:
+sym46:
+sym47:
+sym48:
+sym49:
+sym50:
+sym51:
+sym52:
+sym53:
+sym54:
+sym55:
+sym56:
+sym57:
+sym58:
+sym59:
+sym60:
+sym61:
+sym62:
+sym63:
+sym64:
+sym65:
+sym66:
+sym67:
+sym68:
+sym69:
+sym70:
+sym71:
+sym72:
+sym73:
+sym74:
+sym75:
+sym76:
+sym77:
+sym78:
+sym79:
+sym80:
+sym81:
+sym82:
+sym83:
+sym84:
+sym85:
+sym86:
+sym87:
+sym88:
+sym89:
+sym90:
+sym91:
+sym92:
+sym93:
+sym94:
+sym95:
+sym96:
+sym97:
+sym98:
+sym99:
+sym100:
+sym101:
+sym102:
+sym103:
+sym104:
+sym105:
+sym106:
+sym107:
+sym108:
+sym109:
+sym110:
+sym111:
+sym112:
+sym113:
+sym114:
+sym115:
+sym116:
+sym117:
+sym118:
+sym119:
+sym120:
+sym121:
+sym122:
+sym123:
+sym124:
+sym125:
+sym126:
+sym127:
+sym128:
+sym129:
+sym130:
+sym131:
+sym132:
+sym133:
+sym134:
+sym135:
+sym136:
+sym137:
+sym138:
+sym139:
+sym140:
+sym141:
+sym142:
+sym143:
+sym144:
+sym145:
+sym146:
+sym147:
+sym148:
+sym149:
+sym150:
+sym151:
+sym152:
+sym153:
+sym154:
+sym155:
+sym156:
+sym157:
+sym158:
+sym159:
+sym160:
+sym161:
+sym162:
+sym163:
+sym164:
+sym165:
+sym166:
+sym167:
+sym168:
+sym169:
+sym170:
+sym171:
+sym172:
+sym173:
+sym174:
+sym175:
+sym176:
+sym177:
+sym178:
+sym179:
+sym180:
+sym181:
+sym182:
+sym183:
+sym184:
+sym185:
+sym186:
+sym187:
+sym188:
+sym189:
+sym190:
+sym191:
+sym192:
+sym193:
+sym194:
+  ret
-- 
2.7.4