[lld] r328879 - [lld-link] Add comment explaining that /FIXED behavior is correct despite contradicting MSDN.

[Nico Weber via llvm-commits]

Author: nico
Date: Fri Mar 30 10:17:04 2018
New Revision: 328879

URL: http://llvm.org/viewvc/llvm-project?rev=328879&view=rev
Log:
[lld-link] Add comment explaining that /FIXED behavior is correct despite contradicting MSDN.

Also add a test for /FIXED.
https://reviews.llvm.org/D45087

Added:
    lld/trunk/test/COFF/fixed.test
Modified:
    lld/trunk/COFF/Driver.cpp

Modified: lld/trunk/COFF/Driver.cpp
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/COFF/Driver.cpp?rev=328879&r1=328878&r2=328879&view=diff
==============================================================================
--- lld/trunk/COFF/Driver.cpp (original)
+++ lld/trunk/COFF/Driver.cpp Fri Mar 30 10:17:04 2018
@@ -962,6 +962,9 @@ void LinkerDriver::link(ArrayRef<const c
       DynamicBaseArg->getOption().getID() == OPT_dynamicbase_no)
     Config->DynamicBase = false;
 
+  // MSDN claims "/FIXED:NO is the default setting for a DLL, and /FIXED is the
+  // default setting for any other project type.", but link.exe defaults to
+  // /FIXED:NO for exe outputs as well. Match behavior, not docs.
   bool Fixed = Args.hasFlag(OPT_fixed, OPT_fixed_no, false);
   if (Fixed) {
     if (DynamicBaseArg &&

Added: lld/trunk/test/COFF/fixed.test
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/test/COFF/fixed.test?rev=328879&view=auto
==============================================================================
--- lld/trunk/test/COFF/fixed.test (added)
+++ lld/trunk/test/COFF/fixed.test Fri Mar 30 10:17:04 2018
@@ -0,0 +1,24 @@
+# REQUIRES: x86
+# RUN: yaml2obj < %p/Inputs/hello32.yaml > %t.obj
+#
+# RUN: lld-link %t.obj /fixed %p/Inputs/std32.lib /subsystem:console \
+# RUN:   /entry:main at 0 /debug /out:%t.fixed.exe
+# RUN: llvm-readobj -file-headers %t.fixed.exe | \
+# RUN:   FileCheck -check-prefix=EXEFIXED %s
+#
+# RUN: lld-link %t.obj %p/Inputs/std32.lib /subsystem:console \
+# RUN:   /entry:main at 0 /debug /out:%t.exe
+# RUN: llvm-readobj -file-headers %t.exe | FileCheck -check-prefix=EXEREL %s
+#
+# RUN: yaml2obj < %p/Inputs/export.yaml > %t.obj
+#
+# RUN: lld-link %t.obj /dll /fixed /debug /out:%t.fixed.dll
+# RUN: llvm-readobj -file-headers %t.fixed.dll | FileCheck -check-prefix=DLLFIXED %s
+#
+# RUN: lld-link %t.obj /dll /debug /out:%t.dll
+# RUN: llvm-readobj -file-headers %t.dll | FileCheck -check-prefix=DLLREL %s
+
+EXEFIXED-NOT: IMAGE_DLL_CHARACTERISTICS_DYNAMIC_BASE
+DLLFIXED-NOT: IMAGE_DLL_CHARACTERISTICS_DYNAMIC_BASE
+EXEREL: IMAGE_DLL_CHARACTERISTICS_DYNAMIC_BASE
+DLLREL: IMAGE_DLL_CHARACTERISTICS_DYNAMIC_BASE