[PECOFF] Set ordinal to alias atoms

Atoms are ordered in the output file by ordinal. File has file ordinal,
and atom has atom ordinal which is unique within the file.
No two atoms should have the same combination of ordinals.

However that contract was not satisifed for alias atoms. Alias atom
is defined by /alternatename:sym1=sym2. In this case sym1 is defined
as an alias for sym2. sym1 always got ordinal 0.

As a result LLD failed with an assertion failure.

This patch assigns ordinal to alias atoms.

llvm-svn: 218158

2 files changed, 14 insertions, 3 deletions

diff --git a/lld/lib/ReaderWriter/PECOFF/ReaderCOFF.cpp b/lld/lib/ReaderWriter/PECOFF/ReaderCOFF.cpp
index 353f52cc59a..0b829d745eb 100644
--- a/lld/lib/ReaderWriter/PECOFF/ReaderCOFF.cpp
+++ b/lld/lib/ReaderWriter/PECOFF/ReaderCOFF.cpp
@@ -88,7 +88,8 @@ public:
     return _absoluteAtoms;
   }
 
-  void addDefinedAtom(const DefinedAtom *atom) {
+  void addDefinedAtom(AliasAtom *atom) {
+    atom->setOrdinal(_ordinal++);
     _definedAtoms._atoms.push_back(atom);
   }
 
@@ -1068,13 +1069,13 @@ private:
 
   // Iterates over defined atoms and create alias atoms if needed.
   void createAlternateNameAtoms(FileCOFF &file) const {
-    std::vector<const DefinedAtom *> aliases;
+    std::vector<AliasAtom *> aliases;
     for (const DefinedAtom *atom : file.defined()) {
       auto it = _ctx.alternateNames().find(atom->name());
       if (it != _ctx.alternateNames().end())
         aliases.push_back(createAlias(file, it->second, atom));
     }
-    for (const DefinedAtom *alias : aliases) {
+    for (AliasAtom *alias : aliases) {
       file.addDefinedAtom(alias);
     }
   }
diff --git a/lld/test/pecoff/alternatename.test b/lld/test/pecoff/alternatename.test
index ff6617ebdd6..56cd57de00a 100644
--- a/lld/test/pecoff/alternatename.test
+++ b/lld/test/pecoff/alternatename.test
@@ -10,6 +10,10 @@
 #
 # RUN: lld -flavor link /force /out:%t3.exe -- %t3.obj
 # RUN: llvm-objdump -d %t3.exe | FileCheck -check-prefix=CHECK3 %s
+#
+# RUN: lld -flavor link /force /out:%t4.exe /alternatename:_main=_foo \
+# RUN:   /alternatename:_xyz=_foo -- %t1.obj
+# RUN: llvm-objdump -d %t4.exe | FileCheck -check-prefix=CHECK4 %s
 
 CHECK1:      nop
 CHECK1-NEXT: nop
@@ -28,3 +32,9 @@ CHECK3-NEXT: nop
 CHECK3-NEXT: nop
 CHECK3-NEXT: nop
 CHECK3-NOT:  int3
+
+CHECK4:      nop
+CHECK4-NEXT: nop
+CHECK4-NEXT: nop
+CHECK4-NEXT: nop
+CHECK4-NOT:  int3