[lld] r282295 - Warn if we can't find the entry symbol.

[Rafael Espindola via llvm-commits]

Author: rafael
Date: Fri Sep 23 16:04:56 2016
New Revision: 282295

URL: http://llvm.org/viewvc/llvm-project?rev=282295&view=rev
Log:
Warn if we can't find the entry symbol.

Fixes pr30465.

Modified:
    lld/trunk/ELF/Driver.cpp
    lld/trunk/test/ELF/entry.s

Modified: lld/trunk/ELF/Driver.cpp
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/ELF/Driver.cpp?rev=282295&r1=282294&r2=282295&view=diff
==============================================================================
--- lld/trunk/ELF/Driver.cpp (original)
+++ lld/trunk/ELF/Driver.cpp Fri Sep 23 16:04:56 2016
@@ -665,17 +665,22 @@ template <class ELFT> void LinkerDriver:
   // Add the start symbol.
   // It initializes either Config->Entry or Config->EntryAddr.
   // Note that AMDGPU binaries have no entries.
+  bool HasEntryAddr = false;
   if (!Config->Entry.empty()) {
     // It is either "-e <addr>" or "-e <symbol>".
-    Config->Entry.getAsInteger(0, Config->EntryAddr);
+    HasEntryAddr = !Config->Entry.getAsInteger(0, Config->EntryAddr);
   } else if (!Config->Shared && !Config->Relocatable &&
              Config->EMachine != EM_AMDGPU) {
     // -e was not specified. Use the default start symbol name
     // if it is resolvable.
     Config->Entry = (Config->EMachine == EM_MIPS) ? "__start" : "_start";
   }
-  if (Symtab.find(Config->Entry))
-    Config->EntrySym = Symtab.addUndefined(Config->Entry);
+  if (!HasEntryAddr) {
+    if (Symtab.find(Config->Entry))
+      Config->EntrySym = Symtab.addUndefined(Config->Entry);
+    else
+      warning("entry symbol " + Config->Entry + " not found, assuming 0");
+  }
 
   if (HasError)
     return; // There were duplicate symbols or incompatible files

Modified: lld/trunk/test/ELF/entry.s
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/test/ELF/entry.s?rev=282295&r1=282294&r2=282295&view=diff
==============================================================================
--- lld/trunk/test/ELF/entry.s (original)
+++ lld/trunk/test/ELF/entry.s Fri Sep 23 16:04:56 2016
@@ -1,5 +1,5 @@
 # RUN: llvm-mc -filetype=obj -triple=x86_64-unknown-linux %s -o %t1
-# RUN: ld.lld %t1 -o %t2
+# RUN: ld.lld -e foobar %t1 -o %t2 2>&1 | FileCheck -check-prefix=WARN %s
 # RUN: llvm-readobj -file-headers %t2 | FileCheck -check-prefix=NOENTRY %s
 # RUN: ld.lld %t1 -o %t2 -e entry
 # RUN: llvm-readobj -file-headers %t2 | FileCheck -check-prefix=SYM %s
@@ -12,6 +12,8 @@
 # RUN: ld.lld %t1 -o %t2 -e 0777
 # RUN: llvm-readobj -file-headers %t2 | FileCheck -check-prefix=OCT %s
 
+# WARN: entry symbol foobar not found, assuming 0
+
 # NOENTRY: Entry: 0x0
 # SYM: Entry: 0x11000
 # DSO: Entry: 0x1000