For PR998:
Fix an infinite loop in the Linker and a few other assorted link problems.
Patch contributed by Scott Michel. Thanks, Scott!
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@31680 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Linker/LinkArchives.cpp b/lib/Linker/LinkArchives.cpp
index 63e263a..152b0b1 100644
--- a/lib/Linker/LinkArchives.cpp
+++ b/lib/Linker/LinkArchives.cpp
@@ -124,8 +124,12 @@
// variable is used to "set_subtract" from the set of undefined symbols.
std::set<std::string> NotDefinedByArchive;
- // While we are linking in object files, loop.
- while (true) {
+ // Save the current set of undefined symbols, because we may have to make
+ // multiple passes over the archive:
+ std::set<std::string> CurrentlyUndefinedSymbols;
+
+ do {
+ CurrentlyUndefinedSymbols = UndefinedSymbols;
// Find the modules we need to link into the target module
std::set<ModuleProvider*> Modules;
@@ -149,17 +153,26 @@
I != E; ++I) {
// Get the module we must link in.
- std::auto_ptr<Module> AutoModule( (*I)->releaseModule() );
+ std::string moduleErrorMsg;
+ std::auto_ptr<Module> AutoModule((*I)->releaseModule( &moduleErrorMsg ));
Module* aModule = AutoModule.get();
- verbose(" Linking in module: " + aModule->getModuleIdentifier());
+ if (aModule != NULL) {
+ verbose(" Linking in module: " + aModule->getModuleIdentifier());
- // Link it in
- if (LinkInModule(aModule))
- return error("Cannot link in module '" +
- aModule->getModuleIdentifier() + "': " + Error);
+ // Link it in
+ if (LinkInModule(aModule, &moduleErrorMsg)) {
+ return error("Cannot link in module '" +
+ aModule->getModuleIdentifier() + "': " + moduleErrorMsg);
+ }
+ } else {
+ // (scottm) NOTE: For some reason, Modules.empty() isn't entirely
+ // accurrate, least with gcc 4.1.2 on Debian and doesn't return true
+ // when it ought. Consequently, aModule can be NULL -- ignore it for
+ // the time being, since it seems relatively benign.
+ }
}
-
+
// Get the undefined symbols from the aggregate module. This recomputes the
// symbols we still need after the new modules have been linked in.
GetAllUndefinedSymbols(Composite, UndefinedSymbols);
@@ -175,7 +188,7 @@
// archive.
if (UndefinedSymbols.empty())
break;
- }
+ } while (CurrentlyUndefinedSymbols != UndefinedSymbols);
return false;
}