averello/swift-mirror
1
0
Fork 0
mirror of https://github.com/apple/swift.git synced 2025-12-21 12:14:44 +01:00
Code Issues Packages Projects Releases Wiki Activity

[sil-module] Fix a pretty serious bug when a wrong function was returned using SILModule::lookUpSILFunctionFromVTable.

Browse Source 
This bug would manifest itself only when a module with multiple files is being compiled and some derived classes are defined in a file different from the one where a base class is defined. Due to this bug a method from a base class would be invoked instead of a method from a derived class when devirtualization was performed. The problem was that we were saying that failure to link a vtable is equivalent to failure to find a function in the vtable itself in which case we would go up to the parent vtable.

To avoid this kind of bug in the future a test case with a module consisting of multiple files is added to the test suite.

rdar://19334105 rdar://19337398

Swift SVN r24264
This commit is contained in:
Roman Levenstein
2015-01-08 04:05:27 +00:00
parent a8944f4540
commit 0368074f43
4 changed files with 65 additions and 4 deletions
Download Patch File Download Diff File Expand all files Collapse all files

6
lib/SIL/SILModule.cpp
View File

@@ -811,11 +811,9 @@ lookUpSILFunctionFromVTable(ClassDecl *Class, SILDeclRef Member) {
// Try to lookup a VTable for Class from the module...
auto *Vtbl = lookUpVTable(Class);
// If the lookup fails, skip Class and attempt to resolve the method in
// the VTable of the super class of Class if it exists...
// Bail, if the lookup of VTable fails.
if (!Vtbl) {
Class = getClassDeclSuperClass(Class);
continue;
return nullptr;
}
// Ok, we have a VTable. Try to lookup the SILFunction implementation from