[llvm] 0de3d1c - [llvm] Add assertions for the smart pointers with the possibility to be null in ModuleLazyLoaderCache::operator()

[Teresa Johnson via llvm-commits]

Author: Ella Ma
Date: 2021-03-19T13:52:34-07:00
New Revision: 0de3d1c81428c2a7a4f9a23a5105aa2243fad778

URL: https://github.com/llvm/llvm-project/commit/0de3d1c81428c2a7a4f9a23a5105aa2243fad778
DIFF: https://github.com/llvm/llvm-project/commit/0de3d1c81428c2a7a4f9a23a5105aa2243fad778.diff

LOG: [llvm] Add assertions for the smart pointers with the possibility to be null in ModuleLazyLoaderCache::operator()

Split from D91844.

The return value of function `ModuleLazyLoaderCache::operator()` in file llvm/tools/llvm-link/llvm-link.cpp. According to the bug report of my static analyzer, the std::function variable `ModuleLazyLoaderCache::createLazyModule` points to function `loadFile`, which may return `nullptr` when error. And the pointer is dereferenced without a check.

Reviewed By: tejohnson

Differential Revision: https://reviews.llvm.org/D97258

Added: 
    

Modified: 
    llvm/tools/llvm-link/llvm-link.cpp

Removed: 
    


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diff  --git a/llvm/tools/llvm-link/llvm-link.cpp b/llvm/tools/llvm-link/llvm-link.cpp
index eed49c438335..b01270de727a 100644
--- a/llvm/tools/llvm-link/llvm-link.cpp
+++ b/llvm/tools/llvm-link/llvm-link.cpp
@@ -246,8 +246,10 @@ class ModuleLazyLoaderCache {
 Module &ModuleLazyLoaderCache::operator()(const char *argv0,
                                           const std::string &Identifier) {
   auto &Module = ModuleMap[Identifier];
-  if (!Module)
+  if (!Module) {
     Module = createLazyModule(argv0, Identifier);
+    assert(Module && "Failed to create lazy module!");
+  }
   return *Module;
 }
 } // anonymous namespace