[flang-commits] [flang] 6da1f22 - [Flang] Fix usage of uninitialized resolution variable

[Paul Scoropan via flang-commits]

Author: Paul Scoropan
Date: 2023-04-05T15:00:56Z
New Revision: 6da1f2277dd1fbd560204c6ab0e129eb3cb0906b

URL: https://github.com/llvm/llvm-project/commit/6da1f2277dd1fbd560204c6ab0e129eb3cb0906b
DIFF: https://github.com/llvm/llvm-project/commit/6da1f2277dd1fbd560204c6ab0e129eb3cb0906b.diff

LOG: [Flang] Fix usage of uninitialized resolution variable

Recent Flang PowerPC intrinsics patch used resolution variable without checking if it exists first, causing segmentation faults in some scenarios. This patch checks that the resolution variable exists first before usage.

Reviewed By: DanielCChen

Differential Revision: https://reviews.llvm.org/D147616

Added: 
    

Modified: 
    flang/lib/Semantics/expression.cpp

Removed: 
    


################################################################################
diff  --git a/flang/lib/Semantics/expression.cpp b/flang/lib/Semantics/expression.cpp
index 06226f282c1cd..cec936c8f5e42 100644
--- a/flang/lib/Semantics/expression.cpp
+++ b/flang/lib/Semantics/expression.cpp
@@ -2518,12 +2518,12 @@ auto ExpressionAnalyzer::GetCalleeAndArguments(const parser::Name &name,
         mightBeStructureConstructor)};
     resolution = pair.first;
     dueToAmbiguity = pair.second;
-    if (context_.GetPPCBuiltinsScope() &&
-        resolution->name().ToString().rfind("__ppc_", 0) == 0) {
-      semantics::CheckPPCIntrinsic(
-          *symbol, *resolution, arguments, GetFoldingContext());
-    }
     if (resolution) {
+      if (context_.GetPPCBuiltinsScope() &&
+          resolution->name().ToString().rfind("__ppc_", 0) == 0) {
+        semantics::CheckPPCIntrinsic(
+            *symbol, *resolution, arguments, GetFoldingContext());
+      }
       // re-resolve name to the specific procedure
       name.symbol = const_cast<Symbol *>(resolution);
     }