[Mlir-commits] [mlir] 1331750 - [mlir] Add a null pointer check in symbol lookup (#115165)

[llvmlistbot at llvm.org]

Author: Shlomi Regev
Date: 2024-11-12T23:31:25+01:00
New Revision: 13317502da8ee3885854f67700140586c0edafee

URL: https://github.com/llvm/llvm-project/commit/13317502da8ee3885854f67700140586c0edafee
DIFF: https://github.com/llvm/llvm-project/commit/13317502da8ee3885854f67700140586c0edafee.diff

LOG: [mlir] Add a null pointer check in symbol lookup (#115165)

Dead code analysis crashed because a symbol that is called/used didn't appear in the symbol
table. 
This patch fixes this by adding a nullptr check after symbol table lookup.

Added: 
    

Modified: 
    mlir/lib/Analysis/DataFlow/DeadCodeAnalysis.cpp
    mlir/test/Analysis/DataFlow/test-dead-code-analysis.mlir

Removed: 
    


################################################################################
diff  --git a/mlir/lib/Analysis/DataFlow/DeadCodeAnalysis.cpp b/mlir/lib/Analysis/DataFlow/DeadCodeAnalysis.cpp
index 3c190d4e991919..e805e21d878bf9 100644
--- a/mlir/lib/Analysis/DataFlow/DeadCodeAnalysis.cpp
+++ b/mlir/lib/Analysis/DataFlow/DeadCodeAnalysis.cpp
@@ -186,6 +186,8 @@ void DeadCodeAnalysis::initializeSymbolCallables(Operation *top) {
       // If a callable symbol has a non-call use, then we can't be guaranteed to
       // know all callsites.
       Operation *symbol = symbolTable.lookupSymbolIn(top, use.getSymbolRef());
+      if (!symbol)
+        continue;
       auto *state = getOrCreate<PredecessorState>(getProgramPointAfter(symbol));
       propagateIfChanged(state, state->setHasUnknownPredecessors());
     }

diff  --git a/mlir/test/Analysis/DataFlow/test-dead-code-analysis.mlir b/mlir/test/Analysis/DataFlow/test-dead-code-analysis.mlir
index 70becc72beb96a..1ae68553515067 100644
--- a/mlir/test/Analysis/DataFlow/test-dead-code-analysis.mlir
+++ b/mlir/test/Analysis/DataFlow/test-dead-code-analysis.mlir
@@ -265,3 +265,7 @@ func.func @test_dca_doesnt_crash() -> () {
   }  
   return
 }
+
+func.func @test_dca_doesnt_crash_2() -> () attributes {symbol = @notexistant} {
+   return
+}