[PATCH] D66444: [BlockExtractor] Avoid assert with wrong line format

[Jinsong Ji via Phabricator via llvm-commits]

jsji created this revision.
jsji added reviewers: qcolombet, volkan.
Herald added subscribers: llvm-commits, hiraditya.
Herald added a project: LLVM.

When the line format is wrong, we may end up accessing out of bound
memory. eg: the test with invalide line will cause assert.
Assertion `idx < size()' failed

The fix is to report fatal when we found mismatched line format.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D66444

Files:
  llvm/lib/Transforms/IPO/BlockExtractor.cpp
  llvm/test/Transforms/BlockExtractor/invalid-line.ll


Index: llvm/test/Transforms/BlockExtractor/invalid-line.ll
===================================================================
--- /dev/null
+++ llvm/test/Transforms/BlockExtractor/invalid-line.ll
@@ -0,0 +1,9 @@
+; RUN: echo 'foo' > %t
+; RUN: not opt -S -extract-blocks -extract-blocks-file=%t %s 2>&1 | FileCheck %s
+
+; CHECK: Invalid line
+define void @bar() {
+bb:
+  ret void
+}
+
Index: llvm/lib/Transforms/IPO/BlockExtractor.cpp
===================================================================
--- llvm/lib/Transforms/IPO/BlockExtractor.cpp
+++ llvm/lib/Transforms/IPO/BlockExtractor.cpp
@@ -119,6 +119,8 @@
                /*KeepEmpty=*/false);
     if (LineSplit.empty())
       continue;
+    if (LineSplit.size()!=2)
+      report_fatal_error("Invalid line format, expecting lines like: 'funcname bb1[;bb2..]'");
     SmallVector<StringRef, 4> BBNames;
     LineSplit[1].split(BBNames, ';', /*MaxSplit=*/-1,
                        /*KeepEmpty=*/false);


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