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[analyzer][NFC] Remove outdated FIXME comment #68211

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merged 1 commit into from
Oct 9, 2023

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NagyDonat
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This trivial commit removes a 13-year-old FIXME comment from MallocChecker.cpp because it was fixed at least 10 years ago when getConjuredHeapSymbolVal() was added.

This trivial commit removes a 13-year-old FIXME comment from
MallocChecker.cpp because it was fixed at least 10 years ago when
`getConjuredHeapSymbolVal()` was added.
@llvmbot llvmbot added clang Clang issues not falling into any other category clang:static analyzer labels Oct 4, 2023
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llvmbot commented Oct 4, 2023

@llvm/pr-subscribers-clang-static-analyzer-1

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This trivial commit removes a 13-year-old FIXME comment from MallocChecker.cpp because it was fixed at least 10 years ago when getConjuredHeapSymbolVal() was added.


Full diff: https://github.com/llvm/llvm-project/pull/68211.diff

1 Files Affected:

  • (modified) clang/lib/StaticAnalyzer/Checkers/MallocChecker.cpp (+4-7)
diff --git a/clang/lib/StaticAnalyzer/Checkers/MallocChecker.cpp b/clang/lib/StaticAnalyzer/Checkers/MallocChecker.cpp
index 18c7f3e4f6e6b92..d3a4020280616b0 100644
--- a/clang/lib/StaticAnalyzer/Checkers/MallocChecker.cpp
+++ b/clang/lib/StaticAnalyzer/Checkers/MallocChecker.cpp
@@ -1961,13 +1961,10 @@ ProgramStateRef MallocChecker::FreeMemAux(
   // Parameters, locals, statics, globals, and memory returned by
   // __builtin_alloca() shouldn't be freed.
   if (!isa<UnknownSpaceRegion, HeapSpaceRegion>(MS)) {
-    // FIXME: at the time this code was written, malloc() regions were
-    // represented by conjured symbols, which are all in UnknownSpaceRegion.
-    // This means that there isn't actually anything from HeapSpaceRegion
-    // that should be freed, even though we allow it here.
-    // Of course, free() can work on memory allocated outside the current
-    // function, so UnknownSpaceRegion is always a possibility.
-    // False negatives are better than false positives.
+    // Regions returned by malloc() are represented by SymbolicRegion objects
+    // within HeapSpaceRegion. Of course, free() can work on memory allocated
+    // outside the current function, so UnknownSpaceRegion is also a
+    // possibility here.
 
     if (isa<AllocaRegion>(R))
       HandleFreeAlloca(C, ArgVal, ArgExpr->getSourceRange());

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@gamesh411 gamesh411 left a comment

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I can confirm the claims about HeapSymRegion being used:
image

@NagyDonat NagyDonat merged commit 2856e72 into llvm:main Oct 9, 2023
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@NagyDonat NagyDonat deleted the remove_malloc_fixme branch October 9, 2023 11:56
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@steakhal steakhal left a comment

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LGTM Thanks.

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4 participants