[llvm-branch-commits] [flang] 3e41ab1 - [flang] Fix dangling pointer in LabelEnforce

[Tim Keith via llvm-branch-commits]

Author: Tim Keith
Date: 2021-01-14T06:52:21-08:00
New Revision: 3e41ab18db2255028c288a11665c08d260654299

URL: https://github.com/llvm/llvm-project/commit/3e41ab18db2255028c288a11665c08d260654299
DIFF: https://github.com/llvm/llvm-project/commit/3e41ab18db2255028c288a11665c08d260654299.diff

LOG: [flang] Fix dangling pointer in LabelEnforce

`DirectiveStructureChecker` was passing in a pointer to a temporary
string for the `construct` argument to the constructor for `LabelEnforce`.
The `LabelEnforce` object had a lifetime longer than the temporary,
resulting in accessing a dangling pointer when emitting an error message
for `omp-parallell01.f90`.

The fix is to make the lifetime of the temporary as long as the lifetime
of the `LabelEnforce` object.

Differential Revision: https://reviews.llvm.org/D94618

Added: 
    

Modified: 
    flang/lib/Semantics/check-directive-structure.h

Removed: 
    


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diff  --git a/flang/lib/Semantics/check-directive-structure.h b/flang/lib/Semantics/check-directive-structure.h
index 1075087feb4f..76157ac93925 100644
--- a/flang/lib/Semantics/check-directive-structure.h
+++ b/flang/lib/Semantics/check-directive-structure.h
@@ -280,9 +280,9 @@ void DirectiveStructureChecker<D, C, PC, ClauseEnumSize>::CheckNoBranching(
       context_, directiveSource, directive, ContextDirectiveAsFortran()};
   parser::Walk(block, noBranchingEnforce);
 
+  auto construct{parser::ToUpperCaseLetters(getDirectiveName(directive).str())};
   LabelEnforce directiveLabelEnforce{context_, noBranchingEnforce.labels(),
-      directiveSource,
-      parser::ToUpperCaseLetters(getDirectiveName(directive).str()).c_str()};
+      directiveSource, construct.c_str()};
   parser::Walk(block, directiveLabelEnforce);
 }