[flang-commits] [flang] ff82884 - [flang] Fix crash in error recovery (#140768)

[via flang-commits]

Author: Peter Klausler
Date: 2025-05-28T13:59:48-07:00
New Revision: ff8288442dad15d66b7a22ccad94e926e2f56deb

URL: https://github.com/llvm/llvm-project/commit/ff8288442dad15d66b7a22ccad94e926e2f56deb
DIFF: https://github.com/llvm/llvm-project/commit/ff8288442dad15d66b7a22ccad94e926e2f56deb.diff

LOG: [flang] Fix crash in error recovery (#140768)

When a TYPE(*) dummy argument is erroneously used as a component value
in a structure constructor, semantics crashes if the structure
constructor had been initially parsed as a potential function reference.
Clean out stale typed expressions when reanalyzing the reconstructed
parse subtree to ensure that errors are caught the next time around.

Added: 
    flang/test/Semantics/bug869.f90

Modified: 
    flang/lib/Semantics/expression.cpp

Removed: 
    


################################################################################
diff  --git a/flang/lib/Semantics/expression.cpp b/flang/lib/Semantics/expression.cpp
index b3ad608ee6744..d68e71f57f141 100644
--- a/flang/lib/Semantics/expression.cpp
+++ b/flang/lib/Semantics/expression.cpp
@@ -3376,6 +3376,10 @@ MaybeExpr ExpressionAnalyzer::Analyze(const parser::FunctionReference &funcRef,
         auto &mutableRef{const_cast<parser::FunctionReference &>(funcRef)};
         *structureConstructor =
             mutableRef.ConvertToStructureConstructor(type.derivedTypeSpec());
+        // Don't use saved typed expressions left over from argument
+        // analysis; they might not be valid structure components
+        // (e.g., a TYPE(*) argument)
+        auto restorer{DoNotUseSavedTypedExprs()};
         return Analyze(structureConstructor->value());
       }
     }
@@ -4058,7 +4062,7 @@ MaybeExpr ExpressionAnalyzer::ExprOrVariable(
       // first to be sure.
       std::optional<parser::StructureConstructor> ctor;
       result = Analyze(funcRef->value(), &ctor);
-      if (result && ctor) {
+      if (ctor) {
         // A misparsed function reference is really a structure
         // constructor.  Repair the parse tree in situ.
         const_cast<PARSED &>(x).u = std::move(*ctor);

diff  --git a/flang/test/Semantics/bug869.f90 b/flang/test/Semantics/bug869.f90
new file mode 100644
index 0000000000000..ddc7dffcc2fa4
--- /dev/null
+++ b/flang/test/Semantics/bug869.f90
@@ -0,0 +1,10 @@
+! RUN: %python %S/test_errors.py %s %flang_fc1
+! Regression test for crash
+subroutine sub(xx)
+  type(*) :: xx
+  type ty
+  end type
+  type(ty) obj
+  !ERROR: TYPE(*) dummy argument may only be used as an actual argument
+  obj = ty(xx)
+end