[llvm-branch-commits] [flang] release/20.x: [flang] Fix missed case of symbol renaming in module file generation (#132475) (PR #133223)

[Paul Osmialowski via llvm-branch-commits]

https://github.com/pawosm-arm updated https://github.com/llvm/llvm-project/pull/133223

>From 78b0eb25e001071d7793bd8f253c3d2efc5cbf0a Mon Sep 17 00:00:00 2001
From: Peter Klausler <pklausler at nvidia.com>
Date: Wed, 26 Mar 2025 12:09:38 -0700
Subject: [PATCH] [flang] Fix missed case of symbol renaming in module file
 generation (#132475)

The map of symbols requiring new local aliases for USE association needs
to use the symbols' ultimate resolutions to avoid missing cases that can
arise in convoluted codes with lots of confusing renamings.

Fixes https://github.com/llvm/llvm-project/issues/132435.

(cherry picked from commit 6df27dd42d827a2468dcf4b4b1ee1a8e8af1a408)
---
 flang/lib/Evaluate/formatting.cpp  |  3 +-
 flang/lib/Semantics/mod-file.cpp   |  2 +-
 flang/test/Semantics/bug132435.f90 | 85 ++++++++++++++++++++++++++++++
 3 files changed, 88 insertions(+), 2 deletions(-)
 create mode 100644 flang/test/Semantics/bug132435.f90

diff --git a/flang/lib/Evaluate/formatting.cpp b/flang/lib/Evaluate/formatting.cpp
index f3a53c1f983df..cf0b43bc94c36 100644
--- a/flang/lib/Evaluate/formatting.cpp
+++ b/flang/lib/Evaluate/formatting.cpp
@@ -129,7 +129,8 @@ llvm::raw_ostream &Constant<Type<TypeCategory::Character, KIND>>::AsFortran(
 llvm::raw_ostream &EmitVar(llvm::raw_ostream &o, const Symbol &symbol,
     std::optional<parser::CharBlock> name = std::nullopt) {
   const auto &renamings{symbol.owner().context().moduleFileOutputRenamings()};
-  if (auto iter{renamings.find(&symbol)}; iter != renamings.end()) {
+  if (auto iter{renamings.find(&symbol.GetUltimate())};
+      iter != renamings.end()) {
     return o << iter->second.ToString();
   } else if (name) {
     return o << name->ToString();
diff --git a/flang/lib/Semantics/mod-file.cpp b/flang/lib/Semantics/mod-file.cpp
index b45f1c060da2f..ea3eae8468b50 100644
--- a/flang/lib/Semantics/mod-file.cpp
+++ b/flang/lib/Semantics/mod-file.cpp
@@ -346,7 +346,7 @@ void ModFileWriter::PrepareRenamings(const Scope &scope) {
     uses_ << DEREF(sMod->symbol()).name() << ",only:";
     if (rename != s->name()) {
       uses_ << rename << "=>";
-      renamings.emplace(&*s, rename);
+      renamings.emplace(&s->GetUltimate(), rename);
     }
     uses_ << s->name() << '\n';
     useExtraAttrs_ << "private::" << rename << '\n';
diff --git a/flang/test/Semantics/bug132435.f90 b/flang/test/Semantics/bug132435.f90
new file mode 100644
index 0000000000000..be8b661fcf6cc
--- /dev/null
+++ b/flang/test/Semantics/bug132435.f90
@@ -0,0 +1,85 @@
+! RUN: %python %S/test_modfile.py %s %flang_fc1
+module m1
+  type foo
+    integer :: c1 = 123
+  end type
+end
+
+module m2
+  use m1, only: foo
+  type baz
+    type(foo) :: d = foo()
+  end type
+  type bar
+    type(baz) :: e = baz()
+  end type
+end
+
+module m3
+  use m1, only: m1foo => foo
+  type foo
+    type(m1foo), private :: c2 = m1foo()
+  end type
+end
+
+module m4
+  use m2, only: m3foo => foo
+  type foo
+    type(m3foo), private :: c3 = m3foo()
+  end type
+end
+
+module m5
+  use m2, only: m2bar => bar
+  use m4, only: foo
+  type blah
+    type(m2bar) :: f = m2bar()
+  end type
+end
+
+!Expect: m1.mod
+!module m1
+!type::foo
+!integer(4)::c1=123_4
+!end type
+!end
+
+!Expect: m2.mod
+!module m2
+!use m1,only:foo
+!type::baz
+!type(foo)::d=foo(c1=123_4)
+!end type
+!type::bar
+!type(baz)::e=baz(d=foo(c1=123_4))
+!end type
+!end
+
+!Expect: m3.mod
+!module m3
+!use m1,only:m1foo=>foo
+!type::foo
+!type(m1foo),private::c2=m1foo(c1=123_4)
+!end type
+!end
+
+!Expect: m4.mod
+!module m4
+!use m2,only:m3foo=>foo
+!type::foo
+!type(m3foo),private::c3=m3foo(c1=123_4)
+!end type
+!end
+
+!Expect: m5.mod
+!module m5
+!use m2,only:m2$foo=>foo
+!use m2,only:baz
+!use m2,only:m2bar=>bar
+!use m4,only:foo
+!private::m2$foo
+!private::baz
+!type::blah
+!type(m2bar)::f=m2bar(e=baz(d=m2$foo(c1=123_4)))
+!end type
+!end