[flang-commits] [flang] Fix semantic check for default declare mappers (PR #139593)

[via flang-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-flang-semantics

Author: Akash Banerjee (TIFitis)

<details>
<summary>Changes</summary>

The current semantic check in place is incorrect, this patch fixes this.

Up to 1 'default' named mapper is allowed for each derived type.
The current semantic check only allows up to 1 'default' named mapper across all derived types.

Co-authored-by: Raghu Maddhipatla <Raghu.Maddhipatla@<!-- -->amd.com>

---
Full diff: https://github.com/llvm/llvm-project/pull/139593.diff


3 Files Affected:

- (modified) flang/lib/Semantics/resolve-names.cpp (+13-8) 
- (modified) flang/test/Semantics/OpenMP/declare-mapper-symbols.f90 (+9-9) 
- (modified) flang/test/Semantics/OpenMP/declare-mapper03.f90 (+1-5) 


``````````diff
diff --git a/flang/lib/Semantics/resolve-names.cpp b/flang/lib/Semantics/resolve-names.cpp
index b2979690f78e7..1fd0ea007319d 100644
--- a/flang/lib/Semantics/resolve-names.cpp
+++ b/flang/lib/Semantics/resolve-names.cpp
@@ -38,6 +38,7 @@
 #include "flang/Semantics/type.h"
 #include "flang/Support/Fortran.h"
 #include "flang/Support/default-kinds.h"
+#include "llvm/ADT/SmallVector.h"
 #include "llvm/Support/raw_ostream.h"
 #include <list>
 #include <map>
@@ -1766,14 +1767,6 @@ void OmpVisitor::ProcessMapperSpecifier(const parser::OmpMapperSpecifier &spec,
   // just following the natural flow, the map clauses gets processed before
   // the type has been fully processed.
   BeginDeclTypeSpec();
-  if (auto &mapperName{std::get<std::optional<parser::Name>>(spec.t)}) {
-    mapperName->symbol =
-        &MakeSymbol(*mapperName, MiscDetails{MiscDetails::Kind::ConstructName});
-  } else {
-    const parser::CharBlock defaultName{"default", 7};
-    MakeSymbol(
-        defaultName, Attrs{}, MiscDetails{MiscDetails::Kind::ConstructName});
-  }
 
   PushScope(Scope::Kind::OtherConstruct, nullptr);
   Walk(std::get<parser::TypeSpec>(spec.t));
@@ -1783,6 +1776,18 @@ void OmpVisitor::ProcessMapperSpecifier(const parser::OmpMapperSpecifier &spec,
   Walk(clauses);
   EndDeclTypeSpec();
   PopScope();
+
+  if (auto &mapperName{std::get<std::optional<parser::Name>>(spec.t)}) {
+    mapperName->symbol =
+        &MakeSymbol(*mapperName, MiscDetails{MiscDetails::Kind::ConstructName});
+  } else {
+    const auto &type = std::get<parser::TypeSpec>(spec.t);
+    static llvm::SmallVector<std::string> defaultNames;
+    defaultNames.emplace_back(
+        type.declTypeSpec->derivedTypeSpec().name().ToString() + ".default");
+    MakeSymbol(defaultNames.back(), Attrs{},
+        MiscDetails{MiscDetails::Kind::ConstructName});
+  }
 }
 
 void OmpVisitor::ProcessReductionSpecifier(
diff --git a/flang/test/Semantics/OpenMP/declare-mapper-symbols.f90 b/flang/test/Semantics/OpenMP/declare-mapper-symbols.f90
index b4e03bd1632e5..0dda5b4456987 100644
--- a/flang/test/Semantics/OpenMP/declare-mapper-symbols.f90
+++ b/flang/test/Semantics/OpenMP/declare-mapper-symbols.f90
@@ -2,23 +2,23 @@
 
 program main
 !CHECK-LABEL: MainProgram scope: main
-  implicit none
+   implicit none
 
-  type ty
-     integer :: x
-  end type ty
-  !$omp declare mapper(mymapper : ty :: mapped) map(mapped, mapped%x)
-  !$omp declare mapper(ty :: maptwo) map(maptwo, maptwo%x)
+   type ty
+      integer :: x
+   end type ty
+   !$omp declare mapper(mymapper : ty :: mapped) map(mapped, mapped%x)
+   !$omp declare mapper(ty :: maptwo) map(maptwo, maptwo%x)
 
 !! Note, symbols come out in their respective scope, but not in declaration order.
-!CHECK: default: Misc ConstructName
 !CHECK: mymapper: Misc ConstructName
 !CHECK: ty: DerivedType components: x
+!CHECK: ty.default: Misc ConstructName
 !CHECK: DerivedType scope: ty
 !CHECK: OtherConstruct scope:
 !CHECK: mapped (OmpMapToFrom) {{.*}} ObjectEntity type: TYPE(ty)
-!CHECK: OtherConstruct scope:  
+!CHECK: OtherConstruct scope:
 !CHECK: maptwo (OmpMapToFrom) {{.*}} ObjectEntity type: TYPE(ty)
-  
+
 end program main
 
diff --git a/flang/test/Semantics/OpenMP/declare-mapper03.f90 b/flang/test/Semantics/OpenMP/declare-mapper03.f90
index b70b8a67f33e0..84fc3efafb3ad 100644
--- a/flang/test/Semantics/OpenMP/declare-mapper03.f90
+++ b/flang/test/Semantics/OpenMP/declare-mapper03.f90
@@ -5,12 +5,8 @@
    integer :: y
 end type t1
 
-type :: t2
-   real :: y, z
-end type t2
-
 !error: 'default' is already declared in this scoping unit
 
 !$omp declare mapper(t1::x) map(x, x%y)
-!$omp declare mapper(t2::w) map(w, w%y, w%z)
+!$omp declare mapper(t1::x) map(x)
 end

``````````

</details>


https://github.com/llvm/llvm-project/pull/139593