[flang-commits] [flang] 1f9c53c - [flang][cuda] Emit better error when subprogram attribute is absent or bad (#176501)

[via flang-commits]

Author: Valentin Clement (バレンタイン クレメン)
Date: 2026-01-16T16:26:33-08:00
New Revision: 1f9c53c6a35ecfdf81a4f80169e31860c5158d51

URL: https://github.com/llvm/llvm-project/commit/1f9c53c6a35ecfdf81a4f80169e31860c5158d51
DIFF: https://github.com/llvm/llvm-project/commit/1f9c53c6a35ecfdf81a4f80169e31860c5158d51.diff

LOG: [flang][cuda] Emit better error when subprogram attribute is absent or bad (#176501)

this patch update the parser for CUDA Fortran subprogram attribute to
emit more precise error.

Instead of having error like: 

```
error: expected 'END'
      attributes(managed) integer function fooj()
      ^
```

The parser will emit: 
```
 expected DEVICE, GLOBAL, GRID_GLOBAL, or HOST attribute
  attributes(managed) integer function fooj()
             ^
```

Added: 
    flang/test/Semantics/cuf-proc-attr-error.cuf

Modified: 
    flang/lib/Parser/program-parsers.cpp

Removed: 
    


################################################################################
diff  --git a/flang/lib/Parser/program-parsers.cpp b/flang/lib/Parser/program-parsers.cpp
index 303335934a37a..36a9c00a4f30d 100644
--- a/flang/lib/Parser/program-parsers.cpp
+++ b/flang/lib/Parser/program-parsers.cpp
@@ -533,10 +533,12 @@ TYPE_PARSER(construct<AltReturnSpec>(star >> label))
 //         NON_RECURSIVE | PURE | RECURSIVE |
 // (CUDA)  ATTRIBUTES ( (DEVICE | GLOBAL | GRID_GLOBAL | HOST)... ) |
 //         LAUNCH_BOUNDS(expr-list) | CLUSTER_DIMS(expr-list)
-TYPE_PARSER(first("DEVICE" >> pure(common::CUDASubprogramAttrs::Device),
-    "GLOBAL" >> pure(common::CUDASubprogramAttrs::Global),
-    "GRID_GLOBAL" >> pure(common::CUDASubprogramAttrs::Grid_Global),
-    "HOST" >> pure(common::CUDASubprogramAttrs::Host)))
+TYPE_PARSER(withMessage(
+    "expected DEVICE, GLOBAL, GRID_GLOBAL, or HOST attribute"_err_en_US,
+    first("DEVICE" >> pure(common::CUDASubprogramAttrs::Device),
+        "GLOBAL" >> pure(common::CUDASubprogramAttrs::Global),
+        "GRID_GLOBAL" >> pure(common::CUDASubprogramAttrs::Grid_Global),
+        "HOST" >> pure(common::CUDASubprogramAttrs::Host))))
 TYPE_PARSER(first(construct<PrefixSpec>(declarationTypeSpec),
     construct<PrefixSpec>(construct<PrefixSpec::Elemental>("ELEMENTAL"_tok)),
     construct<PrefixSpec>(construct<PrefixSpec::Impure>("IMPURE"_tok)),
@@ -546,9 +548,12 @@ TYPE_PARSER(first(construct<PrefixSpec>(declarationTypeSpec),
     construct<PrefixSpec>(construct<PrefixSpec::Pure>("PURE"_tok)),
     construct<PrefixSpec>(construct<PrefixSpec::Recursive>("RECURSIVE"_tok)),
     extension<LanguageFeature::CUDA>(
-        construct<PrefixSpec>(construct<PrefixSpec::Attributes>("ATTRIBUTES" >>
-            parenthesized(
-                optionalList(Parser<common::CUDASubprogramAttrs>{}))))),
+        construct<PrefixSpec>(construct<PrefixSpec::Attributes>(
+            localRecovery("expected valid ATTRIBUTES specification"_err_en_US,
+                "ATTRIBUTES" >> parenthesized(nonemptyList(
+                                    Parser<common::CUDASubprogramAttrs>{})),
+                "ATTRIBUTES" >> SkipTo<')'>{} >> ")"_ch >>
+                    pure<std::list<common::CUDASubprogramAttrs>>())))),
     extension<LanguageFeature::CUDA>(construct<PrefixSpec>(
         construct<PrefixSpec::Launch_Bounds>("LAUNCH_BOUNDS" >>
             parenthesized(nonemptyList(

diff  --git a/flang/test/Semantics/cuf-proc-attr-error.cuf b/flang/test/Semantics/cuf-proc-attr-error.cuf
new file mode 100644
index 0000000000000..54bed74c27687
--- /dev/null
+++ b/flang/test/Semantics/cuf-proc-attr-error.cuf
@@ -0,0 +1,9 @@
+! RUN: %python %S/test_errors.py %s %flang_fc1
+! Test conflicting CUDA subprogram attributes
+module m1
+ contains
+  !ERROR: expected DEVICE, GLOBAL, GRID_GLOBAL, or HOST attribute
+  attributes() subroutine empty1; end
+  !ERROR: expected DEVICE, GLOBAL, GRID_GLOBAL, or HOST attribute
+  attributes(managed) subroutine badAttr1; end
+end