[flang][cuda] Allow GOTO, EXIT, CYCLE and SELECT CASE in device procedures

[clementval]

These statements are allowed in device procedures in the reference compiler. Keep the error for the CUF KERNEL case for now.

[llvmbot]

@llvm/pr-subscribers-flang-semantics

Author: Valentin Clement (バレンタイン クレメン) (clementval)

Changes

These statements are allowed in device procedures in the reference compiler. Keep the error for the CUF KERNEL case for now.

---

Full diff: https://github.com/llvm/llvm-project/pull/121612.diff

2 Files Affected:

• (modified) flang/lib/Semantics/check-cuda.cpp (+23)
• (modified) flang/test/Semantics/cuf09.cuf (+53)

diff --git a/flang/lib/Semantics/check-cuda.cpp b/flang/lib/Semantics/check-cuda.cpp
index d497ac20e7017b..d8a5639227648f 100644
--- a/flang/lib/Semantics/check-cuda.cpp
+++ b/flang/lib/Semantics/check-cuda.cpp
@@ -302,6 +302,14 @@ template <bool IsCUFKernelDo> class DeviceContextChecker {
             [&](const common::Indirection<parser::IfConstruct> &x) {
               Check(x.value());
             },
+            [&](const common::Indirection<parser::CaseConstruct> &x) {
+              const auto &caseList{
+                  std::get<std::list<parser::CaseConstruct::Case>>(
+                      x.value().t)};
+              for (const parser::CaseConstruct::Case &c : caseList) {
+                Check(std::get<parser::Block>(c.t));
+              }
+            },
             [&](const auto &x) {
               if (auto source{parser::GetSource(x)}) {
                 context_.Say(*source,
@@ -347,9 +355,24 @@ template <bool IsCUFKernelDo> class DeviceContextChecker {
           hostArray->name());
     }
   }
+  void ErrorInCUFKernel(parser::CharBlock source) {
+    if (IsCUFKernelDo) {
+      context_.Say(
+          source, "Statement may not appear in cuf kernel code"_err_en_US);
+    }
+  }
   void Check(const parser::ActionStmt &stmt, const parser::CharBlock &source) {
     common::visit(
         common::visitors{
+            [&](const common::Indirection<parser::CycleStmt> &) {
+              ErrorInCUFKernel(source);
+            },
+            [&](const common::Indirection<parser::ExitStmt> &) {
+              ErrorInCUFKernel(source);
+            },
+            [&](const common::Indirection<parser::GotoStmt> &) {
+              ErrorInCUFKernel(source);
+            },
             [&](const common::Indirection<parser::StopStmt> &) { return; },
             [&](const common::Indirection<parser::PrintStmt> &) {},
             [&](const common::Indirection<parser::WriteStmt> &x) {
diff --git a/flang/test/Semantics/cuf09.cuf b/flang/test/Semantics/cuf09.cuf
index 3307e2a8626729..06c9070fcbcd00 100644
--- a/flang/test/Semantics/cuf09.cuf
+++ b/flang/test/Semantics/cuf09.cuf
@@ -54,6 +54,59 @@ module m
     print*,threadIdx%x
     stop ! ok
   end subroutine
+
+  attributes(global) subroutine cycletest()
+    integer :: i
+    do i = 1, 10
+      cycle ! ok
+    end do
+  end subroutine
+
+  attributes(global) subroutine gototest()
+    integer :: i
+    goto 10
+    10 print *, "X is negative!" 
+  end subroutine
+
+  attributes(global) subroutine exittest()
+    integer :: i
+    do i = 1, 10
+      if (i == 1) then
+        exit ! ok
+      end if
+    end do
+  end subroutine
+
+  attributes(global) subroutine selectcasetest()
+    integer :: i
+    select case(i)
+    case (1)
+      print*,'main'
+    case default
+      print*, 'default'
+    end select
+  end subroutine
+
+  subroutine host()
+    integer :: i
+    !$cuf kernel do
+    do i = 1, 10
+      !ERROR: Statement may not appear in cuf kernel code
+      cycle
+    end do
+
+    !$cuf kernel do
+    do i = 1, 10
+      if (i == 1) then
+        !ERROR: Statement may not appear in cuf kernel code
+        exit ! ok
+      end if
+
+      !ERROR: Statement may not appear in cuf kernel code
+      goto 10
+      10 print *, "X is negative!"
+    end do
+  end subroutine
 end
 
 program main