[flang-commits] [flang] cf637b7 - [flang][OpenMP] Fix goto within SECTION (#144502)

[via flang-commits]

Author: Tom Eccles
Date: 2025-06-17T16:57:32+01:00
New Revision: cf637b7e3554976419a0d672ad4c252137dc34f3

URL: https://github.com/llvm/llvm-project/commit/cf637b7e3554976419a0d672ad4c252137dc34f3
DIFF: https://github.com/llvm/llvm-project/commit/cf637b7e3554976419a0d672ad4c252137dc34f3.diff

LOG: [flang][OpenMP] Fix goto within SECTION (#144502)

Previously we didn't push any context for SECTION and they are not
modelled with differing scopes and so goto detection couldn't tell that
GOTOs between two SECTIONs were between constructs rather than just
staying inside of the parent SECTIONS construct.

Fixes #143231

Added: 
    flang/test/Semantics/OpenMP/sections-goto.f90

Modified: 
    flang/lib/Semantics/resolve-directives.cpp
    flang/test/Semantics/OpenMP/parallel-sections01.f90
    flang/test/Semantics/OpenMP/sections02.f90

Removed: 
    


################################################################################
diff  --git a/flang/lib/Semantics/resolve-directives.cpp b/flang/lib/Semantics/resolve-directives.cpp
index b5f8667fe36f2..282660684e78a 100644
--- a/flang/lib/Semantics/resolve-directives.cpp
+++ b/flang/lib/Semantics/resolve-directives.cpp
@@ -384,6 +384,9 @@ class OmpAttributeVisitor : DirectiveAttributeVisitor<llvm::omp::Directive> {
   bool Pre(const parser::OpenMPSectionsConstruct &);
   void Post(const parser::OpenMPSectionsConstruct &) { PopContext(); }
 
+  bool Pre(const parser::OpenMPSectionConstruct &);
+  void Post(const parser::OpenMPSectionConstruct &) { PopContext(); }
+
   bool Pre(const parser::OpenMPCriticalConstruct &critical);
   void Post(const parser::OpenMPCriticalConstruct &) { PopContext(); }
 
@@ -2003,6 +2006,12 @@ bool OmpAttributeVisitor::Pre(const parser::OpenMPSectionsConstruct &x) {
   return true;
 }
 
+bool OmpAttributeVisitor::Pre(const parser::OpenMPSectionConstruct &x) {
+  PushContext(x.source, llvm::omp::Directive::OMPD_section);
+  GetContext().withinConstruct = true;
+  return true;
+}
+
 bool OmpAttributeVisitor::Pre(const parser::OpenMPCriticalConstruct &x) {
   const auto &beginCriticalDir{std::get<parser::OmpCriticalDirective>(x.t)};
   const auto &endCriticalDir{std::get<parser::OmpEndCriticalDirective>(x.t)};
@@ -3024,8 +3033,13 @@ void OmpAttributeVisitor::CheckLabelContext(const parser::CharBlock source,
     const parser::CharBlock target, std::optional<DirContext> sourceContext,
     std::optional<DirContext> targetContext) {
   auto dirContextsSame = [](DirContext &lhs, DirContext &rhs) -> bool {
-    // Sometimes nested constructs share a scope but are 
diff erent contexts
-    return (lhs.scope == rhs.scope) && (lhs.directive == rhs.directive);
+    // Sometimes nested constructs share a scope but are 
diff erent contexts.
+    // The directiveSource comparison is for OmpSection. Sections do not have
+    // their own scopes and two 
diff erent sections both have the same directive.
+    // Their source however is 
diff erent. This string comparison is unfortunate
+    // but should only happen for GOTOs inside of SECTION.
+    return (lhs.scope == rhs.scope) && (lhs.directive == rhs.directive) &&
+        (lhs.directiveSource == rhs.directiveSource);
   };
   unsigned version{context_.langOptions().OpenMPVersion};
   if (targetContext &&

diff  --git a/flang/test/Semantics/OpenMP/parallel-sections01.f90 b/flang/test/Semantics/OpenMP/parallel-sections01.f90
index 6c5a053bf49c9..19448258af766 100644
--- a/flang/test/Semantics/OpenMP/parallel-sections01.f90
+++ b/flang/test/Semantics/OpenMP/parallel-sections01.f90
@@ -35,6 +35,8 @@ program OmpConstructSections01
    !$omp section
    print *, "This is a single statement structured block"
    !$omp section
+   !ERROR: invalid branch into an OpenMP structured block
+   !ERROR: invalid branch leaving an OpenMP structured block
    open (10, file="random-file-name.txt", err=30)
    !ERROR: invalid branch into an OpenMP structured block
    !ERROR: invalid branch leaving an OpenMP structured block

diff  --git a/flang/test/Semantics/OpenMP/sections-goto.f90 b/flang/test/Semantics/OpenMP/sections-goto.f90
new file mode 100644
index 0000000000000..9fa9df9f50b9c
--- /dev/null
+++ b/flang/test/Semantics/OpenMP/sections-goto.f90
@@ -0,0 +1,11 @@
+! RUN: %python %S/../test_errors.py %s %flang -fopenmp
+! Regression test for #143231
+
+!$omp sections
+! ERROR: invalid branch into an OpenMP structured block
+! ERROR: invalid branch leaving an OpenMP structured block
+goto 10
+!$omp section
+10 print *, "Invalid jump"
+!$omp end sections
+end

diff  --git a/flang/test/Semantics/OpenMP/sections02.f90 b/flang/test/Semantics/OpenMP/sections02.f90
index ee29922a72c08..8144b491071d8 100644
--- a/flang/test/Semantics/OpenMP/sections02.f90
+++ b/flang/test/Semantics/OpenMP/sections02.f90
@@ -19,6 +19,8 @@ program OmpConstructSections01
    !$omp section
    print *, "This is a single statement structured block"
    !$omp section
+   !ERROR: invalid branch into an OpenMP structured block
+   !ERROR: invalid branch leaving an OpenMP structured block
    open (10, file="random-file-name.txt", err=30)
    !ERROR: invalid branch into an OpenMP structured block
    !ERROR: invalid branch leaving an OpenMP structured block