[flang] Improve OpenACC SELF clause parser (#135883)
The current parser can fail on "self(x * 2)" by recognizing just "x" as
a one-element list of object names and then failing at a higher level
because it never reached the right parenthesis. Add lookahead checks and
error recovery.
Fixes https://github.com/llvm/llvm-project/issues/135810.
diff --git a/flang/lib/Parser/openacc-parsers.cpp b/flang/lib/Parser/openacc-parsers.cpp
index 072eba9..ad035e6 100644
--- a/flang/lib/Parser/openacc-parsers.cpp
+++ b/flang/lib/Parser/openacc-parsers.cpp
@@ -126,8 +126,13 @@
// SELF clause is either a simple optional condition for compute construct
// or a synonym of the HOST clause for the update directive 2.14.4 holding
// an object list.
-TYPE_PARSER(construct<AccSelfClause>(Parser<AccObjectList>{}) ||
- construct<AccSelfClause>(scalarLogicalExpr))
+TYPE_PARSER(
+ construct<AccSelfClause>(Parser<AccObjectList>{}) / lookAhead(")"_tok) ||
+ construct<AccSelfClause>(scalarLogicalExpr / lookAhead(")"_tok)) ||
+ construct<AccSelfClause>(
+ recovery(fail<std::optional<ScalarLogicalExpr>>(
+ "logical expression or object list expected"_err_en_US),
+ SkipTo<')'>{} >> pure<std::optional<ScalarLogicalExpr>>())))
// Modifier for copyin, copyout, cache and create
TYPE_PARSER(construct<AccDataModifier>(
diff --git a/flang/test/Semantics/OpenACC/bug135810-1.f90 b/flang/test/Semantics/OpenACC/bug135810-1.f90
new file mode 100644
index 0000000..a4e1bba
--- /dev/null
+++ b/flang/test/Semantics/OpenACC/bug135810-1.f90
@@ -0,0 +1,14 @@
+! RUN: %python %S/../test_errors.py %s %flang -fopenacc
+integer function square(x, y)
+ implicit none
+ integer, intent(in) :: x, y
+ !$acc parallel self(x * 2 > x) ! ok
+ !$acc end parallel
+!ERROR: Must have LOGICAL type, but is INTEGER(4)
+ !$acc parallel self(x * 2)
+ !$acc end parallel
+!ERROR: SELF clause on the PARALLEL directive only accepts optional scalar logical expression
+ !$acc parallel self(x, y)
+ !$acc end parallel
+ square = x * x
+end function square
diff --git a/flang/test/Semantics/OpenACC/bug135810-2.f90 b/flang/test/Semantics/OpenACC/bug135810-2.f90
new file mode 100644
index 0000000..8ed608b
--- /dev/null
+++ b/flang/test/Semantics/OpenACC/bug135810-2.f90
@@ -0,0 +1,12 @@
+! RUN: %python %S/../test_errors.py %s %flang -fopenacc
+integer function square(x)
+ implicit none
+ integer, intent(in) :: x
+!ERROR: logical expression or object list expected
+ !$acc parallel self(,)
+ !$acc end parallel
+!ERROR: logical expression or object list expected
+ !$acc parallel self(.true., )
+ !$acc end parallel
+ square = x * x
+end function square
