diff --git a/flang/docs/Extensions.md b/flang/docs/Extensions.md
--- a/flang/docs/Extensions.md
+++ b/flang/docs/Extensions.md
@@ -90,6 +90,7 @@
"not yet implemented" message.
* Structure field access with `.field`
* `BYTE` as synonym for `INTEGER(KIND=1)`; but not when spelled `TYPE(BYTE)`.
+* When kind-param is used for REAL literals, allow a matching exponent letter
* Quad precision REAL literals with `Q`
* `X` prefix/suffix as synonym for `Z` on hexadecimal literals
* `B`, `O`, `Z`, and `X` accepted as suffixes as well as prefixes
diff --git a/flang/include/flang/Common/Fortran-features.h b/flang/include/flang/Common/Fortran-features.h
--- a/flang/include/flang/Common/Fortran-features.h
+++ b/flang/include/flang/Common/Fortran-features.h
@@ -19,14 +19,14 @@
FixedFormContinuationWithColumn1Ampersand, LogicalAbbreviations,
XOROperator, PunctuationInNames, OptionalFreeFormSpace, BOZExtensions,
EmptyStatement, AlternativeNE, ExecutionPartNamelist, DECStructures,
- DoubleComplex, Byte, StarKind, QuadPrecision, SlashInitialization,
- TripletInArrayConstructor, MissingColons, SignedComplexLiteral,
- OldStyleParameter, ComplexConstructor, PercentLOC, SignedPrimary, FileName,
- Carriagecontrol, Convert, Dispose, IOListLeadingComma,
- AbbreviatedEditDescriptor, ProgramParentheses, PercentRefAndVal,
- OmitFunctionDummies, CrayPointer, Hollerith, ArithmeticIF, Assign,
- AssignedGOTO, Pause, OpenACC, OpenMP, CruftAfterAmpersand, ClassicCComments,
- AdditionalFormats, BigIntLiterals, RealDoControls,
+ DoubleComplex, Byte, StarKind, ExponentMatchingKindParam, QuadPrecision,
+ SlashInitialization, TripletInArrayConstructor, MissingColons,
+ SignedComplexLiteral, OldStyleParameter, ComplexConstructor, PercentLOC,
+ SignedPrimary, FileName, Carriagecontrol, Convert, Dispose,
+ IOListLeadingComma, AbbreviatedEditDescriptor, ProgramParentheses,
+ PercentRefAndVal, OmitFunctionDummies, CrayPointer, Hollerith, ArithmeticIF,
+ Assign, AssignedGOTO, Pause, OpenACC, OpenMP, CruftAfterAmpersand,
+ ClassicCComments, AdditionalFormats, BigIntLiterals, RealDoControls,
EquivalenceNumericWithCharacter, EquivalenceNonDefaultNumeric,
EquivalenceSameNonSequence, AdditionalIntrinsics, AnonymousParents,
OldLabelDoEndStatements, LogicalIntegerAssignment, EmptySourceFile,
diff --git a/flang/lib/Semantics/expression.cpp b/flang/lib/Semantics/expression.cpp
--- a/flang/lib/Semantics/expression.cpp
+++ b/flang/lib/Semantics/expression.cpp
@@ -552,12 +552,20 @@
if (letterKind) {
defaultKind = *letterKind;
}
- // C716 requires 'E' as an exponent, but this is more useful
+ // C716 requires 'E' as an exponent.
+ // Extension: allow exponent-letter matching the kind-param.
auto kind{AnalyzeKindParam(x.kind, defaultKind)};
- if (letterKind && kind != *letterKind && expoLetter != 'e') {
- Say("Explicit kind parameter on real constant disagrees with "
- "exponent letter '%c'"_port_en_US,
- expoLetter);
+ if (letterKind && expoLetter != 'e') {
+ if (kind != *letterKind) {
+ Say("Explicit kind parameter on real constant disagrees with "
+ "exponent letter '%c'"_port_en_US,
+ expoLetter);
+ } else if (x.kind &&
+ context_.ShouldWarn(
+ common::LanguageFeature::ExponentMatchingKindParam)) {
+ Say("Explicit kind parameter together with non-'E' exponent letter "
+ "is not standard"_port_en_US);
+ }
}
auto result{common::SearchTypes(
RealTypeVisitor{kind, x.real.source, GetFoldingContext()})};
diff --git a/flang/test/Semantics/kinds04.f90 b/flang/test/Semantics/kinds04_q10.f90
rename from flang/test/Semantics/kinds04.f90
rename to flang/test/Semantics/kinds04_q10.f90
--- a/flang/test/Semantics/kinds04.f90
+++ b/flang/test/Semantics/kinds04_q10.f90
@@ -1,24 +1,32 @@
! RUN: %python %S/test_errors.py %s %flang_fc1
-! C716 If both kind-param and exponent-letter appear, exponent-letter
-! shall be E.
-! C717 The value of kind-param shall specify an approximation method that
+! C716 If both kind-param and exponent-letter appear, exponent-letter
+! shall be E. (As an extension we also allow an exponent-letter which matches
+! the kind-param)
+! C717 The value of kind-param shall specify an approximation method that
! exists on the processor.
+!
+! This test is for x86_64, where exponent-letter 'q' is for
+! 10-byte extended precision
+! REQUIRES: x86-registered-target
subroutine s(var)
real :: realvar1 = 4.0E6_4
real :: realvar2 = 4.0D6
real :: realvar3 = 4.0Q6
real :: realvar4 = 4.0D6_8
- real :: realvar5 = 4.0Q6_16
- real :: realvar6 = 4.0E6_8
- real :: realvar7 = 4.0E6_10
- real :: realvar8 = 4.0E6_16
+ real :: realvar5 = 4.0Q6_10
+ !WARNING: Explicit kind parameter on real constant disagrees with exponent letter 'q'
+ real :: realvar6 = 4.0Q6_16
+ real :: realvar7 = 4.0E6_8
+ real :: realvar8 = 4.0E6_10
+ real :: realvar9 = 4.0E6_16
!ERROR: Unsupported REAL(KIND=32)
- real :: realvar9 = 4.0E6_32
+ real :: realvar10 = 4.0E6_32
double precision :: doublevar1 = 4.0E6_4
double precision :: doublevar2 = 4.0D6
double precision :: doublevar3 = 4.0Q6
double precision :: doublevar4 = 4.0D6_8
+ !WARNING: Explicit kind parameter on real constant disagrees with exponent letter 'q'
double precision :: doublevar5 = 4.0Q6_16
double precision :: doublevar6 = 4.0E6_8
double precision :: doublevar7 = 4.0E6_10
diff --git a/flang/test/Semantics/kinds04.f90 b/flang/test/Semantics/kinds04_q16.f90
rename from flang/test/Semantics/kinds04.f90
rename to flang/test/Semantics/kinds04_q16.f90
--- a/flang/test/Semantics/kinds04.f90
+++ b/flang/test/Semantics/kinds04_q16.f90
@@ -1,19 +1,26 @@
! RUN: %python %S/test_errors.py %s %flang_fc1
-! C716 If both kind-param and exponent-letter appear, exponent-letter
-! shall be E.
-! C717 The value of kind-param shall specify an approximation method that
+! C716 If both kind-param and exponent-letter appear, exponent-letter
+! shall be E. (As an extension we also allow an exponent-letter which matches
+! the kind-param)
+! C717 The value of kind-param shall specify an approximation method that
! exists on the processor.
+!
+! This test is for non-x86_64, where exponent-letter 'q' is for
+! 16-byte quadruple precision
+! UNSUPPORTED: x86-registered-target
subroutine s(var)
real :: realvar1 = 4.0E6_4
real :: realvar2 = 4.0D6
real :: realvar3 = 4.0Q6
real :: realvar4 = 4.0D6_8
- real :: realvar5 = 4.0Q6_16
- real :: realvar6 = 4.0E6_8
- real :: realvar7 = 4.0E6_10
- real :: realvar8 = 4.0E6_16
+ !WARNING: Explicit kind parameter on real constant disagrees with exponent letter 'q'
+ real :: realvar5 = 4.0Q6_10
+ real :: realvar6 = 4.0Q6_16
+ real :: realvar7 = 4.0E6_8
+ real :: realvar8 = 4.0E6_10
+ real :: realvar9 = 4.0E6_16
!ERROR: Unsupported REAL(KIND=32)
- real :: realvar9 = 4.0E6_32
+ real :: realvar10 = 4.0E6_32
double precision :: doublevar1 = 4.0E6_4
double precision :: doublevar2 = 4.0D6
diff --git a/flang/test/Semantics/kinds05.f90 b/flang/test/Semantics/kinds05.f90
new file mode 100644
--- /dev/null
+++ b/flang/test/Semantics/kinds05.f90
@@ -0,0 +1,18 @@
+! RUN: %python %S/test_errors.py %s %flang_fc1 -pedantic
+! Check that we get portability warnings for the extensions
+! - exponent-letter 'Q'
+! - matching but non-'E' exponent letter together with kind-param
+
+subroutine s
+ real :: realvar1 = 4.0
+ real :: realvar2 = 4.0D6
+ real :: realvar3 = 4.0_8
+ real :: realvar4 = 4.0E6_4
+ real :: realvar5 = 4.0E6_8
+ !WARNING: nonstandard usage: Q exponent
+ real :: realvar6 = 4.0Q6
+ !WARNING: Explicit kind parameter together with non-'E' exponent letter is not standard
+ real :: realvar7 = 4.0D6_8
+ !WARNING: Explicit kind parameter on real constant disagrees with exponent letter 'd'
+ real :: realvar8 = 4.0D6_4
+end subroutine s