[clang] [flang] [flang][Driver] Accept (and ignore) some gfortran-specific options (PR #165579)
Tarun Prabhu via cfe-commits
cfe-commits at lists.llvm.org
Wed Oct 29 08:36:03 PDT 2025
https://github.com/tarunprabhu updated https://github.com/llvm/llvm-project/pull/165579
>From 95baa7db0f943863c56326453adfb8a0197c4ed6 Mon Sep 17 00:00:00 2001
From: Tarun Prabhu <tarun.prabhu at gmail.com>
Date: Tue, 28 Oct 2025 19:35:27 -0600
Subject: [PATCH] [flang][Driver] Accept (and ignore) some gfortran-specific
options
Enable the clang_ignored_gcc_optimization_f_group in flang. These options are
accepted by clang, but ignored after emitting a warning message. flang's
behavior now mirrors both clang and gfortran.
Fixes #158436
---
clang/include/clang/Driver/Options.td | 3 +-
clang/lib/Driver/ToolChains/Flang.cpp | 8 ++
flang/test/Driver/flang-f-opts.f90 | 125 +++++++++++++++++++++++++-
3 files changed, 132 insertions(+), 4 deletions(-)
diff --git a/clang/include/clang/Driver/Options.td b/clang/include/clang/Driver/Options.td
index cb5cb888c6da7..402cadab53e0e 100644
--- a/clang/include/clang/Driver/Options.td
+++ b/clang/include/clang/Driver/Options.td
@@ -316,7 +316,8 @@ def mno_mpx : Flag<["-"], "mno-mpx">, Group<clang_ignored_legacy_options_Group>;
// Group that ignores all gcc optimizations that won't be implemented
def clang_ignored_gcc_optimization_f_Group : OptionGroup<
- "<clang_ignored_gcc_optimization_f_Group>">, Group<f_Group>, Flags<[Ignored]>;
+ "<clang_ignored_gcc_optimization_f_Group>">,
+ Group<f_Group>, Flags<[Ignored]>, Visibility<[ClangOption, FlangOption]>;
class DiagnosticOpts<string base>
: KeyPathAndMacro<"DiagnosticOpts->", base, "DIAG_"> {}
diff --git a/clang/lib/Driver/ToolChains/Flang.cpp b/clang/lib/Driver/ToolChains/Flang.cpp
index 88bce181d40d2..b1e7643e8fd97 100644
--- a/clang/lib/Driver/ToolChains/Flang.cpp
+++ b/clang/lib/Driver/ToolChains/Flang.cpp
@@ -952,6 +952,14 @@ void Flang::ConstructJob(Compilation &C, const JobAction &JA,
if (const Arg *A = Args.getLastArg(Opt))
D.Diag(diag::warn_drv_invalid_argument_for_flang) << A->getSpelling();
+ // Warn about options that are ignored by flang. These are options that are
+ // accepted by gfortran, but have no equivalent in flang.
+ for (const Arg *A :
+ Args.filtered(options::OPT_clang_ignored_gcc_optimization_f_Group)) {
+ D.Diag(diag::warn_ignored_gcc_optimization) << A->getAsString(Args);
+ A->claim();
+ }
+
const InputInfo &Input = Inputs[0];
types::ID InputType = Input.getType();
diff --git a/flang/test/Driver/flang-f-opts.f90 b/flang/test/Driver/flang-f-opts.f90
index 9ef0abaa176f0..e29d7c1d5e671 100644
--- a/flang/test/Driver/flang-f-opts.f90
+++ b/flang/test/Driver/flang-f-opts.f90
@@ -14,19 +14,21 @@
! RUN: %flang -### -S -fprofile-use=%S %s 2>&1 | FileCheck -check-prefix=CHECK-PROFILE-USE-DIR %s
! CHECK-PROFILE-USE-DIR: "-fprofile-use={{.*}}"
+! ------------------------------------------------------------------------------
! RUN: %flang -### -fbuiltin %s 2>&1 \
! RUN: | FileCheck %s -check-prefix=WARN-BUILTIN
! WARN-BUILTIN: warning: '-fbuiltin' is not valid for Fortran
-
+!
! RUN: %flang -### -fno-builtin %s 2>&1 \
! RUN: | FileCheck %s -check-prefix=WARN-NO-BUILTIN
! WARN-NO-BUILTIN: warning: '-fno-builtin' is not valid for Fortran
-
+!
! RUN: %flang -### -fbuiltin -fno-builtin %s 2>&1 \
! RUN: | FileCheck %s -check-prefix=WARN-BUILTIN-MULTIPLE
! WARN-BUILTIN-MULTIPLE: warning: '-fbuiltin' is not valid for Fortran
! WARN-BUILTIN-MULTIPLE: warning: '-fno-builtin' is not valid for Fortran
-
+!
+!-------------------------------------------------------------------------------
! When emitting an error with a suggestion, ensure that the diagnostic message
! uses '-Xflang' instead of '-Xclang'. This is typically emitted when an option
! that is available for `flang -fc1` is passed to `flang`. We use -complex-range
@@ -43,3 +45,120 @@
! RUN: | FileCheck %s -check-prefix UNKNOWN-NO-SUGGEST
!
! UNKNOWN-NO-SUGGEST: error: unknown argument: '-not-an-option'{{$}}
+!
+!-------------------------------------------------------------------------------
+! The options in the command below are gfortran-specific optimization flags that
+! are accepted by flang's driver but ignored. Check that the correct warning
+! message is displayed when these are used.
+!
+! RUN: %flang -### %s \
+! RUN: -finline-limit=1000 \
+! RUN: -finline-limit \
+! RUN: -fexpensive-optimizations \
+! RUN: -fno-expensive-optimizations \
+! RUN: -fno-defer-pop \
+! RUN: -fkeep-inline-functions \
+! RUN: -fno-keep-inline-functions \
+! RUN: -freorder-blocks \
+! RUN: -ffloat-store \
+! RUN: -fgcse \
+! RUN: -fivopts \
+! RUN: -fprefetch-loop-arrays \
+! RUN: -fprofile-correction \
+! RUN: -fprofile-values \
+! RUN: -fschedule-insns \
+! RUN: -fsignaling-nans \
+! RUN: -fstrength-reduce \
+! RUN: -ftracer \
+! RUN: -funroll-all-loops \
+! RUN: -funswitch-loops \
+! RUN: -falign-labels \
+! RUN: -falign-labels=100 \
+! RUN: -falign-jumps \
+! RUN: -falign-jumps=100 \
+! RUN: -fbranch-count-reg \
+! RUN: -fcaller-saves \
+! RUN: -fno-default-inline \
+! RUN: -fgcse-after-reload \
+! RUN: -fgcse-las \
+! RUN: -fgcse-sm \
+! RUN: -fipa-cp \
+! RUN: -finline-functions-called-once \
+! RUN: -fmodulo-sched \
+! RUN: -fmodulo-sched-allow-regmoves \
+! RUN: -fpeel-loops \
+! RUN: -frename-registers \
+! RUN: -fschedule-insns2 \
+! RUN: -fsingle-precision-constant \
+! RUN: -funsafe-loop-optimizations \
+! RUN: -fuse-linker-plugin \
+! RUN: -fvect-cost-model \
+! RUN: -fvariable-expansion-in-unroller \
+! RUN: -fweb \
+! RUN: -fwhole-program \
+! RUN: -fcaller-saves \
+! RUN: -freorder-blocks \
+! RUN: -ffat-lto-objects \
+! RUN: -fmerge-constants \
+! RUN: -finline-small-functions \
+! RUN: -ftree-dce \
+! RUN: -ftree-ter \
+! RUN: -ftree-vrp \
+! RUN: -fno-devirtualize \
+! RUN: -fno-devirtualize-speculatively 2>&1 \
+! RUN: | FileCheck --check-prefix=CHECK-WARNING %s
+! CHECK-WARNING-DAG: optimization flag '-finline-limit=1000' is not supported
+! CHECK-WARNING-DAG: optimization flag '-finline-limit' is not supported
+! CHECK-WARNING-DAG: optimization flag '-fexpensive-optimizations' is not supported
+! CHECK-WARNING-DAG: optimization flag '-fno-expensive-optimizations' is not supported
+! CHECK-WARNING-DAG: optimization flag '-fno-defer-pop' is not supported
+! CHECK-WARNING-DAG: optimization flag '-fkeep-inline-functions' is not supported
+! CHECK-WARNING-DAG: optimization flag '-fno-keep-inline-functions' is not supported
+! CHECK-WARNING-DAG: optimization flag '-freorder-blocks' is not supported
+! CHECK-WARNING-DAG: optimization flag '-ffloat-store' is not supported
+! CHECK-WARNING-DAG: optimization flag '-fgcse' is not supported
+! CHECK-WARNING-DAG: optimization flag '-fivopts' is not supported
+! CHECK-WARNING-DAG: optimization flag '-fprefetch-loop-arrays' is not supported
+! CHECK-WARNING-DAG: optimization flag '-fprofile-correction' is not supported
+! CHECK-WARNING-DAG: optimization flag '-fprofile-values' is not supported
+! CHECK-WARNING-DAG: optimization flag '-fschedule-insns' is not supported
+! CHECK-WARNING-DAG: optimization flag '-fsignaling-nans' is not supported
+! CHECK-WARNING-DAG: optimization flag '-fstrength-reduce' is not supported
+! CHECK-WARNING-DAG: optimization flag '-ftracer' is not supported
+! CHECK-WARNING-DAG: optimization flag '-funroll-all-loops' is not supported
+! CHECK-WARNING-DAG: optimization flag '-funswitch-loops' is not supported
+! CHECK-WARNING-DAG: optimization flag '-falign-labels' is not supported
+! CHECK-WARNING-DAG: optimization flag '-falign-labels=100' is not supported
+! CHECK-WARNING-DAG: optimization flag '-falign-jumps' is not supported
+! CHECK-WARNING-DAG: optimization flag '-falign-jumps=100' is not supported
+! CHECK-WARNING-DAG: optimization flag '-fbranch-count-reg' is not supported
+! CHECK-WARNING-DAG: optimization flag '-fcaller-saves' is not supported
+! CHECK-WARNING-DAG: optimization flag '-fno-default-inline' is not supported
+! CHECK-WARNING-DAG: optimization flag '-fgcse-after-reload' is not supported
+! CHECK-WARNING-DAG: optimization flag '-fgcse-las' is not supported
+! CHECK-WARNING-DAG: optimization flag '-fgcse-sm' is not supported
+! CHECK-WARNING-DAG: optimization flag '-fipa-cp' is not supported
+! CHECK-WARNING-DAG: optimization flag '-finline-functions-called-once' is not supported
+! CHECK-WARNING-DAG: optimization flag '-fmodulo-sched' is not supported
+! CHECK-WARNING-DAG: optimization flag '-fmodulo-sched-allow-regmoves' is not supported
+! CHECK-WARNING-DAG: optimization flag '-fpeel-loops' is not supported
+! CHECK-WARNING-DAG: optimization flag '-frename-registers' is not supported
+! CHECK-WARNING-DAG: optimization flag '-fschedule-insns2' is not supported
+! CHECK-WARNING-DAG: optimization flag '-fsingle-precision-constant' is not supported
+! CHECK-WARNING-DAG: optimization flag '-funsafe-loop-optimizations' is not supported
+! CHECK-WARNING-DAG: optimization flag '-fuse-linker-plugin' is not supported
+! CHECK-WARNING-DAG: optimization flag '-fvect-cost-model' is not supported
+! CHECK-WARNING-DAG: optimization flag '-fvariable-expansion-in-unroller' is not supported
+! CHECK-WARNING-DAG: optimization flag '-fweb' is not supported
+! CHECK-WARNING-DAG: optimization flag '-fwhole-program' is not supported
+! CHECK-WARNING-DAG: optimization flag '-fcaller-saves' is not supported
+! CHECK-WARNING-DAG: optimization flag '-freorder-blocks' is not supported
+! CHECK-WARNING-DAG: optimization flag '-fmerge-constants' is not supported
+! CHECK-WARNING-DAG: optimization flag '-finline-small-functions' is not supported
+! CHECK-WARNING-DAG: optimization flag '-ftree-dce' is not supported
+! CHECK-WARNING-DAG: optimization flag '-ftree-ter' is not supported
+! CHECK-WARNING-DAG: optimization flag '-ftree-vrp' is not supported
+! CHECK-WARNING-DAG: optimization flag '-fno-devirtualize' is not supported
+! CHECK-WARNING-DAG: optimization flag '-fno-devirtualize-speculatively' is not supported
+!
+! ------------------------------------------------------------------------------
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