[clang] 81d82ca - [flang] Treat pre-processed input as fixed (#117563)

[via cfe-commits]

Author: macurtis-amd
Date: 2024-12-03T06:59:57-06:00
New Revision: 81d82cac8c4cbd006bf991fd7380de2d72858d1c

URL: https://github.com/llvm/llvm-project/commit/81d82cac8c4cbd006bf991fd7380de2d72858d1c
DIFF: https://github.com/llvm/llvm-project/commit/81d82cac8c4cbd006bf991fd7380de2d72858d1c.diff

LOG: [flang] Treat pre-processed input as fixed (#117563)

Fixes an issue introduced by

9fb2db1e1f42 [flang] Retain spaces when preprocessing fixed-form source

Where flang -fc1 fails to parse preprocessor output because it now
remains in fixed form.

Added: 
    flang/test/Driver/pp-fixed-form.f90

Modified: 
    clang/lib/Driver/ToolChains/Flang.cpp

Removed: 
    


################################################################################
diff  --git a/clang/lib/Driver/ToolChains/Flang.cpp b/clang/lib/Driver/ToolChains/Flang.cpp
index 8c18c88fbde7f7..72c0787d7df993 100644
--- a/clang/lib/Driver/ToolChains/Flang.cpp
+++ b/clang/lib/Driver/ToolChains/Flang.cpp
@@ -777,6 +777,13 @@ void Flang::ConstructJob(Compilation &C, const JobAction &JA,
 
   addFortranDialectOptions(Args, CmdArgs);
 
+  // 'flang -E' always produces output that is suitable for use as fixed form
+  // Fortran. However it is only valid free form source if the original is also
+  // free form.
+  if (InputType == types::TY_PP_Fortran &&
+      !Args.getLastArg(options::OPT_ffixed_form, options::OPT_ffree_form))
+    CmdArgs.push_back("-ffixed-form");
+
   handleColorDiagnosticsArgs(D, Args, CmdArgs);
 
   // LTO mode is parsed by the Clang driver library.

diff  --git a/flang/test/Driver/pp-fixed-form.f90 b/flang/test/Driver/pp-fixed-form.f90
new file mode 100644
index 00000000000000..4695da78763ae5
--- /dev/null
+++ b/flang/test/Driver/pp-fixed-form.f90
@@ -0,0 +1,19 @@
+!RUN: %flang -save-temps -### %S/Inputs/free-form-test.f90  2>&1 | FileCheck %s --check-prefix=FREE
+FREE:       "-fc1" {{.*}} "-o" "free-form-test.i" {{.*}} "-x" "f95-cpp-input" "{{.*}}/free-form-test.f90"
+FREE-NEXT:  "-fc1" {{.*}} "-ffixed-form" {{.*}} "-x" "f95" "free-form-test.i"
+
+!RUN: %flang -save-temps -### %S/Inputs/fixed-form-test.f  2>&1 | FileCheck %s --check-prefix=FIXED
+FIXED:      "-fc1" {{.*}} "-o" "fixed-form-test.i" {{.*}} "-x" "f95-cpp-input" "{{.*}}/fixed-form-test.f"
+FIXED-NEXT: "-fc1" {{.*}} "-ffixed-form" {{.*}} "-x" "f95" "fixed-form-test.i"
+
+!RUN: %flang -save-temps -### -ffree-form %S/Inputs/free-form-test.f90  2>&1 | FileCheck %s --check-prefix=FREE-FLAG
+FREE-FLAG:           "-fc1" {{.*}} "-o" "free-form-test.i" {{.*}} "-x" "f95-cpp-input" "{{.*}}/free-form-test.f90"
+FREE-FLAG-NEXT:      "-fc1" {{.*}} "-emit-llvm-bc" "-ffree-form"
+FREE-FLAG-NOT:       "-ffixed-form"
+FREE-FLAG-SAME:      "-x" "f95" "free-form-test.i"
+
+!RUN: %flang -save-temps -### -ffixed-form %S/Inputs/fixed-form-test.f  2>&1 | FileCheck %s --check-prefix=FIXED-FLAG
+FIXED-FLAG:          "-fc1" {{.*}} "-o" "fixed-form-test.i" {{.*}} "-x" "f95-cpp-input" "{{.*}}/fixed-form-test.f"
+FIXED-FLAG-NEXT:     "-fc1" {{.*}} "-emit-llvm-bc" "-ffixed-form"
+FIXED-FLAG-NOT:      "-ffixed-form"
+FIXED-FLAG-SAME:     "-x" "f95" "fixed-form-test.i"