[flang][driver] Disallow non-existent input files in the frontend driver
This patch adds a check that verifies that the input file used when
calling the frontend driver (i.e. `flang-new -fc1`) actually exists.
This was not required for the compiler driver, `flang-new`, as that's
already handled in libclangDriver.
Once all input/output file management is moved to the driver, we should
also check that for input from `stdin` the corresponding file descriptor
was successfully acquired.
This patch also makes sure that the default action in the frontend is
`ParseSyntaxOnly`. This is consistent with Clang. Before this change
`flang-new -fc1` would do nothing, which makes testing changes like the
one introduced here a bit tricky.
Reviewed By: SouraVX
Differential Revision: https://reviews.llvm.org/D95127
GitOrigin-RevId: 760e6c4ce58324856d8f105b37bb974564e0f170
diff --git a/lib/Frontend/CompilerInvocation.cpp b/lib/Frontend/CompilerInvocation.cpp
index b34b47a..5077d06 100644
--- a/lib/Frontend/CompilerInvocation.cpp
+++ b/lib/Frontend/CompilerInvocation.cpp
@@ -84,6 +84,10 @@
static InputKind ParseFrontendArgs(FrontendOptions &opts,
llvm::opt::ArgList &args, clang::DiagnosticsEngine &diags) {
+
+ // By default the frontend driver creates a ParseSyntaxOnly action.
+ opts.programAction_ = ParseSyntaxOnly;
+
// Identify the action (i.e. opts.ProgramAction)
if (const llvm::opt::Arg *a =
args.getLastArg(clang::driver::options::OPT_Action_Group)) {
diff --git a/lib/Frontend/FrontendAction.cpp b/lib/Frontend/FrontendAction.cpp
index 1a403bb..027024b 100644
--- a/lib/Frontend/FrontendAction.cpp
+++ b/lib/Frontend/FrontendAction.cpp
@@ -11,7 +11,9 @@
#include "flang/Frontend/FrontendActions.h"
#include "flang/Frontend/FrontendOptions.h"
#include "flang/FrontendTool/Utils.h"
+#include "clang/Basic/DiagnosticFrontend.h"
#include "llvm/Support/Errc.h"
+#include "llvm/Support/VirtualFileSystem.h"
using namespace Fortran::frontend;
@@ -31,6 +33,30 @@
CompilerInstance &ci, const FrontendInputFile &realInput) {
FrontendInputFile input(realInput);
+
+ // Return immediately if the input file does not exist or is not a file. Note
+ // that we cannot check this for input from stdin.
+ if (input.file() != "-") {
+ if (!llvm::sys::fs::is_regular_file(input.file())) {
+ // Create an diagnostic ID to report
+ unsigned diagID;
+ if (llvm::vfs::getRealFileSystem()->exists(input.file())) {
+ ci.diagnostics().Report(clang::diag::err_fe_error_reading)
+ << input.file();
+ diagID = ci.diagnostics().getCustomDiagID(
+ clang::DiagnosticsEngine::Error, "%0 is not a regular file");
+ } else {
+ diagID = ci.diagnostics().getCustomDiagID(
+ clang::DiagnosticsEngine::Error, "%0 does not exist");
+ }
+
+ // Report the diagnostic and return
+ ci.diagnostics().Report(diagID) << input.file();
+ BeginSourceFileCleanUp(*this, ci);
+ return false;
+ }
+ }
+
assert(!instance_ && "Already processing a source file!");
assert(!realInput.IsEmpty() && "Unexpected empty filename!");
set_currentInput(realInput);
diff --git a/test/Flang-Driver/missing-input.f90 b/test/Flang-Driver/missing-input.f90
index 5e46395..962b304 100644
--- a/test/Flang-Driver/missing-input.f90
+++ b/test/Flang-Driver/missing-input.f90
@@ -1,5 +1,31 @@
-! RUN: not %flang-new 2>&1 | FileCheck %s
-
! REQUIRES: new-flang-driver
-! CHECK: flang-new: error: no input files
+! Test the behaviour of the driver when input is missing or is invalid. Note
+! that with the compiler driver (flang-new), the input _has_ to be specified.
+! Indeed, the driver decides what "job/command" to create based on the input
+! file's extension. No input file means that it doesn't know what to do
+! (compile? preprocess? link?). The frontend driver (flang-new -fc1) simply
+! assumes that "no explicit input == read from stdin"
+
+!--------------------------
+! FLANG DRIVER (flang-new)
+!--------------------------
+! RUN: not %flang-new 2>&1 | FileCheck %s --check-prefix=FLANG-NO-FILE
+! RUN: not %flang-new %t 2>&1 | FileCheck %s --check-prefix=FLANG-NONEXISTENT-FILE
+
+!-----------------------------------------
+! FLANG FRONTEND DRIVER (flang-new -fc1)
+!-----------------------------------------
+! RUN: not %flang-new -fc1 %t 2>&1 | FileCheck %s --check-prefix=FLANG-FC1-NONEXISTENT-FILE
+! RUN: not %flang-new -fc1 %S 2>&1 | FileCheck %s --check-prefix=FLANG-FC1-DIR
+
+!-----------------------
+! EXPECTED OUTPUT
+!-----------------------
+! FLANG-NO-FILE: flang-new: error: no input files
+
+! FLANG-NONEXISTENT-FILE: flang-new: error: no such file or directory: {{.*}}
+! FLANG-NONEXISTENT-FILE: flang-new: error: no input files
+
+! FLANG-FC1-NONEXISTENT-FILE: error: {{.*}} does not exist
+! FLANG-FC1-DIR: error: {{.*}} is not a regular file
