[Flang][Driver] Enable the -B option

[kiranchandramohan]

The option provides the search prefix for executables, libraries and data files.

The option is implemented in the common portion of the Driver and only needs to be enabled in Flang. Test added is a copy of the relevant test in Clang.

[llvmbot]

@llvm/pr-subscribers-clang-driver
@llvm/pr-subscribers-flang-driver

@llvm/pr-subscribers-clang

Author: Kiran Chandramohan (kiranchandramohan)

Changes

The option provides the search prefix for executables, libraries and data files.

The option is implemented in the common portion of the Driver and only needs to be enabled in Flang. Test added is a copy of the relevant test in Clang.

---

Full diff: https://github.com/llvm/llvm-project/pull/109965.diff

6 Files Affected:

• (modified) clang/include/clang/Driver/Options.td (+1)
• (added) flang/test/Driver/B-opt.c (+12)
• (added) flang/test/Driver/Inputs/B_opt_tree/dir1/i386-unknown-linux-ld ()
• (added) flang/test/Driver/Inputs/B_opt_tree/dir1/ld ()
• (added) flang/test/Driver/Inputs/B_opt_tree/dir2/ld ()
• (added) flang/test/Driver/Inputs/B_opt_tree/dir3/prefix-ld ()

diff --git a/clang/include/clang/Driver/Options.td b/clang/include/clang/Driver/Options.td
index 002f60350543d9..020f4f92e8735a 100644
--- a/clang/include/clang/Driver/Options.td
+++ b/clang/include/clang/Driver/Options.td
@@ -816,6 +816,7 @@ def _DASH_DASH : Option<["--"], "", KIND_REMAINING_ARGS>,
 def A : JoinedOrSeparate<["-"], "A">, Flags<[RenderJoined]>,
   Group<gfortran_Group>;
 def B : JoinedOrSeparate<["-"], "B">, MetaVarName<"<prefix>">,
+    Visibility<[ClangOption, FlangOption]>,
     HelpText<"Search $prefix$file for executables, libraries, and data files. "
     "If $prefix is a directory, search $prefix/$file">;
 def gcc_install_dir_EQ : Joined<["--"], "gcc-install-dir=">,
diff --git a/flang/test/Driver/B-opt.c b/flang/test/Driver/B-opt.c
new file mode 100644
index 00000000000000..16f3b87aee65e6
--- /dev/null
+++ b/flang/test/Driver/B-opt.c
@@ -0,0 +1,12 @@
+// Check -B driver option.
+
+/// Target triple prefix is not detected for -B.
+// RUN: %flang %s -### -o %t.o -target i386-unknown-linux \
+// RUN:     -B %S/Inputs/B_opt_tree/dir1 -fuse-ld=ld 2>&1 \
+// RUN:   | FileCheck --check-prefix=CHECK-B-OPT-TRIPLE %s
+// CHECK-B-OPT-TRIPLE-NOT: "{{.*}}/Inputs/B_opt_tree/dir1{{/|\\\\}}i386-unknown-linux-ld"
+//
+// RUN: %flang %s -### -o %t.o -target i386-unknown-linux \
+// RUN:     -B %S/Inputs/B_opt_tree/dir2 -fuse-ld=ld 2>&1 \
+// RUN:   | FileCheck --check-prefix=CHECK-B-OPT-DIR %s
+// CHECK-B-OPT-DIR: "{{.*}}/Inputs/B_opt_tree/dir2{{/|\\\\}}ld" 
diff --git a/flang/test/Driver/Inputs/B_opt_tree/dir1/i386-unknown-linux-ld b/flang/test/Driver/Inputs/B_opt_tree/dir1/i386-unknown-linux-ld
new file mode 100755
index 00000000000000..e69de29bb2d1d6
diff --git a/flang/test/Driver/Inputs/B_opt_tree/dir1/ld b/flang/test/Driver/Inputs/B_opt_tree/dir1/ld
new file mode 100755
index 00000000000000..e69de29bb2d1d6
diff --git a/flang/test/Driver/Inputs/B_opt_tree/dir2/ld b/flang/test/Driver/Inputs/B_opt_tree/dir2/ld
new file mode 100755
index 00000000000000..e69de29bb2d1d6
diff --git a/flang/test/Driver/Inputs/B_opt_tree/dir3/prefix-ld b/flang/test/Driver/Inputs/B_opt_tree/dir3/prefix-ld
new file mode 100755
index 00000000000000..e69de29bb2d1d6

[github-actions]

✅ With the latest revision this PR passed the C/C++ code formatter.

[tblah]

LGTM

[tblah]

It is a bit surprising that we take the first version of -B. Most things use the last argument.

But if this is just copied from clang, it is better to mimic clang's behavior, and I don't think this would be safe to fix in clang because it could break existing build scripts.

[kiranchandramohan]

That is a good spot.

This seems to be the behaviour for similar options like -I. There is probably a difference between overriding options (last one wins) and appending options (the latter paths are in the search patch but will be used only after searching the first ones).

[MaskRay]

Use --target=

-target has been deprecated since around clang 3.4

[kiranchandramohan]

Thanks. Done. Modified tests for both drivers.

[kiranchandramohan]

@MaskRay Is it OK to land this?

[banach-space]

LGTM, thanks!

Looks like you've addressed all comments, so feel free to land it.