[clang] [clang-cl] Allow a colon after /Fo option (PR #87209)

[Russell Greene via cfe-commits]

https://github.com/russelltg created https://github.com/llvm/llvm-project/pull/87209

Modeled after https://github.com/llvm/llvm-project/commit/8513a681f7d8d1188706762e712168aebc3119dd#

According to https://learn.microsoft.com/en-us/cpp/build/reference/fo-object-file-name?view=msvc-170, `/Fo` accepts a trailing-colon variant. This is also tested in practice. This allows clang-cl to parse this.

I just copied one of the existing tests, let me know if this is not the best way to do this. I tested that the test does not pass beofre the Options.td change, and that it does after.

See also #46065 

>From dff943cd29a80a88221bf9ffc37282d4fcaf384b Mon Sep 17 00:00:00 2001
From: Russell Greene <russell at shotover.com>
Date: Sun, 31 Mar 2024 17:46:22 -0600
Subject: [PATCH] [clang-cl] Allow a colon after /Fo option

---
 clang/include/clang/Driver/Options.td | 1 +
 clang/test/Driver/cl-outputs.c        | 3 +++
 2 files changed, 4 insertions(+)

diff --git a/clang/include/clang/Driver/Options.td b/clang/include/clang/Driver/Options.td
index 04eb87f0d5d1aa..f5289fb00c895e 100644
--- a/clang/include/clang/Driver/Options.td
+++ b/clang/include/clang/Driver/Options.td
@@ -8313,6 +8313,7 @@ def _SLASH_Fi : CLCompileJoined<"Fi">,
 def _SLASH_Fo : CLCompileJoined<"Fo">,
   HelpText<"Set output object file (with /c)">,
   MetaVarName<"<file or dir/>">;
+def _SLASH_Fo_COLON : CLCompileJoined<"Fo:">, Alias<_SLASH_Fo>;
 def _SLASH_guard : CLJoined<"guard:">,
   HelpText<"Enable Control Flow Guard with /guard:cf, or only the table with /guard:cf,nochecks. "
            "Enable EH Continuation Guard with /guard:ehcont">;
diff --git a/clang/test/Driver/cl-outputs.c b/clang/test/Driver/cl-outputs.c
index 07ff43642a62be..4d58f0fb548b57 100644
--- a/clang/test/Driver/cl-outputs.c
+++ b/clang/test/Driver/cl-outputs.c
@@ -301,5 +301,8 @@
 // RUN: %clang_cl -fdebug-compilation-dir=. /Z7 /Foa.obj -### -- %s 2>&1 | FileCheck -check-prefix=RELATIVE_OBJPATH1 %s
 // RELATIVE_OBJPATH1: "-object-file-name=a.obj"
 
+// RUN: %clang_cl -fdebug-compilation-dir=. /Z7 /Fo:a.obj -### -- %s 2>&1 | FileCheck -check-prefix=RELATIVE_OBJPATH1_COLON %s
+// RELATIVE_OBJPATH1_COLON: "-object-file-name=a.obj"
+
 // RUN: %clang_cl -fdebug-compilation-dir=. /Z7 /Fofoo/a.obj -### -- %s 2>&1 | FileCheck -check-prefix=RELATIVE_OBJPATH2 %s
 // RELATIVE_OBJPATH2: "-object-file-name=foo\\a.obj"