CodeGen: support static linking for libclosure (#125384)

When building on Windows, dealing with the BlocksRuntime is slightly
more complicated. As we are not guaranteed a formward declaration for
the blocks runtime ABI symbols, we may generate the declarations for
them. In order to properly link against the well-known types, we always
annotated them as `__declspec(dllimport)`. This would require the
dynamic linking of the blocks runtime under all conditions. However,
this is the only the only possible way to us the library. We may be
building a fully sealed (static) executable. In such a case, the well
known symbols should not be marked as `dllimport` as they are assumed to
be statically available with the static linking to the BlocksRuntime.

Introduce a new driver/cc1 option `-static-libclosure` which mirrors the
myriad of similar options (`-static-libgcc`, `-static-libstdc++`,
-static-libsan`, etc).

1 files changed, 5 insertions, 0 deletions

diff --git a/clang/lib/Frontend/CompilerInvocation.cpp b/clang/lib/Frontend/CompilerInvocation.cpp
index 95d3eac7..8b1bbf1 100644
--- a/clang/lib/Frontend/CompilerInvocation.cpp
+++ b/clang/lib/Frontend/CompilerInvocation.cpp
@@ -1843,6 +1843,9 @@ void CompilerInvocationBase::GenerateCodeGenArgs(const CodeGenOptions &Opts,
     GenerateArg(Consumer, OPT_fno_finite_loops);
     break;
   }
+
+  if (Opts.StaticClosure)
+    GenerateArg(Consumer, OPT_static_libclosure);
 }
 
 bool CompilerInvocation::ParseCodeGenArgs(CodeGenOptions &Opts, ArgList &Args,
@@ -2330,6 +2333,8 @@ bool CompilerInvocation::ParseCodeGenArgs(CodeGenOptions &Opts, ArgList &Args,
   if (!Opts.EmitIEEENaNCompliantInsts && !LangOptsRef.NoHonorNaNs)
     Diags.Report(diag::err_drv_amdgpu_ieee_without_no_honor_nans);
 
+  Opts.StaticClosure = Args.hasArg(options::OPT_static_libclosure);
+
   return Diags.getNumErrors() == NumErrorsBefore;
 }