[clang][WebAssembly] Pass `-Wl,-no-type-check` through to the MC layer

[sbc100]

Summary

I took as an example the -Wa,--noexecstack clang flag that maps down
to -cc1 -mnoexecstack.

See https://github.com/llvm/llvm-project/issues/56935

[sbc100]

Work in progress -- still needs a test.

[MaskRay]

Test?

And we should not have llvm::dbgs() << "Main " << Opts.NoTypeCheck << "\n"; by default.

[sbc100]

In D131217#3701363, @MaskRay wrote:

Test?

And we should not have llvm::dbgs() << "Main " << Opts.NoTypeCheck << "\n"; by default.

Sorry, as as said above "Work in progress -- still needs a test."

[sbc100]

• remove debugging

[sbc100]

ptal

[sbc100]

add test

[sbc100]

improve test

[dschuff]

This looks good to me from the wasm perspective

clang/include/clang/Basic/CodeGenOptions.def

 CODEGENOPT(MergeFunctions    , 1, 0) ///< Set when -fmerge-functions is enabled.
 CODEGENOPT(NoCommon          , 1, 0) ///< Set when -fno-common or C++ is enabled.
 CODEGENOPT(NoDwarfDirectoryAsm , 1, 0) ///< Set when -fno-dwarf-directory-asm is
                                        ///< enabled.
 CODEGENOPT(NoExecStack       , 1, 0) ///< Set when -Wa,--noexecstack is enabled.
 CODEGENOPT(FatalWarnings     , 1, 0) ///< Set when -Wa,--fatal-warnings is
                                      ///< enabled.
 CODEGENOPT(NoWarn            , 1, 0) ///< Set when -Wa,--no-warn is enabled.
+CODEGENOPT(NoTypeCheck       , 1, 0) ///< Set when -Wa,--no-type-check is enabled.
 CODEGENOPT(MisExpect         , 1, 0) ///< Set when -Wmisexpect is enabled
 CODEGENOPT(EnableSegmentedStacks , 1, 0) ///< Set when -fsplit-stack is enabled.
 CODEGENOPT(NoInlineLineTables, 1, 0) ///< Whether debug info should contain
                                      ///< inline line tables.
 CODEGENOPT(StackClashProtector, 1, 0) ///< Set when -fstack-clash-protection is enabled.
 CODEGENOPT(NoImplicitFloat   , 1, 0) ///< Set when -mno-implicit-float is enabled.
 CODEGENOPT(NullPointerIsValid , 1, 0) ///< Assume Null pointer deference is defined.
 CODEGENOPT(OpenCLCorrectlyRoundedDivSqrt, 1, 0) ///< -cl-fp32-correctly-rounded-divide-sqrt

clang/include/clang/Driver/Options.td

 def mrelax_relocations : Flag<["--"], "mrelax-relocations">,
     HelpText<"Use relaxable elf relocations">,
     MarshallingInfoFlag<CodeGenOpts<"RelaxELFRelocations">>;
 def msave_temp_labels : Flag<["-"], "msave-temp-labels">,
   HelpText<"Save temporary labels in the symbol table. "
            "Note this may change .s semantics and shouldn't generally be used "
            "on compiler-generated code.">,
   MarshallingInfoFlag<CodeGenOpts<"SaveTempLabels">>;
+def mno_type_check : Flag<["-"], "mno-type-check">,
+  HelpText<"Don't perform type checking of the assembly code (wasm only)">,
+  MarshallingInfoFlag<CodeGenOpts<"NoTypeCheck">>;
 def fno_math_builtin : Flag<["-"], "fno-math-builtin">,
   HelpText<"Disable implicit builtin knowledge of math functions">,
   MarshallingInfoFlag<LangOpts<"NoMathBuiltin">>;
 def fno_use_ctor_homing: Flag<["-"], "fno-use-ctor-homing">,
     HelpText<"Don't use constructor homing for debug info">;
 def fuse_ctor_homing: Flag<["-"], "fuse-ctor-homing">,
     HelpText<"Use constructor homing if we are using limited debug info already">;
 

clang/lib/Driver/ToolChains/Clang.cpp

for (StringRef Value : A->getValues()) {
 
       if (C.getDefaultToolChain().getTriple().isOSBinFormatCOFF() &&
           Value == "-mbig-obj")
         continue; // LLVM handles bigobj automatically
 
       switch (C.getDefaultToolChain().getArch()) {
       default:
         break;
+      case llvm::Triple::wasm32:
+      case llvm::Triple::wasm64:
+        if (Value == "--no-type-check") {
+          CmdArgs.push_back("-mno-type-check");
+          continue;
+        }
+        break;
       case llvm::Triple::thumb:
       case llvm::Triple::thumbeb:
       case llvm::Triple::arm:
       case llvm::Triple::armeb:
         if (Value.startswith("-mimplicit-it=")) {
           // Only store the value; the last value set takes effect.
           ImplicitIt = Value.split("=").second;
           if (CheckARMImplicitITArg(ImplicitIt))

clang/test/Driver/notypecheck.s

+# REQUIRES: webassembly-registered-target
+
+# RUN: %clang -### %s -c -o tmp.o -target wasm32-unknown-unknown -Wa,--no-type-check 2>&1 | FileCheck %s
+# CHECK: "-cc1as" {{.*}} "-mno-type-check"
+
+# Verify that without -Wa,--no-type-check the assembler will error out
+# RUN: not %clang %s -c -o tmp.o -target wasm32-unknown-unknown 2>&1 | FileCheck --check-prefix=ERROR %s
+# ERROR: error: popped i64, expected i32
+
+foo:
+  .functype  foo () -> (i32)
+  i64.const 42
+  end_function

clang/tools/driver/cc1as_main.cpp

struct AssemblerInvocation {
   /// @}
   /// @name Assembler Options
   /// @{
 
   unsigned RelaxAll : 1;
   unsigned NoExecStack : 1;
   unsigned FatalWarnings : 1;
   unsigned NoWarn : 1;
+  unsigned NoTypeCheck : 1;
   unsigned IncrementalLinkerCompatible : 1;
   unsigned EmbedBitcode : 1;
 
   /// Whether to emit DWARF unwind info.
   EmitDwarfUnwindType EmitDwarfUnwind;
 
   /// The name of the relocation model to use.
   std::string RelocationModel;
AssemblerInvocation() {
     OutputType = FT_Asm;
     OutputAsmVariant = 0;
     ShowInst = 0;
     ShowEncoding = 0;
     RelaxAll = 0;
     NoExecStack = 0;
     FatalWarnings = 0;
     NoWarn = 0;
+    NoTypeCheck = 0;
     IncrementalLinkerCompatible = 0;
     Dwarf64 = 0;
     DwarfVersion = 0;
     EmbedBitcode = 0;
     EmitDwarfUnwind = EmitDwarfUnwindType::Default;
   }
 
   static bool CreateFromArgs(AssemblerInvocation &Res,
bool AssemblerInvocation::CreateFromArgs(AssemblerInvocation &Opts,
   Opts.ShowEncoding = Args.hasArg(OPT_show_encoding);
   Opts.ShowInst = Args.hasArg(OPT_show_inst);
 
   // Assemble Options
   Opts.RelaxAll = Args.hasArg(OPT_mrelax_all);
   Opts.NoExecStack = Args.hasArg(OPT_mno_exec_stack);
   Opts.FatalWarnings = Args.hasArg(OPT_massembler_fatal_warnings);
   Opts.NoWarn = Args.hasArg(OPT_massembler_no_warn);
+  Opts.NoTypeCheck = Args.hasArg(OPT_mno_type_check);
   Opts.RelocationModel =
       std::string(Args.getLastArgValue(OPT_mrelocation_model, "pic"));
   Opts.TargetABI = std::string(Args.getLastArgValue(OPT_target_abi));
   Opts.IncrementalLinkerCompatible =
       Args.hasArg(OPT_mincremental_linker_compatible);
   Opts.SymbolDefs = Args.getAllArgValues(OPT_defsym);
 
   // EmbedBitcode Option. If -fembed-bitcode is enabled, set the flag.
static bool ExecuteAssemblerImpl(AssemblerInvocation &Opts,
   std::unique_ptr<MCInstrInfo> MCII(TheTarget->createMCInstrInfo());
   assert(MCII && "Unable to create instruction info!");
 
   raw_pwrite_stream *Out = FDOS.get();
   std::unique_ptr<buffer_ostream> BOS;
 
   MCOptions.MCNoWarn = Opts.NoWarn;
   MCOptions.MCFatalWarnings = Opts.FatalWarnings;
+  MCOptions.MCNoTypeCheck = Opts.NoTypeCheck;
   MCOptions.ABIName = Opts.TargetABI;
 
   // FIXME: There is a bit of code duplication with addPassesToEmitFile.
   if (Opts.OutputType == AssemblerInvocation::FT_Asm) {
     MCInstPrinter *IP = TheTarget->createMCInstPrinter(
         llvm::Triple(Opts.Triple), Opts.OutputAsmVariant, *MAI, *MCII, *MRI);
 
     std::unique_ptr<MCCodeEmitter> CE;