Remove dependency of SILFunction in IRGenOptions

SILFunction::shouldBePreservedForDebugger checks if some optimizations
are enabled to decide whether a function should be preserved so its
accessible form the debugger or not. Some of these settings used to live
only in IRGenOptions making SILFunction depend on IRGenOptions.

(cherry picked from commit 4aec4e7)

Author: augusto2112

include/swift/AST/SILOptions.h

@@ -298,6 +298,10 @@ class SILOptions {
   /// The format used for serializing remarks (default: YAML)
   llvm::remarks::Format OptRecordFormat = llvm::remarks::Format::YAML;
 
+  /// Are there any options that indicate that functions should not be preserved
+  /// for the debugger?
+  bool ShouldFunctionsBePreservedToDebugger = true;
+
   SILOptions() {}
 
   /// Return a hash code of any components from these options that should

lib/Frontend/CompilerInvocation.cpp

@@ -2242,6 +2242,22 @@ void parseExclusivityEnforcementOptions(const llvm::opt::Arg *A,
   }
 }
 
+static std::optional<IRGenLLVMLTOKind>
+ParseLLVMLTOKind(const ArgList &Args, DiagnosticEngine &Diags) {
+  std::optional<IRGenLLVMLTOKind> LLVMLTOKind;
+  if (const Arg *A = Args.getLastArg(options::OPT_lto)) {
+    LLVMLTOKind =
+        llvm::StringSwitch<std::optional<IRGenLLVMLTOKind>>(A->getValue())
+            .Case("llvm-thin", IRGenLLVMLTOKind::Thin)
+            .Case("llvm-full", IRGenLLVMLTOKind::Full)
+            .Default(std::nullopt);
+    if (!LLVMLTOKind)
+      Diags.diagnose(SourceLoc(), diag::error_invalid_arg_value,
+                     A->getAsString(Args), A->getValue());
+  }
+  return LLVMLTOKind;
+}
+
 static bool ParseSILArgs(SILOptions &Opts, ArgList &Args,
                          IRGenOptions &IRGenOpts, const FrontendOptions &FEOpts,
                          const TypeCheckerOptions &TCOpts,
@@ -2629,6 +2645,16 @@ static bool ParseSILArgs(SILOptions &Opts, ArgList &Args,
 
   Opts.NoAllocations = Args.hasArg(OPT_no_allocations);
 
+  // If these optimizations are enabled never preserve functions for the
+  // debugger.
+  Opts.ShouldFunctionsBePreservedToDebugger =
+      !Args.hasArg(OPT_enable_llvm_wme);
+  Opts.ShouldFunctionsBePreservedToDebugger &=
+      !Args.hasArg(OPT_enable_llvm_vfe);
+  if (auto LTOKind = ParseLLVMLTOKind(Args, Diags))
+    Opts.ShouldFunctionsBePreservedToDebugger &=
+        LTOKind.value() == IRGenLLVMLTOKind::None;
+
   return false;
 }
 
@@ -2975,18 +3001,8 @@ static bool ParseIRGenArgs(IRGenOptions &Opts, ArgList &Args,
     }
   }
 
-  if (const Arg *A = Args.getLastArg(options::OPT_lto)) {
-    auto LLVMLTOKind =
-        llvm::StringSwitch<std::optional<IRGenLLVMLTOKind>>(A->getValue())
-            .Case("llvm-thin", IRGenLLVMLTOKind::Thin)
-            .Case("llvm-full", IRGenLLVMLTOKind::Full)
-            .Default(std::nullopt);
-    if (LLVMLTOKind)
-      Opts.LLVMLTOKind = LLVMLTOKind.value();
-    else
-      Diags.diagnose(SourceLoc(), diag::error_invalid_arg_value,
-                     A->getAsString(Args), A->getValue());
-  }
+  if (auto LTOKind = ParseLLVMLTOKind(Args, Diags))
+     Opts.LLVMLTOKind = LTOKind.value();
 
   if (const Arg *A = Args.getLastArg(options::OPT_sanitize_coverage_EQ)) {
     Opts.SanitizeCoverage =

lib/SIL/IR/SILFunction.cpp

@@ -16,7 +16,6 @@
 #include "swift/AST/Availability.h"
 #include "swift/AST/Expr.h"
 #include "swift/AST/GenericEnvironment.h"
-#include "swift/AST/IRGenOptions.h"
 #include "swift/AST/Module.h"
 #include "swift/AST/Stmt.h"
 #include "swift/Basic/OptimizationMode.h"
@@ -943,16 +942,11 @@ bool SILFunction::shouldBePreservedForDebugger() const {
   if (getEffectiveOptimizationMode() != OptimizationMode::NoOptimization)
     return false;
 
-  if (getModule().getASTContext().LangOpts.hasFeature(Feature::Embedded))
+  if (!getModule().getOptions().ShouldFunctionsBePreservedToDebugger)
     return false;
 
-  if (const IRGenOptions *options = getModule().getIRGenOptionsOrNull()) {
-    if (options->WitnessMethodElimination ||
-        options->VirtualFunctionElimination ||
-        options->LLVMLTOKind != IRGenLLVMLTOKind::None) {
-      return false;
-    }
-  }
+  if (getModule().getASTContext().LangOpts.hasFeature(Feature::Embedded))
+    return false;
 
   if (isAvailableExternally())
     return false;