[clang][modules] Serialize `CodeGenOptions` (#146422)

Some `LangOptions` duplicate their `CodeGenOptions` counterparts. My
understanding is that this was done solely because some infrastructure
(like preprocessor initialization, serialization, module compatibility
checks, etc.) were only possible/convenient for `LangOptions`. This PR
implements the missing support for `CodeGenOptions`, which makes it
possible to remove some duplicate `LangOptions` fields and simplify the
logic. Motivated by https://github.com/llvm/llvm-project/pull/146342.

1 files changed, 18 insertions, 19 deletions

diff --git a/clang/lib/Frontend/CompilerInvocation.cpp b/clang/lib/Frontend/CompilerInvocation.cpp
index 08cf0ae..56d10ce 100644
--- a/clang/lib/Frontend/CompilerInvocation.cpp
+++ b/clang/lib/Frontend/CompilerInvocation.cpp
@@ -4470,22 +4470,6 @@ bool CompilerInvocation::ParseLangArgs(LangOptions &Opts, ArgList &Args,
       Opts.OpenACCMacroOverride = A->getValue();
   }
 
-  // FIXME: Eliminate this dependency.
-  unsigned Opt = getOptimizationLevel(Args, IK, Diags),
-       OptSize = getOptimizationLevelSize(Args);
-  Opts.Optimize = Opt != 0;
-  Opts.OptimizeSize = OptSize != 0;
-
-  // This is the __NO_INLINE__ define, which just depends on things like the
-  // optimization level and -fno-inline, not actually whether the backend has
-  // inlining enabled.
-  Opts.NoInlineDefine = !Opts.Optimize;
-  if (Arg *InlineArg = Args.getLastArg(
-          options::OPT_finline_functions, options::OPT_finline_hint_functions,
-          options::OPT_fno_inline_functions, options::OPT_fno_inline))
-    if (InlineArg->getOption().matches(options::OPT_fno_inline))
-      Opts.NoInlineDefine = true;
-
   if (Arg *A = Args.getLastArg(OPT_ffp_contract)) {
     StringRef Val = A->getValue();
     if (Val == "fast")
@@ -5335,6 +5319,21 @@ std::string CompilerInvocation::getModuleHash() const {
       HBuilder.add(*Build);
   }
 
+  // Extend the signature with affecting codegen options.
+  {
+    using CK = CodeGenOptions::CompatibilityKind;
+#define CODEGENOPT(Name, Bits, Default, Compatibility)                         \
+  if constexpr (CK::Compatibility != CK::Benign)                               \
+    HBuilder.add(CodeGenOpts->Name);
+#define ENUM_CODEGENOPT(Name, Type, Bits, Default, Compatibility)              \
+  if constexpr (CK::Compatibility != CK::Benign)                               \
+    HBuilder.add(static_cast<unsigned>(CodeGenOpts->get##Name()));
+#define DEBUGOPT(Name, Bits, Default, Compatibility)
+#define VALUE_DEBUGOPT(Name, Bits, Default, Compatibility)
+#define ENUM_DEBUGOPT(Name, Type, Bits, Default, Compatibility)
+#include "clang/Basic/CodeGenOptions.def"
+  }
+
   // When compiling with -gmodules, also hash -fdebug-prefix-map as it
   // affects the debug info in the PCM.
   if (getCodeGenOpts().DebugTypeExtRefs)
@@ -5345,13 +5344,13 @@ std::string CompilerInvocation::getModuleHash() const {
     // FIXME: Replace with C++20 `using enum CodeGenOptions::CompatibilityKind`.
     using CK = CodeGenOptions::CompatibilityKind;
 #define DEBUGOPT(Name, Bits, Default, Compatibility)                           \
-  if constexpr (CK::Compatibility == CK::Affecting)                            \
+  if constexpr (CK::Compatibility != CK::Benign)                               \
     HBuilder.add(CodeGenOpts->Name);
 #define VALUE_DEBUGOPT(Name, Bits, Default, Compatibility)                     \
-  if constexpr (CK::Compatibility == CK::Affecting)                            \
+  if constexpr (CK::Compatibility != CK::Benign)                               \
     HBuilder.add(CodeGenOpts->Name);
 #define ENUM_DEBUGOPT(Name, Type, Bits, Default, Compatibility)                \
-  if constexpr (CK::Compatibility == CK::Affecting)                            \
+  if constexpr (CK::Compatibility != CK::Benign)                               \
     HBuilder.add(static_cast<unsigned>(CodeGenOpts->get##Name()));
 #include "clang/Basic/DebugOptions.def"
   }