ldc/ldc-1.32.2-llvm-16-use_std_optional_api.patch

From 8e1dffa5203439996d6c461485cad566ec321884 Mon Sep 17 00:00:00 2001
From: Ikey Doherty <ikey@serpentos.com>
Date: Mon, 22 May 2023 10:53:55 +0100
Subject: [PATCH] For LLVM >= 16, use std::optional APIs

Unfortunately when building with LLVM < 15, we're using C++-11,
so the std::optional bits are only available in C++-17.

Even more unfortunately we can't really override this, rather
inherit the fact of using C++-17 when using LLVM > 16.

Thus, we add a slightly messy conditional compilation situation
to allow usage of LDC on older LLVM versions, and with newer
LLVM/libcxx.

Signed-off-by: Ikey Doherty <ikey@serpentos.com>
---
 driver/args.cpp           |  4 ++++
 driver/linker.cpp         |  4 ++++
 driver/linker.h           |  4 ++++
 gen/dcompute/druntime.cpp |  7 ++++++-
 gen/dibuilder.cpp         | 21 +++++++++++++++++++++
 gen/optimizer.cpp         |  5 +++++
 gen/uda.cpp               |  4 ++++
 utils/not.cpp             |  4 ++++
 8 files changed, 52 insertions(+), 1 deletion(-)

diff --git a/driver/args.cpp b/driver/args.cpp
index da291202d1..bad8e45dee 100644
--- a/driver/args.cpp
+++ b/driver/args.cpp
@@ -175,7 +175,11 @@ int executeAndWait(std::vector<const char *> fullArgs,
   }
 
   const std::vector<llvm::StringRef> argv = toRefsVector(fullArgs);
+#if LDC_LLVM_VER < 1600
   auto envVars = llvm::None;
+#else
+  auto envVars = std::nullopt;
+#endif
 
   return llvm::sys::ExecuteAndWait(argv[0], argv, envVars, {}, 0, 0, errorMsg);
 }
diff --git a/driver/linker.cpp b/driver/linker.cpp
index 76266379d2..803d5e883e 100644
--- a/driver/linker.cpp
+++ b/driver/linker.cpp
@@ -195,7 +195,11 @@ static std::vector<std::string> getDefaultLibNames() {
 llvm::Optional<std::vector<std::string>> getExplicitPlatformLibs() {
   if (platformLib.getNumOccurrences() > 0)
     return parseLibNames(platformLib);
+#if LDC_LLVM_VER < 1600
   return llvm::None;
+#else
+  return std::nullopt;
+#endif
 }
 
 //////////////////////////////////////////////////////////////////////////////
diff --git a/driver/linker.h b/driver/linker.h
index f962054efa..28362d8652 100644
--- a/driver/linker.h
+++ b/driver/linker.h
@@ -42,7 +42,11 @@ bool linkAgainstSharedDefaultLibs();
 /**
  * Returns the -platformlib library names, if specified.
  */
+#if LDC_LLVM_VER < 1600
 llvm::Optional<std::vector<std::string>> getExplicitPlatformLibs();
+#else
+std::optional<std::vector<std::string>> getExplicitPlatformLibs();
+#endif
 
 /**
  * Returns the value of -mscrtlib.
diff --git a/gen/dcompute/druntime.cpp b/gen/dcompute/druntime.cpp
index 6867765466..aee93f4c53 100644
--- a/gen/dcompute/druntime.cpp
+++ b/gen/dcompute/druntime.cpp
@@ -42,8 +42,13 @@ bool isFromLDC_OpenCL(Dsymbol *sym) {
 }
 
 llvm::Optional<DcomputePointer> toDcomputePointer(StructDeclaration *sd) {
-  if (sd->ident != Id::dcPointer || !isFromLDC_DCompute(sd))
+  if (sd->ident != Id::dcPointer || !isFromLDC_DCompute(sd)) {
+#if LDC_LLVM_VER < 1600
     return llvm::Optional<DcomputePointer>(llvm::None);
+#else
+    return std::optional<DcomputePointer>(std::nullopt);
+#endif
+  }
 
   TemplateInstance *ti = sd->isInstantiated();
   int addrspace = isExpression((*ti->tiargs)[0])->toInteger();
diff --git a/gen/dibuilder.cpp b/gen/dibuilder.cpp
index 1e817ee3f4..f7068294dd 100644
--- a/gen/dibuilder.cpp
+++ b/gen/dibuilder.cpp
@@ -372,7 +372,11 @@ DIType DIBuilder::CreateEnumType(TypeEnum *type) {
 DIType DIBuilder::CreatePointerType(TypePointer *type) {
   // TODO: The addressspace is important for dcompute targets. See e.g.
   // https://www.mail-archive.com/dwarf-discuss@lists.dwarfstd.org/msg00326.html
+#if LDC_LLVM_VER < 1600
   const llvm::Optional<unsigned> DWARFAddressSpace = llvm::None;
+#else
+  const std::optional<unsigned> DWARFAddressSpace = std::nullopt;
+#endif
 
   const auto name = processDIName(type->toPrettyChars(true));
 
@@ -730,7 +734,11 @@ DISubroutineType DIBuilder::CreateFunctionType(Type *type) {
 }
 
 DISubroutineType DIBuilder::CreateEmptyFunctionType() {
+#if LDC_LLVM_VER < 1600
   auto paramsArray = DBuilder.getOrCreateTypeArray(llvm::None);
+#else
+  auto paramsArray = DBuilder.getOrCreateTypeArray(std::nullopt);
+#endif
   return DBuilder.createSubroutineType(paramsArray);
 }
 
@@ -774,9 +782,16 @@ DIType DIBuilder::CreateTypeDescription(Type *t, bool voidToUbyte) {
     return nullptr;
   if (t->ty == TY::Tnull) {
     // display null as void*
+#if LDC_LLVM_VER < 1600
     return DBuilder.createPointerType(
         CreateTypeDescription(Type::tvoid), target.ptrsize * 8, 0,
         /* DWARFAddressSpace */ llvm::None, "typeof(null)");
+#else
+    return DBuilder.createPointerType(
+        CreateTypeDescription(Type::tvoid), target.ptrsize * 8, 0,
+        /* DWARFAddressSpace */ std::nullopt, "typeof(null)");
+#endif
+
   }
   if (auto te = t->isTypeEnum())
     return CreateEnumType(te);
@@ -798,8 +813,14 @@ DIType DIBuilder::CreateTypeDescription(Type *t, bool voidToUbyte) {
     const auto aggregateDIType = CreateCompositeType(t);
     const auto name =
         (tc->sym->toPrettyChars(true) + llvm::StringRef("*")).str();
+#if LDC_LLVM_VER < 1600
     return DBuilder.createPointerType(aggregateDIType, target.ptrsize * 8, 0,
                                       llvm::None, processDIName(name));
+#else
+    return DBuilder.createPointerType(aggregateDIType, target.ptrsize * 8, 0,
+                                      std::nullopt, processDIName(name));
+#endif
+
   }
   if (auto tf = t->isTypeFunction())
     return CreateFunctionType(tf);
diff --git a/gen/optimizer.cpp b/gen/optimizer.cpp
index 86146bf6f3..13bad60a04 100644
--- a/gen/optimizer.cpp
+++ b/gen/optimizer.cpp
@@ -572,8 +572,13 @@ static llvm::Optional<PGOOptions> getPGOOptions() {
                      PGOOptions::CSPGOAction::NoCSAction,
                      debugInfoForProfiling, pseudoProbeForProfiling);
   }
+#if LDC_LLVM_VER < 1600
   return None;
+#else
+  return std::nullopt;
+#endif
 }
+
 static PipelineTuningOptions getPipelineTuningOptions(unsigned optLevelVal, unsigned sizeLevelVal) {
   PipelineTuningOptions pto;
 
diff --git a/gen/uda.cpp b/gen/uda.cpp
index 371b565b38..521205c5da 100644
--- a/gen/uda.cpp
+++ b/gen/uda.cpp
@@ -219,7 +219,11 @@ void applyAttrAllocSize(StructLiteralExp *sle, IrFunction *irFunc) {
   if (numArgIdx >= 0) {
     builder.addAllocSizeAttr(llvmSizeIdx, llvmNumIdx);
   } else {
+#if LDC_LLVM_VER < 1600
     builder.addAllocSizeAttr(llvmSizeIdx, llvm::Optional<unsigned>());
+#else
+    builder.addAllocSizeAttr(llvmSizeIdx, std::optional<unsigned>());
+#endif
   }
 
   llvm::Function *func = irFunc->getLLVMFunc();
diff --git a/utils/not.cpp b/utils/not.cpp
index b434af7331..7ca8d1d8a6 100644
--- a/utils/not.cpp
+++ b/utils/not.cpp
@@ -43,7 +43,11 @@ int main(int argc, const char **argv) {
   Argv.reserve(argc);
   for (int i = 0; i < argc; ++i)
     Argv.push_back(argv[i]);
+#if LDC_LLVM_VER < 1600
   auto Env = llvm::None;
+#else
+  auto Env = std::nullopt;
+#endif
 
   std::string ErrMsg;
   int Result = sys::ExecuteAndWait(*Program, Argv, Env, {}, 0, 0, &ErrMsg);