[DIBuilder] Remove .zero default alignments

Putting 0 alignments in here goes against DWARF

Author: matthewseaman

Sources/LLVM/DIBuilder.swift

@@ -394,7 +394,7 @@ extension DIBuilder {
     named name: String,
     scope: DIScope, file: FileMetadata, line: Int,
     type: DIType, alwaysPreserve: Bool = false,
-    flags: DIFlags = [], alignment: Alignment = .zero
+    flags: DIFlags = [], alignment: Alignment
   ) -> LocalVariableMetadata {
     let radix = UInt32(self.module.dataLayout.intPointerType().width)
     guard let variable = LLVMDIBuilderCreateAutoVariable(
@@ -502,7 +502,7 @@ extension DIBuilder {
   ///   - file: File where this member is defined.
   ///   - line: Line number.
   ///   - size: Member size.
-  ///   - alignmemnt: Member alignment.
+  ///   - alignment: Member alignment.
   ///   - elements: Enumeration elements.
   ///   - numElements: Number of enumeration elements.
   ///   - underlyingType: Underlying type of a C++11/ObjC fixed enum.
@@ -675,7 +675,7 @@ extension DIBuilder {
   ///   - addressSpace: The address space the pointer type reside in.
   ///   - name: The name of the pointer type.
   public func buildPointerType(
-    pointee: DIType, size: Size, alignment: Alignment = .zero,
+    pointee: DIType, size: Size, alignment: Alignment,
     addressSpace: AddressSpace = .zero, name: String = ""
   ) -> DIType {
     let radix = UInt32(self.module.dataLayout.intPointerType().width)
@@ -1258,15 +1258,14 @@ extension DIBuilder {
   ///   - expression: The location of the global relative to the attached
   ///     GlobalVariable.
   ///   - declaration: Reference to the corresponding declaration.
-  ///   - alignment: Variable alignment(or 0 if no alignment attr was
-  ///     specified)
+  ///   - alignment: Variable alignment
   public func buildGlobalExpression(
     named name: String, linkageName: String, type: DIType,
     scope: DIScope, file: FileMetadata, line: Int,
     isLocal: Bool = true,
     expression: ExpressionMetadata? = nil,
     declaration: IRMetadata? = nil,
-    alignment: Alignment = .zero
+    alignment: Alignment
   ) -> ExpressionMetadata {
     let radix = UInt32(self.module.dataLayout.intPointerType().width)
     guard let ty = LLVMDIBuilderCreateGlobalVariableExpression(

Tests/LLVMTests/BFC.swift

@@ -261,11 +261,13 @@ private func compileProgramBody(
                                           encoding: .signed, flags: [],
                                           size: builder.module.dataLayout.abiSize(of: cellType))
   let diPtrTy = dibuilder.buildPointerType(pointee: diDataTy,
-                                           size: builder.module.dataLayout.pointerSize())
+                                            size: builder.module.dataLayout.pointerSize(),
+                                           alignment: .one)
   let diVariable = dibuilder.buildLocalVariable(named: "this",
                                                 scope: entryScope,
                                                 file: file, line: startPoint.0,
-                                                type: diPtrTy, flags: .artificial)
+                                                type: diPtrTy, flags: .artificial,
+                                                alignment: .one)
 
   var sourceLine = startPoint.0 + 1
   var sourceColumn = startPoint.1 + 1

Tests/LLVMTests/DIBuilderSpec.swift

@@ -47,7 +47,7 @@ class DIBuilderSpec : XCTestCase {
       // DIEXPRESSION: !{{[0-9]+}} = !DIGlobalVariableExpression(var: !{{[0-9]+}}, expr: !{{[0-9]+}})
       let expr = debugBuilder.buildGlobalExpression(
         named: "global", linkageName: "global", type: globalTy,
-        scope: cu, file: file, line: 42)
+        scope: cu, file: file, line: 42, alignment: global.alignment)
       // DIEXPRESSION: !{{[0-9]+}} = distinct !DIGlobalVariable(name: "unattached", linkageName: "unattached", scope: !0, file: !{{[0-9]+}}, line: 42, type: !{{[0-9]+}}, isLocal: true, isDefinition: true)
       _ = debugBuilder.buildGlobalExpression(
         named: "unattached", linkageName: "unattached",