[bindings] Update Go bindings to DIBuilder

[axw]

Summary

Update the Go bindings to DIBuilder to match
the split of creating local variables into
auto and parameter variables.

[pcc]

LGTM

bindings/go/llvm/DIBuilderBindings.h

LLVMMetadataRef LLVMDIBuilderCreateLexicalBlockFile(LLVMDIBuilderRef D,
                                                     unsigned Discriminator);
 
 LLVMMetadataRef LLVMDIBuilderCreateFunction(
     LLVMDIBuilderRef D, LLVMMetadataRef Scope, const char *Name,
     const char *LinkageName, LLVMMetadataRef File, unsigned Line,
     LLVMMetadataRef CompositeType, int IsLocalToUnit, int IsDefinition,
     unsigned ScopeLine, unsigned Flags, int IsOptimized, LLVMValueRef Function);
 
-LLVMMetadataRef LLVMDIBuilderCreateLocalVariable(
-    LLVMDIBuilderRef D, unsigned Tag, LLVMMetadataRef Scope, const char *Name,
+LLVMMetadataRef
+LLVMDIBuilderCreateAutoVariable(LLVMDIBuilderRef D, LLVMMetadataRef Scope,
+                                const char *Name, LLVMMetadataRef File,
+                                unsigned Line, LLVMMetadataRef Ty,
+                                int AlwaysPreserve, unsigned Flags);
+
+LLVMMetadataRef LLVMDIBuilderCreateParameterVariable(
+    LLVMDIBuilderRef D, LLVMMetadataRef Scope, const char *Name, unsigned ArgNo,
     LLVMMetadataRef File, unsigned Line, LLVMMetadataRef Ty, int AlwaysPreserve,
-    unsigned Flags, unsigned ArgNo);
+    unsigned Flags);
 
 LLVMMetadataRef LLVMDIBuilderCreateBasicType(LLVMDIBuilderRef D,
                                              const char *Name,
                                              uint64_t SizeInBits,
                                              uint64_t AlignInBits,
                                              unsigned Encoding);
 
 LLVMMetadataRef LLVMDIBuilderCreatePointerType(LLVMDIBuilderRef D,

bindings/go/llvm/DIBuilderBindings.cpp

LLVMMetadataRef LLVMDIBuilderCreateFunction(
   DIBuilder *D = unwrap(Dref);
   return wrap(D->createFunction(unwrap<DIScope>(Scope), Name, LinkageName,
                                 File ? unwrap<DIFile>(File) : nullptr, Line,
                                 unwrap<DISubroutineType>(CompositeType),
                                 IsLocalToUnit, IsDefinition, ScopeLine, Flags,
                                 IsOptimized, unwrap<Function>(Func)));
 }
 
-LLVMMetadataRef LLVMDIBuilderCreateLocalVariable(
-    LLVMDIBuilderRef Dref, unsigned, LLVMMetadataRef Scope,
-    const char *Name, LLVMMetadataRef File, unsigned Line, LLVMMetadataRef Ty,
-    int AlwaysPreserve, unsigned Flags, unsigned ArgNo) {
+LLVMMetadataRef
+LLVMDIBuilderCreateAutoVariable(LLVMDIBuilderRef Dref, LLVMMetadataRef Scope,
+                                const char *Name, LLVMMetadataRef File,
+                                unsigned Line, LLVMMetadataRef Ty,
+                                int AlwaysPreserve, unsigned Flags) {
   DIBuilder *D = unwrap(Dref);
-  // FIXME: Update the Go bindings to match the DIBuilder API.
-  if (ArgNo)
-    return wrap(D->createParameterVariable(
-        unwrap<DIScope>(Scope), Name, ArgNo, unwrap<DIFile>(File), Line,
-        unwrap<DIType>(Ty), AlwaysPreserve, Flags));
   return wrap(D->createAutoVariable(unwrap<DIScope>(Scope), Name,
                                     unwrap<DIFile>(File), Line,
                                     unwrap<DIType>(Ty), AlwaysPreserve, Flags));
 }
 
+LLVMMetadataRef LLVMDIBuilderCreateParameterVariable(
+    LLVMDIBuilderRef Dref, LLVMMetadataRef Scope, const char *Name,
+    unsigned ArgNo, LLVMMetadataRef File, unsigned Line, LLVMMetadataRef Ty,
+    int AlwaysPreserve, unsigned Flags) {
+  DIBuilder *D = unwrap(Dref);
+  return wrap(D->createParameterVariable(
+      unwrap<DIScope>(Scope), Name, ArgNo, unwrap<DIFile>(File), Line,
+      unwrap<DIType>(Ty), AlwaysPreserve, Flags));
+}
+
 LLVMMetadataRef LLVMDIBuilderCreateBasicType(LLVMDIBuilderRef Dref,
                                              const char *Name,
                                              uint64_t SizeInBits,
                                              uint64_t AlignInBits,
                                              unsigned Encoding) {
   DIBuilder *D = unwrap(Dref);
   return wrap(D->createBasicType(Name, SizeInBits, AlignInBits, Encoding));
 }

bindings/go/llvm/dibuilder.go

result := C.LLVMDIBuilderCreateFunction(
     C.unsigned(f.ScopeLine),
     C.unsigned(f.Flags),
     boolToCInt(f.Optimized),
     f.Function.C,
   )
   return Metadata{C: result}
 }
 
-// DILocalVariable holds the values for creating local variable debug metadata.
-type DILocalVariable struct {
-  Tag            dwarf.Tag
+// DIAutoVariable holds the values for creating auto variable debug metadata.
+type DIAutoVariable struct {
+  Name           string
+  File           Metadata
+  Line           int
+  Type           Metadata
+  AlwaysPreserve bool
+  Flags          int
+}
+
+// CreateAutoVariable creates local variable debug metadata.
+func (d *DIBuilder) CreateAutoVariable(scope Metadata, v DIAutoVariable) Metadata {
+  name := C.CString(v.Name)
+  defer C.free(unsafe.Pointer(name))
+  result := C.LLVMDIBuilderCreateAutoVariable(
+    d.ref,
+    scope.C,
+    name,
+    v.File.C,
+    C.unsigned(v.Line),
+    v.Type.C,
+    boolToCInt(v.AlwaysPreserve),
+    C.unsigned(v.Flags),
+  )
+  return Metadata{C: result}
+}
+
+// DIParameterVariable holds the values for creating parameter variable debug metadata.
+type DIParameterVariable struct {
   Name           string
   File           Metadata
   Line           int
   Type           Metadata
   AlwaysPreserve bool
   Flags          int
 
   // ArgNo is the 1-based index of the argument in the function's
-  // parameter list if it is an argument, or 0 otherwise.
+  // parameter list.
   ArgNo int
 }
 
-// CreateLocalVariable creates local variable debug metadata.
-func (d *DIBuilder) CreateLocalVariable(scope Metadata, v DILocalVariable) Metadata {
+// CreateParameterVariable creates parameter variable debug metadata.
+func (d *DIBuilder) CreateParameterVariable(scope Metadata, v DIParameterVariable) Metadata {
   name := C.CString(v.Name)
   defer C.free(unsafe.Pointer(name))
-  result := C.LLVMDIBuilderCreateLocalVariable(
+  result := C.LLVMDIBuilderCreateParameterVariable(
     d.ref,
-    C.unsigned(v.Tag),
     scope.C,
     name,
+    C.unsigned(v.ArgNo),
     v.File.C,
     C.unsigned(v.Line),
     v.Type.C,
     boolToCInt(v.AlwaysPreserve),
     C.unsigned(v.Flags),
-    C.unsigned(v.ArgNo),
   )
   return Metadata{C: result}
 }
 
 // DIBasicType holds the values for creating basic type debug metadata.
 type DIBasicType struct {
   Name        string
   SizeInBits  uint64