From fc504e18d2d3d57f66554abc930fdfdf469aba57 Mon Sep 17 00:00:00 2001
From: xushiwei <x@goplus.org>
Date: Tue, 28 May 2024 16:59:47 +0800
Subject: [PATCH] TypeSizes: goProgram

---
 internal/build/build.go   |  2 +-
 internal/llgen/llgenf.go  |  4 ++--
 internal/packages/load.go | 10 +++++-----
 ssa/package.go            |  1 +
 ssa/type.go               | 30 ++++++++++++++++++++++++++++--
 5 files changed, 37 insertions(+), 10 deletions(-)

diff --git a/internal/build/build.go b/internal/build/build.go
index e7da46b7..ec9d73c3 100644
--- a/internal/build/build.go
+++ b/internal/build/build.go
@@ -89,7 +89,7 @@ const (
 
 func Do(args []string, conf *Config) {
 	prog := llssa.NewProgram(nil)
-	sizes := prog.TypeSizes()
+	sizes := prog.TypeSizes
 
 	flags, patterns, verbose := ParseArgs(args, buildFlags)
 	cfg := &packages.Config{
diff --git a/internal/llgen/llgenf.go b/internal/llgen/llgenf.go
index 34489f2d..cabbc234 100644
--- a/internal/llgen/llgenf.go
+++ b/internal/llgen/llgenf.go
@@ -43,7 +43,7 @@ func initRtAndPy(prog llssa.Program, cfg *packages.Config) {
 	load := func() []*packages.Package {
 		if pkgRtAndPy == nil {
 			var err error
-			pkgRtAndPy, err = packages.LoadEx(prog.TypeSizes(), cfg, llssa.PkgRuntime, llssa.PkgPython)
+			pkgRtAndPy, err = packages.LoadEx(prog.TypeSizes, cfg, llssa.PkgRuntime, llssa.PkgPython)
 			check(err)
 		}
 		return pkgRtAndPy
@@ -65,7 +65,7 @@ func GenFrom(fileOrPkg string) string {
 	cfg := &packages.Config{
 		Mode: loadSyntax | packages.NeedDeps,
 	}
-	initial, err := packages.LoadEx(prog.TypeSizes(), cfg, fileOrPkg)
+	initial, err := packages.LoadEx(prog.TypeSizes, cfg, fileOrPkg)
 	check(err)
 
 	_, pkgs := ssautil.AllPackages(initial, ssa.SanityCheckFunctions)
diff --git a/internal/packages/load.go b/internal/packages/load.go
index 0797e099..18d49d63 100644
--- a/internal/packages/load.go
+++ b/internal/packages/load.go
@@ -101,17 +101,14 @@ func refine(ld *loader, response *packages.DriverResponse) ([]*Package, error)
 // return an error. Clients may need to handle such errors before
 // proceeding with further analysis. The PrintErrors function is
 // provided for convenient display of all errors.
-func LoadEx(sizes types.Sizes, cfg *Config, patterns ...string) ([]*Package, error) {
+func LoadEx(sizes func(types.Sizes) types.Sizes, cfg *Config, patterns ...string) ([]*Package, error) {
 	ld := newLoader(cfg)
 	response, external, err := defaultDriver(&ld.Config, patterns...)
 	if err != nil {
 		return nil, err
 	}
 
-	if sizes == nil {
-		sizes = types.SizesFor(response.Compiler, response.Arch)
-	}
-	ld.sizes = sizes
+	ld.sizes = types.SizesFor(response.Compiler, response.Arch)
 	if ld.sizes == nil && ld.Config.Mode&(NeedTypes|NeedTypesSizes|NeedTypesInfo) != 0 {
 		// Type size information is needed but unavailable.
 		if external {
@@ -130,6 +127,9 @@ func LoadEx(sizes types.Sizes, cfg *Config, patterns ...string) ([]*Package, err
 		}
 	}
 
+	if sizes != nil {
+		ld.sizes = sizes(ld.sizes)
+	}
 	return refine(ld, response)
 }
 
diff --git a/ssa/package.go b/ssa/package.go
index b80d06e9..38fa3ae5 100644
--- a/ssa/package.go
+++ b/ssa/package.go
@@ -101,6 +101,7 @@ func Initialize(flags InitFlags) {
 type aProgram struct {
 	ctx   llvm.Context
 	typs  typeutil.Map // rawType -> Type
+	sizes types.Sizes  // provided by Go compiler
 	gocvt goTypes
 
 	rt    *types.Package
diff --git a/ssa/type.go b/ssa/type.go
index b112fdfb..1dfa1afd 100644
--- a/ssa/type.go
+++ b/ssa/type.go
@@ -74,6 +74,31 @@ func indexType(t types.Type) types.Type {
 
 // -----------------------------------------------------------------------------
 
+type goProgram aProgram
+
+// Alignof returns the alignment of a variable of type T.
+// Alignof must implement the alignment guarantees required by the spec.
+// The result must be >= 1.
+func (p *goProgram) Alignof(T types.Type) int64 {
+	return p.sizes.Alignof(T)
+}
+
+// Offsetsof returns the offsets of the given struct fields, in bytes.
+// Offsetsof must implement the offset guarantees required by the spec.
+// A negative entry in the result indicates that the struct is too large.
+func (p *goProgram) Offsetsof(fields []*types.Var) []int64 {
+	return p.sizes.Offsetsof(fields)
+}
+
+// Sizeof returns the size of a variable of type T.
+// Sizeof must implement the size guarantees required by the spec.
+// A negative result indicates that T is too large.
+func (p *goProgram) Sizeof(T types.Type) int64 {
+	return p.sizes.Sizeof(T)
+}
+
+// -----------------------------------------------------------------------------
+
 type rawType struct {
 	Type types.Type
 }
@@ -92,8 +117,9 @@ func (t Type) RawType() types.Type {
 }
 
 // TypeSizes returns the sizes of the types.
-func (p Program) TypeSizes() types.Sizes {
-	return nil // TODO(xsw)
+func (p Program) TypeSizes(sizes types.Sizes) types.Sizes {
+	p.sizes = sizes
+	return (*goProgram)(p)
 }
 
 // TODO(xsw):