llgo/ssa: SetBlockEx AfterInit

cl/_testpy/callpy/out.ll

@@ -8,6 +8,10 @@ source_filename = "main"
 @__llgo_py.os.getcwd = linkonce global ptr null
 @0 = private unnamed_addr constant [14 x i8] c"sqrt(2) = %f\0A\00", align 1
 @1 = private unnamed_addr constant [10 x i8] c"cwd = %s\0A\00", align 1
+@__llgo_py.math = external global ptr
+@2 = private unnamed_addr constant [5 x i8] c"sqrt\00", align 1
+@__llgo_py.os = external global ptr
+@3 = private unnamed_addr constant [7 x i8] c"getcwd\00", align 1
 
 define void @main.init() {
 _llgo_0:
@@ -18,6 +22,10 @@ _llgo_1:                                          ; preds = %_llgo_0
   store i1 true, ptr @"main.init$guard", align 1
   call void @"github.com/goplus/llgo/py/math.init"()
   call void @"github.com/goplus/llgo/py/os.init"()
+  %1 = load ptr, ptr @__llgo_py.math, align 8
+  call void (ptr, ...) @llgoLoadPyModSyms(ptr %1, ptr @2, ptr @__llgo_py.math.sqrt, ptr null)
+  %2 = load ptr, ptr @__llgo_py.os, align 8
+  call void (ptr, ...) @llgoLoadPyModSyms(ptr %2, ptr @3, ptr @__llgo_py.os.getcwd, ptr null)
   br label %_llgo_2
 
 _llgo_2:                                          ; preds = %_llgo_1, %_llgo_0
@@ -59,4 +67,6 @@ declare i32 @printf(ptr, ...)
 
 declare ptr @PyBytes_AsString()
 
+declare void @llgoLoadPyModSyms(ptr, ...)
+
 declare void @Py_Initialize()

cl/compile.go

@@ -355,7 +355,7 @@ func (p *context) compileBlock(b llssa.Builder, block *ssa.BasicBlock, n int, do
 					modName := modOf(name)
 					mods[modName] = append(mods[modName], obj)
 				}
-				b.SetBlockEx(ret, llssa.AtStart)
+				b.SetBlockEx(ret, llssa.AfterInit)
 				for modName, objs := range mods {
 					b.LoadPyModSyms(modName, objs...)
 				}

ssa/stmt_builder.go

@@ -21,6 +21,7 @@ import (
 	"fmt"
 	"go/types"
 	"log"
+	"strings"
 
 	"github.com/goplus/llvm"
 )
@@ -76,6 +77,7 @@ type InsertPoint int
 const (
 	AtEnd InsertPoint = iota
 	AtStart
+	AfterInit
 )
 
 // SetBlockEx sets blk as current basic block and pos as its insert point.
@@ -88,12 +90,35 @@ func (b Builder) SetBlockEx(blk BasicBlock, pos InsertPoint) Builder {
 		b.impl.SetInsertPointAtEnd(blk.impl)
 	case AtStart:
 		b.impl.SetInsertPointBefore(blk.impl.FirstInstruction())
+	case AfterInit:
+		b.impl.SetInsertPointBefore(instrAfterInit(blk.impl))
 	default:
 		panic("SetBlockEx: invalid pos")
 	}
 	return b
 }
 
+func instrAfterInit(blk llvm.BasicBlock) llvm.Value {
+	instr := blk.FirstInstruction()
+	for {
+		instr = llvm.NextInstruction(instr)
+		if notInit(instr) {
+			return instr
+		}
+	}
+}
+
+func notInit(instr llvm.Value) bool {
+	switch op := instr.InstructionOpcode(); op {
+	case llvm.Call:
+		if n := instr.OperandsCount(); n == 1 {
+			fn := instr.Operand(0)
+			return !strings.HasSuffix(fn.Name(), ".init")
+		}
+	}
+	return true
+}
+
 // Panic emits a panic instruction.
 func (b Builder) Panic(v Expr) {
 	if debugInstr {