From 7e7ac3a6f7bcdacbe912d9267f25b86755982dfc Mon Sep 17 00:00:00 2001
From: Christian Kamm <kamm@incasoftware.de>
Date: Mon, 14 Jul 2008 11:07:15 +0200
Subject: [PATCH] [svn r374] Move label target basic block from AST to
 IRFunction. This is a first step to allowing labels to be emitted multiple
 times. (for instance within finally blocks)

---
 dmd/statement.c     |  1 -
 dmd/statement.h     |  1 -
 gen/llvmhelpers.cpp |  9 ++++++---
 gen/statements.cpp  | 16 ++++++++++------
 ir/irfunction.h     |  4 ++++
 5 files changed, 20 insertions(+), 11 deletions(-)

diff --git a/dmd/statement.c b/dmd/statement.c
index 1a46907a..0f08a134 100644
--- a/dmd/statement.c
+++ b/dmd/statement.c
@@ -3883,7 +3883,6 @@ LabelStatement::LabelStatement(Loc loc, Identifier *ident, Statement *statement)
     this->enclosinghandler = NULL;
     this->lblock = NULL;
     this->isReturnLabel = 0;
-    this->llvmBB = NULL;
     this->asmLabel = false;
 }
 
diff --git a/dmd/statement.h b/dmd/statement.h
index ab1d0043..f04baf91 100644
--- a/dmd/statement.h
+++ b/dmd/statement.h
@@ -871,7 +871,6 @@ struct LabelStatement : Statement
     void toIR(IRState *irs);
 
     // LLVMDC
-    llvm::BasicBlock* llvmBB;
     bool asmLabel;       // for labels inside inline assembler
 };
 
diff --git a/gen/llvmhelpers.cpp b/gen/llvmhelpers.cpp
index f47e0232..564abdc1 100644
--- a/gen/llvmhelpers.cpp
+++ b/gen/llvmhelpers.cpp
@@ -186,8 +186,11 @@ void DtoGoto(Loc* loc, Identifier* target, EnclosingHandler* enclosinghandler)
     if(lblstmt->asmLabel)
         error("cannot goto into inline asm block", loc->toChars());
 
-    if (lblstmt->llvmBB == NULL)
-        lblstmt->llvmBB = llvm::BasicBlock::Create("label", gIR->topfunc());
+    // find target basic block
+    std::string labelname = target->toChars();
+    llvm::BasicBlock*& targetBB = gIR->func()->labelToBB[labelname];
+    if (targetBB == NULL)
+        targetBB = llvm::BasicBlock::Create("label", gIR->topfunc());
 
     // find finallys between goto and label
     EnclosingHandler* endfinally = enclosinghandler;
@@ -202,7 +205,7 @@ void DtoGoto(Loc* loc, Identifier* target, EnclosingHandler* enclosinghandler)
     // emit code for finallys between goto and label
     DtoEnclosingHandlers(enclosinghandler, endfinally);
 
-    llvm::BranchInst::Create(lblstmt->llvmBB, gIR->scopebb());
+    llvm::BranchInst::Create(targetBB, gIR->scopebb());
 }
 
 /****************************************************************************************/
diff --git a/gen/statements.cpp b/gen/statements.cpp
index f971c046..56e30415 100644
--- a/gen/statements.cpp
+++ b/gen/statements.cpp
@@ -1033,16 +1033,20 @@ void LabelStatement::toIR(IRState* p)
     }
     else
     {
+        std::string labelname = ident->toChars();
+        llvm::BasicBlock*& labelBB = p->func()->labelToBB[labelname];
+
         llvm::BasicBlock* oldend = gIR->scopeend();
-        if (llvmBB)
-                llvmBB->moveBefore(oldend);
-        else
-                llvmBB = llvm::BasicBlock::Create("label", p->topfunc(), oldend);
+        if (labelBB != NULL) {
+                labelBB->moveBefore(oldend);
+        } else {
+                labelBB = llvm::BasicBlock::Create("label", p->topfunc(), oldend);
+        }
 
         if (!p->scopereturned())
-                llvm::BranchInst::Create(llvmBB, p->scopebb());
+                llvm::BranchInst::Create(labelBB, p->scopebb());
 
-        p->scope() = IRScope(llvmBB,oldend);
+        p->scope() = IRScope(labelBB,oldend);
     }
 
     if (statement)
diff --git a/ir/irfunction.h b/ir/irfunction.h
index 31cb20e8..ac98ad97 100644
--- a/ir/irfunction.h
+++ b/ir/irfunction.h
@@ -26,6 +26,10 @@ struct IrFunction : IrBase
     llvm::AllocaInst* srcfileArg;
     llvm::AllocaInst* msgArg;
 
+    // label to basic block lookup
+    typedef std::map<std::string, llvm::BasicBlock*> LabelToBBMap;
+    LabelToBBMap labelToBB;
+
     // landing pads for try statements
     IRLandingPad landingPad;