[PATCH] D43586: CodeGen: handle blocks correctly when inalloca'ed

[Saleem Abdulrasool via Phabricator via cfe-commits]

compnerd created this revision.
compnerd added a reviewer: rnk.
Herald added a subscriber: cfe-commits.

When using blocks with C++ on Windows x86, it is possible to have the
block literal be pushed into the inalloca'ed parameters.  Teach IRGen to
handle the case properly by extracting the block literal from the
inalloca parameter.  This fixes the use of blocks with C++ on Windows
x86.


Repository:
  rC Clang

https://reviews.llvm.org/D43586

Files:
  lib/CodeGen/CGDecl.cpp
  test/CodeGenCXX/block-inalloca.cpp


Index: test/CodeGenCXX/block-inalloca.cpp
===================================================================
--- /dev/null
+++ test/CodeGenCXX/block-inalloca.cpp
@@ -0,0 +1,11 @@
+// RUN: %clang_cc1 -triple i686-unknown-windows-msvc -fblocks -emit-llvm -o - %s | FileCheck %s
+
+struct S {
+  S(const struct S &) {}
+};
+
+void (^b)(S) = ^(S) {};
+
+// CHECK: [[DESCRIPTOR:%.*]] = getelementptr inbounds <{ i8*, %struct.S, [3 x i8] }>, <{ i8*, %struct.S, [3 x i8] }>* %0, i32 0, i32 0
+// CHECK: load i8*, i8** [[DESCRIPTOR]]
+
Index: lib/CodeGen/CGDecl.cpp
===================================================================
--- lib/CodeGen/CGDecl.cpp
+++ lib/CodeGen/CGDecl.cpp
@@ -1850,7 +1850,10 @@
     // The only implicit argument a block has is its literal.
     // We assume this is always passed directly.
     if (BlockInfo) {
-      setBlockContextParameter(IPD, ArgNo, Arg.getDirectValue());
+      llvm::Value *V = Arg.isIndirect()
+                           ? Builder.CreateLoad(Arg.getIndirectAddress())
+                           : Arg.getDirectValue();
+      setBlockContextParameter(IPD, ArgNo, V);
       return;
     }
   }


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