DO NOT MERGE - Write legacy function attributes properly.

Bug: 9503142

A prior LLVM rebase accidentally overwrote the various bitcode writer
implementations with respect to function attributes. They were writing a new
style section, which would not be able to be parsed/used on older devices.
This change restores the generation of the legacy function attribute bitcode
format.

Change-Id: Ib6afc5ae405303881605c51c34b6966e4754c29d

7 files changed, 62 insertions, 15 deletions

diff --git a/BitWriter_2_9/Android.mk b/BitWriter_2_9/Android.mk
index 28d3133..9df336e 100644
--- a/BitWriter_2_9/Android.mk
+++ b/BitWriter_2_9/Android.mk
@@ -3,8 +3,6 @@ LOCAL_PATH:= $(call my-dir)
 LLVM_ROOT_PATH := $(LOCAL_PATH)/../../../../external/llvm
 include $(LLVM_ROOT_PATH)/llvm.mk
 
-LOCAL_CFLAGS += $(local_cflags_for_slang)
-
 bitcode_writer_2_9_SRC_FILES :=	\
 	BitcodeWriter.cpp	\
 	BitcodeWriterPass.cpp	\
@@ -14,6 +12,9 @@ bitcode_writer_2_9_SRC_FILES :=	\
 # =====================================================
 include $(CLEAR_VARS)
 
+LOCAL_CFLAGS += $(local_cflags_for_slang)
+LOCAL_C_INCLUDES += frameworks/compile/slang
+
 LOCAL_SRC_FILES := $(bitcode_writer_2_9_SRC_FILES)
 
 LOCAL_MODULE:= libLLVMBitWriter_2_9
diff --git a/BitWriter_2_9/BitcodeWriter.cpp b/BitWriter_2_9/BitcodeWriter.cpp
index e8a8aa5..0d45193 100644
--- a/BitWriter_2_9/BitcodeWriter.cpp
+++ b/BitWriter_2_9/BitcodeWriter.cpp
@@ -12,6 +12,7 @@
 //===----------------------------------------------------------------------===//
 
 #include "ReaderWriter_2_9.h"
+#include "legacy_bitcode.h"
 #include "ValueEnumerator.h"
 #include "llvm/ADT/Triple.h"
 #include "llvm/Bitcode/BitstreamWriter.h"
@@ -142,10 +143,13 @@ static void WriteAttributeTable(const llvm_2_9::ValueEnumerator &VE,
   SmallVector<uint64_t, 64> Record;
   for (unsigned i = 0, e = Attrs.size(); i != e; ++i) {
     const AttributeSet &A = Attrs[i];
-    for (unsigned i = 0, e = A.getNumSlots(); i != e; ++i)
-      Record.push_back(VE.getAttributeGroupID(A.getSlotAttributes(i)));
+    for (unsigned i = 0, e = A.getNumSlots(); i != e; ++i) {
+      Record.push_back(A.getSlotIndex(i));
+      Record.push_back(encodeLLVMAttributesForBitcode(A, A.getSlotIndex(i)));
+    }
 
-    Stream.EmitRecord(bitc::PARAMATTR_CODE_ENTRY, Record);
+    // This needs to use the 3.2 entry type
+    Stream.EmitRecord(bitc::PARAMATTR_CODE_ENTRY_OLD, Record);
     Record.clear();
   }
 
diff --git a/BitWriter_2_9_func/Android.mk b/BitWriter_2_9_func/Android.mk
index 638c817..07b77d9 100644
--- a/BitWriter_2_9_func/Android.mk
+++ b/BitWriter_2_9_func/Android.mk
@@ -3,8 +3,6 @@ LOCAL_PATH:= $(call my-dir)
 LLVM_ROOT_PATH := $(LOCAL_PATH)/../../../../external/llvm
 include $(LLVM_ROOT_PATH)/llvm.mk
 
-LOCAL_CFLAGS += $(local_cflags_for_slang)
-
 bitcode_writer_2_9_func_SRC_FILES :=	\
 	BitcodeWriter.cpp	\
 	BitcodeWriterPass.cpp	\
@@ -14,6 +12,9 @@ bitcode_writer_2_9_func_SRC_FILES :=	\
 # =====================================================
 include $(CLEAR_VARS)
 
+LOCAL_CFLAGS += $(local_cflags_for_slang)
+LOCAL_C_INCLUDES += frameworks/compile/slang
+
 LOCAL_SRC_FILES := $(bitcode_writer_2_9_func_SRC_FILES)
 
 LOCAL_MODULE:= libLLVMBitWriter_2_9_func
diff --git a/BitWriter_2_9_func/BitcodeWriter.cpp b/BitWriter_2_9_func/BitcodeWriter.cpp
index ac02fad..828d891 100644
--- a/BitWriter_2_9_func/BitcodeWriter.cpp
+++ b/BitWriter_2_9_func/BitcodeWriter.cpp
@@ -12,6 +12,7 @@
 //===----------------------------------------------------------------------===//
 
 #include "ReaderWriter_2_9_func.h"
+#include "legacy_bitcode.h"
 #include "ValueEnumerator.h"
 #include "llvm/ADT/Triple.h"
 #include "llvm/Bitcode/BitstreamWriter.h"
@@ -165,10 +166,13 @@ static void WriteAttributeTable(const llvm_2_9_func::ValueEnumerator &VE,
   SmallVector<uint64_t, 64> Record;
   for (unsigned i = 0, e = Attrs.size(); i != e; ++i) {
     const AttributeSet &A = Attrs[i];
-    for (unsigned i = 0, e = A.getNumSlots(); i != e; ++i)
-      Record.push_back(VE.getAttributeGroupID(A.getSlotAttributes(i)));
+    for (unsigned i = 0, e = A.getNumSlots(); i != e; ++i) {
+      Record.push_back(A.getSlotIndex(i));
+      Record.push_back(encodeLLVMAttributesForBitcode(A, A.getSlotIndex(i)));
+    }
 
-    Stream.EmitRecord(bitc::PARAMATTR_CODE_ENTRY, Record);
+    // This needs to use the 3.2 entry type
+    Stream.EmitRecord(bitc::PARAMATTR_CODE_ENTRY_OLD, Record);
     Record.clear();
   }
 
diff --git a/BitWriter_3_2/Android.mk b/BitWriter_3_2/Android.mk
index f9ce5aa..6860880 100644
--- a/BitWriter_3_2/Android.mk
+++ b/BitWriter_3_2/Android.mk
@@ -3,8 +3,6 @@ LOCAL_PATH:= $(call my-dir)
 LLVM_ROOT_PATH := $(LOCAL_PATH)/../../../../external/llvm
 include $(LLVM_ROOT_PATH)/llvm.mk
 
-LOCAL_CFLAGS += $(local_cflags_for_slang)
-
 bitcode_writer_3_2_SRC_FILES :=	\
 	BitcodeWriter.cpp	\
 	BitcodeWriterPass.cpp	\
@@ -14,6 +12,9 @@ bitcode_writer_3_2_SRC_FILES :=	\
 # =====================================================
 include $(CLEAR_VARS)
 
+LOCAL_CFLAGS += $(local_cflags_for_slang)
+LOCAL_C_INCLUDES += frameworks/compile/slang
+
 LOCAL_SRC_FILES := $(bitcode_writer_3_2_SRC_FILES)
 
 LOCAL_MODULE:= libLLVMBitWriter_3_2
diff --git a/BitWriter_3_2/BitcodeWriter.cpp b/BitWriter_3_2/BitcodeWriter.cpp
index 0e3f907..ebd4d13 100644
--- a/BitWriter_3_2/BitcodeWriter.cpp
+++ b/BitWriter_3_2/BitcodeWriter.cpp
@@ -12,6 +12,7 @@
 //===----------------------------------------------------------------------===//
 
 #include "ReaderWriter_3_2.h"
+#include "legacy_bitcode.h"
 #include "ValueEnumerator.h"
 #include "llvm/ADT/Triple.h"
 #include "llvm/Bitcode/BitstreamWriter.h"
@@ -174,10 +175,13 @@ static void WriteAttributeTable(const llvm_3_2::ValueEnumerator &VE,
   SmallVector<uint64_t, 64> Record;
   for (unsigned i = 0, e = Attrs.size(); i != e; ++i) {
     const AttributeSet &A = Attrs[i];
-    for (unsigned i = 0, e = A.getNumSlots(); i != e; ++i)
-      Record.push_back(VE.getAttributeGroupID(A.getSlotAttributes(i)));
+    for (unsigned i = 0, e = A.getNumSlots(); i != e; ++i) {
+      Record.push_back(A.getSlotIndex(i));
+      Record.push_back(encodeLLVMAttributesForBitcode(A, A.getSlotIndex(i)));
+    }
 
-    Stream.EmitRecord(bitc::PARAMATTR_CODE_ENTRY, Record);
+    // This needs to use the 3.2 entry type
+    Stream.EmitRecord(bitc::PARAMATTR_CODE_ENTRY_OLD, Record);
     Record.clear();
   }
 
diff --git a/legacy_bitcode.h b/legacy_bitcode.h
new file mode 100644
index 0000000..5d45a1b
--- /dev/null
+++ b/legacy_bitcode.h
@@ -0,0 +1,32 @@
+/*
+ * Copyright 2013, The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "llvm/IR/Attributes.h"
+
+// Shared functionality for legacy function attribute encoding.
+static inline uint64_t encodeLLVMAttributesForBitcode(llvm::AttributeSet A,
+                                                      unsigned i) {
+  uint64_t EncodedAttrs = A.Raw(i) & 0xffff;
+  if (A.hasAttribute(i, llvm::Attribute::Alignment)) {
+    // The alignment is stored as an actual power of 2 value (instead of the
+    // compressed log2 form). It occupies bits 31-16 inclusive.
+    EncodedAttrs |= (A.getParamAlignment(i) << 16);
+  }
+  // There are only 12 remaining attributes (bits 21-32), hence our 0xfff mask.
+  EncodedAttrs |= (A.Raw(i) & (0xfffull << 21))  << 11;
+  return EncodedAttrs;
+}
+