From: Justin Hibbits <jrh29@alumni.cwru.edu>
Date: Fri, 7 Nov 2014 04:46:10 +0000 (+0000)
Subject: Add Position-independent Code model Module API.
X-Git-Tag: android-x86-7.1-r4~55713
X-Git-Url: http://git.osdn.net/view?a=commitdiff_plain;h=893f22f88245d29487e1fff662ac9e78f86f8e91;p=android-x86%2Fexternal-llvm.git

Add Position-independent Code model Module API.

Summary:
This makes PIC levels a Module flag attribute, which can be queried by the
backend.  The flag is named `PIC Level`, and can have a value of:

  0 - Backend-default
  1 - Small-model (-fpic)
  2 - Large-model (-fPIC)

These match the `-pic-level' command line argument for clang, and the value of the
preprocessor macro `__PIC__'.

Test Plan:
New flags tests specific for the 'PIC Level' module flag.
Tests to be added as part of a future commit for PowerPC, which will use this new API.

Reviewers: rafael, echristo

Reviewed By: rafael, echristo

Subscribers: rafael, llvm-commits

Differential Revision: http://reviews.llvm.org/D5882

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221510 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/include/llvm/IR/Module.h b/include/llvm/IR/Module.h
index 8bf67a3efea..23bdde56c71 100644
--- a/include/llvm/IR/Module.h
+++ b/include/llvm/IR/Module.h
@@ -23,6 +23,7 @@
 #include "llvm/IR/GlobalVariable.h"
 #include "llvm/IR/Metadata.h"
 #include "llvm/Support/CBindingWrapping.h"
+#include "llvm/Support/CodeGen.h"
 #include "llvm/Support/DataTypes.h"
 #include <system_error>
 
@@ -634,6 +635,15 @@ public:
   unsigned getDwarfVersion() const;
 
 /// @}
+/// @name Utility functions for querying and setting PIC level
+/// @{
+
+  /// \brief Returns the PIC level (small or large model)
+  PICLevel::Level getPICLevel() const;
+
+  /// \brief Set the PIC level (small or large model)
+  void setPICLevel(PICLevel::Level PL);
+/// @}
 };
 
 /// An raw_ostream inserter for modules.
diff --git a/include/llvm/Support/CodeGen.h b/include/llvm/Support/CodeGen.h
index 240eba6c8a4..243f2dd7498 100644
--- a/include/llvm/Support/CodeGen.h
+++ b/include/llvm/Support/CodeGen.h
@@ -30,6 +30,10 @@ namespace llvm {
     enum Model { Default, JITDefault, Small, Kernel, Medium, Large };
   }
 
+  namespace PICLevel {
+    enum Level { Default=0, Small=1, Large=2 };
+  }
+
   // TLS models.
   namespace TLSModel {
     enum Model {
diff --git a/lib/IR/Module.cpp b/lib/IR/Module.cpp
index 35d28481fcb..bc50db3f56c 100644
--- a/lib/IR/Module.cpp
+++ b/lib/IR/Module.cpp
@@ -459,3 +459,16 @@ Comdat *Module::getOrInsertComdat(StringRef Name) {
   Entry.second.Name = &Entry;
   return &Entry.second;
 }
+
+PICLevel::Level Module::getPICLevel() const {
+  Value *Val = getModuleFlag("PIC Level");
+
+  if (Val == NULL)
+    return PICLevel::Default;
+
+  return static_cast<PICLevel::Level>(cast<ConstantInt>(Val)->getZExtValue());
+}
+
+void Module::setPICLevel(PICLevel::Level PL) {
+  addModuleFlag(ModFlagBehavior::Error, "PIC Level", PL);
+}
diff --git a/test/Linker/Inputs/module-flags-pic-1-b.ll b/test/Linker/Inputs/module-flags-pic-1-b.ll
new file mode 100644
index 00000000000..8b137891791
--- /dev/null
+++ b/test/Linker/Inputs/module-flags-pic-1-b.ll
@@ -0,0 +1 @@
+
diff --git a/test/Linker/Inputs/module-flags-pic-2-b.ll b/test/Linker/Inputs/module-flags-pic-2-b.ll
new file mode 100644
index 00000000000..228e04ab4da
--- /dev/null
+++ b/test/Linker/Inputs/module-flags-pic-2-b.ll
@@ -0,0 +1,3 @@
+!0 = metadata !{ i32 1, metadata !"PIC Level", i32 2 }
+
+!llvm.module.flags = !{!0}
diff --git a/test/Linker/module-flags-pic-1-a.ll b/test/Linker/module-flags-pic-1-a.ll
new file mode 100644
index 00000000000..bc4da9541ac
--- /dev/null
+++ b/test/Linker/module-flags-pic-1-a.ll
@@ -0,0 +1,9 @@
+; RUN: llvm-link %s %p/Inputs/module-flags-pic-1-b.ll -S -o - | FileCheck %s
+
+; test linking modules with specified and default PIC levels
+
+!0 = metadata !{ i32 1, metadata !"PIC Level", i32 1 }
+
+!llvm.module.flags = !{!0}
+; CHECK: !llvm.module.flags = !{!0}
+; CHECK: !0 = metadata !{i32 1, metadata !"PIC Level", i32 1}
diff --git a/test/Linker/module-flags-pic-2-a.ll b/test/Linker/module-flags-pic-2-a.ll
new file mode 100644
index 00000000000..3ff9c8ffe83
--- /dev/null
+++ b/test/Linker/module-flags-pic-2-a.ll
@@ -0,0 +1,10 @@
+; RUN: not llvm-link %s %p/Inputs/module-flags-pic-2-b.ll -S -o - 2> %t
+; RUN: FileCheck --check-prefix=CHECK-ERRORS < %t %s
+
+; test linking modules with two different PIC levels
+
+!0 = metadata !{ i32 1, metadata !"PIC Level", i32 1 }
+
+!llvm.module.flags = !{!0}
+
+; CHECK-ERRORS: ERROR: linking module flags 'PIC Level': IDs have conflicting values