Make the llvm mangler depend only on DataLayout.

Before this patch any program that wanted to know the final symbol name of a
GlobalValue had to link with Target.

This patch implements a compromise solution where the mangler uses DataLayout.
This way, any tool that already links with Target (llc, clang) gets the exact
behavior as before and new IR files can be mangled without linking with Target.

With this patch the mangler is constructed with just a DataLayout and DataLayout
is extended to include the information the Mangler needs.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@198438 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 53 insertions, 0 deletions

diff --git a/include/llvm/IR/DataLayout.h b/include/llvm/IR/DataLayout.h
index a1776fbf9b..520d4ede18 100644
--- a/include/llvm/IR/DataLayout.h
+++ b/include/llvm/IR/DataLayout.h
@@ -34,6 +34,7 @@ class Type;
 class IntegerType;
 class StructType;
 class StructLayout;
+class Triple;
 class GlobalVariable;
 class LLVMContext;
 template<typename T>
@@ -99,6 +100,15 @@ private:
   bool          LittleEndian;          ///< Defaults to false
   unsigned      StackNaturalAlign;     ///< Stack natural alignment
 
+  enum ManglingModeT {
+    MM_None,
+    MM_ELF,
+    MM_MachO,
+    MM_COFF,
+    MM_Mips
+  };
+  ManglingModeT ManglingMode;
+
   SmallVector<unsigned char, 8> LegalIntWidths; ///< Legal Integers.
 
   /// Alignments - Where the primitive type alignment data is stored.
@@ -174,6 +184,7 @@ public:
     ImmutablePass(ID),
     LittleEndian(DL.isLittleEndian()),
     StackNaturalAlign(DL.StackNaturalAlign),
+    ManglingMode(DL.ManglingMode),
     LegalIntWidths(DL.LegalIntWidths),
     Alignments(DL.Alignments),
     Pointers(DL.Pointers),
@@ -222,6 +233,48 @@ public:
     return (StackNaturalAlign != 0) && (Align > StackNaturalAlign);
   }
 
+  bool hasMicrosoftFastStdCallMangling() const {
+    return ManglingMode == MM_COFF;
+  }
+
+  bool hasLinkerPrivateGlobalPrefix() const {
+    return ManglingMode == MM_MachO;
+  }
+
+  const char *getLinkerPrivateGlobalPrefix() const {
+    if (ManglingMode == MM_MachO)
+      return "l";
+    return getPrivateGlobalPrefix();
+  }
+
+  char getGlobalPrefix() const {
+    switch (ManglingMode) {
+    case MM_None:
+    case MM_ELF:
+    case MM_Mips:
+      return '\0';
+    case MM_MachO:
+    case MM_COFF:
+      return '_';
+    }
+  }
+
+  const char *getPrivateGlobalPrefix() const {
+    switch (ManglingMode) {
+    case MM_None:
+      return "";
+    case MM_ELF:
+      return ".L";
+    case MM_Mips:
+      return "$";
+    case MM_MachO:
+    case MM_COFF:
+      return "L";
+    }
+  }
+
+  static const char *getManglingComponent(const Triple &T);
+
   /// fitsInLegalInteger - This function returns true if the specified type fits
   /// in a native integer type supported by the CPU.  For example, if the CPU
   /// only supports i32 as a native integer type, then i27 fits in a legal