Add a target asm info hook to specify that particular bits of data in the FDE

should be forced to 32-bits (.long) even on 64-bit architectures. Darwin wants
these bits to be 64-bits (.quad). However, other platforms may disagree.

This is just the info right now and is part of a work-in-progress which needs
this. We'll add the actual *use* of this soon.

llvm-svn: 80024

llvm/include/llvm/MC/MCAsmInfo.h

@@ -254,34 +254,28 @@ namespace llvm {
     //===--- Dwarf Emission Directives -----------------------------------===//
 
     /// AbsoluteDebugSectionOffsets - True if we should emit abolute section
-    /// offsets for debug information. Defaults to false.
-    bool AbsoluteDebugSectionOffsets;
+    /// offsets for debug information.
+    bool AbsoluteDebugSectionOffsets;        // Defaults to false.
 
     /// AbsoluteEHSectionOffsets - True if we should emit abolute section
     /// offsets for EH information. Defaults to false.
     bool AbsoluteEHSectionOffsets;
 
     /// HasLEB128 - True if target asm supports leb128 directives.
-    ///
     bool HasLEB128;                          // Defaults to false.
 
     /// hasDotLocAndDotFile - True if target asm supports .loc and .file
     /// directives for emitting debugging information.
-    ///
     bool HasDotLocAndDotFile;                // Defaults to false.
 
     /// SupportsDebugInformation - True if target supports emission of debugging
     /// information.
-    bool SupportsDebugInformation;
+    bool SupportsDebugInformation;           // Defaults to false.
 
-    /// SupportsExceptionHandling - True if target supports
-    /// exception handling.
-    ///
-    // Defaults to None
-    ExceptionHandling::ExceptionsType ExceptionsType;
+    /// SupportsExceptionHandling - True if target supports exception handling.
+    ExceptionHandling::ExceptionsType ExceptionsType; // Defaults to None
 
     /// RequiresFrameSection - true if the Dwarf2 output needs a frame section
-    ///
     bool DwarfRequiresFrameSection;          // Defaults to true.
 
     /// DwarfUsesInlineInfoSection - True if DwarfDebugInlineSection is used to
@@ -292,9 +286,12 @@ namespace llvm {
     /// doesn't show up in the symbol table of the object file.
     bool Is_EHSymbolPrivate;                 // Defaults to true.
 
+    /// ForceEncodingOfFDETo32Bits - If set, the encoding of some of the FDE
+    /// data is forced to 32-bit.
+    bool ForceEncodingOfFDETo32Bits;         // Defaults to true.
+
     /// GlobalEHDirective - This is the directive used to make exception frame
     /// tables globally visible.
-    ///
     const char *GlobalEHDirective;           // Defaults to NULL.
 
     /// SupportsWeakEmptyEHFrame - True if target assembler and linker will
@@ -508,6 +505,9 @@ namespace llvm {
     bool is_EHSymbolPrivate() const {
       return Is_EHSymbolPrivate;
     }
+    bool forceEncodingOfFDETo32Bits() const {
+      return ForceEncodingOfFDETo32Bits;
+    }
     const char *getGlobalEHDirective() const {
       return GlobalEHDirective;
     }

llvm/lib/MC/MCAsmInfo.cpp

@@ -78,6 +78,7 @@ MCAsmInfo::MCAsmInfo() {
   DwarfRequiresFrameSection = true;
   DwarfUsesInlineInfoSection = false;
   Is_EHSymbolPrivate = true;
+  ForceEncodingOfFDETo32Bits = true;
   GlobalEHDirective = 0;
   SupportsWeakOmittedEHFrame = true;
   DwarfSectionOffsetDirective = 0;

llvm/lib/MC/MCAsmInfoDarwin.cpp

@@ -52,6 +52,7 @@ MCAsmInfoDarwin::MCAsmInfoDarwin() {
   // doesn't hurt anything.
   // FIXME: I need to get this from Triple.
   Is_EHSymbolPrivate = false;
+  ForceEncodingOfFDETo32Bits = false;
   GlobalEHDirective = "\t.globl\t";
   SupportsWeakOmittedEHFrame = false;