Sorry for such a large commit. The summary is that only MachO cares about the

actuall addresses in a .o file, so it is better to let the MachO writer compute
it.

This is good for two reasons. First, areas that shouldn't care about
addresses now don't have access to it. Second, the layout of each section
is independent. I should use this in a subsequent commit to speed it up.

Most of the patch is just removing the section address computation. The two
interesting parts are the change on how we handle padding in the end
of sections and how MachO can get the address of a-b when a and b are in
different sections.

Since now the expression evaluation normally doesn't know the section address,
it will think that a-b needs relocation and let the MachO writer know. Once
it has computed the section addresses, it calls back the expression evaluation
with the section addresses to resolve these expressions.

The remaining problem is the handling of padding. Currently it will create
a special alignment fragment at the end. Since that fragment doesn't update
the alignment of the section, it needs the real address to be computed.

Since now the layout will not compute a-b with a and b in different sections,
the only effect that the special alignment fragment has is update the
address size of the section. This can also be done by the MachO writer.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121076 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 0 insertions, 23 deletions

diff --git a/include/llvm/MC/MCAsmLayout.h b/include/llvm/MC/MCAsmLayout.h
index ce9692dcaf..805af6257f 100644
--- a/include/llvm/MC/MCAsmLayout.h
+++ b/include/llvm/MC/MCAsmLayout.h
@@ -66,11 +66,6 @@ public:
   /// been initialized.
   void LayoutFragment(MCFragment *Fragment);
 
-  /// \brief Performs initial layout for a single section, assuming that the
-  /// previous section (including its fragments) has already been layed out
-  /// correctly.
-  void LayoutSection(MCSectionData *SD);
-
   /// @name Section Access (in layout order)
   /// @{
 
@@ -93,20 +88,9 @@ public:
   uint64_t getFragmentOffset(const MCFragment *F) const;
 
   /// @}
-  /// @name Section Layout Data
-  /// @{
-
-  /// \brief Get the computed address of the given section.
-  uint64_t getSectionAddress(const MCSectionData *SD) const;
-
-  /// @}
   /// @name Utility Functions
   /// @{
 
-  /// \brief Get the address of the given fragment, as computed in the current
-  /// layout.
-  uint64_t getFragmentAddress(const MCFragment *F) const;
-
   /// \brief Get the address space size of the given section, as it effects
   /// layout. This may differ from the size reported by \see getSectionSize() by
   /// not including section tail padding.
@@ -116,13 +100,6 @@ public:
   /// file. This may include additional padding, or be 0 for virtual sections.
   uint64_t getSectionFileSize(const MCSectionData *SD) const;
 
-  /// \brief Get the logical data size of the given section.
-  uint64_t getSectionSize(const MCSectionData *SD) const;
-
-  /// \brief Get the address of the given symbol, as computed in the current
-  /// layout.
-  uint64_t getSymbolAddress(const MCSymbolData *SD) const;
-
   /// \brief Get the offset of the given symbol, as computed in the current
   /// layout.
   uint64_t getSymbolOffset(const MCSymbolData *SD) const;