[libunwind][NFC] Fix whitespace in comments

Author: ldionne

libunwind/include/mach-o/compact_unwind_encoding.h

@@ -108,7 +108,7 @@ enum {
 //    are encoded in the UNWIND_X86_EBP_FRAME_REGISTERS bits as five 3-bit entries.
 //    Each entry contains which register to restore.
 // UNWIND_X86_MODE_STACK_IMMD:
-//    A "frameless" (EBP not used as frame pointer) function with a small 
+//    A "frameless" (EBP not used as frame pointer) function with a small
 //    constant stack size.  To return, a constant (encoded in the compact
 //    unwind encoding) is added to the ESP. Then the return is done by
 //    popping the stack into the pc.
@@ -119,16 +119,16 @@ enum {
 //    UNWIND_X86_FRAMELESS_STACK_REG_PERMUTATION contains which registers were
 //    saved and their order.
 // UNWIND_X86_MODE_STACK_IND:
-//    A "frameless" (EBP not used as frame pointer) function large constant 
+//    A "frameless" (EBP not used as frame pointer) function large constant
 //    stack size.  This case is like the previous, except the stack size is too
-//    large to encode in the compact unwind encoding.  Instead it requires that 
-//    the function contains "subl $nnnnnnnn,ESP" in its prolog.  The compact 
+//    large to encode in the compact unwind encoding.  Instead it requires that
+//    the function contains "subl $nnnnnnnn,ESP" in its prolog.  The compact
 //    encoding contains the offset to the nnnnnnnn value in the function in
-//    UNWIND_X86_FRAMELESS_STACK_SIZE.  
+//    UNWIND_X86_FRAMELESS_STACK_SIZE.
 // UNWIND_X86_MODE_DWARF:
 //    No compact unwind encoding is available.  Instead the low 24-bits of the
 //    compact encoding is the offset of the DWARF FDE in the __eh_frame section.
-//    This mode is never used in object files.  It is only generated by the 
+//    This mode is never used in object files.  It is only generated by the
 //    linker in final linked images which have only DWARF unwind info for a
 //    function.
 //
@@ -233,36 +233,36 @@ enum {
 // For x86_64 there are four modes for the compact unwind encoding:
 // UNWIND_X86_64_MODE_RBP_FRAME:
 //    RBP based frame where RBP is push on stack immediately after return address,
-//    then RSP is moved to RBP. Thus, to unwind RSP is restored with the current 
-//    EPB value, then RBP is restored by popping off the stack, and the return 
+//    then RSP is moved to RBP. Thus, to unwind RSP is restored with the current
+//    EPB value, then RBP is restored by popping off the stack, and the return
 //    is done by popping the stack once more into the pc.
 //    All non-volatile registers that need to be restored must have been saved
-//    in a small range in the stack that starts RBP-8 to RBP-2040.  The offset/8 
+//    in a small range in the stack that starts RBP-8 to RBP-2040.  The offset/8
 //    is encoded in the UNWIND_X86_64_RBP_FRAME_OFFSET bits.  The registers saved
 //    are encoded in the UNWIND_X86_64_RBP_FRAME_REGISTERS bits as five 3-bit entries.
-//    Each entry contains which register to restore.  
+//    Each entry contains which register to restore.
 // UNWIND_X86_64_MODE_STACK_IMMD:
-//    A "frameless" (RBP not used as frame pointer) function with a small 
-//    constant stack size.  To return, a constant (encoded in the compact 
-//    unwind encoding) is added to the RSP. Then the return is done by 
+//    A "frameless" (RBP not used as frame pointer) function with a small
+//    constant stack size.  To return, a constant (encoded in the compact
+//    unwind encoding) is added to the RSP. Then the return is done by
 //    popping the stack into the pc.
 //    All non-volatile registers that need to be restored must have been saved
 //    on the stack immediately after the return address.  The stack_size/8 is
 //    encoded in the UNWIND_X86_64_FRAMELESS_STACK_SIZE (max stack size is 2048).
 //    The number of registers saved is encoded in UNWIND_X86_64_FRAMELESS_STACK_REG_COUNT.
 //    UNWIND_X86_64_FRAMELESS_STACK_REG_PERMUTATION contains which registers were
-//    saved and their order.  
+//    saved and their order.
 // UNWIND_X86_64_MODE_STACK_IND:
-//    A "frameless" (RBP not used as frame pointer) function large constant 
+//    A "frameless" (RBP not used as frame pointer) function large constant
 //    stack size.  This case is like the previous, except the stack size is too
-//    large to encode in the compact unwind encoding.  Instead it requires that 
-//    the function contains "subq $nnnnnnnn,RSP" in its prolog.  The compact 
+//    large to encode in the compact unwind encoding.  Instead it requires that
+//    the function contains "subq $nnnnnnnn,RSP" in its prolog.  The compact
 //    encoding contains the offset to the nnnnnnnn value in the function in
-//    UNWIND_X86_64_FRAMELESS_STACK_SIZE.  
+//    UNWIND_X86_64_FRAMELESS_STACK_SIZE.
 // UNWIND_X86_64_MODE_DWARF:
 //    No compact unwind encoding is available.  Instead the low 24-bits of the
 //    compact encoding is the offset of the DWARF FDE in the __eh_frame section.
-//    This mode is never used in object files.  It is only generated by the 
+//    This mode is never used in object files.  It is only generated by the
 //    linker in final linked images which have only DWARF unwind info for a
 //    function.
 //
@@ -307,20 +307,20 @@ enum {
 //    This is a standard arm64 prolog where FP/LR are immediately pushed on the
 //    stack, then SP is copied to FP. If there are any non-volatile registers
 //    saved, then are copied into the stack frame in pairs in a contiguous
-//    range right below the saved FP/LR pair.  Any subset of the five X pairs 
+//    range right below the saved FP/LR pair.  Any subset of the five X pairs
 //    and four D pairs can be saved, but the memory layout must be in register
-//    number order.  
+//    number order.
 // UNWIND_ARM64_MODE_FRAMELESS:
-//    A "frameless" leaf function, where FP/LR are not saved. The return address 
+//    A "frameless" leaf function, where FP/LR are not saved. The return address
 //    remains in LR throughout the function. If any non-volatile registers
 //    are saved, they must be pushed onto the stack before any stack space is
 //    allocated for local variables.  The stack sized (including any saved
-//    non-volatile registers) divided by 16 is encoded in the bits 
+//    non-volatile registers) divided by 16 is encoded in the bits
 //    UNWIND_ARM64_FRAMELESS_STACK_SIZE_MASK.
 // UNWIND_ARM64_MODE_DWARF:
 //    No compact unwind encoding is available.  Instead the low 24-bits of the
 //    compact encoding is the offset of the DWARF FDE in the __eh_frame section.
-//    This mode is never used in object files.  It is only generated by the 
+//    This mode is never used in object files.  It is only generated by the
 //    linker in final linked images which have only DWARF unwind info for a
 //    function.
 //
@@ -337,19 +337,19 @@ enum {
 
 //
 // A compiler can generated compact unwind information for a function by adding
-// a "row" to the __LD,__compact_unwind section.  This section has the 
-// S_ATTR_DEBUG bit set, so the section will be ignored by older linkers. 
-// It is removed by the new linker, so never ends up in final executables. 
-// This section is a table, initially with one row per function (that needs 
+// a "row" to the __LD,__compact_unwind section.  This section has the
+// S_ATTR_DEBUG bit set, so the section will be ignored by older linkers.
+// It is removed by the new linker, so never ends up in final executables.
+// This section is a table, initially with one row per function (that needs
 // unwind info).  The table columns and some conceptual entries are:
 //
 //     range-start               pointer to start of function/range
-//     range-length              
-//     compact-unwind-encoding   32-bit encoding  
+//     range-length
+//     compact-unwind-encoding   32-bit encoding
 //     personality-function      or zero if no personality function
 //     lsda                      or zero if no LSDA data
 //
-// The length and encoding fields are 32-bits.  The other are all pointer sized. 
+// The length and encoding fields are 32-bits.  The other are all pointer sized.
 //
 // In x86_64 assembly, these entry would look like:
 //
@@ -372,23 +372,23 @@ enum {
 //     .quad    except_tab1
 //
 //
-// Notes: There is no need for any labels in the the __compact_unwind section.  
-//        The use of the .set directive is to force the evaluation of the 
+// Notes: There is no need for any labels in the the __compact_unwind section.
+//        The use of the .set directive is to force the evaluation of the
 //        range-length at assembly time, instead of generating relocations.
 //
-// To support future compiler optimizations where which non-volatile registers 
+// To support future compiler optimizations where which non-volatile registers
 // are saved changes within a function (e.g. delay saving non-volatiles until
 // necessary), there can by multiple lines in the __compact_unwind table for one
-// function, each with a different (non-overlapping) range and each with 
-// different compact unwind encodings that correspond to the non-volatiles 
+// function, each with a different (non-overlapping) range and each with
+// different compact unwind encodings that correspond to the non-volatiles
 // saved at that range of the function.
 //
 // If a particular function is so wacky that there is no compact unwind way
-// to encode it, then the compiler can emit traditional DWARF unwind info.  
+// to encode it, then the compiler can emit traditional DWARF unwind info.
 // The runtime will use which ever is available.
 //
-// Runtime support for compact unwind encodings are only available on 10.6 
-// and later.  So, the compiler should not generate it when targeting pre-10.6. 
+// Runtime support for compact unwind encodings are only available on 10.6
+// and later.  So, the compiler should not generate it when targeting pre-10.6.
 
 
 
@@ -402,7 +402,7 @@ enum {
 //
 // The __TEXT,__unwind_info section is laid out for an efficient two level lookup.
 // The header of the section contains a coarse index that maps function address
-// to the page (4096 byte block) containing the unwind info for that function.  
+// to the page (4096 byte block) containing the unwind info for that function.
 //
 
 #define UNWIND_SECTION_VERSION 1