libunwind related patch from David Mosberger

[pf3gnuchains/gcc-fork.git] / gcc / doc / tm.texi

diff --git a/gcc/doc/tm.texi b/gcc/doc/tm.texi
index 8a0ff9b..e560412 100644 (file)
--- a/gcc/doc/tm.texi
+++ b/gcc/doc/tm.texi
@@ -50,6 +50,7 @@ through the macros defined in the @file{.h} file.
 * Mode Switching::      Insertion of mode-switching instructions.
 * Target Attributes::   Defining target-specific uses of @code{__attribute__}.
 * MIPS Coprocessors::   MIPS coprocessor support and how to customize it.
+* PCH Target::          Validity checking for precompiled headers.
 * Misc::                Everything else.
 @end menu
 
@@ -328,7 +329,7 @@ et al, within sysroot+suffix.
 @defmac SYSROOT_HEADERS_SUFFIX_SPEC
 Define this macro to add a headers_suffix to the target sysroot when
 GCC is configured with a sysroot.  This will cause GCC to pass the
-updated sysroot+headers_suffix to CPP@, causing it to search for
+updated sysroot+headers_suffix to CPP, causing it to search for
 usr/include, et al, within sysroot+headers_suffix.
 @end defmac
 
@@ -3902,6 +3903,18 @@ need more space than is implied by @code{FUNCTION_VALUE_REGNO_P} for
 saving and restoring an arbitrary return value.
 @end defmac
 
+@deftypefn {Target Hook} bool TARGET_RETURN_IN_MSB (tree @var{type})
+This hook should return true if values of type @var{type} are returned
+at the most significant end of a register (in other words, if they are
+padded at the least significant end).  You can assume that @var{type}
+is returned in a register; the caller is required to check this.
+
+Note that the register provided by @code{FUNCTION_VALUE} must be able
+to hold the complete return value.  For example, if a 1-, 2- or 3-byte
+structure is returned at the most significant end of a 4-byte register,
+@code{FUNCTION_VALUE} should provide an @code{SImode} rtx.
+@end deftypefn
+
 @node Aggregate Return
 @subsection How Large Values Are Returned
 @cindex aggregates as return values
@@ -7199,12 +7212,6 @@ writing conditional output routines in those patterns.
 If this macro is not defined, it is equivalent to a null statement.
 @end defmac
 
-@defmac FINAL_PRESCAN_LABEL
-If defined, @code{FINAL_PRESCAN_INSN} will be called on each
-@code{CODE_LABEL}.  In that case, @var{opvec} will be a null pointer and
-@var{noperands} will be zero.
-@end defmac
-
 @defmac PRINT_OPERAND (@var{stream}, @var{x}, @var{code})
 A C compound statement to output to stdio stream @var{stream} the
 assembler syntax for an instruction operand @var{x}.  @var{x} is an
@@ -8387,6 +8394,30 @@ alternate names of coprocessor registers.  The format of each entry should be
 Default: empty.
 @end defmac
 
+@node PCH Target
+@section Parameters for Precompiled Header Validity Checking
+@cindex parameters, precompiled headers
+
+@deftypefn {Target Hook} void * TARGET_GET_PCH_VALIDITY (size_t * @var{sz})
+Define this hook if your target needs to check a different collection
+of flags than the default, which is every flag defined by
+@code{TARGET_SWITCHES} and @code{TARGET_OPTIONS}.  It should return
+some data which will be saved in the PCH file and presented to
+@code{TARGET_PCH_VALID_P} later; it should set @code{SZ} to the size
+of the data.
+@end deftypefn
+
+@deftypefn {Target Hook} const char * TARGET_PCH_VALID_P (const void * @var{data}, size_t @var{sz})
+Define this hook if your target needs to check a different collection of
+flags than the default, which is every flag defined by @code{TARGET_SWITCHES}
+and @code{TARGET_OPTIONS}.  It is given data which came from
+@code{TARGET_GET_PCH_VALIDITY} (in this version of this compiler, so there
+is no need for extensive validity checking).  It returns @code{NULL} if
+it is safe to load a PCH file with this data, or a suitable error message
+if not.  The error message will be presented to the user, so it should
+be localised.
+@end deftypefn
+
 @node Misc
 @section Miscellaneous Parameters
 @cindex parameters, miscellaneous