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Diffstat (limited to 'gcc/doc/tm.texi')
| -rw-r--r-- | gcc/doc/tm.texi | 18 |
1 files changed, 18 insertions, 0 deletions
diff --git a/gcc/doc/tm.texi b/gcc/doc/tm.texi index 721e161..cd4ec28 100644 --- a/gcc/doc/tm.texi +++ b/gcc/doc/tm.texi @@ -1597,6 +1597,18 @@ In general, you should not have to define this macro. On architectures in which function addresses are always even, according to @code{FUNCTION_BOUNDARY}, GCC will automatically define this macro to @code{ptrmemfunc_vbit_in_pfn}. + +@findex TARGET_VTABLE_USES_DESCRIPTORS +@item TARGET_VTABLE_USES_DESCRIPTORS +Normally, the C++ compiler uses function pointers in vtables. This +macro allows the target to change to use ``function descriptors'' +instead. Function descriptors are found on targets for whom a +function pointer is actually a small data structure. Normally the +data structure consists of the actual code address plus a data +pointer to which the function's data is relative. + +If vtables are used, the value of this macro should be the number +of words that the function descriptor occupies. @end table @node Escape Sequences @@ -6012,6 +6024,12 @@ If the assembler has a @code{.ascii} pseudo-op as found in the Berkeley Unix assembler, do not define the macro @code{ASM_OUTPUT_ASCII}. +@findex ASM_OUTPUT_FDESC +@item ASM_OUTPUT_FDESC (@var{stream}, @var{decl}, @var{n}) +A C statement to output word @var{n} of a function descriptor for +@var{decl}. This must be defined if @code{TARGET_VTABLE_USES_DESCRIPTORS} +is defined, and is otherwise unused. + @findex CONSTANT_POOL_BEFORE_FUNCTION @item CONSTANT_POOL_BEFORE_FUNCTION You may define this macro as a C expression. You should define the |