From f7cb2b90b11696971f7de991de3a38e71320f85c Mon Sep 17 00:00:00 2001 From: Jim Blandy Date: Wed, 23 Feb 2000 19:45:45 +0000 Subject: [PATCH] * gdbint.texinfo (FUNCTION_START_OFFSET): Document. --- gdb/doc/gdbint.texinfo | 14 ++++++++++++++ 1 file changed, 14 insertions(+) diff --git a/gdb/doc/gdbint.texinfo b/gdb/doc/gdbint.texinfo index 7b4a4f4..15dc2aa 100644 --- a/gdb/doc/gdbint.texinfo +++ b/gdb/doc/gdbint.texinfo @@ -1440,6 +1440,20 @@ function end symbol is 0. For such targets, you must define @code{FUNCTION_EPILOGUE_SIZE} to expand into the standard size of a function's epilogue. +@item FUNCTION_START_OFFSET +An integer, giving the offset in bytes from a function's address (as +used in the values of symbols, function pointers, etc.), and the +function's first genuine instruction. + +This is zero on almost all machines: the function's address is usually +the address of its first instruction. However, on the VAX, for example, +each function starts with two bytes containing a bitmask indicating +which registers to save upon entry to the function. The VAX @code{call} +instructions check this value, and save the appropriate registers +automatically. Thus, since the offset from the function's address to +its first instruction is two bytes, @code{FUNCTION_START_OFFSET} would +be 2 on the VAX. + @item GCC_COMPILED_FLAG_SYMBOL @item GCC2_COMPILED_FLAG_SYMBOL If defined, these are the names of the symbols that GDB will look for to -- 2.7.4