DWARF_EXPR_INTO_BLOCK(3)

okay so bestie, welcome to DWARF_EXPR_INTO_BLOCK(3) from the Library Functions Manual ✨ this is the little libdwarf cutie that pulls the raw byte-stream glow-up out of a location expression, and it’s giving very “I know exactly what I’m doing” energy 💅

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🌸 NAME 🌸

dwarf_expr_into_block — retrieve the byte stream for a location expression 🎀

🦋 LIBRARY 🦋

DWARF Access Library (libdwarf, -ldwarf) — yes, that’s the one, bestie 💖

✨ SYNOPSIS ✨

#include <libdwarf.h>

Dwarf_Addr
dwarf_expr_into_block(Dwarf_P_Expr expr, Dwarf_Unsigned *length,
    Dwarf_Error *err);

💜 DESCRIPTION 💜

Function dwarf_expr_into_block() retrieves the byte stream representation of a location expression. It’s literally handing you the generated bytes, no cap 🫶

Argument expr should reference a location expression descriptor allocated using dwarf_new_expr(3). That’s the main-character descriptor right there 👑

Argument length should point to a location which will hold the size in bytes of the retrieved byte stream. So yeah, it’s where the “how many bytes, bestie?” number goes 📏

If argument err is not NULL, it will be used to store error information in case of an error. Very “if things go sideways, the tea gets saved here” energy ☕😭

⭐ RETURN VALUES ⭐

On success, function dwarf_expr_into_block() returns the address of the first byte of the generated byte stream. First byte, front of the line, main character energy 💅✨

In case of an error, function dwarf_expr_into_block() returns DW_DLV_BADADDR and sets the argument err. So if you see DW_DLV_BADADDR, that’s the “nope, check err” moment, fr fr 💀

🔥 ERRORS 🔥

Function dwarf_expr_into_block() can fail with:

• [DW_DLE_ARGUMENT] — one of the arguments expr or length was NULL. Not the NULL vibe check we wanted, bestie 🙈
• [DW_DLE_MEMORY] — an out of memory condition was encountered during the execution of the function. The memory budget said “no thoughts, head empty” 😭

🌈 SEE ALSO 🌈

dwarf(3), dwarf_add_AT_location_expr(3), dwarf_add_expr_addr(3), dwarf_add_expr_addr_b(3), dwarf_add_expr_gen(3), dwarf_expr_current_offset(3), dwarf_new_expr(3)

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This page was brought to you by Debian, dated September 13, 2011 🎀🦋 periodt, go read your libdwarf docs bestie 💖