tools/devshell/contrib/dis

#!/bin/bash
# Copyright 2021 The Fuchsia Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.

#### CATEGORY=Diagnostic
### Dumps disassembly for binaries from the build.

## usage: fx dis [-l | -S | -n] BINARY...
##
## Dump disassembly for a binary to a file in the build directory.
##
##   -l                        list source locations interleaved with assembly
##   -S                        list source code lines interleaved with assembly
##   -r                        list relocations interleaved with assembly
##   -n                        do not demangle symbol names
##   -L                        use llvm-objdump rather than GNU objdump
##
## Each BINARY can be the name of the binary file without directory, e.g.
## "libzircon.so" or "zircon.elf"; or the name of a GN target, e.g. "zircon".
##
## The disassembly will be written to a file next to the binary file in
## the build directory, using its name with ".lst" suffix.

set -o errexit

source "$(cd "$(dirname "${BASH_SOURCE[0]}")" >/dev/null 2>&1 && pwd)"/../lib/vars.sh || exit $?
fx-config-read

readonly BINARIES_JSON="$FUCHSIA_BUILD_DIR/binaries.json"

DEMANGLE=true
USE_LLVM=false
OBJDUMP_ARGS=()

while getopts lSrLn OPT; do
  case $OPT in
  [lSr]) OBJDUMP_ARGS+=(-$OPT) ;;
  L) USE_LLVM=true ;;
  n) DEMANGLE=false ;;
  esac
done
shift $((OPTIND-1))

if $DEMANGLE; then
  OBJDUMP_ARGS+=(--demangle)
fi

if [[ $# -eq 0 ]]; then
  fx-command-help
  exit 1
fi

FILTER=".[] | select(false"

for BINARY in "$@"; do
  DEBUG_RE="(^|/)$BINARY([.]debug)?\$"
  LABEL_RE=":$BINARY[(]"
  FILTER+=" or (.debug | test(\"$DEBUG_RE\")) or (.label | test(\"$LABEL_RE\"))"
done

FILTER+=") | [.cpu, .debug, .label] | join(\" \")"

PATHS=($(fx-command-run jq --raw-output "$FILTER" "$BINARIES_JSON"))

if (( ${#PATHS[@]} == 0 )); then
  fx-error "No binaries matched $BINARY"
  exit 1
fi

disassemble() {
  local BINARY_CPU="$1" BINARY_PATH="$2" BINARY_LABEL="$3"
  local -a CMD

  if $USE_LLVM; then
    CMD=("$PREBUILT_CLANG_DIR/bin/llvm-objdump")
  else
    case "$BINARY_CPU" in
    arm64) CMD=("$PREBUILT_GCC_DIR/bin/aarch64-elf-objdump" -m aarch64) ;;
    x64) CMD=("$PREBUILT_GCC_DIR/bin/x86_64-elf-objdump" -m i386:x86-64) ;;
    *)
      fx-error "Can't handle binary $BINARY_PATH with CPU type $BINARY_CPU"
      exit 1
      ;;
    esac
  fi

  CMD+=(-d)

  "${CMD[@]}" "${OBJDUMP_ARGS[@]}" "$FUCHSIA_BUILD_DIR/$BINARY_PATH" > "$FUCHSIA_BUILD_DIR/${BINARY_PATH}.lst"
  fx-info Wrote "${BINARY_PATH}.lst" for "$BINARY_LABEL"
}

i=0
while (( i < ${#PATHS[@]} )); do
  disassemble "${PATHS[$i]}" "${PATHS[$((i+1))]}" "${PATHS[$((i+2))]}"
  ((i+=3))
done