From 693a48f0700aec9406a71a1e77583977f90c9453 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Th=C3=A9ophile=20Bastian?= <contact@tobast.fr>
Date: Mon, 18 Mar 2019 14:27:24 +0100
Subject: [PATCH] Add synthesize_dwarf.sh

Update documentation and Makefile accordingly.
---
 .gitignore          |  2 ++
 Makefile            |  7 +++-
 README.md           | 22 +++++++++++--
 synthesize_dwarf.sh | 80 +++++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 108 insertions(+), 3 deletions(-)
 create mode 100755 synthesize_dwarf.sh

diff --git a/.gitignore b/.gitignore
index c5fb759..654dfd7 100644
--- a/.gitignore
+++ b/.gitignore
@@ -21,3 +21,5 @@ setup.data
 setup.log
 
 *.plugin
+ml_dwarf_write.bin
+tmp.marshal
diff --git a/Makefile b/Makefile
index 9a80d49..9fbfc32 100644
--- a/Makefile
+++ b/Makefile
@@ -3,7 +3,12 @@ BAPBUNDLE=bapbundle
 ROOT_MODULE=dwarfsynth
 
 
-all: install
+all: install ml_dwarf_write.bin
+
+.PHONY: ml_dwarf_write.bin
+ml_dwarf_write.bin:
+	$(MAKE) -C DwarfSynth/c_bindings
+	ln -fs DwarfSynth/c_bindings/ml_dwarf_write.bin .
 
 .PHONY: $(ROOT_MODULE).plugin
 $(ROOT_MODULE).plugin:
diff --git a/README.md b/README.md
index 857f0d7..b0a51cd 100644
--- a/README.md
+++ b/README.md
@@ -11,9 +11,27 @@ examine its assembly code and, based solely on that, generate the corresponding
 This tool relies on [BAP](https://github.com/BinaryAnalysisPlatform/bap), which
 is available through OPAM.
 
-## Running
+## Compiling
 
-First, run `make` to compile and install the BAP plugin.
+Simply run `make` to compile all the necessary tools, including compiling and
+installing the BAP plugin `dwarfsynth`.
+
+## Running with a wrapper script
+
+To generate an `.eh_frame` section for some binary `foo.bin` and write the
+output as `foo.eh.bin`, you can run
+
+```
+./synthesize_dwarf foo.bin foo.eh.bin
+```
+
+You can also omit the second parameter to simply overwrite `foo.bin`.
+
+## Running by hand
+
+If you want, for some reason, to run by hand the multiple components, you can
+follow this procedure (by using more appropriate file names, and, possibly, a
+temporary directory -- see `mktemp -d`).
 
 ### Running the BAP plugin
 
diff --git a/synthesize_dwarf.sh b/synthesize_dwarf.sh
new file mode 100755
index 0000000..9a66881
--- /dev/null
+++ b/synthesize_dwarf.sh
@@ -0,0 +1,80 @@
+#!/bin/bash
+
+###############################################################################
+USAGE="$0 <binary_input_file> [<binary_output_file>]"
+
+HELP_TEXT="synthesize_dwarf.sh
+Script that sticks all the parts of dwarf-synthesis together.
+
+Usage: $USAGE
+
+The provided <binary_input_file> is expected **NOT** to have any .eh_frame
+section.
+
+If <binary_output_file> is provided, a binary file equivalent to
+<binary_input_file> that contains an .eh_frame ELF section will be written as
+<binary_output_file>.
+
+If not, the input file will be overwriten with such a file."
+###############################################################################
+
+function find_ml_dwarf_write {
+    out=$(which "ml_dwarf_write.bin" 2>/dev/null)
+    if [ -n "$out" ] ; then
+        echo $out
+        return 0
+    fi
+    for location in . "$(dirname $0)" ; do
+        out="$location/ml_dwarf_write.bin"
+        if [ -x "$out" ] ; then
+            echo $out
+            return 0
+        fi
+    done
+    return 1
+}
+
+function bap_synth {
+    bap "$INPUT_FILE" -p dwarfsynth --dwarfsynth-output "$TMP_DIR/marshal" \
+        > /dev/null
+    return $?
+}
+
+function dwarf_write_synth {
+    $ML_DWARF_WRITE "$TMP_DIR/marshal" "$INPUT_FILE" "$TMP_DIR/eh_frame" \
+        > /dev/null
+    return $?
+}
+
+function dwarf_plug {
+    objcopy \
+        --add-section .eh_frame="$TMP_DIR/eh_frame" \
+        "$INPUT_FILE" "$OUTPUT_FILE"
+    return $?
+}
+
+if [ "$#" -lt "1" ] ; then
+    >&2 echo -e "Missing argument.\n\n$HELP_TEXT"
+    exit 1
+fi
+
+ML_DWARF_WRITE=$(find_ml_dwarf_write)
+if [ "$?" -ne "0" ] ; then
+    >&2 echo -e "Cannot find ml_dwarf_write"
+    exit 1
+fi
+
+INPUT_FILE="$1"
+OUTPUT_FILE="$2"
+
+if ! [ -f "$INPUT_FILE" ] ; then
+    >&2 echo -e "$INPUT_FILE: no such file.\n\n$HELP_TEXT"
+fi
+
+TMP_DIR="$(mktemp -d)"
+
+bap_synth \
+    && dwarf_write_synth \
+    && dwarf_plug
+
+rm -rf "$TMP_DIR"