linking pdfium on linux - c++

Question

I'm trying to use the pdfium libraries in linux(debian 64-bit). I managed (finally) to compile the release _x64 version of pdfium and the test programs seem to work. However, I can't seem to to use the libraries in a separate project.
This is my file:
#include <iostream>
#include "fpdfview.h"
#include "fpdftext.h"
#include "fpdfdoc.h"
#include "fpdfedit.h"
main(){
FPDF_InitLibrary();
std::cout << "Hello World!"<<std::endl;
return 0;
}
And this is my Makefile:
CC = g++
CFLAGS = -Wall -g -Wno-unused-variable -Wno-reorder -I/usr/include/pdfium/core/include -I/usr/include/pdfium/fpdfsdk/include -I/usr/include/pdfium/third_party -I/usr/include/pdfium/v8/include
LIBS_pdfium = -static -L/usr/lib/pdfium
LDFLAGS = $(LIBS_pdfium)
Main : Main.o
${CC} ${CFLAGS} Main.o ${LDFLAGS} -o Main
Main.o : Main.cpp
${CC} ${CFLAGS} -c -std=c++11 Main.cpp
clean:
rm *o Main
When I run the makefile the result is:
g++ -Wall -g -Wno-unused-variable -Wno-reorder -I/usr/include/pdfium/core/include -I/usr/include/pdfium/fpdfsdk/include -I/usr/include/pdfium/third_party -I/usr/include/pdfium/v8/include Main.o -static -L/usr/lib/pdfium -o Main
Main.cpp:11: error: undefined reference to 'FPDF_InitLibrary'
collect2: error: ld returned 1 exit status
I've also tried to use the libraries in /home/username/pdfium/out/Release_x64/obj but got the same error
I know that error: undefined reference to FPDF_InitLibrary means that there is a linking error. Therefore I checked the libraries in /home/username/pdfium/out/Release_x64/obj using objdump and one of them contained the InitLibrary symbol. This doesn't seem to make sense...
I don't know if I am referring to the wrong paths in the include or the libraries or if it is something else that is wrong.
I tried to understand the chromiums pdf plugin project makefile since I thought that might help me understand what I am supposed to use but unfortunately it didn't help.
Any ideas for what I am doing wrong?

Answer 1

To compile with PDFium the link line will depend on if you've compiled V8 and/or XFA into your PDFium binary.
With neither of those things enabled you'll need something similar to:
PDF_LIBS="-lpdfium -lfpdfapi -lfxge -lfpdfdoc -lfxcrt -lfx_agg \
-lfxcodec -lfx_lpng -lfx_libopenjpeg -lfx_lcms2 -lfx_freetype -ljpeg \
-lfx_zlib -lfdrm -lpdfwindow -lbigint -lformfiller -ljavascript \
-lfxedit"
PDF_DIR=<path/to/pdfium>
clang -I $PDF_DIR/public -o foo foo.c -L $PDF_DIR/out/Debug -lstdc++ -framework AppKit $PDF_LIBS
public/ is the only directory you should use when working with PDFium for headers. The -framework AppKit is needed on OSX. The PDFium headers are in plain C but you need -lstdc++ as PDFium uses C++ internally and it needs to be able to link in new/delete.
If you're working with V8 you'll need to add in:
-lv8_libbase -lv8_libplatform -lv8_snapshot -licui18n -licuuc -licudata
and if you're using XFA you'll need the V8 includes plus:
-lfpdfxfa -lxfa -lfx_tiff
EDIT
There was recently a pdf_is_complete_lib option added to the PDFium build. Setting that to true in your gn args will create a single libpdfium that can be linked agains. Note, this has only been tested with V8 and XFA disabled.

Answer 2

Args file..
# Build arguments go here.
# See "gn args <out_dir> --list" for available build arguments.
is_debug = false
pdf_is_standalone = true
pdf_use_skia = false
pdf_use_skia_paths = false
pdf_enable_xfa = false
pdf_enable_v8 = false
is_component_build = false
clang_use_chrome_plugins = false
pdf_is_complete_lib = true
use_custom_libcxx = false
Then gn gen your/dir/catalog.
Then ninja -C your/dir/catalog pdfium_all and you take pdfium.a
In Linker
...
g++ -L-I/usr/include/glib-2.0 -o bin/debug/pdfium_test obj/debug/main.o
...
you must have
-pg -s -Wl,--start-group /home/a/repo/pdfium/out/release/obj/libpdfium.a -Wl,--end-group -lpthread -ldl -lpthread
Linking is ok.

Answer 3

I haven't personally built it - because it was too time taking. But I managed to make it work with my golang application using cgo. I used ubuntu 16.04 as my base image in docker. This depends on https://github.com/bblanchon/pdfium-binaries
Following dockerfile downloads the pdfium binary and links to the app you are developing using pkg-config.
FROM ubuntu:16.04
# Specify pdfium version
ARG PdfiumVersion=4026
# Install pkg-config, etc.
RUN apt-get -yqq update && apt-get clean && apt-get install -yqq apt-utils pkg-config tzdata && dpkg-reconfigure -f noninteractive tzdata
# Create .pc file for pkg-config
RUN echo "\n" \
"prefix=/home\n" \
"Name: pdfium\n" \
"Description: pdfium\n" \
"Version: $PdfiumVersion\n" \
"Requires:\n" \
"Libs: -L/home/lib -lpdfium\n" \
"Cflags: -I/home/include\n" > /home/pdfium.pc
# Download and extract pdfium binary
RUN cd /home && wget --quiet https://github.com/bblanchon/pdfium-binaries/releases/download/chromium%2F$PdfiumVersion/pdfium-linux.tgz \
&& tar -xf pdfium-linux.tgz && rm pdfium-linux.tgz
# Setting up paths for pkg-config
ENV LD_LIBRARY_PATH=/home/lib
ENV PKG_CONFIG_PATH=/home/
## COPY YOUR APP TO /app/src/yourApp
# BUILD YOUR APP
WORKDIR /app/src/yourApp
# RUN your app which is linked to pdfium
ENTRYPOINT [“./yourApp"]