[Driver][OpenMP][CUDA] Add capability to bundle object files in secti…

…ons of the host binary format.

Summary:
This patch adds the capability to bundle object files in sections of the host binary using a designated naming convention for these sections. This patch uses the functionality of the object reader already in the LLVM library to read bundled files, and invokes clang with the incremental linking options to create bundle files. 

Bundling files involves creating an IR file with the contents of the bundle assigned as initializers of globals binded to the designated sections. This way the bundling implementation is agnostic of the host object format.

The features added by this patch were requested in the RFC discussion in  http://lists.llvm.org/pipermail/cfe-dev/2016-February/047547.html.

Reviewers: echristo, tra, jlebar, hfinkel, ABataev, Hahnfeld

Subscribers: mkuron, whchung, cfe-commits, andreybokhanko, Hahnfeld, arpith-jacob, carlo.bertolli, mehdi_amini, caomhin

Differential Revision: https://reviews.llvm.org/D21851

llvm-svn: 279634

clang/test/Driver/clang-offload-bundler.c

@@ -6,6 +6,7 @@
 // RUN: %clang -O0 -target powerpc64le-ibm-linux-gnu %s -S -emit-llvm -o %t.ll
 // RUN: %clang -O0 -target powerpc64le-ibm-linux-gnu %s -c -emit-llvm -o %t.bc
 // RUN: %clang -O0 -target powerpc64le-ibm-linux-gnu %s -S -o %t.s
+// RUN: %clang -O0 -target powerpc64le-ibm-linux-gnu %s -c -o %t.o
 // RUN: %clang -O0 -target powerpc64le-ibm-linux-gnu %s -emit-ast -o %t.ast
 
 //
@@ -215,6 +216,40 @@
 // RUN: diff %t.empty %t.res.tgt1
 // RUN: diff %t.empty %t.res.tgt2
 
+//
+// Check object bundle/unbundle. The content should be bundled into an ELF
+// section (we are using a PowerPC little-endian host which uses ELF). We
+// have an already bundled file to check the unbundle and do a dry run on the
+// bundling as it cannot be tested in all host platforms that will run these
+// tests.
+//
+
+// RUN: clang-offload-bundler -type=o -targets=host-powerpc64le-ibm-linux-gnu,openmp-powerpc64le-ibm-linux-gnu,openmp-x86_64-pc-linux-gnu -inputs=%t.o,%t.tgt1,%t.tgt2 -outputs=%t.bundle3.o -### -dump-temporary-files 2>&1 \
+// RUN: | FileCheck %s --check-prefix CK-OBJ-CMD
+// CK-OBJ-CMD: private constant [1 x i8] zeroinitializer, section "__CLANG_OFFLOAD_BUNDLE__host-powerpc64le-ibm-linux-gnu"
+// CK-OBJ-CMD: private constant [25 x i8] c"Content of device file 1\0A", section "__CLANG_OFFLOAD_BUNDLE__openmp-powerpc64le-ibm-linux-gnu"
+// CK-OBJ-CMD: private constant [25 x i8] c"Content of device file 2\0A", section "__CLANG_OFFLOAD_BUNDLE__openmp-x86_64-pc-linux-gnu"
+// CK-OBJ-CMD: clang" "-r" "-target" "powerpc64le-ibm-linux-gnu" "-o" "{{.+}}.o" "{{.+}}.o" "{{.+}}.bc" "-nostdlib"
+
+// RUN: clang-offload-bundler -type=o -targets=host-powerpc64le-ibm-linux-gnu,openmp-powerpc64le-ibm-linux-gnu,openmp-x86_64-pc-linux-gnu -outputs=%t.res.o,%t.res.tgt1,%t.res.tgt2 -inputs=%s.o -unbundle
+// RUN: diff %s.o %t.res.o
+// RUN: diff %t.tgt1 %t.res.tgt1
+// RUN: diff %t.tgt2 %t.res.tgt2
+// RUN: clang-offload-bundler -type=o -targets=openmp-powerpc64le-ibm-linux-gnu,host-powerpc64le-ibm-linux-gnu,openmp-x86_64-pc-linux-gnu -outputs=%t.res.tgt1,%t.res.o,%t.res.tgt2 -inputs=%s.o -unbundle
+// RUN: diff %s.o %t.res.o
+// RUN: diff %t.tgt1 %t.res.tgt1
+// RUN: diff %t.tgt2 %t.res.tgt2
+
+// Check if we can unbundle a file with no magic strings.
+// RUN: clang-offload-bundler -type=o -targets=host-powerpc64le-ibm-linux-gnu,openmp-powerpc64le-ibm-linux-gnu,openmp-x86_64-pc-linux-gnu -outputs=%t.res.o,%t.res.tgt1,%t.res.tgt2 -inputs=%t.o -unbundle
+// RUN: diff %t.o %t.res.o
+// RUN: diff %t.empty %t.res.tgt1
+// RUN: diff %t.empty %t.res.tgt2
+// RUN: clang-offload-bundler -type=o -targets=openmp-powerpc64le-ibm-linux-gnu,host-powerpc64le-ibm-linux-gnu,openmp-x86_64-pc-linux-gnu -outputs=%t.res.tgt1,%t.res.o,%t.res.tgt2 -inputs=%t.o -unbundle
+// RUN: diff %t.o %t.res.o
+// RUN: diff %t.empty %t.res.tgt1
+// RUN: diff %t.empty %t.res.tgt2
+
 // Some code so that we can create a binary out of this file.
 int A = 0;
 void test_func(void) {