Remove runtime dependency on gcc stdarg headers and make

Remove the runtime dependency on gcc's stdarg.h. Do this by packaging
the (non-GPL) version shipped with clang. This allows the bulk of
kbuild_helper to be removed, at the expense of hardcoding the kernel
include paths. If in the future the kernel make system changes again to
require different -I paths, we'll have to think this through again.
Signed-off-by: Brenden Blanco <bblanco@plumgrid.com>

SPECS/bcc.el6.spec

@@ -88,7 +88,6 @@ make install/strip DESTDIR=%{buildroot}
 
 %package -n libbcc
 Summary: Shared Library for BPF Compiler Collection (BCC)
-Requires: make, gcc
 %description -n libbcc
 Shared Library for BPF Compiler Collection (BCC)
 
@@ -109,6 +108,7 @@ Python bindings for BPF Compiler Collection (BCC)
 %files -n libbcc
 /usr/lib64/*
 /usr/share/bcc/include/*
+/usr/share/bcc/lib/*
 /usr/include/bcc/*
 
 %files -n libbcc-examples

SPECS/bcc.el6.spec.in

@@ -88,7 +88,6 @@ make install/strip DESTDIR=%{buildroot}
 
 %package -n libbcc
 Summary: Shared Library for BPF Compiler Collection (BCC)
-Requires: make, gcc
 %description -n libbcc
 Shared Library for BPF Compiler Collection (BCC)
 
@@ -109,6 +108,7 @@ Python bindings for BPF Compiler Collection (BCC)
 %files -n libbcc
 /usr/lib64/*
 /usr/share/bcc/include/*
+/usr/share/bcc/lib/*
 /usr/include/bcc/*
 
 %files -n libbcc-examples

SPECS/bcc.el7.spec

@@ -57,7 +57,6 @@ make install/strip DESTDIR=%{buildroot}
 
 %package -n libbcc
 Summary: Shared Library for BPF Compiler Collection (BCC)
-Requires: make, gcc
 %description -n libbcc
 Shared Library for BPF Compiler Collection (BCC)
 
@@ -78,6 +77,7 @@ Python bindings for BPF Compiler Collection (BCC)
 %files -n libbcc
 /usr/lib64/*
 /usr/share/bcc/include/*
+/usr/share/bcc/lib/*
 /usr/include/bcc/*
 
 %files -n libbcc-examples

SPECS/bcc.el7.spec.in

@@ -57,7 +57,6 @@ make install/strip DESTDIR=%{buildroot}
 
 %package -n libbcc
 Summary: Shared Library for BPF Compiler Collection (BCC)
-Requires: make, gcc
 %description -n libbcc
 Shared Library for BPF Compiler Collection (BCC)
 
@@ -78,6 +77,7 @@ Python bindings for BPF Compiler Collection (BCC)
 %files -n libbcc
 /usr/lib64/*
 /usr/share/bcc/include/*
+/usr/share/bcc/lib/*
 /usr/include/bcc/*
 
 %files -n libbcc-examples

SPECS/bcc.f22.spec

@@ -57,7 +57,6 @@ make install/strip DESTDIR=%{buildroot}
 
 %package -n libbcc
 Summary: Shared Library for BPF Compiler Collection (BCC)
-Requires: make, gcc
 %description -n libbcc
 Shared Library for BPF Compiler Collection (BCC)
 
@@ -78,6 +77,7 @@ Python bindings for BPF Compiler Collection (BCC)
 %files -n libbcc
 /usr/lib64/*
 /usr/share/bcc/include/*
+/usr/share/bcc/lib/*
 /usr/include/bcc/*
 
 %files -n libbcc-examples

SPECS/bcc.f22.spec.in

@@ -57,7 +57,6 @@ make install/strip DESTDIR=%{buildroot}
 
 %package -n libbcc
 Summary: Shared Library for BPF Compiler Collection (BCC)
-Requires: make, gcc
 %description -n libbcc
 Shared Library for BPF Compiler Collection (BCC)
 
@@ -78,6 +77,7 @@ Python bindings for BPF Compiler Collection (BCC)
 %files -n libbcc
 /usr/lib64/*
 /usr/share/bcc/include/*
+/usr/share/bcc/lib/*
 /usr/include/bcc/*
 
 %files -n libbcc-examples

SPECS/bcc.spec

@@ -45,7 +45,6 @@ make install/strip DESTDIR=%{buildroot}
 
 %package -n libbcc
 Summary: Shared Library for BPF Compiler Collection (BCC)
-Requires: gcc, make
 %description -n libbcc
 Shared Library for BPF Compiler Collection (BCC)
 
@@ -73,6 +72,7 @@ Command line tools for BPF Compiler Collection (BCC)
 %files -n libbcc
 /usr/lib64/*
 /usr/share/bcc/include/*
+/usr/share/bcc/lib/*
 /usr/include/bcc/*
 
 %files -n libbcc-examples

debian/control

@@ -8,7 +8,7 @@ Homepage: https://github.com/iovisor/bcc
 
 Package: libbcc
 Architecture: amd64
-Depends: libc6, libstdc++6, make, gcc
+Depends: libc6, libstdc++6
 Description: Shared Library for BPF Compiler Collection (BCC)
  Shared Library for BPF Compiler Collection to control BPF programs
  from userspace.

debian/libbcc.install

 usr/include/bcc/*
 usr/lib/x86_64-linux-gnu/libbcc*
 usr/share/bcc/include/*
+usr/share/bcc/lib/*

src/cc/CMakeLists.txt

@@ -62,5 +62,8 @@ install(DIRECTORY compat/linux/ COMPONENT libbcc
   FILES_MATCHING PATTERN "*.h")
 install(FILES ${CMAKE_CURRENT_BINARY_DIR}/libbcc.pc COMPONENT libbcc
   DESTINATION ${CMAKE_INSTALL_LIBDIR}/pkgconfig)
+install(DIRECTORY clang COMPONENT libbcc
+  DESTINATION share/bcc/lib
+  FILES_MATCHING PATTERN "*.h")
 
 add_subdirectory(frontends)

src/cc/clang/include/stdarg.h

+/*===---- stdarg.h - Variable argument handling ----------------------------===
+ *
+ * Copyright (c) 2008 Eli Friedman
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ *
+ *===-----------------------------------------------------------------------===
+ */
+
+#ifndef __STDARG_H
+#define __STDARG_H
+
+#ifndef _VA_LIST
+typedef __builtin_va_list va_list;
+#define _VA_LIST
+#endif
+#define va_start(ap, param) __builtin_va_start(ap, param)
+#define va_end(ap)          __builtin_va_end(ap)
+#define va_arg(ap, type)    __builtin_va_arg(ap, type)
+
+/* GCC always defines __va_copy, but does not define va_copy unless in c99 mode
+ * or -ansi is not specified, since it was not part of C90.
+ */
+#define __va_copy(d,s) __builtin_va_copy(d,s)
+
+#if __STDC_VERSION__ >= 199901L || __cplusplus >= 201103L || !defined(__STRICT_ANSI__)
+#define va_copy(dest, src)  __builtin_va_copy(dest, src)
+#endif
+
+/* Hack required to make standard headers work, at least on Ubuntu */
+#ifndef __GNUC_VA_LIST
+#define __GNUC_VA_LIST 1
+#endif
+typedef __builtin_va_list __gnuc_va_list;
+
+#endif /* __STDARG_H */

src/cc/frontends/clang/kbuild_helper.cc

@@ -23,70 +23,54 @@ using std::string;
 using std::vector;
 
 KBuildHelper::KBuildHelper() {
-  char *home = ::getenv("HOME");
-  if (home)
-    cache_dir_ = string(home) + "/.cache/bcc";
-  else
-    cache_dir_ = "/var/run/bcc";
-}
-
-// Makefile helper for kbuild_flags
-int KBuildHelper::learn_flags(const string &tmpdir, const char *uname_release, const char *cachefile) {
-  {
-    // Create a kbuild file to generate the flags
-    string makefile = tmpdir + "/Makefile";
-    FILEPtr mf(::fopen(makefile.c_str(), "w"));
-    if (!mf)
-      return -1;
-    fprintf(&*mf, "obj-y := dummy.o\n");
-    fprintf(&*mf, "CACHEDIR=$(dir %s)\n", cachefile);
-    fprintf(&*mf, "$(CACHEDIR):\n");
-    fprintf(&*mf, "\t@mkdir -p $(CACHEDIR)\n");
-    fprintf(&*mf, "$(obj)/%%.o: $(src)/%%.c $(CACHEDIR)\n");
-    fprintf(&*mf, "\t@echo -n \"$(NOSTDINC_FLAGS) $(LINUXINCLUDE) $(EXTRA_CFLAGS) "
-                    "-D__KERNEL__ -Wno-unused-value -Wno-pointer-sign \" > %s\n", cachefile);
-  }
-  {
-    string cfile = tmpdir + "/dummy.c";
-    FILEPtr cf(::fopen(cfile.c_str(), "w"));
-    if (!cf)
-      return -1;
-  }
-  string cmd = "make CROSS_COMPILE= -s";
-  cmd += " -C " KERNEL_MODULES_DIR "/" + string(uname_release) + "/build";
-  cmd += " M=" + tmpdir + " dummy.o";
-  int rc = ::system(cmd.c_str());
-  if (rc < 0) {
-    ::perror("system");
-    return -1;
-  }
-  return ::open(cachefile, O_RDONLY);
 }
 
 // read the flags from cache or learn
-int KBuildHelper::get_flags(const char *uname_release, vector<string> *cflags) {
-  char cachefile[256];
-  snprintf(cachefile, sizeof(cachefile), "%s/%s.flags", cache_dir_.c_str(), uname_release);
-  int cachefd = ::open(cachefile, O_RDONLY);
-  if (cachefd < 0) {
-    TmpDir tmpdir;
-    if (!tmpdir.ok())
-      return -1;
-    cachefd = learn_flags(tmpdir.str(), uname_release, cachefile);
-    if (cachefd < 0)
-      return -1;
-  }
-  FILEPtr f(::fdopen(cachefd, "r"));
-  size_t len = 0;
-  char *line = NULL;
-  ssize_t nread;
-  while ((nread = getdelim(&line, &len, ' ', &*f)) >= 0) {
-    if (nread == 0 || (nread == 1 && line[0] == ' ')) continue;
-    if (line[nread - 1] == ' ')
-      --nread;
-    cflags->push_back(string(line, nread));
+int KBuildHelper::get_flags(const char *uname_machine, vector<string> *cflags) {
+  //uname -m | sed -e s/i.86/x86/ -e s/x86_64/x86/ -e s/sun4u/sparc64/ -e s/arm.*/arm/
+  //               -e s/sa110/arm/ -e s/s390x/s390/ -e s/parisc64/parisc/
+  //               -e s/ppc.*/powerpc/ -e s/mips.*/mips/ -e s/sh[234].*/sh/
+  //               -e s/aarch64.*/arm64/
+
+  string arch = uname_machine;
+  if (!strncmp(uname_machine, "x86_64", 6)) {
+    arch = "x86";
+  } else if (uname_machine[0] == 'i' && !strncmp(&uname_machine[2], "86", 2)) {
+    arch = "x86";
+  } else if (!strncmp(uname_machine, "arm", 3)) {
+    arch = "arm";
+  } else if (!strncmp(uname_machine, "sa110", 5)) {
+    arch = "arm";
+  } else if (!strncmp(uname_machine, "s390x", 5)) {
+    arch = "s390";
+  } else if (!strncmp(uname_machine, "parisc64", 8)) {
+    arch = "parisc";
+  } else if (!strncmp(uname_machine, "ppc", 3)) {
+    arch = "powerpc";
+  } else if (!strncmp(uname_machine, "mips", 4)) {
+    arch = "mips";
+  } else if (!strncmp(uname_machine, "sh", 2)) {
+    arch = "sh";
+  } else if (!strncmp(uname_machine, "aarch64", 7)) {
+    arch = "arm64";
   }
-  free(line);
+
+  cflags->push_back("-nostdinc");
+  cflags->push_back("-isystem");
+  cflags->push_back(BCC_INSTALL_PREFIX "/share/bcc/lib/clang/include");
+  cflags->push_back("-I./arch/"+arch+"/include");
+  cflags->push_back("-Iarch/"+arch+"/include/generated/uapi");
+  cflags->push_back("-Iarch/"+arch+"/include/generated");
+  cflags->push_back("-Iinclude");
+  cflags->push_back("-I./arch/"+arch+"/include/uapi");
+  cflags->push_back("-Iarch/"+arch+"/include/generated/uapi");
+  cflags->push_back("-I./include/uapi");
+  cflags->push_back("-Iinclude/generated/uapi");
+  cflags->push_back("-include");
+  cflags->push_back("./include/linux/kconfig.h");
+  cflags->push_back("-D__KERNEL__");
+  cflags->push_back("-Wno-unused-value");
+  cflags->push_back("-Wno-pointer-sign");
   return 0;
 }
 

src/cc/frontends/clang/kbuild_helper.h

@@ -93,13 +93,9 @@ class TmpDir {
 //  Note: Depending on environment, different cache locations may be desired. In
 //  case we eventually support non-root user programs, cache in $HOME.
 class KBuildHelper {
- private:
-  int learn_flags(const std::string &tmpdir, const char *uname_release, const char *cachefile);
  public:
   KBuildHelper();
-  int get_flags(const char *uname_release, std::vector<std::string> *cflags);
- private:
-  std::string cache_dir_;
+  int get_flags(const char *uname_machine, std::vector<std::string> *cflags);
 };
 
 }  // namespace ebpf

src/cc/frontends/clang/loader.cc

@@ -90,11 +90,12 @@ int ClangLoader::parse(unique_ptr<llvm::Module> *mod, unique_ptr<vector<TableDes
 
   vector<const char *> flags_cstr({"-O0", "-emit-llvm", "-I", dstack.cwd(),
                                    "-Wno-deprecated-declarations",
+                                   "-Wno-gnu-variable-sized-type-not-at-end",
                                    "-x", "c", "-c", abs_file.c_str()});
 
   KBuildHelper kbuild_helper;
   vector<string> kflags;
-  if (kbuild_helper.get_flags(un.release, &kflags))
+  if (kbuild_helper.get_flags(un.machine, &kflags))
     return -1;
   kflags.push_back("-include");
   kflags.push_back(BCC_INSTALL_PREFIX "/share/bcc/include/bcc/helpers.h");