clang: backport -I= support

This solves some clang issues. A few recipes rely on gcc's
-I= syntax. This is a backport of the feature to the 3.8
branch. It's already in 3.9.

See https://llvm.org/bugs/show_bug.cgi?id=26965

Signed-off-by: Daniel McGregor <daniel.mcgregor@vecima.com>

2 files changed, 100 insertions, 0 deletions

diff --git a/recipes-devtools/clang/clang/0001-Frontend-support-I-path-for-sysroot-expansion.patch b/recipes-devtools/clang/clang/0001-Frontend-support-I-path-for-sysroot-expansion.patch
new file mode 100644
index 0000000..76c214a
--- /dev/null
+++ b/recipes-devtools/clang/clang/0001-Frontend-support-I-path-for-sysroot-expansion.patch
@@ -0,0 +1,99 @@
+Upstream-Status: backport
+
+From 0632c1bf6c41f6c89f21957e1379232ef7668d4a Mon Sep 17 00:00:00 2001
+From: Saleem Abdulrasool <compnerd@compnerd.org>
+Date: Fri, 6 May 2016 19:13:55 +0000
+Subject: [PATCH] Frontend: support -I=path for sysroot expansion
+
+From the GCC manpage:
+
+  -I dir
+    ... If dir begins with =, then the = will be replaced by the sysroot prefix;
+    see --sysroot and -isysroot.
+
+Add support to expand the `=` as a prefix of the include path with the sysroot
+if specified.  `-isysroot` takes precedence over `--sysroot` as the normal
+argument behaviour occurs.  The ordering of the `-isysroot` is relevant to the
+path substituted.  If no `--sysroot=` or `-isysroot` option is present, the = is
+not expanded.
+
+Resolves PR26965!
+
+git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@268777 91177308-0d34-0410-b5e6-96231b3b80d8
+---
+ lib/Frontend/CompilerInvocation.cpp | 16 ++++++++++++++--
+ test/Preprocessor/sysroot-prefix.c  | 28 ++++++++++++++++++++++++++++
+ 2 files changed, 42 insertions(+), 2 deletions(-)
+ create mode 100644 test/Preprocessor/sysroot-prefix.c
+
+diff --git a/lib/Frontend/CompilerInvocation.cpp b/lib/Frontend/CompilerInvocation.cpp
+index 237a447..845dffc 100644
+--- a/lib/Frontend/CompilerInvocation.cpp
++++ b/lib/Frontend/CompilerInvocation.cpp
+@@ -1243,6 +1243,8 @@ static void ParseHeaderSearchArgs(HeaderSearchOptions &Opts, ArgList &Args) {
+ 
+   // Add -I..., -F..., and -index-header-map options in order.
+   bool IsIndexHeaderMap = false;
++  bool IsSysrootSpecified =
++      Args.hasArg(OPT__sysroot_EQ) || Args.hasArg(OPT_isysroot);
+   for (const Arg *A : Args.filtered(OPT_I, OPT_F, OPT_index_header_map)) {
+     if (A->getOption().matches(OPT_index_header_map)) {
+       // -index-header-map applies to the next -I or -F.
+@@ -1253,8 +1255,18 @@ static void ParseHeaderSearchArgs(HeaderSearchOptions &Opts, ArgList &Args) {
+     frontend::IncludeDirGroup Group =
+         IsIndexHeaderMap ? frontend::IndexHeaderMap : frontend::Angled;
+ 
+-    Opts.AddPath(A->getValue(), Group,
+-                 /*IsFramework=*/A->getOption().matches(OPT_F), true);
++    bool IsFramework = A->getOption().matches(OPT_F);
++    std::string Path = A->getValue();
++
++    if (IsSysrootSpecified && !IsFramework && A->getValue()[0] == '=') {
++      SmallString<32> Buffer;
++      llvm::sys::path::append(Buffer, Opts.Sysroot,
++                              llvm::StringRef(A->getValue()).substr(1));
++      Path = Buffer.str();
++    }
++
++    Opts.AddPath(Path.c_str(), Group, IsFramework,
++                 /*IgnoreSysroot*/ true);
+     IsIndexHeaderMap = false;
+   }
+ 
+diff --git a/test/Preprocessor/sysroot-prefix.c b/test/Preprocessor/sysroot-prefix.c
+new file mode 100644
+index 0000000..feea502
+--- /dev/null
++++ b/test/Preprocessor/sysroot-prefix.c
+@@ -0,0 +1,28 @@
++// RUN: %clang_cc1 -v -isysroot /var/empty -I /dev/null -E %s -o /dev/null 2>&1 | FileCheck -check-prefix CHECK-ISYSROOT_NO_SYSROOT %s
++// RUN: %clang_cc1 -v -isysroot /var/empty -I =/dev/null -E %s -o /dev/null 2>&1 | FileCheck -check-prefix CHECK-ISYSROOT_SYSROOT_DEV_NULL %s
++// RUN: %clang_cc1 -v -I =/dev/null -E %s -o /dev/null 2>&1 | FileCheck -check-prefix CHECK-NO_ISYSROOT_SYSROOT_DEV_NULL %s
++// RUN: %clang_cc1 -v -isysroot /var/empty -I =null -E %s -o /dev/null 2>&1 | FileCheck -check-prefix CHECK-ISYSROOT_SYSROOT_NULL %s
++// RUN: %clang_cc1 -v -isysroot /var/empty -isysroot /var/empty/root -I =null -E %s -o /dev/null 2>&1 | FileCheck -check-prefix CHECK-ISYSROOT_ISYSROOT_SYSROOT_NULL %s
++// RUN: %clang_cc1 -v -isysroot /var/empty/root -isysroot /var/empty -I =null -E %s -o /dev/null 2>&1 | FileCheck -check-prefix CHECK-ISYSROOT_ISYSROOT_SWAPPED_SYSROOT_NULL %s
++
++// CHECK-ISYSROOT_NO_SYSROOT: ignoring nonexistent directory "/dev/null"
++// CHECK-ISYSROOT_NO_SYSROOT-NOT: ignoring nonexistent directory "/var/empty/dev/null"
++
++// CHECK-NO_ISYSROOT_SYSROOT_DEV_NULL: ignoring nonexistent directory "=/dev/null"
++// CHECK-NO_ISYSROOT_SYSROOT_DEV_NULL-NOT: ignoring nonexistent directory "/dev/null"
++
++// CHECK-ISYSROOT_SYSROOT_DEV_NULL: ignoring nonexistent directory "/var/empty/dev/null"
++// CHECK-ISYSROOT_SYSROOT_DEV_NULL-NOT: ignoring nonexistent directory "/dev/null"
++
++// CHECK-NO_ISYSROOT_SYSROOT: ignoring nonexistent directory "=/dev/null"
++// CHECK-NO_ISYSROOT_SYSROOT-NOT: ignoring nonexistent directory "/var/empty/dev/null"
++
++// CHECK-ISYSROOT_SYSROOT_NULL: ignoring nonexistent directory "/var/empty/null"
++// CHECK-ISYSROOT_SYSROOT_NULL-NOT: ignoring nonexistent directory "=null"
++
++// CHECK-ISYSROOT_ISYSROOT_SYSROOT_NULL: ignoring nonexistent directory "/var/empty/root/null"
++// CHECK-ISYSROOT_ISYSROOT_SYSROOT_NULL-NOT: ignoring nonexistent directory "=null"
++
++// CHECK-ISYSROOT_ISYSROOT_SWAPPED_SYSROOT_NULL: ignoring nonexistent directory "/var/empty/null"
++// CHECK-ISYSROOT_ISYSROOT_SWAPPED_SYSROOT_NULL-NOT: ignoring nonexistent directory "=null"
++
+-- 
+2.8.2
+
diff --git a/recipes-devtools/clang/clang_git.bb b/recipes-devtools/clang/clang_git.bb
index 6b30ee0..4fc2fa7 100644
--- a/recipes-devtools/clang/clang_git.bb
+++ b/recipes-devtools/clang/clang_git.bb
@@ -21,6 +21,7 @@ SRC_URI = "${LLVM_GIT}/llvm.git;protocol=${LLVM_GIT_PROTOCOL};branch=${BRANCH};n
            file://0001-driver-Add-musl-ldso-support.patch;patchdir=tools/clang \
            file://0001-driver-Use-lib-for-ldso-on-OE.patch;patchdir=tools/clang \
            file://0001-musl-ppc-does-not-support-128-bit-long-double.patch;patchdir=tools/clang \
+           file://0001-Frontend-support-I-path-for-sysroot-expansion.patch;patchdir=tools/clang \
           "
 
 SRC_URI_append_libc-musl_class-target = " file://0001-remove-fopen64-fseeko64-ftello64-tmpfile64-on-musl.patch "