gnu: llvm: Update to 3.8.1.

* gnu/packages/llvm.scm (llvm, clang-runtime, clang): Update to 3.8.1.
(llvm-3.7, clang-runtime-3.7, clang-3.7): New variables.
(clang-runtime-from-llvm)[arguments]: Disable tests, which were not
being run for previous versions anyhow but now fail hard.
(clang-from-llvm): Add #:patches keyword argument.
* gnu/packages/patches/clang-3.8-libc-search-path.patch: New patch.
* gnu/local.mk (dist_patch_DATA): Add it.

Co-authored-by: Dennis Mungai <dmngaie@gmail.scm>

gnu/local.mk

@@ -452,6 +452,7 @@ dist_patch_DATA =						\
   %D%/packages/patches/cdparanoia-fpic.patch			\
   %D%/packages/patches/chmlib-inttypes.patch			\
   %D%/packages/patches/clang-libc-search-path.patch		\
+  %D%/packages/patches/clang-3.8-libc-search-path.patch		\
   %D%/packages/patches/clucene-pkgconfig.patch			\
   %D%/packages/patches/cmake-fix-tests.patch			\
   %D%/packages/patches/cpio-gets-undeclared.patch		\

gnu/packages/llvm.scm

@@ -38,7 +38,7 @@
 (define-public llvm
   (package
     (name "llvm")
-    (version "3.7.1")
+    (version "3.8.1")
     (source
      (origin
       (method url-fetch)
@@ -46,7 +46,7 @@
                           version "/llvm-" version ".src.tar.xz"))
       (sha256
        (base32
-        "1masakdp9g2dan1yrazg7md5am2vacbkb3nahb3dchpc1knr8xxy"))))
+        "1ybmnid4pw2hxn12ax5qa5kl1ldfns0njg8533y3mzslvd5cx0kf"))))
     (build-system cmake-build-system)
     (native-inputs
      `(("python" ,python-2) ;bytes->str conversion in clang>=3.7 needs python-2
@@ -85,8 +85,8 @@ of programming tools as well as libraries with equivalent functionality.")
      `(("llvm" ,llvm)))
     (arguments
      `(;; Don't use '-g' during the build to save space.
-       #:build-type "Release"))
-
+       #:build-type "Release"
+       #:tests? #f))                    ; Tests require gtest
     (home-page "http://compiler-rt.llvm.org")
     (synopsis "Runtime library for Clang/LLVM")
     (description
@@ -99,7 +99,8 @@ compiler.  In LLVM this library is called \"compiler-rt\".")
     ;; <http://compiler-rt.llvm.org/> doesn't list MIPS as supported.
     (supported-systems (delete "mips64el-linux" %supported-systems))))
 
-(define (clang-from-llvm llvm clang-runtime hash)
+(define* (clang-from-llvm llvm clang-runtime hash
+                          #:key (patches '("clang-libc-search-path.patch")))
   (package
     (name "clang")
     (version (package-version llvm))
@@ -109,7 +110,7 @@ compiler.  In LLVM this library is called \"compiler-rt\".")
        (uri (string-append "http://llvm.org/releases/"
                            version "/cfe-" version ".src.tar.xz"))
        (sha256 (base32 hash))
-       (patches (search-patches "clang-libc-search-path.patch"))))
+       (patches (map search-patch patches))))
     ;; Using cmake allows us to treat llvm as an external library.  There
     ;; doesn't seem to be any way to do this with clang's autotools-based
     ;; build system.
@@ -182,10 +183,32 @@ code analysis tools.")
 (define-public clang-runtime
   (clang-runtime-from-llvm
    llvm
-   "10c1mz2q4bdq9bqfgr3dirc6hz1h3sq8573srd5q5lr7m7j6jiwx"))
+   "0p0y85c7izndbpg2l816z7z7558axq11d5pwkm4h11sdw7d13w0d"))
 
 (define-public clang
   (clang-from-llvm llvm clang-runtime
+                   "1prc72xmkgx8wrzmrr337776676nhsp1qd3mw2bvb22bzdnq7lsc"
+                   #:patches '("clang-3.8-libc-search-path.patch")))
+
+(define-public llvm-3.7
+  (package (inherit llvm)
+    (version "3.7.1")
+    (source
+     (origin
+       (method url-fetch)
+       (uri (string-append "http://llvm.org/releases/"
+                           version "/llvm-" version ".src.tar.xz"))
+       (sha256
+        (base32
+         "1masakdp9g2dan1yrazg7md5am2vacbkb3nahb3dchpc1knr8xxy"))))))
+
+(define-public clang-runtime-3.7
+  (clang-runtime-from-llvm
+   llvm-3.7
+   "10c1mz2q4bdq9bqfgr3dirc6hz1h3sq8573srd5q5lr7m7j6jiwx"))
+
+(define-public clang-3.7
+  (clang-from-llvm llvm-3.7 clang-runtime-3.7
                    "0x065d0w9b51xvdjxwfzjxng0gzpbx45fgiaxpap45ragi61dqjn"))
 
 (define-public llvm-3.6

gnu/packages/patches/clang-3.8-libc-search-path.patch

@@ -0,0 +1,69 @@
+Clang attempts to guess file names based on the OS and distro (yes!),
+but unfortunately, that doesn't work for us.
+
+This patch makes it easy to insert libc's $libdir so that Clang passes the
+correct absolute file name of crt1.o etc. to 'ld'.  It also disables all
+the distro-specific stuff and removes the hard-coded FHS directory names
+to make sure Clang also works on non-GuixSD systems.
+
+This patch makes slight adjustments over "clang-libc-search-path.patch" for
+changes in clang 3.8.
+
+--- cfe-3.8.0.src/lib/Driver/ToolChains.cpp
++++ cfe-3.8.0.src/lib/Driver/ToolChains.cpp
+@@ -3661,6 +3661,9 @@
+                          GCCInstallation.getTriple().str() + "/bin")
+                        .str());
+ 
++  // Comment out the distro-specific tweaks so that they don't bite when
++  // using Guix on a foreign distro.
++#if 0
+   Distro Distro = DetectDistro(D, Arch);
+ 
+   if (IsOpenSUSE(Distro) || IsUbuntu(Distro)) {
+@@ -3702,6 +3705,7 @@
+ 
+   if (IsOpenSUSE(Distro))
+     ExtraOpts.push_back("--enable-new-dtags");
++#endif
+ 
+   // The selection of paths to try here is designed to match the patterns which
+   // the GCC driver itself uses, as this is part of the GCC-compatible driver.
+@@ -3771,14 +3775,12 @@
+     addPathIfExists(D, D.Dir + "/../" + OSLibDir, Paths);
+   }
+ 
+-  addPathIfExists(D, SysRoot + "/lib/" + MultiarchTriple, Paths);
+-  addPathIfExists(D, SysRoot + "/lib/../" + OSLibDir, Paths);
+-  addPathIfExists(D, SysRoot + "/usr/lib/" + MultiarchTriple, Paths);
+-  addPathIfExists(D, SysRoot + "/usr/lib/../" + OSLibDir, Paths);
+-
+   // Try walking via the GCC triple path in case of biarch or multiarch GCC
+   // installations with strange symlinks.
+   if (GCCInstallation.isValid()) {
++    // The following code would end up adding things like
++    // "/usr/lib/x86_64-unknown-linux-gnu/../../lib64" to the search path.
++#if 0
+     addPathIfExists(D,
+                     SysRoot + "/usr/lib/" + GCCInstallation.getTriple().str() +
+                         "/../../" + OSLibDir,
+@@ -3791,6 +3793,7 @@
+                              BiarchSibling.gccSuffix(),
+                       Paths);
+     }
++#endif
+ 
+     // See comments above on the multilib variant for details of why this is
+     // included even from outside the sysroot.
+@@ -3815,8 +3818,9 @@
+   if (StringRef(D.Dir).startswith(SysRoot))
+     addPathIfExists(D, D.Dir + "/../lib", Paths);
+ 
+-  addPathIfExists(D, SysRoot + "/lib", Paths);
+-  addPathIfExists(D, SysRoot + "/usr/lib", Paths);
++  // Add libc's lib/ directory to the search path, so that crt1.o, crti.o,
++  // and friends can be found.
++  addPathIfExists(D, "@GLIBC_LIBDIR@", Paths);
+ }
+ 
+ bool Linux::HasNativeLLVMSupport() const { return true; }