[Driver] Adapt Linux::GCCVersion::Parse to match GCC 5 installations

[bryanpkc]

Summary

Some GCC 5 installations store the libstdc++ includes and GCC-specific files in paths without
the minor part of the version number, such as

/usr/include/c++/5
/usr/lib64/gcc/x86_64-suse-linux/5

[jroelofs]

testcase?

[thiagomacieira]

v2: fix accidental breakage of GCC 4

[thiagomacieira]

In D14727#290539, @jroelofs wrote:

testcase?

Gladly, but where are the tests for GCCVersion located?

[jroelofs]

hHave a look at the svn-blame for this file, then find other commits which changed this part of the file, and see where those commits added tests.

[thiagomacieira]

In D14727#290661, @jroelofs wrote:

hHave a look at the svn-blame for this file, then find other commits which changed this part of the file, and see where those commits added tests.

Thanks, looks like 189212 has a way to do it.

[thiagomacieira]

v3: updated to add unit testing

[thiagomacieira]

What happens now?

[jroelofs]

I'm getting a couple of test failures from this patch:

Clang :: Driver/linux-header-search.cpp
Clang :: Driver/solaris-header-search.cpp

For the latter of the two, the driver picks:

test/Driver/Inputs/sparc-sun-solaris2.11/usr/gcc/.8/include/c++/4.8.2/sparc-sun-solaris2.11

as the -internal-isystem directory, which doesn't exist. It should be finding:

test/Driver/Inputs/sparc-sun-solaris2.11/usr/gcc/4.8.2/include/c++/4.8.2/sparc-sun-solaris2.11

I think it might be because GoodVersion.MajorStr is no longer set.

[thiagomacieira]

Ping?

[thiagomacieira]

Ah, I see a comment. Sorry about that. I'll see if I can fix it, but I had no failures when I tried...

[bryanpkc]

Fixed the code to set GoodVersion.MajorStr before returning, and removed an unnecessary file (test/Driver/Inputs/gcc_version_parsing5/lib/gcc/i386-unknown-linux/4.9.2/crtbegin.o).

[jroelofs]

In D14727#441758, @bryanpkc wrote:

Fixed the code to set GoodVersion.MajorStr before returning, and removed an unnecessary file (test/Driver/Inputs/gcc_version_parsing5/lib/gcc/i386-unknown-linux/4.9.2/crtbegin.o).

That file is not unnecessary... The test is to make sure that if there are multiple versions installed in the same spot, that the latest one is picked up.

[bryanpkc]

Re-added test/Driver/Inputs/gcc_version_parsing5/lib/gcc/i386-unknown-linux/4.9.2/crtbegin.o.

[bryanpkc]

Ping?

[jroelofs]

LGTM. Do you want me to commit it for you?

[bryanpkc]

Thanks for the review! I have committed the patch.

lib/Driver/ToolChains.cpp

Generic_GCC::GCCVersion Linux::GCCVersion::Parse(StringRef VersionText) {
   const GCCVersion BadVersion = {VersionText.str(), -1, -1, -1, "", "", ""};
   std::pair<StringRef, StringRef> First = VersionText.split('.');
   std::pair<StringRef, StringRef> Second = First.second.split('.');
 
   GCCVersion GoodVersion = {VersionText.str(), -1, -1, -1, "", "", ""};
   if (First.first.getAsInteger(10, GoodVersion.Major) || GoodVersion.Major < 0)
     return BadVersion;
   GoodVersion.MajorStr = First.first.str();
+  if (First.second.empty())
+    return GoodVersion;
   if (Second.first.getAsInteger(10, GoodVersion.Minor) || GoodVersion.Minor < 0)
     return BadVersion;
   GoodVersion.MinorStr = Second.first.str();
 
   // First look for a number prefix and parse that if present. Otherwise just
   // stash the entire patch string in the suffix, and leave the number
   // unspecified. This covers versions strings such as:
+  //   5        (handled above)
   //   4.4
   //   4.4.0
   //   4.4.x
   //   4.4.2-rc4
   //   4.4.x-patched
   // And retains any patch number it finds.
   StringRef PatchText = GoodVersion.PatchSuffix = Second.second.str();
   if (!PatchText.empty()) {

test/Driver/linux-ld.c

 // RUN:     --target=i386-unknown-linux -m32 \
 // RUN:     -ccc-install-dir %S/Inputs/gcc_version_parsing4/bin \
 // RUN:     --gcc-toolchain="" \
 // RUN:     --sysroot=%S/Inputs/basic_linux_tree \
 // RUN:   | FileCheck --check-prefix=CHECK-GCC-VERSION4 %s
 // CHECK-GCC-VERSION4: "{{.*}}ld{{(.exe)?}}" "--sysroot=[[SYSROOT:[^"]+]]"
 // CHECK-GCC-VERSION4: "{{.*}}/Inputs/gcc_version_parsing4/bin/../lib/gcc/i386-unknown-linux/4.7.99{{/|\\\\}}crtbegin.o"
 // CHECK-GCC-VERSION4: "-L{{.*}}/Inputs/gcc_version_parsing4/bin/../lib/gcc/i386-unknown-linux/4.7.99"
+// RUN: %clang -no-canonical-prefixes %s -### -o %t.o 2>&1 \
+// RUN:     --target=i386-unknown-linux -m32 \
+// RUN:     -ccc-install-dir %S/Inputs/gcc_version_parsing5/bin \
+// RUN:     --gcc-toolchain="" \
+// RUN:     --sysroot=%S/Inputs/basic_linux_tree \
+// RUN:   | FileCheck --check-prefix=CHECK-GCC-VERSION5 %s
+// CHECK-GCC-VERSION5: "{{.*}}ld{{(.exe)?}}" "--sysroot=[[SYSROOT:[^"]+]]"
+// CHECK-GCC-VERSION5: "{{.*}}/Inputs/gcc_version_parsing5/bin/../lib/gcc/i386-unknown-linux/5{{/|\\\\}}crtbegin.o"
+// CHECK-GCC-VERSION5: "-L{{.*}}/Inputs/gcc_version_parsing5/bin/../lib/gcc/i386-unknown-linux/5"
 //
 // Test a simulated installation of libc++ on Linux, both through sysroot and
 // the installation path of Clang.
 // RUN: %clangxx -no-canonical-prefixes -x c++ %s -### -o %t.o 2>&1 \
 // RUN:     -target x86_64-unknown-linux-gnu \
 // RUN:     -stdlib=libc++ \
 // RUN:     -ccc-install-dir %S/Inputs/basic_linux_tree/usr/bin \
 // RUN:     --gcc-toolchain="" \