[clang][Driver] Fix tool path priority test failures

Summary:
Failure type 1:
This test can fail when the path of the build includes the strings
we're checking for. E.g "/gcc" is found in ".../gcc_7.3.0/..."

To correct this look for '"' on the end of all matches. So that we
only match the end of paths printed by clang -###.
(which would be ".../gcc_7.3.0/.../gcc" for the example)

Also look for other gcc names like gcc-x.y.z in the first check.
This confirms that the copy of clang we made is isolated as expected.

Failure type 2:
If you use a triple like "powerpc64le-linux-gnu" clang actually reports
"powerpc64le-unknown-linux-gnu". Then it searches for the
former.

That combined with Mac OS adding a version number to cmake's triple
means we can't trust cmake or clang to give us the one default triple.
To fix the test, write to both names. As they don't overlap with our
fake triple, we're still showing that the lookup works.

Reviewers: MaskRay, stevewan

Reviewed By: stevewan

Subscribers: miyuki, JDevlieghere, steven.zhang, stevewan, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D83055

Author: DavidSpickett

clang/test/Driver/program-path-priority.c

@@ -13,6 +13,11 @@
 /// so only name priority is accounted for, unless we fail to find
 /// anything at all in the prefix.
 
+/// Note: All matches are expected to be at the end of file paths.
+/// So we match " on the end to account for build systems that
+/// put the name of the compiler in the build path.
+/// E.g. /build/gcc_X.Y.Z/0/...
+
 /// Symlink clang to a new dir which will be its
 /// "program path" for these tests
 // RUN: rm -rf %t && mkdir -p %t
@@ -21,89 +26,108 @@
 /// No gccs at all, nothing is found
 // RUN: env "PATH=" %t/clang -### -target notreal-none-elf %s 2>&1 | \
 // RUN:   FileCheck --check-prefix=NO_NOTREAL_GCC %s
-// NO_NOTREAL_GCC-NOT: notreal-none-elf-gcc
-// NO_NOTREAL_GCC-NOT: /gcc
+// NO_NOTREAL_GCC-NOT: notreal-none-elf-gcc"
+/// Some systems will have "gcc-x.y.z" so for this first check
+/// make sure we don't find "gcc" or "gcc-x.y.z". If we do find either
+/// then there is no point continuing as this copy of clang is not
+/// isolated as we expected.
+// NO_NOTREAL_GCC-NOT: {{/gcc[^/]*"}}
 
 /// <triple>-gcc in program path is found
 // RUN: touch %t/notreal-none-elf-gcc && chmod +x %t/notreal-none-elf-gcc
 // RUN: env "PATH=" %t/clang -### -target notreal-none-elf %s 2>&1 | \
 // RUN:   FileCheck --check-prefix=PROG_PATH_NOTREAL_GCC %s
-// PROG_PATH_NOTREAL_GCC: notreal-none-elf-gcc
+// PROG_PATH_NOTREAL_GCC: notreal-none-elf-gcc"
 
 /// <triple>-gcc on the PATH is found
 // RUN: mkdir -p %t/env
 // RUN: rm %t/notreal-none-elf-gcc
 // RUN: touch %t/env/notreal-none-elf-gcc && chmod +x %t/env/notreal-none-elf-gcc
 // RUN: env "PATH=%t/env/" %t/clang -### -target notreal-none-elf %s 2>&1 | \
 // RUN:   FileCheck --check-prefix=ENV_PATH_NOTREAL_GCC %s
-// ENV_PATH_NOTREAL_GCC: env/notreal-none-elf-gcc
+// ENV_PATH_NOTREAL_GCC: env/notreal-none-elf-gcc"
 
 /// <triple>-gcc in program path is preferred to one on the PATH
 // RUN: touch %t/notreal-none-elf-gcc && chmod +x %t/notreal-none-elf-gcc
 // RUN: env "PATH=%t/env/" %t/clang -### -target notreal-none-elf %s 2>&1 | \
 // RUN:   FileCheck --check-prefix=BOTH_NOTREAL_GCC %s
-// BOTH_NOTREAL_GCC: notreal-none-elf-gcc
-// BOTH_NOTREAL_GCC-NOT: env/notreal-none-elf-gcc
+// BOTH_NOTREAL_GCC: notreal-none-elf-gcc"
+// BOTH_NOTREAL_GCC-NOT: env/notreal-none-elf-gcc"
 
 /// On program path, <triple>-gcc is preferred to plain gcc
 // RUN: touch %t/gcc && chmod +x %t/gcc
 // RUN: env "PATH=" %t/clang -### -target notreal-none-elf %s 2>&1 | \
 // RUN:   FileCheck --check-prefix=NOTREAL_GCC_PREFERRED %s
-// NOTREAL_GCC_PREFERRED: notreal-none-elf-gcc
-// NOTREAL_GCC_PREFERRED-NOT: /gcc
+// NOTREAL_GCC_PREFERRED: notreal-none-elf-gcc"
+// NOTREAL_GCC_PREFERRED-NOT: /gcc"
 
 /// <triple>-gcc on the PATH is preferred to gcc in program path
 // RUN: rm %t/notreal-none-elf-gcc
 // RUN: env "PATH=%t/env/" %t/clang -### -target notreal-none-elf %s 2>&1 | \
 // RUN:   FileCheck --check-prefix=NOTREAL_PATH_OVER_GCC_PROG %s
-// NOTREAL_PATH_OVER_GCC_PROG: env/notreal-none-elf-gcc
-// NOTREAL_PATH_OVER_GCC_PROG-NOT: /gcc
+// NOTREAL_PATH_OVER_GCC_PROG: env/notreal-none-elf-gcc"
+// NOTREAL_PATH_OVER_GCC_PROG-NOT: /gcc"
 
 /// <triple>-gcc on the PATH is preferred to gcc on the PATH
 // RUN: rm %t/gcc
 // RUN: touch %t/env/gcc && chmod +x %t/env/gcc
 // RUN: env "PATH=%t/env/" %t/clang -### -target notreal-none-elf %s 2>&1 | \
 // RUN:   FileCheck --check-prefix=NOTREAL_PATH_OVER_GCC_PATH %s
-// NOTREAL_PATH_OVER_GCC_PATH: env/notreal-none-elf-gcc
-// NOTREAL_PATH_OVER_GCC_PATH-NOT: /gcc
+// NOTREAL_PATH_OVER_GCC_PATH: env/notreal-none-elf-gcc"
+// NOTREAL_PATH_OVER_GCC_PATH-NOT: /gcc"
+
+/// We cannot trust clang --version, or cmake's LLVM_DEFAULT_TARGET_TRIPLE
+/// to give us the one and only default triple.
+/// Can't trust cmake because on Darwin, triples have a verison appended to them.
+/// (and clang uses the versioned string to search)
+/// Can't trust --version because it will pad 3 item triples to 4 e.g.
+/// powerpc64le-linux-gnu -> powerpc64le-unknown-linux-gnu
+/// (and clang uses the former to search)
+/// So we write to both names which is a bit odd but still proves that the
+/// lookup is working.
 
 /// <default-triple>-gcc has lowest priority so <triple>-gcc
 /// on PATH beats default triple in program path
-/// Darwin triples have a version appended to them, even if set via
-/// LLVM_DEFAULT_TARGET_TRIPLE. So the only way to know for sure is to ask clang.
 // RUN: DEFAULT_TRIPLE=`%t/clang --version | grep "Target:" | cut -d ' ' -f2`
 // RUN: touch %t/$DEFAULT_TRIPLE-gcc && chmod +x %t/$DEFAULT_TRIPLE-gcc
+// RUN: touch %t/%target_triple-gcc && chmod +x %t/%target_triple-gcc
 // RUN: env "PATH=%t/env/" %t/clang -### -target notreal-none-elf %s 2>&1 | \
 // RUN:   FileCheck --check-prefix=DEFAULT_TRIPLE_GCC %s
-// DEFAULT_TRIPLE_GCC: env/notreal-none-elf-gcc
+// DEFAULT_TRIPLE_GCC: env/notreal-none-elf-gcc"
 
 /// plain gcc on PATH beats default triple in program path
 // RUN: rm %t/env/notreal-none-elf-gcc
 // RUN: env "PATH=%t/env/" %t/clang -### -target notreal-none-elf %s 2>&1 | \
 // RUN:   FileCheck --check-prefix=DEFAULT_TRIPLE_NO_NOTREAL %s
-// DEFAULT_TRIPLE_NO_NOTREAL: env/gcc
-// DEFAULT_TRIPLE_NO_NOTREAL-NOT: -gcc
+// DEFAULT_TRIPLE_NO_NOTREAL: env/gcc"
+// DEFAULT_TRIPLE_NO_NOTREAL-NOT: -gcc"
 
 /// default triple only chosen when no others are present
 // RUN: rm %t/env/gcc
 // RUN: env "PATH=%t/env/" %t/clang -### -target notreal-none-elf %s 2>&1 | \
 // RUN:   FileCheck --check-prefix=DEFAULT_TRIPLE_NO_OTHERS %s
-// DEFAULT_TRIPLE_NO_OTHERS: -gcc
-// DEFAULT_TRIPLE_NO_OTHERS-NOT: notreal-none-elf-gcc
-// DEFAULT_TRIPLE_NO_OTHERS-NOT: /gcc
+// DEFAULT_TRIPLE_NO_OTHERS: -gcc"
+// DEFAULT_TRIPLE_NO_OTHERS-NOT: notreal-none-elf-gcc"
+// DEFAULT_TRIPLE_NO_OTHERS-NOT: /gcc"
 
 /// -B paths are searched separately so default triple will win
 /// if put in one of those even if other paths have higher priority names
 // RUN: mkdir -p %t/prefix
-// RUN: mv %t/$DEFAULT_TRIPLE-gcc %t/prefix
+/// One of these will fail when $DEFAULT_TRIPLE == %target_triple
+// RUN: test -f %t/$DEFAULT_TRIPLE-gcc && \
+// RUN:   mv %t/$DEFAULT_TRIPLE-gcc %t/prefix || true
+// RUN: test -f %t/%target_triple-gcc && \
+// RUN:   mv %t/%target_triple-gcc %t/prefix || true
 // RUN: touch %t/notreal-none-elf-gcc && chmod +x %t/notreal-none-elf-gcc
 // RUN: env "PATH=" %t/clang -### -target notreal-none-elf %s -B %t/prefix 2>&1 | \
 // RUN:   FileCheck --check-prefix=DEFAULT_TRIPLE_IN_PREFIX %s
-// DEFAULT_TRIPLE_IN_PREFIX: prefix/{{.*}}-gcc
-// DEFAULT_TRIPLE_IN_PREFIX-NOT: notreal-none-elf-gcc
+// DEFAULT_TRIPLE_IN_PREFIX: prefix/{{.*}}-gcc"
+// DEFAULT_TRIPLE_IN_PREFIX-NOT: notreal-none-elf-gcc"
 
 /// Only if there is nothing in the prefix will we search other paths
-// RUN: rm %t/prefix/$DEFAULT_TRIPLE-gcc
+/// -f in case $DEFAULT_TRIPLE == %target_triple
+// RUN: rm -f %t/prefix/$DEFAULT_TRIPLE-gcc
+// RUN: rm -f %t/prefix/%target_triple-gcc
 // RUN: env "PATH=" %t/clang -### -target notreal-none-elf %s -B %t/prefix 2>&1 | \
 // RUN:   FileCheck --check-prefix=EMPTY_PREFIX_DIR %s
-// EMPTY_PREFIX_DIR: notreal-none-elf-gcc
+// EMPTY_PREFIX_DIR: notreal-none-elf-gcc"

clang/test/lit.cfg.py

@@ -46,6 +46,8 @@
 config.substitutions.append(
     ('%src_include_dir', config.clang_src_dir + '/include'))
 
+config.substitutions.append(
+    ('%target_triple', config.target_triple))
 
 # Propagate path to symbolizer for ASan/MSan.
 llvm_config.with_system_environment(