4c2da86410
In GCC, if `-B $prefix` is specified, `$prefix` is used to find executable files and startup files.
`$prefix/include` is added as an include search directory.
Clang overloads -B with GCC installation detection semantics which make the
behavior less predictable (due to the "largest GCC version wins" rule) and
interact poorly with --gcc-toolchain (--gcc-toolchain can be overridden by -B).
* `clang++ foo.cpp` detects GCC installation under `/usr`.
* `clang++ --gcc-toolchain=Inputs foo.cpp` detects GCC installation under `Inputs`.
* `clang++ -BA --gcc-toolchain=B foo.cpp` detects GCC installation under A and B and the larger version wins. With this patch, only B is used for detection.
* `clang++ -BA foo.cpp` detects GCC installation under `A` and `/usr`, and the larger GCC version wins. With this patch `A` is not used for detection.
This patch changes -B to drop the GCC detection semantics. Its executable
searching semantics are preserved. --gcc-toolchain is the recommended option to
specify the GCC installation detection directory.
(
Note: Clang detects GCC installation in various target dependent directories.
`$sysroot/usr` (sysroot defaults to "") is a common directory used by most targets.
Such a directory is expected to contain something like `lib{,32,64}/gcc{,-cross}/$triple`.
Clang will then construct library/include paths from the directory.
)
Differential Revision: https://reviews.llvm.org/D97993
29 lines
1.2 KiB
C
29 lines
1.2 KiB
C
// RUN: %clang -no-canonical-prefixes %s -### -o %t.o 2>/dev/null \
|
|
// RUN: -target i386-none-linux \
|
|
// RUN: --sysroot=%S/Inputs/multilib_64bit_linux_tree/usr \
|
|
// RUN: -print-multi-directory \
|
|
// RUN: | FileCheck --match-full-lines --check-prefix=CHECK-X86-MULTILIBS %s
|
|
|
|
// CHECK-X86-MULTILIBS: 32
|
|
// CHECK-X86-MULTILIBS-NOT: {{^.+$}}
|
|
|
|
// RUN: %clang -no-canonical-prefixes %s -### -o %t.o 2>/dev/null \
|
|
// RUN: -target i386-none-linux -m64 \
|
|
// RUN: --sysroot=%S/Inputs/multilib_64bit_linux_tree/usr \
|
|
// RUN: -print-multi-directory \
|
|
// RUN: | FileCheck --match-full-lines --check-prefix=CHECK-X86_64-MULTILIBS %s
|
|
|
|
// CHECK-X86_64-MULTILIBS: .
|
|
// CHECK-X86_64-MULTILIBS-NOT: {{^.+$}}
|
|
|
|
// RUN: %clang -no-canonical-prefixes %s -### -o %t.o 2>/dev/null \
|
|
// RUN: -target arm-linux-androideabi21 \
|
|
// RUN: -mthumb \
|
|
// RUN: --gcc-toolchain=%S/Inputs/basic_android_ndk_tree \
|
|
// RUN: --sysroot=%S/Inputs/basic_android_ndk_tree/sysroot \
|
|
// RUN: -print-multi-directory \
|
|
// RUN: | FileCheck --match-full-lines --check-prefix=CHECK-ARM-MULTILIBS %s
|
|
|
|
// CHECK-ARM-MULTILIBS: thumb
|
|
// CHECK-ARM-MULTILIBS-NOT: {{^.+$}}
|