Enable configuration files in clang

Clang is inherently a cross compiler and can generate code for any target
enabled during build. It however requires to specify many parameters in the
invocation, which could be hardcoded during configuration process in the
case of single-target compiler. The purpose of configuration files is to
make specifying clang arguments easier.

A configuration file is a collection of driver options, which are inserted
into command line before other options specified in the clang invocation.
It groups related options together and allows specifying them in simpler,
more flexible and less error prone way than just listing the options
somewhere in build scripts. Configuration file may be thought as a "macro"
that names an option set and is expanded when the driver is called.

Use of configuration files is described in `UserManual.rst`.

Differential Revision: https://reviews.llvm.org/D24933

llvm-svn: 321621

1 files changed, 98 insertions, 0 deletions

diff --git a/clang/test/Driver/config-file3.c b/clang/test/Driver/config-file3.c
new file mode 100644
index 00000000000..c1b523cbf97
--- /dev/null
+++ b/clang/test/Driver/config-file3.c
@@ -0,0 +1,98 @@
+// REQUIRES: shell
+// REQUIRES: x86-registered-target
+
+//--- If config file is specified by relative path (workdir/cfg-s2), it is searched for by that path.
+//
+// RUN: mkdir -p %T/workdir
+// RUN: echo "@subdir/cfg-s2" > %T/workdir/cfg-1
+// RUN: mkdir -p %T/workdir/subdir
+// RUN: echo "-Wundefined-var-template" > %T/workdir/subdir/cfg-s2
+//
+// RUN: ( cd %T && %clang --config workdir/cfg-1 -c %s -### 2>&1 | FileCheck %s -check-prefix CHECK-REL )
+//
+// CHECK-REL: Configuration file: {{.*}}/workdir/cfg-1
+// CHECK-REL: -Wundefined-var-template
+
+
+//--- Invocation qqq-clang-g++ tries to find config file qqq-clang-g++.cfg first.
+//
+// RUN: mkdir -p %T/testdmode
+// RUN: [ ! -s %T/testdmode/qqq-clang-g++ ] || rm %T/testdmode/qqq-clang-g++
+// RUN: ln -s %clang %T/testdmode/qqq-clang-g++
+// RUN: echo "-Wundefined-func-template" > %T/testdmode/qqq-clang-g++.cfg
+// RUN: echo "-Werror" > %T/testdmode/qqq.cfg
+// RUN: %T/testdmode/qqq-clang-g++ --config-system-dir= --config-user-dir= -c -no-canonical-prefixes %s -### 2>&1 | FileCheck %s -check-prefix FULL-NAME
+//
+// FULL-NAME: Configuration file: {{.*}}/testdmode/qqq-clang-g++.cfg
+// FULL-NAME: -Wundefined-func-template
+// FULL-NAME-NOT: -Werror
+//
+//--- File specified by --config overrides config inferred from clang executable.
+//
+// RUN: %T/testdmode/qqq-clang-g++ --config-system-dir=%S/Inputs/config --config-user-dir= --config i386-qqq -c -no-canonical-prefixes %s -### 2>&1 | FileCheck %s -check-prefix CHECK-EXPLICIT
+//
+// CHECK-EXPLICIT: Configuration file: {{.*}}/Inputs/config/i386-qqq.cfg
+//
+//--- Invocation qqq-clang-g++ tries to find config file qqq.cfg if qqq-clang-g++.cfg is not found.
+//
+// RUN: rm %T/testdmode/qqq-clang-g++.cfg
+// RUN: %T/testdmode/qqq-clang-g++ --config-system-dir= --config-user-dir= -c -no-canonical-prefixes %s -### 2>&1 | FileCheck %s -check-prefix SHORT-NAME
+//
+// SHORT-NAME: Configuration file: {{.*}}/testdmode/qqq.cfg
+// SHORT-NAME: -Werror
+// SHORT-NAME-NOT: -Wundefined-func-template
+
+
+//--- Config files are searched for in binary directory as well.
+//
+// RUN: mkdir -p %T/testbin
+// RUN: [ ! -s %T/testbin/clang ] || rm %T/testbin/clang
+// RUN: ln -s %clang %T/testbin/clang
+// RUN: echo "-Werror" > %T/testbin/aaa.cfg
+// RUN: %T/testbin/clang --config-system-dir= --config-user-dir= --config aaa.cfg -c -no-canonical-prefixes %s -### 2>&1 | FileCheck %s -check-prefix CHECK-BIN
+//
+// CHECK-BIN: Configuration file: {{.*}}/testbin/aaa.cfg
+// CHECK-BIN: -Werror
+
+
+//--- If command line contains options that change triple (for instance, -m32), clang tries
+//    reloading config file.
+
+//--- When reloading config file, x86_64-clang-g++ tries to find config i386-clang-g++.cfg first.
+//
+// RUN: mkdir -p %T/testreload
+// RUN: [ ! -s %T/testreload/x86_64-clang-g++ ] || rm %T/testreload/x86_64-clang-g++
+// RUN: ln -s %clang %T/testreload/x86_64-clang-g++
+// RUN: echo "-Wundefined-func-template" > %T/testreload/i386-clang-g++.cfg
+// RUN: echo "-Werror" > %T/testreload/i386.cfg
+// RUN: %T/testreload/x86_64-clang-g++ --config-system-dir= --config-user-dir= -c -m32 -no-canonical-prefixes %s -### 2>&1 | FileCheck %s -check-prefix CHECK-RELOAD
+//
+// CHECK-RELOAD: Configuration file: {{.*}}/testreload/i386-clang-g++.cfg
+// CHECK-RELOAD: -Wundefined-func-template
+// CHECK-RELOAD-NOT: -Werror
+
+//--- If config file is specified by --config and its name does not start with architecture, it is used without reloading.
+//
+// RUN: %T/testreload/x86_64-clang-g++ --config-system-dir=%S/Inputs --config-user-dir= --config config-3 -c -m32 -no-canonical-prefixes %s -### 2>&1 | FileCheck %s -check-prefix CHECK-RELOAD1a
+//
+// CHECK-RELOAD1a: Configuration file: {{.*}}/Inputs/config-3.cfg
+//
+// RUN: %T/testreload/x86_64-clang-g++ --config-system-dir=%S/Inputs --config-user-dir= --config config-3 -c -target i386 -no-canonical-prefixes %s -### 2>&1 | FileCheck %s -check-prefix CHECK-RELOAD1b
+//
+// CHECK-RELOAD1b: Configuration file: {{.*}}/Inputs/config-3.cfg
+
+//--- If config file is specified by --config and its name starts with architecture, it is reloaded.
+//
+// RUN: %T/testreload/x86_64-clang-g++ --config-system-dir=%S/Inputs/config --config-user-dir= --config x86_64-qqq -c -m32 -no-canonical-prefixes %s -### 2>&1 | FileCheck %s -check-prefix CHECK-RELOAD1c
+//
+// CHECK-RELOAD1c: Configuration file: {{.*}}/Inputs/config/i386-qqq.cfg
+
+//--- x86_64-clang-g++ tries to find config i386.cfg if i386-clang-g++.cfg is not found.
+//
+// RUN: rm %T/testreload/i386-clang-g++.cfg
+// RUN: %T/testreload/x86_64-clang-g++ --config-system-dir= --config-user-dir= -c -m32 -no-canonical-prefixes %s -### 2>&1 | FileCheck %s -check-prefix CHECK-RELOAD1d
+//
+// CHECK-RELOAD1d: Configuration file: {{.*}}/testreload/i386.cfg
+// CHECK-RELOAD1d: -Werror
+// CHECK-RELOAD1d-NOT: -Wundefined-func-template
+