[Frontend][PCH]-Add support for ignoring PCH options (-ignore-pch). by MaggieYingYi · Pull Request #142409 · llvm/llvm-project (original) (raw)
@llvm/pr-subscribers-clang-driver
@llvm/pr-subscribers-clang
Author: None (MaggieYingYi)
Changes
As part of the mixed host bring up, the support of PCH (precompiled headers) has been raised as a potential issue. Visual Studio has an argument to ignore all PCH related switches. clang-cl has also support option /Y-. Having the same option in clang would be helpful. This commit is to add support for ignoring PCH options (-ignore-pch).
Full diff: https://github.com/llvm/llvm-project/pull/142409.diff
6 Files Affected:
- (modified) clang/docs/PCHInternals.rst (+10)
- (modified) clang/docs/UsersManual.rst (+14)
- (modified) clang/include/clang/Driver/Options.td (+2)
- (modified) clang/lib/Frontend/CompilerInvocation.cpp (+9)
- (added) clang/test/PCH/Inputs/ignored-pch.h (+6)
- (added) clang/test/PCH/ignored-pch.c (+114)
diff --git a/clang/docs/PCHInternals.rst b/clang/docs/PCHInternals.rst
index 079fba16711dc..de0b341460cac 100644
--- a/clang/docs/PCHInternals.rst
+++ b/clang/docs/PCHInternals.rst
@@ -31,6 +31,16 @@ option:
$ clang -cc1 -include-pch test.h.pch test.c -o test.s
+To ignore PCH options using clang -cc1, use the option -ignore-pch:
+
+.. code-block:: bash
+
+ $ clang -cc1 test.h -emit-pch -ignore-pch -o test.h.pch
+ $ clang -cc1 -include-pch test.h.pch -ignore-pch test.c -o test.s
+
+This option disables precompiled headers, overrides -emit-pch and -include-pch.
+test.h.pch is not generated and not used as a prefix header.
+
Design Philosophy
diff --git a/clang/docs/UsersManual.rst b/clang/docs/UsersManual.rst
index eb9a812f0c1c9..f12b6b4c02193 100644
--- a/clang/docs/UsersManual.rst
+++ b/clang/docs/UsersManual.rst
@@ -1458,6 +1458,20 @@ will be processed from the PCH file. Otherwise, Clang will report an error.
test.h since test.h was included directly in the source file and not
specified on the command line using -include-pch.
+Ignoring a PCH File
+^^^^^^^^^^^^^^^^^^^
+
+To ignore a PCH file using Clang, the -Xclang -ignore-pch option is passed to
+clang:
+
+.. code-block:: console
+
- $ clang -x c-header test.h -Xclang -ignore-pch -o test.h.pch
- $ clang -include-pch test.h.pch -Xclang -ignore-pch test.c -o test
- +This option disables precompiled headers, overrides -emit-pch and -include-pch. +test.h.pch is not generated and not used as a prefix header.
- Relocatable PCH Files ^^^^^^^^^^^^^^^^^^^^^
diff --git a/clang/include/clang/Driver/Options.td b/clang/include/clang/Driver/Options.td index 5ca31c253ed8f..3ed87608bf592 100644 --- a/clang/include/clang/Driver/Options.td +++ b/clang/include/clang/Driver/Options.td @@ -8127,6 +8127,8 @@ def emit_header_unit : Flag<["-"], "emit-header-unit">, HelpText<"Generate C++20 header units from header files">; def emit_pch : Flag<["-"], "emit-pch">, HelpText<"Generate pre-compiled header file">; +def ignore_pch : Flag<["-"], "ignore-pch">,
- HelpText<"Ignore pre-compiled header options">; def emit_llvm_only : Flag<["-"], "emit-llvm-only">, HelpText<"Build ASTs and convert to LLVM, discarding output">; def emit_codegen_only : Flag<["-"], "emit-codegen-only">, diff --git a/clang/lib/Frontend/CompilerInvocation.cpp b/clang/lib/Frontend/CompilerInvocation.cpp index 2c02719121c73..19f81ff2fbe9d 100644 --- a/clang/lib/Frontend/CompilerInvocation.cpp +++ b/clang/lib/Frontend/CompilerInvocation.cpp @@ -2982,6 +2982,15 @@ static bool ParseFrontendArgs(FrontendOptions &Opts, ArgList &Args,
#undef FRONTEND_OPTION_WITH_MARSHALLING
Opts.ProgramAction = frontend::ParseSyntaxOnly; +
- // If -ignore-pch is used, all pch handling is disabled. clang pch-related
- // flags are removed.
- if (Args.hasArg(options::OPT_ignore_pch)) {
- Args.eraseArg(options::OPT_emit_pch);
- Args.eraseArg(options::OPT_include_pch);
- Args.eraseArg(options::OPT_ignore_pch);
- }
- if (const Arg *A = Args.getLastArg(OPT_Action_Group)) { OptSpecifier Opt = OptSpecifier(A->getOption().getID()); std::optionalfrontend::ActionKind ProgramAction = getFrontendAction(Opt);
diff --git a/clang/test/PCH/Inputs/ignored-pch.h b/clang/test/PCH/Inputs/ignored-pch.h new file mode 100644 index 0000000000000..0956f9da1cb16 --- /dev/null +++ b/clang/test/PCH/Inputs/ignored-pch.h @@ -0,0 +1,6 @@ +#ifndef IGNORED_PCH_H +#define IGNORED_PCH_H +inline int f() {
- return 42; +} +#endif // IGNORED_PCH_H \ No newline at end of file diff --git a/clang/test/PCH/ignored-pch.c b/clang/test/PCH/ignored-pch.c new file mode 100644 index 0000000000000..198ad0fde7d05 --- /dev/null +++ b/clang/test/PCH/ignored-pch.c @@ -0,0 +1,114 @@ +// RUN: rm -rf %t.pch %t.ll +// RUN: %clang_cc1 -x c-header %S/Inputs/ignored-pch.h -emit-pch -o %t.pch +// RUN: %clang_cc1 %s -include-pch %t.pch -emit-llvm -o %t.ll +// RUN: ls %t.pch | FileCheck --check-prefix=CHECK-PCH %s +// RUN: ls %t.ll | FileCheck --check-prefix=CHECK-OBJ %s
- +// Check that -ignore-pch causes -emit-pch and -include-pch options to be ignored. +// RUN: rm -rf %t.pch %t.ll +// RUN: %clang_cc1 -x c-header %S/Inputs/ignored-pch.h -ignore-pch -emit-pch -o %t.pch +// RUN: %clang_cc1 %s -include-pch %t.pch -ignore-pch -emit-llvm -o %t.ll +// RUN: not ls %t.pch 2>&1 | FileCheck --check-prefix=CHECK-ERROR %s +// RUN: ls %t.ll | FileCheck --check-prefix=CHECK-OBJ %s
- +// Check that -ignore-pch is passed through Driver. +// RUN: rm -rf %t.pch %t.ll +// RUN: %clang -x c-header %S/Inputs/ignored-pch.h -Xclang -emit-pch -o %t.pch +// RUN: %clang -S %s -include-pch %t.pch -Xclang -emit-llvm -o %t.ll +// RUN: ls %t.pch | FileCheck --check-prefix=CHECK-PCH %s +// RUN: ls %t.ll | FileCheck --check-prefix=CHECK-OBJ %s
- +// RUN: rm -rf %t.pch %t.ll +// RUN: %clang -x c-header %S/Inputs/ignored-pch.h -Xclang -ignore-pch -Xclang -emit-pch -o %t.pch +// RUN: %clang -S %s -include-pch %t.pch -Xclang -ignore-pch -Xclang -emit-llvm -o %t.ll +// RUN: not ls %t.pch 2>&1 | FileCheck --check-prefix=CHECK-ERROR %s +// RUN: ls %t.ll | FileCheck --check-prefix=CHECK-OBJ %s
- +// Check that -ignore-pch works for multiple PCH related options. +// Test with -building-pch-with-obj. +// RUN: rm -rf %t.pch %t.ll +// RUN: %clang_cc1 -x c-header %S/Inputs/ignored-pch.h -ignore-pch -emit-pch -building-pch-with-obj -o %t.pch +// RUN: %clang_cc1 %s -include-pch %t.pch -ignore-pch -emit-llvm -building-pch-with-obj -o %t.ll +// RUN: not ls %t.pch 2>&1 | FileCheck --check-prefix=CHECK-ERROR %s +// RUN: ls %t.ll | FileCheck --check-prefix=CHECK-OBJ %s
- +// Test with -fallow-pch-with-compiler-errors. +// RUN: rm -rf %t.pch %t.ll +// RUN: %clang_cc1 -x c-header %S/Inputs/ignored-pch.h -ignore-pch -emit-pch -fallow-pch-with-compiler-errors -o %t.pch +// RUN: %clang_cc1 %s -include-pch %t.pch -ignore-pch -emit-llvm -fallow-pch-with-compiler-errors -o %t.ll +// RUN: not ls %t.pch 2>&1 | FileCheck --check-prefix=CHECK-ERROR %s +// RUN: ls %t.ll | FileCheck --check-prefix=CHECK-OBJ %s
- +// Test with -fallow-pch-with-different-modules-cache-path. +// RUN: rm -rf %t.pch %t.ll +// RUN: %clang_cc1 -x c-header %S/Inputs/ignored-pch.h -emit-pch -fallow-pch-with-different-modules-cache-path -o %t.pch +// RUN: %clang_cc1 %s -include-pch %t.pch -emit-llvm -fallow-pch-with-different-modules-cache-path -o %t.ll +// RUN: ls %t.pch | FileCheck --check-prefix=CHECK-PCH %s +// RUN: ls %t.ll | FileCheck --check-prefix=CHECK-OBJ %s
- +// Test with -fpch-codegen. +// RUN: rm -rf %t.pch %t.ll +// RUN: %clang_cc1 -x c-header %S/Inputs/ignored-pch.h -emit-pch -fpch-codegen -o %t.pch +// RUN: %clang_cc1 %s -include-pch %t.pch -emit-llvm -fpch-codegen -o %t.ll +// RUN: ls %t.pch | FileCheck --check-prefix=CHECK-PCH %s +// RUN: ls %t.ll | FileCheck --check-prefix=CHECK-OBJ %s
- +// Test with -fpch-debuginfo. +// RUN: rm -rf %t.pch %t.ll +// RUN: %clang_cc1 -x c-header %S/Inputs/ignored-pch.h -emit-pch -fpch-debuginfo -o %t.pch +// RUN: %clang_cc1 %s -include-pch %t.pch -emit-llvm -fpch-debuginfo -o %t.ll +// RUN: ls %t.pch | FileCheck --check-prefix=CHECK-PCH %s +// RUN: ls %t.ll | FileCheck --check-prefix=CHECK-OBJ %s
- +// Test with -fpch-instantiate-templates. +// RUN: rm -rf %t.pch %t.ll +// RUN: %clang_cc1 -x c-header %S/Inputs/ignored-pch.h -emit-pch -fpch-instantiate-templates -o %t.pch +// RUN: %clang_cc1 %s -include-pch %t.pch -emit-llvm -fpch-instantiate-templates -o %t.ll +// RUN: ls %t.pch | FileCheck --check-prefix=CHECK-PCH %s +// RUN: ls %t.ll | FileCheck --check-prefix=CHECK-OBJ %s
- +// Test with -fno-pch-timestamp. +// RUN: rm -rf %t.pch %t.ll +// RUN: %clang_cc1 -x c-header %S/Inputs/ignored-pch.h -emit-pch -fno-pch-timestamp -o %t.pch +// RUN: %clang_cc1 %s -include-pch %t.pch -emit-llvm -fno-pch-timestamp -o %t.ll +// RUN: ls %t.pch | FileCheck --check-prefix=CHECK-PCH %s +// RUN: ls %t.ll | FileCheck --check-prefix=CHECK-OBJ %s
- +// Test with -fno-validate-pch. +// RUN: rm -rf %t.pch %t.ll +// RUN: %clang_cc1 -x c-header %S/Inputs/ignored-pch.h -emit-pch -fno-validate-pch -o %t.pch +// RUN: %clang_cc1 %s -include-pch %t.pch -emit-llvm -fno-validate-pch -o %t.ll +// RUN: ls %t.pch | FileCheck --check-prefix=CHECK-PCH %s +// RUN: ls %t.ll | FileCheck --check-prefix=CHECK-OBJ %s
- +// Test with -relocatable-pch. +// RUN: rm -rf %t.pch %t.ll +// RUN: %clang_cc1 -x c-header %S/Inputs/ignored-pch.h -emit-pch -relocatable-pch -o %t.pch +// RUN: %clang_cc1 %s -include-pch %t.pch -emit-llvm -relocatable-pch -o %t.ll +// RUN: ls %t.pch | FileCheck --check-prefix=CHECK-PCH %s +// RUN: ls %t.ll | FileCheck --check-prefix=CHECK-OBJ %s
- +// Test with -pch-through-hdrstop-create/-pch-through-hdrstop-use +// RUN: rm -rf %t.pch %t.ll +// RUN: %clang_cc1 -x c-header %S/Inputs/ignored-pch.h -emit-pch -pch-through-hdrstop-create -o %t.pch +// RUN: %clang_cc1 %s -include-pch %t.pch -emit-llvm -pch-through-hdrstop-use -o %t.ll +// RUN: ls %t.pch | FileCheck --check-prefix=CHECK-PCH %s +// RUN: ls %t.ll | FileCheck --check-prefix=CHECK-OBJ %s
- +// Test with AST dump output: +// RUN: rm -rf %t.pch %t.ll +// RUN: %clang_cc1 -x c-header %S/Inputs/ignored-pch.h -emit-pch -o %t.pch +// RUN: %clang_cc1 %s -include-pch %t.pch -ast-dump-all | FileCheck --check-prefix=CHECK-AST-PCH %s +// RUN: %clang_cc1 %s -include-pch %t.pch -ignore-pch -ast-dump-all | FileCheck --check-prefix=CHECK-AST %s
- +// CHECK-PCH: ignored-pch.c.{{.}}.pch +// CHECK-OBJ: ignored-pch.c.{{.}}.ll +// CHECK-ERROR: ignored-pch.c.{{.*}}.pch{{'?}}: No such file or directory +// CHECK-AST-PCH: +// CHECK-AST-NOT:
- +#include "Inputs/ignored-pch.h"
+#pragma hdrstop +int main() {
- return f(); +}