PTH-- Remove feature entirely-

When debugging a boost build with a modified
version of Clang, I discovered that the PTH implementation
stores TokenKind in 8 bits. However, we currently have 368
TokenKinds.

The result is that the value gets truncated and the wrong token
gets picked up when including PTH files. It seems that this will
go wrong every time someone uses a token that uses the 9th bit.

Upon asking on IRC, it was brought up that this was a highly
experimental features that was considered a failure. I discovered
via googling that BoostBuild (mostly Boost.Math) is the only user of
this
feature, using the CC1 flag directly. I believe that this can be
transferred over to normal PCH with minimal effort:
https://github.com/boostorg/build/issues/367

Based on advice on IRC and research showing that this is a nearly
completely unused feature, this patch removes it entirely.

Note: I considered leaving the build-flags in place and making them
emit an error/warning, however since I've basically identified and
warned the only user, it seemed better to just remove them.

Differential Revision: https://reviews.llvm.org/D54547

Change-Id: If32744275ef1f585357bd6c1c813d96973c4d8d9
llvm-svn: 348266

4 files changed, 0 insertions, 29 deletions

diff --git a/clang/test/Driver/pth.c b/clang/test/Driver/pth.c
deleted file mode 100644
index e56c34c93bb..00000000000
--- a/clang/test/Driver/pth.c
+++ /dev/null
@@ -1,12 +0,0 @@
-// Test transparent PTH support.
-
-// RUN: %clang -no-canonical-prefixes -ccc-pch-is-pth -x c-header %s -o %t.h.pth -### 2> %t.log
-// RUN: FileCheck -check-prefix CHECK1 -input-file %t.log %s
-
-// CHECK1: "{{.*[/\\]}}clang{{.*}}" "-cc1" {{.*}} "-o" "{{.*}}.h.pth" "-x" "c-header" "{{.*}}pth.c"
-
-// RUN: touch %t.h.pth
-// RUN: %clang -no-canonical-prefixes -ccc-pch-is-pth -E -include %t.h %s -### 2> %t.log
-// RUN: FileCheck -check-prefix CHECK2 -input-file %t.log %s
-
-// CHECK2: "{{.*[/\\]}}clang{{.*}}" "-cc1" {{.*}}"-include-pth" "{{.*}}.h.pth" {{.*}}"-x" "c" "{{.*}}pth.c"
diff --git a/clang/test/PCH/emit-pth.c b/clang/test/PCH/emit-pth.c
deleted file mode 100644
index 2c0fba7f093..00000000000
--- a/clang/test/PCH/emit-pth.c
+++ /dev/null
@@ -1,7 +0,0 @@
-// RUN: %clang_cc1 -triple i386-unknown-unknown -emit-pth -o %t1 %s
-// RUN: %clang_cc1 -triple i386-unknown-unknown -emit-pth -o - %s > %t2
-// RUN: cmp %t1 %t2
-// RUN: %clang_cc1 -triple i386-unknown-unknown -emit-pth -o - %s | \
-// RUN: FileCheck %s
-
-// CHECK: cfe-pth
diff --git a/clang/test/PCH/pth.c b/clang/test/PCH/pth.c
deleted file mode 100644
index 6f2e4fc7b53..00000000000
--- a/clang/test/PCH/pth.c
+++ /dev/null
@@ -1,7 +0,0 @@
-// RUN: %clang_cc1 -triple i386-unknown-unknown -emit-pth -o %t %S/pth.h
-// RUN: not %clang_cc1 -triple i386-unknown-unknown -include-pth %t -fsyntax-only %s 2>&1 | FileCheck %s
-
-#error This is the only diagnostic
-
-// CHECK: This is the only diagnostic
-// CHECK: 1 error generated.
diff --git a/clang/test/Preprocessor/include-pth.c b/clang/test/Preprocessor/include-pth.c
deleted file mode 100644
index e1d6685d1fa..00000000000
--- a/clang/test/Preprocessor/include-pth.c
+++ /dev/null
@@ -1,3 +0,0 @@
-// RUN: %clang_cc1 -emit-pth %s -o %t
-// RUN: %clang_cc1 -include-pth %t %s -E | grep 'file_to_include' | count 2
-#include "file_to_include.h"