Document my otherwise-inexplicable change
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@107998 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/tools/libclang/CIndex.cpp b/tools/libclang/CIndex.cpp
index ee2e45f..7f32a1c 100644
--- a/tools/libclang/CIndex.cpp
+++ b/tools/libclang/CIndex.cpp
@@ -1184,7 +1184,15 @@
// in the actual argument list.
if (source_filename)
Args.push_back(source_filename);
+
+ // Since the Clang C library is primarily used by batch tools dealing with
+ // (often very broken) source code, where spell-checking can have a
+ // significant negative impact on performance (particularly when
+ // precompiled headers are involved), we disable it by default.
+ // Note that we place this argument early in the list, so that it can be
+ // overridden by the caller with "-fspell-checking".
Args.push_back("-fno-spell-checking");
+
Args.insert(Args.end(), command_line_args,
command_line_args + num_command_line_args);
Args.push_back("-Xclang");
@@ -1248,6 +1256,13 @@
argv.push_back("-o");
char astTmpFile[L_tmpnam];
argv.push_back(tmpnam(astTmpFile));
+
+ // Since the Clang C library is primarily used by batch tools dealing with
+ // (often very broken) source code, where spell-checking can have a
+ // significant negative impact on performance (particularly when
+ // precompiled headers are involved), we disable it by default.
+ // Note that we place this argument early in the list, so that it can be
+ // overridden by the caller with "-fspell-checking".
argv.push_back("-fno-spell-checking");
// Remap any unsaved files to temporary files.