String Literal and Wide String Literal Encoding from the Preprocessor
Adds the __clang_literal_encoding__ and __clang_wide_literal_encoding__
predefined macros to expose the encoding used for string literals to
the preprocessor.
GitOrigin-RevId: 701d70d4c25c4e02b303ba6dee1495708496f615
diff --git a/docs/LanguageExtensions.rst b/docs/LanguageExtensions.rst
index a906dc7..0075911 100644
--- a/docs/LanguageExtensions.rst
+++ b/docs/LanguageExtensions.rst
@@ -383,6 +383,18 @@
Defined to a string that captures the Clang marketing version, including the
Subversion tag or revision number, e.g., "``1.5 (trunk 102332)``".
+``__clang_literal_encoding__``
+ Defined to a narrow string literal that represents the current encoding of
+ narrow string literals, e.g., ``"hello"``. This macro typically expands to
+ "UTF-8" (but may change in the future if the
+ ``-fexec-charset="Encoding-Name"`` option is implemented.)
+
+``__clang_wide_literal_encoding__``
+ Defined to a narrow string literal that represents the current encoding of
+ wide string literals, e.g., ``L"hello"``. This macro typically expands to
+ "UTF-16" or "UTF-32" (but may change in the future if the
+ ``-fwide-exec-charset="Encoding-Name"`` option is implemented.)
+
.. _langext-vectors:
Vectors and Extended Vectors
diff --git a/lib/Frontend/InitPreprocessor.cpp b/lib/Frontend/InitPreprocessor.cpp
index 3d69c59..7876a36 100644
--- a/lib/Frontend/InitPreprocessor.cpp
+++ b/lib/Frontend/InitPreprocessor.cpp
@@ -778,6 +778,21 @@
}
}
+ // Macros to help identify the narrow and wide character sets
+ // FIXME: clang currently ignores -fexec-charset=. If this changes,
+ // then this may need to be updated.
+ Builder.defineMacro("__clang_literal_encoding__", "\"UTF-8\"");
+ if (TI.getTypeWidth(TI.getWCharType()) >= 32) {
+ // FIXME: 32-bit wchar_t signals UTF-32. This may change
+ // if -fwide-exec-charset= is ever supported.
+ Builder.defineMacro("__clang_wide_literal_encoding__", "\"UTF-32\"");
+ } else {
+ // FIXME: Less-than 32-bit wchar_t generally means UTF-16
+ // (e.g., Windows, 32-bit IBM). This may need to be
+ // updated if -fwide-exec-charset= is ever supported.
+ Builder.defineMacro("__clang_wide_literal_encoding__", "\"UTF-16\"");
+ }
+
if (LangOpts.Optimize)
Builder.defineMacro("__OPTIMIZE__");
if (LangOpts.OptimizeSize)
diff --git a/test/Preprocessor/init-x86.c b/test/Preprocessor/init-x86.c
index d22a2ab..527cd39 100644
--- a/test/Preprocessor/init-x86.c
+++ b/test/Preprocessor/init-x86.c
@@ -1306,10 +1306,12 @@
// X86_64-CLOUDABI:#define __amd64 1
// X86_64-CLOUDABI:#define __amd64__ 1
// X86_64-CLOUDABI:#define __clang__ 1
+// X86_64-CLOUDABI:#define __clang_literal_encoding__ {{.*}}
// X86_64-CLOUDABI:#define __clang_major__ {{.*}}
// X86_64-CLOUDABI:#define __clang_minor__ {{.*}}
// X86_64-CLOUDABI:#define __clang_patchlevel__ {{.*}}
// X86_64-CLOUDABI:#define __clang_version__ {{.*}}
+// X86_64-CLOUDABI:#define __clang_wide_literal_encoding__ {{.*}}
// X86_64-CLOUDABI:#define __llvm__ 1
// X86_64-CLOUDABI:#define __x86_64 1
// X86_64-CLOUDABI:#define __x86_64__ 1
diff --git a/test/Preprocessor/init.c b/test/Preprocessor/init.c
index 136200a..0329453 100644
--- a/test/Preprocessor/init.c
+++ b/test/Preprocessor/init.c
@@ -115,10 +115,12 @@
// COMMON:#define __STDC__ 1
// COMMON:#define __VERSION__ {{.*}}
// COMMON:#define __clang__ 1
+// COMMON:#define __clang_literal_encoding__ {{.*}}
// COMMON:#define __clang_major__ {{[0-9]+}}
// COMMON:#define __clang_minor__ {{[0-9]+}}
// COMMON:#define __clang_patchlevel__ {{[0-9]+}}
// COMMON:#define __clang_version__ {{.*}}
+// COMMON:#define __clang_wide_literal_encoding__ {{.*}}
// COMMON:#define __llvm__ 1
//
// RUN: %clang_cc1 -E -dM -triple=x86_64-pc-win32 < /dev/null | FileCheck -match-full-lines -check-prefix C-DEFAULT %s
@@ -1844,10 +1846,12 @@
// WEBASSEMBLY-NOT:#define __WINT_UNSIGNED__
// WEBASSEMBLY-NEXT:#define __WINT_WIDTH__ 32
// WEBASSEMBLY-NEXT:#define __clang__ 1
+// WEBASSEMBLY-NEXT:#define __clang_literal_encoding__ {{.*}}
// WEBASSEMBLY-NEXT:#define __clang_major__ {{.*}}
// WEBASSEMBLY-NEXT:#define __clang_minor__ {{.*}}
// WEBASSEMBLY-NEXT:#define __clang_patchlevel__ {{.*}}
// WEBASSEMBLY-NEXT:#define __clang_version__ "{{.*}}"
+// WEBASSEMBLY-NEXT:#define __clang_wide_literal_encoding__ {{.*}}
// WEBASSEMBLY-NEXT:#define __llvm__ 1
// WEBASSEMBLY-NOT:#define __unix
// WEBASSEMBLY-NOT:#define __unix__
