jackhong12 created this revision.
jackhong12 added a reviewer: aaron.ballman.
Herald added a project: All.
jackhong12 requested review of this revision.
Herald added a project: clang.
Herald added a subscriber: cfe-commits.
- Fixes https://github.com/llvm/llvm-project/issues/56159
Description
-----------
We need to diagnose the macro in commands too. For example, the expected result
of `clang++ -Wreserved-identifier -D__WHY_NOT_ME__ -U__STDC__ tmp.cpp` should be
<command line>:1:9: warning: macro name is a reserved identifier
[-Wreserved-macro-identifier]
#define __WHY_NOT_ME__ 1
^
<command line>:2:8: warning: macro name is a reserved identifier
[-Wreserved-macro-identifier]
#undef __STDC__
^
Currently, clang will not show any warning message when we define or undefine
reserved macro in commands.
Fix
---
We use digital directives in the preprocessor, like
# 1 "<built-in>" 3
#define __llvm__ 1
#define __clang__ 1
...
# 1 "<command line>" 1
#define __WHY_NOT_ME__ 1
#undef __STDC__
#define __GCC_HAVE_DWARF2_CFI_ASM 1
# 1 "<built-in>" 2
I think we should use `PresumedLoc` to determine its `<built-in>` or `<command
line>` section. In this case, the file name will be changed from `<built-in>`
to `<command line>`. However, `SourceMgr.getBufferName` only returns the
first name it matches.
Another issue is that clang will define `__GCC_HAVE_DWARF2_CFI_ASM` in the
command line. But I don't know how to handle this macro. I only add this macro
to the reserved macro list.
Repository:
rG LLVM Github Monorepo
https://reviews.llvm.org/D129061
Files:
clang/lib/Lex/PPDirectives.cpp
Index: clang/lib/Lex/PPDirectives.cpp
===================================================================
--- clang/lib/Lex/PPDirectives.cpp
+++ clang/lib/Lex/PPDirectives.cpp
@@ -164,6 +164,7 @@
"_THREAD_SAFE",
"_XOPEN_SOURCE",
"_XOPEN_SOURCE_EXTENDED",
+ "__GCC_HAVE_DWARF2_CFI_ASM",
"__STDCPP_WANT_MATH_SPEC_FUNCS__",
"__STDC_FORMAT_MACROS",
};
@@ -352,8 +353,9 @@
SourceLocation MacroNameLoc = MacroNameTok.getLocation();
if (ShadowFlag)
*ShadowFlag = false;
- if (!SourceMgr.isInSystemHeader(MacroNameLoc) &&
- (SourceMgr.getBufferName(MacroNameLoc) != "<built-in>")) {
+ PresumedLoc PL = SourceMgr.getPresumedLoc(MacroNameLoc);
+ if (!SourceMgr.isInSystemHeader(MacroNameLoc) && PL.isValid() &&
+ strcmp(PL.getFilename(), "<built-in>")) {
MacroDiag D = MD_NoWarn;
if (isDefineUndef == MU_Define) {
D = shouldWarnOnMacroDef(*this, II);
Index: clang/lib/Lex/PPDirectives.cpp
===================================================================
--- clang/lib/Lex/PPDirectives.cpp
+++ clang/lib/Lex/PPDirectives.cpp
@@ -164,6 +164,7 @@
"_THREAD_SAFE",
"_XOPEN_SOURCE",
"_XOPEN_SOURCE_EXTENDED",
+ "__GCC_HAVE_DWARF2_CFI_ASM",
"__STDCPP_WANT_MATH_SPEC_FUNCS__",
"__STDC_FORMAT_MACROS",
};
@@ -352,8 +353,9 @@
SourceLocation MacroNameLoc = MacroNameTok.getLocation();
if (ShadowFlag)
*ShadowFlag = false;
- if (!SourceMgr.isInSystemHeader(MacroNameLoc) &&
- (SourceMgr.getBufferName(MacroNameLoc) != "<built-in>")) {
+ PresumedLoc PL = SourceMgr.getPresumedLoc(MacroNameLoc);
+ if (!SourceMgr.isInSystemHeader(MacroNameLoc) && PL.isValid() &&
+ strcmp(PL.getFilename(), "<built-in>")) {
MacroDiag D = MD_NoWarn;
if (isDefineUndef == MU_Define) {
D = shouldWarnOnMacroDef(*this, II);
_______________________________________________
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
