Author: Nick Desaulniers
Date: 2020-03-12T15:13:59-07:00
New Revision: 246398ece7115b57a02dbe7876d86ae8e72406ef
URL:
https://github.com/llvm/llvm-project/commit/246398ece7115b57a02dbe7876d86ae8e72406ef
DIFF:
https://github.com/llvm/llvm-project/commit/246398ece7115b57a02dbe7876d86ae8e72406ef.diff
LOG: [clang][Parse] properly parse asm-qualifiers, asm inline
Summary:
The parsing of GNU C extended asm statements was a little brittle and
had a few issues:
- It was using Parse::ParseTypeQualifierListOpt to parse the `volatile`
qualifier. That parser is really meant for TypeQualifiers; an asm
statement doesn't really have a type qualifier. This is still maybe
nice to have, but not necessary. We now can check for the `volatile`
token by properly expanding the grammer, rather than abusing
Parse::ParseTypeQualifierListOpt.
- The parsing of `goto` was position dependent, so `asm goto volatile`
wouldn't parse. The qualifiers should be position independent to one
another. Now they are.
- We would warn on duplicate `volatile`, but the parse error for
duplicate `goto` was a generic parse error and wasn't clear.
- We need to add support for the recent GNU C extension `asm inline`.
Adding support to the parser with the above issues highlighted the
need for this refactoring.
Link: https://gcc.gnu.org/onlinedocs/gcc/Extended-Asm.html
Reviewers: aaron.ballman
Reviewed By: aaron.ballman
Subscribers: aheejin, jfb, nathanchance, cfe-commits, echristo, efriedma,
rsmith, chandlerc, craig.topper, erichkeane, jyu2, void, srhines
Tags: #clang
Differential Revision: https://reviews.llvm.org/D75563
Added:
clang/test/Parser/asm-qualifiers.c
Modified:
clang/docs/ReleaseNotes.rst
clang/include/clang/Basic/DiagnosticGroups.td
clang/include/clang/Basic/DiagnosticParseKinds.td
clang/include/clang/Parse/Parser.h
clang/lib/Parse/ParseStmtAsm.cpp
clang/lib/Parse/Parser.cpp
clang/test/CodeGen/inline-asm-mixed-style.c
clang/test/Parser/asm.c
clang/test/Sema/asm.c
Removed:
diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst
index 664ae4e4167c..710f005985da 100644
--- a/clang/docs/ReleaseNotes.rst
+++ b/clang/docs/ReleaseNotes.rst
@@ -91,6 +91,13 @@ Modified Compiler Flags
of a variable in a header file. In some cases, no specific translation unit
provides a definition of the variable. The previous behavior can be restored
by
specifying ``-fcommon``.
+- -Wasm-ignored-qualifier (ex. `asm const ("")`) has been removed and replaced
+ with an error (this matches a recent change in GCC-9).
+- -Wasm-file-asm-volatile (ex. `asm volatile ("")` at global scope) has been
+ removed and replaced with an error (this matches GCC's behavior).
+- Duplicate qualifiers on asm statements (ex. `asm volatile volatile ("")`) no
+ longer produces a warning via -Wduplicate-decl-specifier, but now an error
+ (this matches GCC's behavior).
New Pragmas in Clang
@@ -111,6 +118,9 @@ C Language Changes in Clang
- The default C language standard used when `-std=` is not specified has been
upgraded from gnu11 to gnu17.
+- Clang now supports the GNU C extension `asm inline`; it won't do anything
+ *yet*, but it will be parsed.
+
- ...
C++ Language Changes in Clang
diff --git a/clang/include/clang/Basic/DiagnosticGroups.td
b/clang/include/clang/Basic/DiagnosticGroups.td
index 2b11298bfcfa..2c28789aac1d 100644
--- a/clang/include/clang/Basic/DiagnosticGroups.td
+++ b/clang/include/clang/Basic/DiagnosticGroups.td
@@ -1090,9 +1090,8 @@ def ObjCSignedCharBool :
DiagGroup<"objc-signed-char-bool",
// Inline ASM warnings.
def ASMOperandWidths : DiagGroup<"asm-operand-widths">;
-def ASMIgnoredQualifier : DiagGroup<"asm-ignored-qualifier">;
def ASM : DiagGroup<"asm", [
-ASMOperandWidths, ASMIgnoredQualifier
+ASMOperandWidths
]>;
// OpenMP warnings.
diff --git a/clang/include/clang/Basic/DiagnosticParseKinds.td
b/clang/include/clang/Basic/DiagnosticParseKinds.td
index ec33a0fcfdc7..f22d3a18d254 100644
--- a/clang/include/clang/Basic/DiagnosticParseKinds.td
+++ b/clang/include/clang/Basic/DiagnosticParseKinds.td
@@ -12,11 +12,10 @@
let Component = "Parse" in {
-def warn_asm_qualifier_ignored : Warning<
- "ignored %0 qualifier on asm">, CatInlineAsm, InGroup;
-def warn_file_asm_volatile : Warning<
- "meaningless 'volatile' on asm outside function">, CatInlineAsm,
- InGroup;
+def err_asm_qualifier_ignored : Error<
+ "expected 'volatile', 'inline', 'goto', or '('">, CatInlineAsm;
+def err_global_asm_qualifier_ignored : Error<
+ "meaningless '%0' on asm outside function">, CatInlineAsm;
let CategoryName = "Inline Assembly Issue" in {
def err_asm_empty : Error<"__asm used with no assembly instructions">;
@@ -29,6 +28,7 @@ def err_gnu_inline_asm_disabled : Error<
"GNU-style inline assembly is disabled">;
def
