From 786c721c2bbd2e0646e314671e010859550423bf Mon Sep 17 00:00:00 2001 From: Ken Matsui <26405363+ken-matsui@users.noreply.github.com> Date: Wed, 11 May 2022 06:38:35 -0400 Subject: [PATCH] Add extension diagnostic for linemarker directives This adds the -Wgnu-line-marker diagnostic flag, grouped under -Wgnu, to warn about use of the GNU linemarker preprocessor extension. Fixes #55067 Differential Revision: https://reviews.llvm.org/D124534 --- clang/docs/ReleaseNotes.rst | 3 ++ clang/include/clang/Basic/DiagnosticGroups.td | 3 +- clang/include/clang/Basic/DiagnosticLexKinds.td | 4 ++ clang/lib/Lex/PPDirectives.cpp | 4 ++ .../Preprocessor/line-directive-system-headers.c | 47 ++++++++++++++++++++++ clang/test/Preprocessor/line-directive.c | 28 +++++++------ clang/test/SemaCXX/constexpr-string.cpp | 4 +- 7 files changed, 77 insertions(+), 16 deletions(-) create mode 100644 clang/test/Preprocessor/line-directive-system-headers.c diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst index 9841ae5..5a3b206 100644 --- a/clang/docs/ReleaseNotes.rst +++ b/clang/docs/ReleaseNotes.rst @@ -214,6 +214,9 @@ Improvements to Clang's diagnostics the ``-Wunreachable-code`` flag) which is enabled by default and warns the user about ``_Generic`` selection associations which are unreachable because the type specified is an array type or a qualified type. +- Added the ``-Wgnu-line-marker`` diagnostic flag (grouped under the ``-Wgnu`` + flag) which is a portability warning about use of GNU linemarker preprocessor + directives. Fixes `Issue 55067 `_. Non-comprehensive list of changes in this release ------------------------------------------------- diff --git a/clang/include/clang/Basic/DiagnosticGroups.td b/clang/include/clang/Basic/DiagnosticGroups.td index 1159f49..a7c3403 100644 --- a/clang/include/clang/Basic/DiagnosticGroups.td +++ b/clang/include/clang/Basic/DiagnosticGroups.td @@ -450,6 +450,7 @@ def : DiagGroup<"init-self">; def : DiagGroup<"inline">; def : DiagGroup<"invalid-pch">; def GNULabelsAsValue : DiagGroup<"gnu-label-as-value">; +def GNULineMarker : DiagGroup<"gnu-line-marker">; def LiteralRange : DiagGroup<"literal-range">; def LocalTypeTemplateArgs : DiagGroup<"local-type-template-args", [CXX98CompatLocalTypeTemplateArgs]>; @@ -1113,7 +1114,7 @@ def GNU : DiagGroup<"gnu", [GNUAlignofExpression, GNUAnonymousStruct, VLAExtension, GNUFlexibleArrayInitializer, GNUFlexibleArrayUnionMember, GNUFoldingConstant, GNUImaginaryConstant, GNUIncludeNext, - GNULabelsAsValue, GNUNullPointerArithmetic, + GNULabelsAsValue, GNULineMarker, GNUNullPointerArithmetic, GNUPointerArith, RedeclaredClassMember, GNURedeclaredEnum, GNUStatementExpression, GNUStaticFloatInit, diff --git a/clang/include/clang/Basic/DiagnosticLexKinds.td b/clang/include/clang/Basic/DiagnosticLexKinds.td index 543ce8a..01866d9 100644 --- a/clang/include/clang/Basic/DiagnosticLexKinds.td +++ b/clang/include/clang/Basic/DiagnosticLexKinds.td @@ -427,6 +427,10 @@ def note_macro_expansion_here : Note<"expansion of macro %0 requested here">; def ext_pp_opencl_variadic_macros : Extension< "variadic macros are a Clang extension in OpenCL">; +def ext_pp_gnu_line_directive : Extension< + "this style of line directive is a GNU extension">, + InGroup; + def err_pp_invalid_directive : Error<"invalid preprocessing directive">; def err_pp_directive_required : Error< "%0 must be used within a preprocessing directive">; diff --git a/clang/lib/Lex/PPDirectives.cpp b/clang/lib/Lex/PPDirectives.cpp index 2d942aa..1ef1ba1 100644 --- a/clang/lib/Lex/PPDirectives.cpp +++ b/clang/lib/Lex/PPDirectives.cpp @@ -1431,6 +1431,7 @@ void Preprocessor::HandleDigitDirective(Token &DigitTok) { // If the StrTok is "eod", then it wasn't present. Otherwise, it must be a // string followed by eod. if (StrTok.is(tok::eod)) { + Diag(StrTok, diag::ext_pp_gnu_line_directive); // Treat this like "#line NN", which doesn't change file characteristics. FileKind = SourceMgr.getFileCharacteristic(DigitTok.getLocation()); } else if (StrTok.isNot(tok::string_literal)) { @@ -1458,6 +1459,9 @@ void Preprocessor::HandleDigitDirective(Token &DigitTok) { // If a filename was present, read any flags that are present. if (ReadLineMarkerFlags(IsFileEntry, IsFileExit, FileKind, *this)) return; + if (!SourceMgr.isWrittenInBuiltinFile(DigitTok.getLocation()) && + !SourceMgr.isWrittenInCommandLineFile(DigitTok.getLocation())) + Diag(StrTok, diag::ext_pp_gnu_line_directive); // Exiting to an empty string means pop to the including file, so leave // FilenameID as -1 in that case. diff --git a/clang/test/Preprocessor/line-directive-system-headers.c b/clang/test/Preprocessor/line-directive-system-headers.c new file mode 100644 index 0000000..cd9e899 --- /dev/null +++ b/clang/test/Preprocessor/line-directive-system-headers.c @@ -0,0 +1,47 @@ +// RUN: %clang_cc1 -fsyntax-only -pedantic -verify %s +// RUN: %clang_cc1 -fsyntax-only -pedantic -verify=system -Wsystem-headers %s + +int x; + +# 42 // #1 +// expected-warning@#1 {{this style of line directive is a GNU extension}} +// system-warning@#1 {{this style of line directive is a GNU extension}} +# 42 "foo" // #2 +// expected-warning@#2 {{this style of line directive is a GNU extension}} +// system-warning@#2 {{this style of line directive is a GNU extension}} +# 42 "foo" 2 // #3 +// expected-error@#3 {{invalid line marker flag '2': cannot pop empty include stack}} +// system-error@#3 {{invalid line marker flag '2': cannot pop empty include stack}} +# 42 "foo" 1 3 // #4: enter +// Warnings silenced when -Wsystem-headers isn't passed. +// system-warning@#4 {{this style of line directive is a GNU extension}} +# 42 "foo" 2 3 // #5: exit +// Warnings silenced when -Wsystem-headers isn't passed. +// system-warning@#5 {{this style of line directive is a GNU extension}} +# 42 "foo" 2 3 4 // #6 +// expected-error@#6 {{invalid line marker flag '2': cannot pop empty include stack}} +// system-error@#6 {{invalid line marker flag '2': cannot pop empty include stack}} +# 42 "foo" 3 4 // #7 +// expected-warning@#7 {{this style of line directive is a GNU extension}} +// system-warning@#7 {{this style of line directive is a GNU extension}} + + +// Verify that linemarker diddling of the system header flag works. + +# 192 "glomp.h" // #8: not a system header. +// expected-warning@#8 {{this style of line directive is a GNU extension}} +// system-warning@#8 {{this style of line directive is a GNU extension}} + +# 192 "glomp.h" 3 // #9: System header. +// Warnings silenced when -Wsystem-headers isn't passed. +// system-warning@#9 {{this style of line directive is a GNU extension}} + +#line 42 "blonk.h" // doesn't change system headerness. + +# 97 // #10: doesn't change system headerness. +// Warnings silenced when -Wsystem-headers isn't passed. +// system-warning@#10 {{this style of line directive is a GNU extension}} + +# 42 "blonk.h" // #11: DOES change system headerness. +// Warnings silenced when -Wsystem-headers isn't passed. +// system-warning@#11 {{this style of line directive is a GNU extension}} diff --git a/clang/test/Preprocessor/line-directive.c b/clang/test/Preprocessor/line-directive.c index d0f6150..29ea709 100644 --- a/clang/test/Preprocessor/line-directive.c +++ b/clang/test/Preprocessor/line-directive.c @@ -9,8 +9,8 @@ # 20 "" 2 // a push/pop before any other line control -# 10 "enter-0" 1 -# 11 "" 2 // pop to main file +# 10 "enter-0" 1 // expected-warning {{this style of line directive is a GNU extension}} +# 11 "" 2 // pop to main file: expected-warning {{this style of line directive is a GNU extension}} #error MAIN7 // expected-error@-1{{MAIN7}} @@ -27,13 +27,15 @@ #define A 42 "foo" #line A -# 42 -# 42 "foo" +# 42 // expected-warning {{this style of line directive is a GNU extension}} +# 42 "foo" // expected-warning {{this style of line directive is a GNU extension}} # 42 "foo" 2 // expected-error {{invalid line marker flag '2': cannot pop empty include stack}} +// The next two lines do not get diagnosed because they are considered to be +// within the system header, where diagnostics are suppressed. # 42 "foo" 1 3 // enter # 42 "foo" 2 3 // exit # 42 "foo" 2 3 4 // expected-error {{invalid line marker flag '2': cannot pop empty include stack}} -# 42 "foo" 3 4 +# 42 "foo" 3 4 // expected-warning {{this style of line directive is a GNU extension}} # 'a' // expected-error {{invalid preprocessing directive}} # 42 'f' // expected-error {{invalid filename for line marker directive}} @@ -54,7 +56,7 @@ // Verify that linemarker diddling of the system header flag works. -# 192 "glomp.h" // not a system header. +# 192 "glomp.h" // not a system header.: expected-warning {{this style of line directive is a GNU extension}} typedef int x; // expected-note {{previous definition is here}} typedef int x; // expected-warning {{redefinition of typedef 'x' is a C11 feature}} @@ -97,7 +99,7 @@ typedef int q; // original definition in system header, should not diagnose. #line 010 // expected-warning {{#line directive interprets number as decimal, not octal}} extern int array[__LINE__ == 10 ? 1:-1]; -# 020 // expected-warning {{GNU line marker directive interprets number as decimal, not octal}} +# 020 // expected-warning {{GNU line marker directive interprets number as decimal, not octal}} expected-warning {{this style of line directive is a GNU extension}} extern int array_gnuline[__LINE__ == 20 ? 1:-1]; /* PR3917 */ @@ -106,7 +108,7 @@ extern char array2[\ _\ _LINE__ == 42 ? 1: -1]; /* line marker is location of first _ */ -# 51 +# 51 // expected-warning {{this style of line directive is a GNU extension}} extern char array2_gnuline[\ _\ _LINE__ == 52 ? 1: -1]; /* line marker is location of first _ */ @@ -115,12 +117,12 @@ _LINE__ == 52 ? 1: -1]; /* line marker is location of first _ */ #line 0 "line-directive.c" // expected-warning {{#line directive with zero argument is a GNU extension}} undefined t; // expected-error {{unknown type name 'undefined'}} -# 115 "main" -# 116 "enter-1" 1 -# 117 "enter-2" 1 -# 118 "" 2 // pop to enter-1 +# 115 "main" // expected-warning {{this style of line directive is a GNU extension}} +# 116 "enter-1" 1 // expected-warning {{this style of line directive is a GNU extension}} +# 117 "enter-2" 1 // expected-warning {{this style of line directive is a GNU extension}} +# 118 "" 2 // pop to enter-1: expected-warning {{this style of line directive is a GNU extension}} #error ENTER1 // expected-error@-1{{ENTER1}} -# 121 "" 2 // pop to "main" +# 121 "" 2 // pop to "main": expected-warning {{this style of line directive is a GNU extension}} #error MAIN2 // expected-error@-1{{MAIN2}} diff --git a/clang/test/SemaCXX/constexpr-string.cpp b/clang/test/SemaCXX/constexpr-string.cpp index 401f649..cfee356 100644 --- a/clang/test/SemaCXX/constexpr-string.cpp +++ b/clang/test/SemaCXX/constexpr-string.cpp @@ -7,7 +7,7 @@ // RUN: %clang_cc1 %s -triple armebv7-unknown-linux -std=c++2a -fsyntax-only -verify -pedantic -Wno-vla-extension -fno-signed-char // RUN: %clang_cc1 %s -triple armebv7-unknown-linux -std=c++2a -fsyntax-only -verify -pedantic -Wno-vla-extension -fno-wchar -DNO_PREDEFINED_WCHAR_T -# 9 "/usr/include/string.h" 1 3 4 +# 9 "/usr/include/string.h" 1 3 4 // expected-warning {{this style of line directive is a GNU extension}} extern "C" { typedef decltype(sizeof(int)) size_t; @@ -29,7 +29,7 @@ extern "C" { } # 25 "SemaCXX/constexpr-string.cpp" 2 -# 27 "/usr/include/wchar.h" 1 3 4 +# 27 "/usr/include/wchar.h" 1 3 4 // expected-warning {{this style of line directive is a GNU extension}} extern "C" { #if NO_PREDEFINED_WCHAR_T typedef decltype(L'0') wchar_t; -- 2.7.4