1da403937e
The patch reapply https://github.com/llvm/llvm-project/pull/173130. This patch implement the following papers: [P1857R3 Modules Dependency Discovery](https://wg21.link/p1857r3). [P3034R1 Module Declarations Shouldn’t be Macros](https://wg21.link/P3034R1). [CWG2947](https://cplusplus.github.io/CWG/issues/2947.html). At the start of phase 4 an import or module token is treated as starting a directive and are converted to their respective keywords iff: - After skipping horizontal whitespace are - at the start of a logical line, or - preceded by an export at the start of the logical line. - Are followed by an identifier pp token (before macro expansion), or - <, ", or : (but not ::) pp tokens for import, or - ; for module Otherwise the token is treated as an identifier. Additionally: - The entire import or module directive (including the closing ;) must be on a single logical line and for module must not come from an #include. - The expansion of macros must not result in an import or module directive introducer that was not there prior to macro expansion. - A module directive may only appear as the first preprocessing tokens in a file (excluding the global module fragment.) - Preprocessor conditionals shall not span a module declaration. After this patch, we handle C++ module-import and module-declaration as a real pp-directive in preprocessor. Additionally, we refactor module name lexing, remove the complex state machine and read full module name during module/import directive handling. Possibly we can introduce a tok::annot_module_name token in the future, avoid duplicatly parsing module name in both preprocessor and parser, but it's makes error recovery much diffcult(eg. import a; import b; in same line). This patch also introduce 2 new keyword `__preprocessed_module` and `__preprocessed_import`. These 2 keyword was generated during `-E` mode. This is useful to avoid confusion with `module` and `import` keyword in preprocessed output: ```cpp export module m; struct import {}; #define EMPTY EMPTY import foo; ``` Fixes https://github.com/llvm/llvm-project/issues/54047 The previous patch has an use-after-free issue in Lexer::LexTokenInternal function. Since C++20, the `export`, `import` and `module` identifiers may be an introducer of a C++ module declaration/importing directive, and the directive will handled in `LexIdentifierContinue`. Unfortunately, the EOF may be encountered in `LexIdentifierContinue` and `CurLexer` might be destructed in `HandleEndOfFile`, If the code after `LexIdentifierContinue` try to access `LangOps` or other class members in this Lexer, it will hit undefined behavior. This patch also fix the use-after-free issue in Lexer by introduce a mechanism to delay the destruction of `CurLexer` in `Preprocessor` class. --------- Signed-off-by: yronglin <yronglin777@gmail.com>
111 lines
3.5 KiB
C++
111 lines
3.5 KiB
C++
// RUN: rm -rf %t
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// RUN: split-file %s %t
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// RUN: %clang_cc1 -std=c++2a -I%t -emit-module-interface %t/interface.cppm -o %t.pcm
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// RUN: %clang_cc1 -std=c++2a -I%t -fmodule-file=A=%t.pcm %t/implA.cppm -verify -fno-modules-error-recovery
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// RUN: %clang_cc1 -std=c++2a -I%t -fmodule-file=A=%t.pcm %t/implB.cppm -verify -fno-modules-error-recovery
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//--- foo.h
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#ifndef FOO_H
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#define FOO_H
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extern int in_header;
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#endif
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//--- interface.cppm
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module;
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#include "foo.h"
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// FIXME: The following need to be moved to a header file. The global module
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// fragment is only permitted to contain preprocessor directives.
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int global_module_fragment;
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export module A;
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export int exported;
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int not_exported;
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static int internal;
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module :private;
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int not_exported_private;
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static int internal_private;
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//--- implA.cppm
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module;
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void test_early() {
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in_header = 1; // expected-error {{use of undeclared identifier 'in_header'}}
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// expected-note@* {{not visible}}
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global_module_fragment = 1; // expected-error {{use of undeclared identifier 'global_module_fragment'}}
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exported = 1; // expected-error {{use of undeclared identifier 'exported'}}
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not_exported = 1; // expected-error {{use of undeclared identifier 'not_exported'}}
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// FIXME: We need better diagnostic message for static variable.
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internal = 1; // expected-error {{use of undeclared identifier 'internal'}}
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not_exported_private = 1; // expected-error {{undeclared identifier}}
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internal_private = 1; // expected-error {{undeclared identifier}}
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}
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module A;
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void test_late() {
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in_header = 1; // expected-error {{missing '#include "foo.h"'; 'in_header' must be declared before it is used}}
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// expected-note@* {{not visible}}
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global_module_fragment = 1; // expected-error {{missing '#include'; 'global_module_fragment' must be declared before it is used}}
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exported = 1;
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not_exported = 1;
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internal = 1; // expected-error {{use of undeclared identifier 'internal'}}
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not_exported_private = 1;
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internal_private = 1; // expected-error {{use of undeclared identifier 'internal_private'}}
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}
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//--- implB.cppm
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module;
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void test_early() {
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in_header = 1; // expected-error {{use of undeclared identifier 'in_header'}}
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// expected-note@* {{not visible}}
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global_module_fragment = 1; // expected-error {{use of undeclared identifier 'global_module_fragment'}}
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exported = 1; // expected-error {{use of undeclared identifier 'exported'}}
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not_exported = 1; // expected-error {{use of undeclared identifier 'not_exported'}}
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// FIXME: We need better diagnostic message for static variable.
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internal = 1; // expected-error {{use of undeclared identifier 'internal'}}
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not_exported_private = 1; // expected-error {{undeclared identifier}}
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internal_private = 1; // expected-error {{undeclared identifier}}
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}
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export module B;
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import A;
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void test_late() {
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in_header = 1; // expected-error {{missing '#include "foo.h"'; 'in_header' must be declared before it is used}}
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// expected-note@* {{not visible}}
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global_module_fragment = 1; // expected-error {{missing '#include'; 'global_module_fragment' must be declared before it is used}}
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exported = 1;
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not_exported = 1; // expected-error {{use of undeclared identifier 'not_exported'; did you mean 'exported'?}}
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// expected-note@* {{'exported' declared here}}
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internal = 1; // expected-error {{use of undeclared identifier 'internal'}}
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not_exported_private = 1;
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// FIXME: should not be visible here
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// expected-error@-2 {{undeclared identifier}}
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internal_private = 1; // expected-error {{use of undeclared identifier 'internal_private'}}
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}
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