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* [Bug c++/99232] New: Exported variable in module gives error: 'lambda' was not declared in this scope @ 2021-02-23 22:39 patrick.kox at commandoregel dot be 2023-08-15 19:00 ` [Bug c++/99232] " yagreg7 at gmail dot com ` (3 more replies) 0 siblings, 4 replies; 5+ messages in thread From: patrick.kox at commandoregel dot be @ 2021-02-23 22:39 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99232 Bug ID: 99232 Summary: Exported variable in module gives error: 'lambda' was not declared in this scope Product: gcc Version: 11.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: c++ Assignee: unassigned at gcc dot gnu.org Reporter: patrick.kox at commandoregel dot be Target Milestone: --- When compiling Ex11-01 from the book "Beginning C++20" by Horton and Van Weert there is an error message that the exported variable (const double) was not declared. here is the code: //math.cpp export module math; export auto square(const auto& x) { return x * x; } // An abbreviated function template export const double lambda{1.303577269034296391257}; // Conway's constant export enum class Oddity { Even, Odd }; bool isOdd(int x) { return x % 2 != 0; } // Module-local function (not exported) export auto getOddity(int x) { return isOdd(x) ? Oddity::Odd : Oddity::Even; } //------------------------------- // main.cpp // Consuming your own module import <iostream>; #define FMT_HEADER_ONLY #include "fmt/format.h" import math; int main() { std::cout << "Lambda squared: " << square(lambda) << std::endl; int number; std::cout << "\nPlease enter an odd number: "; std::cin >> number; std::cout << std::endl; switch (getOddity(number)) { using enum Oddity; case Odd: std::cout << "Well done! And remember: you have to be odd to be number one!"; break; case Even: fmt::print("Odd, {} seems to be even?", number); break; } std::cout << std::endl; } //------------------------------- To compile I do the following: 1. copy iostream into my source directory 2. execute the command: g++ -Wall -Wextra -fmodules-ts -std=c++20 -c -x c++-system-header iostream 3. execute the command: g++ -fmodules-ts -Wall -Wextra -std=c++20 -pedantic -pthread -lfmt math.cpp main.cpp //------------------------------- The full error message is: main.cpp: In function ‘int main()’: main.cpp:13:45: error: ‘lambda’ was not declared in this scope 13 | std::cout << "Lambda squared: " << square(lambda) << std::endl; | //------------------------------- If I move the declaration of the lambda variable to the main.cpp sourcefile the code does compile, so the other exports seem to work correctly. the version of GCC is: g++ (GCC) 11.0.0 20210214 (experimental) ^ permalink raw reply [flat|nested] 5+ messages in thread
* [Bug c++/99232] Exported variable in module gives error: 'lambda' was not declared in this scope 2021-02-23 22:39 [Bug c++/99232] New: Exported variable in module gives error: 'lambda' was not declared in this scope patrick.kox at commandoregel dot be @ 2023-08-15 19:00 ` yagreg7 at gmail dot com 2023-11-24 13:55 ` cvs-commit at gcc dot gnu.org ` (2 subsequent siblings) 3 siblings, 0 replies; 5+ messages in thread From: yagreg7 at gmail dot com @ 2023-08-15 19:00 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99232 Gregory Dushkin <yagreg7 at gmail dot com> changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |yagreg7 at gmail dot com --- Comment #1 from Gregory Dushkin <yagreg7 at gmail dot com> --- The issue is still present in GCC 13.2.1 and appears to only affect the actual variables but not references to them. E.g. the code: ``` // test.cc export module test; export constexpr int a = 42; // main.cc import test; int main() { return a; } ``` would give: ``` $ g++ test.cc -std=c++20 -fmodules-ts -c $ g++ main.cc -std=c++20 -fmodules-ts -c main.cc: In function ‘int main()’: main.cc:4:12: error: ‘a’ was not declared in this scope 4 | return a; | ``` but ``` // test.cc export module test; export constexpr int a_ = 42; export constexpr const int& a = a_; // main.cc import test; int main() { return a; } ``` compiles successfully using the same commands. ^ permalink raw reply [flat|nested] 5+ messages in thread
* [Bug c++/99232] Exported variable in module gives error: 'lambda' was not declared in this scope 2021-02-23 22:39 [Bug c++/99232] New: Exported variable in module gives error: 'lambda' was not declared in this scope patrick.kox at commandoregel dot be 2023-08-15 19:00 ` [Bug c++/99232] " yagreg7 at gmail dot com @ 2023-11-24 13:55 ` cvs-commit at gcc dot gnu.org 2024-02-11 13:42 ` nshead at gcc dot gnu.org 2024-02-11 14:07 ` nshead at gcc dot gnu.org 3 siblings, 0 replies; 5+ messages in thread From: cvs-commit at gcc dot gnu.org @ 2023-11-24 13:55 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99232 --- Comment #2 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The master branch has been updated by Nathaniel Shead <nshead@gcc.gnu.org>: https://gcc.gnu.org/g:726723c476800285cfbdfce612cedde4a9a7ad58 commit r14-5826-g726723c476800285cfbdfce612cedde4a9a7ad58 Author: Nathaniel Shead <nathanieloshead@gmail.com> Date: Wed Nov 15 20:50:53 2023 +1100 c++: Allow exporting const-qualified namespace-scope variables [PR99232] By [basic.link] p3.2.1, a non-template non-volatile const-qualified variable is not necessarily internal linkage in a module declaration, and rather may have module linkage (or external linkage if it is exported, see p4.8). PR c++/99232 gcc/cp/ChangeLog: * decl.cc (grokvardecl): Don't mark variables attached to modules as internal. gcc/testsuite/ChangeLog: * g++.dg/modules/pr99232_a.C: New test. * g++.dg/modules/pr99232_b.C: New test. Signed-off-by: Nathaniel Shead <nathanieloshead@gmail.com> ^ permalink raw reply [flat|nested] 5+ messages in thread
* [Bug c++/99232] Exported variable in module gives error: 'lambda' was not declared in this scope 2021-02-23 22:39 [Bug c++/99232] New: Exported variable in module gives error: 'lambda' was not declared in this scope patrick.kox at commandoregel dot be 2023-08-15 19:00 ` [Bug c++/99232] " yagreg7 at gmail dot com 2023-11-24 13:55 ` cvs-commit at gcc dot gnu.org @ 2024-02-11 13:42 ` nshead at gcc dot gnu.org 2024-02-11 14:07 ` nshead at gcc dot gnu.org 3 siblings, 0 replies; 5+ messages in thread From: nshead at gcc dot gnu.org @ 2024-02-11 13:42 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99232 Nathaniel Shead <nshead at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Resolution|--- |FIXED Assignee|unassigned at gcc dot gnu.org |nshead at gcc dot gnu.org CC| |nshead at gcc dot gnu.org Status|UNCONFIRMED |RESOLVED Target Milestone|--- |14.0 --- Comment #3 from Nathaniel Shead <nshead at gcc dot gnu.org> --- Fixed for GCC 14. ^ permalink raw reply [flat|nested] 5+ messages in thread
* [Bug c++/99232] Exported variable in module gives error: 'lambda' was not declared in this scope 2021-02-23 22:39 [Bug c++/99232] New: Exported variable in module gives error: 'lambda' was not declared in this scope patrick.kox at commandoregel dot be ` (2 preceding siblings ...) 2024-02-11 13:42 ` nshead at gcc dot gnu.org @ 2024-02-11 14:07 ` nshead at gcc dot gnu.org 3 siblings, 0 replies; 5+ messages in thread From: nshead at gcc dot gnu.org @ 2024-02-11 14:07 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99232 Nathaniel Shead <nshead at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |e9leyland at outlook dot com --- Comment #4 from Nathaniel Shead <nshead at gcc dot gnu.org> --- *** Bug 102545 has been marked as a duplicate of this bug. *** ^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2024-02-11 14:07 UTC | newest] Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2021-02-23 22:39 [Bug c++/99232] New: Exported variable in module gives error: 'lambda' was not declared in this scope patrick.kox at commandoregel dot be 2023-08-15 19:00 ` [Bug c++/99232] " yagreg7 at gmail dot com 2023-11-24 13:55 ` cvs-commit at gcc dot gnu.org 2024-02-11 13:42 ` nshead at gcc dot gnu.org 2024-02-11 14:07 ` nshead at gcc dot gnu.org
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