https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88720
--- Comment #3 from Joseph S. Myers <jsm28 at gcc dot gnu.org> --- Author: jsm28 Date: Tue Jan 15 20:32:00 2019 New Revision: 267949 URL: https://gcc.gnu.org/viewcvs?rev=267949&root=gcc&view=rev Log: Fix diagnostics for never-defined inline and nested functions (PR c/88720, PR c/88726). Bugs 88720 and 88726 report issues where a function is declared inline in an inner scope, resulting in spurious diagnostics about it being declared but never defined when that scope is left (possibly in some cases also wrongly referring to the function as a nested function). These are regressions that were introduced with the support for C99 inline semantics in 4.3 (they don't appear with 4.2; it's possible some aspects of the bugs might have been introduced later than 4.3). For the case of functions being wrongly referred to as nested, DECL_EXTERNAL was not the right condition for a function being non-nested; TREE_PUBLIC is appropriate for the case of non-nested functions with external linkage, while !b->nested means this is the outermost scope in which the function was declared and so avoids catching the case of a file-scope static being redeclared inline inside a function. For the non-nested, external-linkage case, the code attempts to avoid duplicate diagnostics by diagnosing only when scope != external_scope, but actually scope == external_scope is more appropriate, as it's only when the file and external scopes are popped that the code can actually tell whether a function ended up being defined, and all such functions will appear in the (GCC-internal) external scope. Bootstrapped with no regressions on x86_64-pc-linux-gnu. gcc/c: Backport from mainline 2019-01-07 Joseph Myers <jos...@codesourcery.com> PR c/88720 PR c/88726 * c-decl.c (pop_scope): Use TREE_PUBLIC and b->nested to determine whether a function is nested, not DECL_EXTERNAL. Diagnose inline functions declared but never defined only for external scope, not for other scopes. gcc/testsuite: Backport from mainline 2019-01-07 Joseph Myers <jos...@codesourcery.com> PR c/88720 PR c/88726 * gcc.dg/inline-40.c, gcc.dg/inline-41.c: New tests. Added: branches/gcc-8-branch/gcc/testsuite/gcc.dg/inline-40.c branches/gcc-8-branch/gcc/testsuite/gcc.dg/inline-41.c Modified: branches/gcc-8-branch/gcc/c/ChangeLog branches/gcc-8-branch/gcc/c/c-decl.c branches/gcc-8-branch/gcc/testsuite/ChangeLog
