From 2a976020603589e897fcfa3276590ef50b489d34 Mon Sep 17 00:00:00 2001 From: "H.J. Lu" Date: Thu, 3 Dec 2020 15:39:59 -0800 Subject: Warn used and not used symbols in section with the same name When SECTION_RETAIN is used, issue a warning when a symbol without used attribute and a symbol with used attribute are placed in the section with the same name, like int __attribute__((used,section(".data.foo"))) foo2 = 2; int __attribute__((section(".data.foo"))) foo1 = 1; since assembler will put them in different sections with the same section name. gcc/ PR target/98146 * varasm.c (switch_to_section): Warn when a symbol without used attribute and a symbol with used attribute are placed in the section with the same name. gcc/testsuite/ PR target/98146 * c-c++-common/attr-used-5.c: Updated. * c-c++-common/attr-used-6.c: Likewise. * c-c++-common/attr-used-7.c: Likewise. * c-c++-common/attr-used-8.c: Likewise. --- gcc/varasm.c | 22 +++++++++++++++++++--- 1 file changed, 19 insertions(+), 3 deletions(-) (limited to 'gcc/varasm.c') diff --git a/gcc/varasm.c b/gcc/varasm.c index cfec870..a1a8d3b 100644 --- a/gcc/varasm.c +++ b/gcc/varasm.c @@ -7765,11 +7765,27 @@ switch_to_section (section *new_section, tree decl) { /* If the SECTION_RETAIN bit doesn't match, switch to a new section. */ + tree used_decl, no_used_decl; + if (DECL_PRESERVE_P (decl)) - new_section->common.flags |= SECTION_RETAIN; + { + new_section->common.flags |= SECTION_RETAIN; + used_decl = decl; + no_used_decl = new_section->named.decl; + } else - new_section->common.flags &= ~(SECTION_RETAIN - | SECTION_DECLARED); + { + new_section->common.flags &= ~(SECTION_RETAIN + | SECTION_DECLARED); + used_decl = new_section->named.decl; + no_used_decl = decl; + } + warning (OPT_Wattributes, + "%+qD without % attribute and %qD with " + "% attribute are placed in a section with " + "the same name", no_used_decl, used_decl); + inform (DECL_SOURCE_LOCATION (used_decl), + "%qD was declared here", used_decl); } else return; -- cgit v1.1