diff options
Diffstat (limited to 'gcc/c-decl.c')
| -rw-r--r-- | gcc/c-decl.c | 39 |
1 files changed, 36 insertions, 3 deletions
diff --git a/gcc/c-decl.c b/gcc/c-decl.c index b6ff3f4..bc90fdd 100644 --- a/gcc/c-decl.c +++ b/gcc/c-decl.c @@ -1164,14 +1164,21 @@ pop_scope (void) case VAR_DECL: /* Warnings for unused variables. */ - if (!TREE_USED (p) + if ((!TREE_USED (p) || !DECL_READ_P (p)) && !TREE_NO_WARNING (p) && !DECL_IN_SYSTEM_HEADER (p) && DECL_NAME (p) && !DECL_ARTIFICIAL (p) && scope != file_scope && scope != external_scope) - warning (OPT_Wunused_variable, "unused variable %q+D", p); + { + if (!TREE_USED (p)) + warning (OPT_Wunused_variable, "unused variable %q+D", p); + else if (DECL_CONTEXT (p) == current_function_decl) + warning_at (DECL_SOURCE_LOCATION (p), + OPT_Wunused_but_set_variable, + "variable %qD set but not used", p); + } if (b->inner_comp) { @@ -2387,6 +2394,8 @@ merge_decls (tree newdecl, tree olddecl, tree newtype, tree oldtype) TREE_USED (newdecl) = 1; else if (TREE_USED (newdecl)) TREE_USED (olddecl) = 1; + if (TREE_CODE (olddecl) == VAR_DECL || TREE_CODE (olddecl) == PARM_DECL) + DECL_READ_P (newdecl) |= DECL_READ_P (olddecl); if (DECL_PRESERVE_P (olddecl)) DECL_PRESERVE_P (newdecl) = 1; else if (DECL_PRESERVE_P (newdecl)) @@ -4232,7 +4241,10 @@ finish_decl (tree decl, location_t init_loc, tree init, } if (TREE_USED (type)) - TREE_USED (decl) = 1; + { + TREE_USED (decl) = 1; + DECL_READ_P (decl) = 1; + } } /* If this is a function and an assembler name is specified, reset DECL_RTL @@ -4380,6 +4392,7 @@ finish_decl (tree decl, location_t init_loc, tree init, /* Don't warn about decl unused; the cleanup uses it. */ TREE_USED (decl) = 1; TREE_USED (cleanup_decl) = 1; + DECL_READ_P (decl) = 1; push_cleanup (decl, cleanup, false); } @@ -4472,6 +4485,7 @@ build_compound_literal (location_t loc, tree type, tree init, bool non_const) TREE_STATIC (decl) = (current_scope == file_scope); DECL_CONTEXT (decl) = current_function_decl; TREE_USED (decl) = 1; + DECL_READ_P (decl) = 1; TREE_TYPE (decl) = type; TREE_READONLY (decl) = TYPE_READONLY (type); store_init_value (loc, decl, init, NULL_TREE); @@ -8060,6 +8074,25 @@ finish_function (void) TREE_NO_WARNING (fndecl) = 1; } + /* Complain about parameters that are only set, but never otherwise used. */ + if (warn_unused_but_set_parameter) + { + tree decl; + + for (decl = DECL_ARGUMENTS (fndecl); + decl; + decl = TREE_CHAIN (decl)) + if (TREE_USED (decl) + && TREE_CODE (decl) == PARM_DECL + && !DECL_READ_P (decl) + && DECL_NAME (decl) + && !DECL_ARTIFICIAL (decl) + && !TREE_NO_WARNING (decl)) + warning_at (DECL_SOURCE_LOCATION (decl), + OPT_Wunused_but_set_parameter, + "parameter %qD set but not used", decl); + } + /* Store the end of the function, so that we get good line number info for the epilogue. */ cfun->function_end_locus = input_location; |