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| author | Alan Modra <amodra@gmail.com> | 2020-05-15 18:06:05 +0930 |
|---|---|---|
| committer | Alan Modra <amodra@gmail.com> | 2020-05-15 18:21:07 +0930 |
| commit | 2a50b401465f74d7f3ee1654915b9070b4dc0fee (patch) | |
| tree | 40b5b90d909e7fef28d2f4099d03f1a1ec5f84a8 /gas/symbols.c | |
| parent | a51951c25813b8d6c763f51d78d3756d9ca85ee1 (diff) | |
| download | gdb-2a50b401465f74d7f3ee1654915b9070b4dc0fee.zip gdb-2a50b401465f74d7f3ee1654915b9070b4dc0fee.tar.gz gdb-2a50b401465f74d7f3ee1654915b9070b4dc0fee.tar.bz2 | |
Fix tight loop on recursively-defined symbols
This patch fixes a bug in GAS where the assembler enters a tight loop
when attempting to resolve recursively-defined symbols, e.g. when
trying to assemble "a=a".
This is a regression introduced between binutils 2.32 and 2.33,
by commit 1903f1385bff9
* symbols.c (struct local_symbol): Update comment.
(resolve_symbol_value): For resolved symbols equated to other
symbols, verify that the referenced symbol is not a local_symbol
before accessing sy_value. Don't leave symbol loops during
finalize_syms resolution.
* testsuite/gas/all/assign-bad-recursive.d: New test.
* testsuite/gas/all/assign-bad-recursive.l: Error output for test.
* testsuite/gas/all/assign-bad-recursive.s: Assembly for test.
* testsuite/gas/all/gas.exp: Run it.
Diffstat (limited to 'gas/symbols.c')
| -rw-r--r-- | gas/symbols.c | 18 |
1 files changed, 15 insertions, 3 deletions
diff --git a/gas/symbols.c b/gas/symbols.c index 160b0f7..711730d 100644 --- a/gas/symbols.c +++ b/gas/symbols.c @@ -114,7 +114,7 @@ struct symbol /* A pointer in the symbol may point to either a complete symbol (struct symbol above) or to a local symbol (struct local_symbol defined here). The symbol code can detect the case by examining - the first field. It is always NULL for a local symbol. + the first field which is present in both structs. We do this because we ordinarily only need a small amount of information for a local symbol. The symbol table takes up a lot of @@ -1237,11 +1237,18 @@ resolve_symbol_value (symbolS *symp) if (symp->sy_flags.sy_resolved) { final_val = 0; - while (symp->sy_value.X_op == O_symbol - && symp->sy_value.X_add_symbol->sy_flags.sy_resolved) + while (symp->sy_value.X_op == O_symbol) { final_val += symp->sy_value.X_add_number; symp = symp->sy_value.X_add_symbol; + if (LOCAL_SYMBOL_CHECK (symp)) + { + struct local_symbol *locsym = (struct local_symbol *) symp; + final_val += locsym->lsy_value; + return final_val; + } + if (!symp->sy_flags.sy_resolved) + return 0; } if (symp->sy_value.X_op == O_constant) final_val += symp->sy_value.X_add_number; @@ -1380,6 +1387,11 @@ resolve_symbol_value (symbolS *symp) break; } + /* Don't leave symbol loops. */ + if (finalize_syms + && add_symbol->sy_flags.sy_resolving) + break; + if (finalize_syms && final_val == 0) { if (LOCAL_SYMBOL_CHECK (add_symbol)) |