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| author | David Malcolm <dmalcolm@redhat.com> | 2023-03-02 14:01:19 -0500 |
|---|---|---|
| committer | David Malcolm <dmalcolm@redhat.com> | 2023-03-02 14:01:19 -0500 |
| commit | 20bd258d0fa09837b3a93478ef92d8789cbcd442 (patch) | |
| tree | 170cf236931de8507df9deb10cda64bec0f3b304 | |
| parent | 4d82022bfd15d36717bf60a11e75e9ea02204269 (diff) | |
| download | gcc-20bd258d0fa09837b3a93478ef92d8789cbcd442.zip gcc-20bd258d0fa09837b3a93478ef92d8789cbcd442.tar.gz gcc-20bd258d0fa09837b3a93478ef92d8789cbcd442.tar.bz2 | |
analyzer: fix uninit false +ves reading from DECL_HARD_REGISTER [PR108968]
gcc/analyzer/ChangeLog:
PR analyzer/108968
* region-model.cc (region_model::get_rvalue_1): Handle VAR_DECLs
with a DECL_HARD_REGISTER by returning UNKNOWN.
gcc/testsuite/ChangeLog:
PR analyzer/108968
* gcc.dg/analyzer/uninit-pr108968-register.c: New test.
Signed-off-by: David Malcolm <dmalcolm@redhat.com>
| -rw-r--r-- | gcc/analyzer/region-model.cc | 9 | ||||
| -rw-r--r-- | gcc/testsuite/gcc.dg/analyzer/uninit-pr108968-register.c | 9 |
2 files changed, 17 insertions, 1 deletions
diff --git a/gcc/analyzer/region-model.cc b/gcc/analyzer/region-model.cc index 2187aec..bf07cec 100644 --- a/gcc/analyzer/region-model.cc +++ b/gcc/analyzer/region-model.cc @@ -2203,9 +2203,16 @@ region_model::get_rvalue_1 (path_var pv, region_model_context *ctxt) const return get_rvalue_for_bits (TREE_TYPE (expr), reg, bits, ctxt); } - case SSA_NAME: case VAR_DECL: + if (DECL_HARD_REGISTER (pv.m_tree)) + { + /* If it has a hard register, it doesn't have a memory region + and can't be referred to as an lvalue. */ + return m_mgr->get_or_create_unknown_svalue (TREE_TYPE (pv.m_tree)); + } + /* Fall through. */ case PARM_DECL: + case SSA_NAME: case RESULT_DECL: case ARRAY_REF: { diff --git a/gcc/testsuite/gcc.dg/analyzer/uninit-pr108968-register.c b/gcc/testsuite/gcc.dg/analyzer/uninit-pr108968-register.c new file mode 100644 index 0000000..a76c09e --- /dev/null +++ b/gcc/testsuite/gcc.dg/analyzer/uninit-pr108968-register.c @@ -0,0 +1,9 @@ +/* { dg-do compile { target x86_64-*-* } } */ + +#define STACK_SIZE 4096 +struct cpu_info {}; +struct cpu_info *get_cpu_info(void) +{ + register unsigned long sp asm("rsp"); + return (struct cpu_info *)((sp | (STACK_SIZE - 1)) + 1) - 1; /* { dg-bogus "use of uninitialized value 'sp'" } */ +} |