Commit Graph

30 Commits

Author SHA1 Message Date
Balazs Benics ffe7950ebc Reland "[analyzer] Deprecate `-analyzer-store region` flag"
I'm trying to remove unused options from the `Analyses.def` file, then
merge the rest of the useful options into the `AnalyzerOptions.def`.
Then make sure one can set these by an `-analyzer-config XXX=YYY` style
flag.
Then surface the `-analyzer-config` to the `clang` frontend;

After all of this, we can pursue the tablegen approach described
https://discourse.llvm.org/t/rfc-tablegen-clang-static-analyzer-engine-options-for-better-documentation/61488

In this patch, I'm proposing flag deprecations.
We should support deprecated analyzer flags for exactly one release. In
this case I'm planning to drop this flag in `clang-16`.

In the clang frontend, now we won't pass this option to the cc1
frontend, rather emit a warning diagnostic reminding the users about
this deprecated flag, which will be turned into error in clang-16.

Unfortunately, I had to remove all the tests referring to this flag,
causing a mass change. I've also added a test for checking this warning.

I've seen that `scan-build` also uses this flag, but I think we should
remove that part only after we turn this into a hard error.

Reviewed By: martong

Differential Revision: https://reviews.llvm.org/D126215
2022-06-14 09:20:41 +02:00
Nico Weber 8406839d19 Revert "[analyzer] Deprecate `-analyzer-store region` flag"
This reverts commit d50d9946d1.
Broke check-clang, see comments on https://reviews.llvm.org/D126067

Also revert dependent change "[analyzer] Deprecate the unused 'analyzer-opt-analyze-nested-blocks' cc1 flag"
This reverts commit 07b4a6d046.

Also revert "[analyzer] Fix buildbots after introducing a new frontend warning"
This reverts commit 90374df15d.
(See https://reviews.llvm.org/rG90374df15ddc58d823ca42326a76f58e748f20eb)
2022-06-10 08:50:13 -04:00
Balazs Benics d50d9946d1 [analyzer] Deprecate `-analyzer-store region` flag
I'm trying to remove unused options from the `Analyses.def` file, then
merge the rest of the useful options into the `AnalyzerOptions.def`.
Then make sure one can set these by an `-analyzer-config XXX=YYY` style
flag.
Then surface the `-analyzer-config` to the `clang` frontend;

After all of this, we can pursue the tablegen approach described
https://discourse.llvm.org/t/rfc-tablegen-clang-static-analyzer-engine-options-for-better-documentation/61488

In this patch, I'm proposing flag deprecations.
We should support deprecated analyzer flags for exactly one release. In
this case I'm planning to drop this flag in `clang-16`.

In the clang frontend, now we won't pass this option to the cc1
frontend, rather emit a warning diagnostic reminding the users about
this deprecated flag, which will be turned into error in clang-16.

Unfortunately, I had to remove all the tests referring to this flag,
causing a mass change. I've also added a test for checking this warning.

I've seen that `scan-build` also uses this flag, but I think we should
remove that part only after we turn this into a hard error.

Reviewed By: martong

Differential Revision: https://reviews.llvm.org/D126215
2022-06-10 12:57:15 +02:00
Balazs Benics 6ad47e1c4f [analyzer] Catch leaking stack addresses via stack variables
Not only global variables can hold references to dead stack variables.
Consider this example:

  void write_stack_address_to(char **q) {
    char local;
    *q = &local;
  }

  void test_stack() {
    char *p;
    write_stack_address_to(&p);
  }

The address of 'local' is assigned to 'p', which becomes a dangling
pointer after 'write_stack_address_to()' returns.

The StackAddrEscapeChecker was looking for bindings in the store which
referred to variables of the popped stack frame, but it only considered
global variables in this regard. This patch relaxes this, catching
stack variable bindings as well.

---

This patch also works for temporary objects like:

  struct Bar {
    const int &ref;
    explicit Bar(int y) : ref(y) {
      // Okay.
    } // End of the constructor call, `ref` is dangling now. Warning!
  };

  void test() {
    Bar{33}; // Temporary object, so the corresponding memregion is
             // *not* a VarRegion.
  }

---

The return value optimization aka. copy-elision might kick in but that
is modeled by passing an imaginary CXXThisRegion which refers to the
parent stack frame which is supposed to be the 'return slot'.
Objects residing in the 'return slot' outlive the scope of the inner
call, thus we should expect no warning about them - except if we
explicitly disable copy-elision.

Reviewed By: NoQ, martong

Differential Revision: https://reviews.llvm.org/D107078
2021-08-27 11:31:16 +02:00
Richard Smith afe48f9d68 Fold -Wreturn-stack-address into general initialization lifetime
checking.

llvm-svn: 337743
2018-07-23 21:21:22 +00:00
Dominic Chen 184c6242fa Reland 4: [analyzer] NFC: Update test infrastructure to support multiple constraint managers
Summary: Replace calls to %clang/%clang_cc1 with %clang_analyze_cc1 when invoking static analyzer, and perform runtime substitution to select the appropriate constraint manager, per D28952.

Reviewers: xazax.hun, NoQ, zaks.anna, dcoughlin

Subscribers: mgorny, rgov, mikhail.ramalho, a.sidorin, cfe-commits

Differential Revision: https://reviews.llvm.org/D30373

llvm-svn: 296895
2017-03-03 18:02:02 +00:00
Dominic Chen 09d66f7528 Revert "Reland 3: [analyzer] NFC: Update test infrastructure to support multiple constraint managers"
This reverts commit ea36f1406e1f36bf456c3f3929839b024128e468.

llvm-svn: 296841
2017-03-02 23:30:53 +00:00
Dominic Chen feaf9ff5ee Reland 3: [analyzer] NFC: Update test infrastructure to support multiple constraint managers
Summary: Replace calls to %clang/%clang_cc1 with %clang_analyze_cc1 when invoking static analyzer, and perform runtime substitution to select the appropriate constraint manager, per D28952.

Reviewers: xazax.hun, NoQ, zaks.anna, dcoughlin

Subscribers: mgorny, rgov, mikhail.ramalho, a.sidorin, cfe-commits

Differential Revision: https://reviews.llvm.org/D30373

llvm-svn: 296837
2017-03-02 23:05:45 +00:00
Dominic Chen 4a90bf8c3f Revert "Reland 2: [analyzer] NFC: Update test infrastructure to support multiple constraint managers"
This reverts commit f93343c099fff646a2314cc7f4925833708298b1.

llvm-svn: 296836
2017-03-02 22:58:06 +00:00
Dominic Chen 1cb0256a3c Reland 2: [analyzer] NFC: Update test infrastructure to support multiple constraint managers
Summary: Replace calls to %clang/%clang_cc1 with %clang_analyze_cc1 when invoking static analyzer, and perform runtime substitution to select the appropriate constraint manager, per D28952.

Reviewers: xazax.hun, NoQ, zaks.anna, dcoughlin

Subscribers: mgorny, rgov, mikhail.ramalho, a.sidorin, cfe-commits

Differential Revision: https://reviews.llvm.org/D30373

llvm-svn: 296835
2017-03-02 22:45:24 +00:00
Dominic Chen 00355a51d0 Revert "Reland: [analyzer] NFC: Update test infrastructure to support multiple constraint managers"
This reverts commit 1b28d0b10e1c8feccb971abb6ef7a18bee589830.

llvm-svn: 296422
2017-02-28 01:50:23 +00:00
Dominic Chen 59cd893320 Reland: [analyzer] NFC: Update test infrastructure to support multiple constraint managers
Summary: Replace calls to %clang/%clang_cc1 with %clang_analyze_cc1 when invoking static analyzer, and perform runtime substitution to select the appropriate constraint manager, per D28952.

Reviewers: xazax.hun, NoQ, zaks.anna, dcoughlin

Subscribers: mgorny, rgov, mikhail.ramalho, a.sidorin, cfe-commits

Differential Revision: https://reviews.llvm.org/D30373

llvm-svn: 296414
2017-02-28 00:02:36 +00:00
Dominic Chen 8589e10c30 Revert "[analyzer] NFC: Update test infrastructure to support multiple constraint managers"
This reverts commit 8e7780b9e59ddaad1800baf533058d2c064d4787.

llvm-svn: 296317
2017-02-27 03:29:25 +00:00
Dominic Chen 02064a3076 [analyzer] NFC: Update test infrastructure to support multiple constraint managers
Summary: Replace calls to %clang/%clang_cc1 with %clang_analyze_cc1 when invoking static analyzer, and perform runtime substitution to select the appropriate constraint manager, per D28952.

Reviewers: xazax.hun, NoQ, zaks.anna, dcoughlin

Subscribers: mgorny, rgov, mikhail.ramalho, a.sidorin, cfe-commits

Differential Revision: https://reviews.llvm.org/D30373

llvm-svn: 296312
2017-02-27 02:36:15 +00:00
Richard Trieu f7432755d0 Add -Wtautological-undefined-compare and -Wundefined-bool-conversion warnings
to detect underfined behavior involving pointers.

llvm-svn: 210372
2014-06-06 21:39:26 +00:00
Pavel Labath cf878bbe65 [analyzer] Fix FP warnings when binding a temporary to a local static variable
Summary:
When binding a temporary object to a static local variable, the analyzer would
complain about a dangling reference even though the temporary's lifetime should
be extended past the end of the function. This commit tries to detect these
cases and construct them in a global memory region instead of a local one.

Reviewers: jordan_rose

CC: cfe-commits

Differential Revision: http://llvm-reviews.chandlerc.com/D1133

llvm-svn: 187196
2013-07-26 11:50:42 +00:00
Jordan Rose dc16628c93 Re-apply "[analyzer] Model casts to bool differently from other numbers."
This doesn't appear to be the cause of the slowdown. I'll have to try a
manual bisect to see if there's really anything there, or if it's just
the bot itself taking on additional load. Meanwhile, this change helps
with correctness.

This changes an assertion and adds a test case, then re-applies r180638,
which was reverted in r180714.

<rdar://problem/13296133> and PR15863

llvm-svn: 180864
2013-05-01 18:19:59 +00:00
Jordan Rose 49f888bbab Revert "[analyzer] Model casts to bool differently from other numbers."
This seems to be causing quite a slowdown on our internal analyzer bot,
and I'm not sure why. Needs further investigation.

This reverts r180638 / 9e161ea981f22ae017b6af09d660bfc3ddf16a09.

llvm-svn: 180714
2013-04-29 17:23:03 +00:00
Jordan Rose 9661c1d18a [analyzer] Model casts to bool differently from other numbers.
Casts to bool (and _Bool) are equivalent to checks against zero,
not truncations to 1 bit or 8 bits.

This improved reasoning does cause a change in the behavior of the alpha
BoolAssignment checker. Previously, this checker complained about statements
like "bool x = y" if 'y' was known not to be 0 or 1. Now it does not, since
that conversion is well-defined. It's hard to say what the "best" behavior
here is: this conversion is safe, but might be better written as an explicit
comparison against zero.

More usefully, besides improving our model of booleans, this fixes spurious
warnings when returning the address of a local variable cast to bool.

<rdar://problem/13296133>

llvm-svn: 180638
2013-04-26 21:42:55 +00:00
Jordan Rose 5772f82d1e [analyzer] Make sure a materialized temporary matches its bindings.
This is a follow-up to r175830, which made sure a temporary object region
created for, say, a struct rvalue matched up with the initial bindings
being stored into it. This does the same for the case in which the AST
actually tells us that we need to create a temporary via a
MaterializeObjectExpr. I've unified the two code paths and moved a static
helper function onto ExprEngine.

This also caused a bit of test churn, causing us to go back to describing
temporary regions without a 'const' qualifier. This seems acceptable; it's
our behavior from a few months ago.

<rdar://problem/13265460> (part 2)

llvm-svn: 175854
2013-02-22 01:51:15 +00:00
Ted Kremenek a3bb2b6044 Fix regression in modeling assignments of an address of a variable to itself. Fixes <rdar://problem/13226577>.
llvm-svn: 175852
2013-02-22 01:39:26 +00:00
Hans Wennborg d799a2b3b9 Better wording for reference self-initialization warning.
llvm-svn: 162198
2012-08-20 08:52:22 +00:00
Hans Wennborg e1fdb059c6 Warn about self-initialization of references.
Initializing a reference with itself, e.g. "int &a = a;" seems like a
very bad idea.

llvm-svn: 162093
2012-08-17 10:12:33 +00:00
Argyrios Kyrtzidis b4015e1877 When going through references to check if the function returns the address
of a local variable, make sure we don't infinitely recurse when the
reference binds to itself.

e.g:

int* func() {
    int& i = i;    // assign non-exist variable to a reference which has same name.
    return &i;    // return pointer
}

rdar://11345441

llvm-svn: 155856
2012-04-30 23:23:55 +00:00
Ted Kremenek 2a14c695eb Fix LiveVariables analysis bug with MaterializeTemporaryExpr and fix handling in ExprEngine. Fixes <rdar://problem/10201666>.
llvm-svn: 140956
2011-10-02 00:54:48 +00:00
Jeffrey Yasskin 0e9cdbbb06 Handle CXXTempObjectRegion in StackAddrEscapeChecker.
Also convert stack-addr-ps.cpp to use the analyzer instead of just Sema, now
that it doesn't crash, and extract the stack-block test into another file since
it errors, and that prevents the analyzer from running.

llvm-svn: 138613
2011-08-26 00:41:31 +00:00
Argyrios Kyrtzidis e72f7154f1 Follow through references to catch returned stack addresses, local blocks, label addresses or references to temporaries, e.g:
const int& g2() {
  int s1;
  int &s2 = s1; // expected-note {{binding reference variable 's2' here}}
  return s2; // expected-warning {{reference to stack memory associated with local variable 's1' returned}}
}

llvm-svn: 120483
2010-11-30 22:57:32 +00:00
Argyrios Kyrtzidis 091d97c709 Revert r120331 since it causes spurious warnings and a possible assertion hit when self-host.
llvm-svn: 120351
2010-11-29 23:42:03 +00:00
Argyrios Kyrtzidis 569cad9734 Emit warnings if we are returning a reference to a local temporary.
The issue was brought to our attention by Matthieu Monrocq.

llvm-svn: 120331
2010-11-29 22:32:08 +00:00
Ted Kremenek b786156b01 Teach SemaChecking::CheckReturnStackAddr about ImplicitCastExprs that convert values to an lvalue. This allows us to warn (again) about returning references to stack variables. (fixes PR 7812).
llvm-svn: 110242
2010-08-04 20:01:07 +00:00