[tools/internal-branch.go1.27-vendor] [internal-branch.go1.27-vendor] go/analysis/passes/modernize: slicesbackward - skip if s[i] is mutated

[Carlos Amedee (Gerrit)]

Carlos Amedee submitted the change

Change information

Commit message:

[internal-branch.go1.27-vendor] go/analysis/passes/modernize: slicesbackward - skip if s[i] is mutated

In the slicesbackward modernizer, we replace backward loops over
slices with a call to slices.Backward. However, if the index
expression s[i] is address-taken or mutated within the loop,
we should not offer this fix. For example:

for i := len(s) - 1; i > 0; i-- {
  s[i].n = 5
}

for _, v := range slices.Backward(s) {
  v.n = 5
}

v is a local copy, so the original s will not get mutated.
To avoid changing the program behavior, we should
not suggest a modernization.

Promote a new function IsAssignedOrAddressTaken that replaces the uses
of isScalarLValue in modernizers and isLValueUse
in the inliner and add tests for it.

Fixes golang/go#80410

Change-Id: I873afe8965dee39994547e16f284ca80541334d6
Reviewed-on: https://go-review.googlesource.com/c/tools/+/802260
LUCI-TryBot-Result: golang...@luci-project-accounts.iam.gserviceaccount.com <golang...@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Alan Donovan <adon...@google.com>
(cherry picked from commit b96d2a55a08943af1de2914a59fb88fe0acbb897)
Reviewed-on: https://go-review.googlesource.com/c/tools/+/805520
Reviewed-by: Carlos Amedee <car...@golang.org>

Files:

• M go/analysis/passes/modernize/minmax.go
• M go/analysis/passes/modernize/modernize.go
• M go/analysis/passes/modernize/rangeint.go
• M go/analysis/passes/modernize/slicesbackward.go
• M go/analysis/passes/modernize/stringscut.go
• M go/analysis/passes/modernize/testdata/src/rangeint/rangeint.go
• M go/analysis/passes/modernize/testdata/src/rangeint/rangeint.go.golden
• M go/analysis/passes/modernize/testdata/src/slicesbackward/slicesbackward.go
• M go/analysis/passes/modernize/testdata/src/slicesbackward/slicesbackward.go.golden
• M gopls/internal/golang/inline.go
• A internal/typesinternal/assignedaddress.go
• A internal/typesinternal/assignedaddress_test.go

Change size: L

Delta: 12 files changed, 603 insertions(+), 107 deletions(-)

Branch: refs/heads/internal-branch.go1.27-vendor

Submit Requirements:

• Code-Review: +2 by Carlos Amedee
• TryBots-Pass: LUCI-TryBot-Result+1 by golang...@luci-project-accounts.iam.gserviceaccount.com

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Gerrit

Gerrit-MessageType: merged

Gerrit-Project: tools

Gerrit-Branch: internal-branch.go1.27-vendor

Gerrit-Change-Id: I873afe8965dee39994547e16f284ca80541334d6

Gerrit-Change-Number: 805520

Gerrit-PatchSet: 2

Gerrit-Owner: Madeline Kalil <mka...@google.com>

Gerrit-Reviewer: Alan Donovan <adon...@google.com>

Gerrit-Reviewer: Carlos Amedee <car...@golang.org>

Gerrit-Reviewer: Madeline Kalil <mka...@google.com>

Gerrit-Reviewer: golang...@luci-project-accounts.iam.gserviceaccount.com <golang...@luci-project-accounts.iam.gserviceaccount.com>