.gitignore added

[dotfiles/.git] / .config / coc / extensions / coc-go-data / tools / pkg / mod / golang.org / x / tools@v0.1.0 / go / analysis / passes / framepointer / framepointer.go

diff --git a/.config/coc/extensions/coc-go-data/tools/pkg/mod/golang.org/x/tools@v0.1.0/go/analysis/passes/framepointer/framepointer.go b/.config/coc/extensions/coc-go-data/tools/pkg/mod/golang.org/x/tools@v0.1.0/go/analysis/passes/framepointer/framepointer.go
new file mode 100644 (file)
index 0000000..741492e
--- /dev/null
+++ b/.config/coc/extensions/coc-go-data/tools/pkg/mod/golang.org/x/tools@v0.1.0/go/analysis/passes/framepointer/framepointer.go
@@ -0,0 +1,91 @@
+// Copyright 2020 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package framepointer defines an Analyzer that reports assembly code
+// that clobbers the frame pointer before saving it.
+package framepointer
+
+import (
+       "go/build"
+       "regexp"
+       "strings"
+
+       "golang.org/x/tools/go/analysis"
+       "golang.org/x/tools/go/analysis/passes/internal/analysisutil"
+)
+
+const Doc = "report assembly that clobbers the frame pointer before saving it"
+
+var Analyzer = &analysis.Analyzer{
+       Name: "framepointer",
+       Doc:  Doc,
+       Run:  run,
+}
+
+var (
+       re             = regexp.MustCompile
+       asmWriteBP     = re(`,\s*BP$`) // TODO: can have false positive, e.g. for TESTQ BP,BP. Seems unlikely.
+       asmMentionBP   = re(`\bBP\b`)
+       asmControlFlow = re(`^(J|RET)`)
+)
+
+func run(pass *analysis.Pass) (interface{}, error) {
+       if build.Default.GOARCH != "amd64" { // TODO: arm64 also?
+               return nil, nil
+       }
+       if build.Default.GOOS != "linux" && build.Default.GOOS != "darwin" {
+               return nil, nil
+       }
+
+       // Find assembly files to work on.
+       var sfiles []string
+       for _, fname := range pass.OtherFiles {
+               if strings.HasSuffix(fname, ".s") && pass.Pkg.Path() != "runtime" {
+                       sfiles = append(sfiles, fname)
+               }
+       }
+
+       for _, fname := range sfiles {
+               content, tf, err := analysisutil.ReadFile(pass.Fset, fname)
+               if err != nil {
+                       return nil, err
+               }
+
+               lines := strings.SplitAfter(string(content), "\n")
+               active := false
+               for lineno, line := range lines {
+                       lineno++
+
+                       // Ignore comments and commented-out code.
+                       if i := strings.Index(line, "//"); i >= 0 {
+                               line = line[:i]
+                       }
+                       line = strings.TrimSpace(line)
+
+                       // We start checking code at a TEXT line for a frameless function.
+                       if strings.HasPrefix(line, "TEXT") && strings.Contains(line, "(SB)") && strings.Contains(line, "$0") {
+                               active = true
+                               continue
+                       }
+                       if !active {
+                               continue
+                       }
+
+                       if asmWriteBP.MatchString(line) { // clobber of BP, function is not OK
+                               pass.Reportf(analysisutil.LineStart(tf, lineno), "frame pointer is clobbered before saving")
+                               active = false
+                               continue
+                       }
+                       if asmMentionBP.MatchString(line) { // any other use of BP might be a read, so function is OK
+                               active = false
+                               continue
+                       }
+                       if asmControlFlow.MatchString(line) { // give up after any branch instruction
+                               active = false
+                               continue
+                       }
+               }
+       }
+       return nil, nil
+}