/delve-example

Example usage of the Delve Go debugger

Primary LanguageGoMIT LicenseMIT

delve-example

Delve: https://github.com/go-delve/delve

Debugging main application

Start Delve

dlv debug delve-example.go

Set breakpoints

(dlv) break delve-example.go:30
Breakpoint 1 set at 0x4ac131 for main.main() ./delve-example.go:30

(dlv) break delve-example.go:21
Breakpoint 2 set at 0x4abeaf for main.output() ./delve-example.go:21

Run until first breakpoint

(dlv) continue
> main.main() ./delve-example.go:30 (hits goroutine(1):1 total:1) (PC: 0x4ac131)
    25:		examples := makeExampleSlice()
    26:	
    27:		exampleSlice1 := append(examples, example{exampleValue: &exampleValue{value: 1}})
    28:		exampleSlice2 := append(examples, example{exampleValue: &exampleValue{value: 2}})
    29:	
=>  30:		output("example1", exampleSlice1)
    31:		output("example2", exampleSlice2)
    32:	}

List function local variables

(dlv) locals
examples = []main.example len: 2, cap: 2, [...]
exampleSlice2 = []main.example len: 3, cap: 4, [...]
exampleSlice1 = []main.example len: 3, cap: 4, [...]

Print value of local variable

(dlv) print exampleSlice1[2]
main.example {
	exampleValue: *main.exampleValue {value: 1},}

Run until second breakpoint

(dlv) continue
> main.output() ./delve-example.go:21 (hits goroutine(1):1 total:1) (PC: 0x4abeaf)
    16:			{exampleValue: &exampleValue{value: 0}},
    17:		}
    18:	}
    19:	
    20:	func output(name string, exampleSlice []example) {
=>  21:		fmt.Printf("%s: %+v\n", name, exampleSlice)
    22:	}
    23:	
    24:	func main() {
    25:		examples := makeExampleSlice()
    26:

List function arguments

(dlv) args
name = "example1"
exampleSlice = []main.example len: 3, cap: 4, [...]

Print value of function argument

(dlv) print exampleSlice[2]
main.example {
	exampleValue: *main.exampleValue {value: 1},}

Debugging tests

Start Delve

dlv test ./internal/pkg/example/

Set breakpoints

(dlv) break example_test.go:9
Breakpoint 1 set at 0x547e5f for github.com/ewohltman/delve-example/internal/pkg/example.TestNew() ./internal/pkg/example/example_test.go:9

(dlv) break example_test.go:29
Breakpoint 2 set at 0x5480a0 for github.com/ewohltman/delve-example/internal/pkg/example.TestNewSlice() ./internal/pkg/example/example_test.go:29

See remaining examples under Debugging main application

Exit Delve

(dlv) exit