Remove support for Go < 1.19 instrumentation

CHANGELOG.md

@@ -16,6 +16,10 @@ OpenTelemetry Go Automatic Instrumentation adheres to [Semantic Versioning](http
 - Support `golang.org/x/net` `0.35.0`. ([#1783](https://github.com/open-telemetry/opentelemetry-go-instrumentation/pull/1783))
 - Support Go `1.24.0`. ([#1795](https://github.com/open-telemetry/opentelemetry-go-instrumentation/pull/1795), [#1798](https://github.com/open-telemetry/opentelemetry-go-instrumentation/pull/1798))
 
+### Changed
+
+- Unused support for instrumentation of Go < 1.19 has been dropped. (#1815)
+
 ### Fixed
 
 - `database/sql` instrumentation for Go < `1.17`. (#1772)

COMPATIBILITY.md

@@ -30,7 +30,7 @@ Tracing instrumentation is provided for the following Go libraries.
 
 Supported version ranges:
 
-- `go1.12` to `go1.24.0`
+- `go1.19` to `go1.24.0`
 
 ### github.com/segmentio/kafka-go
 
@@ -54,4 +54,4 @@ Supported version ranges:
 
 Supported version ranges:
 
-- `go1.12` to `go1.24.0`
+- `go1.19` to `go1.24.0`

internal/include/arguments.h

@@ -45,10 +45,7 @@
 
 #endif
 
-// Injected in init
-volatile const bool is_registers_abi;
-
-static __always_inline void *get_argument_by_reg(struct pt_regs *ctx, int index)
+static __always_inline void *get_argument(struct pt_regs *ctx, int index)
 {
     switch (index)
     {
@@ -75,42 +72,4 @@ static __always_inline void *get_argument_by_reg(struct pt_regs *ctx, int index)
     }
 }
 
-static __always_inline void *get_argument_by_stack(struct pt_regs *ctx, int index)
-{
-    void *ptr = 0;
-    bpf_probe_read(&ptr, sizeof(ptr), (void *)(PT_REGS_SP(ctx) + (index * 8)));
-    return ptr;
-}
-
-static __always_inline void *get_argument(struct pt_regs *ctx, int index)
-{
-    if (is_registers_abi)
-    {
-        return get_argument_by_reg(ctx, index);
-    }
-
-    return get_argument_by_stack(ctx, index);
-}
-
-// Every span created by the auto instrumentation should contain end timestamp.
-// This end timestamp is recorded at the end of probed function by editing the struct that was created at the beginning.
-// Usually probes create an eBPF map to store the span struct and retrieve it at the end of the function.
-// Consistent key is used as a key for that map.
-// For Go < 1.17: consistent key is the address of context.Context.
-// For Go >= 1.17: consistent key is the goroutine address.
-static __always_inline void *get_consistent_key(struct pt_regs *ctx, void *contextContext)
-{
-    if (is_registers_abi)
-    {
-        return (void *)GOROUTINE(ctx);
-    }
-
-    return contextContext;
-}
-
-static __always_inline bool is_register_abi()
-{
-    return is_registers_abi;
-}
-
 #endif

internal/include/uprobe.h

@@ -23,12 +23,10 @@
 // 4. Submit the constructed event to the agent code using perf buffer events_map
 // 5. Delete the span from the global active spans map (in case the span is not tracked in the active spans map, this will be a no-op)
 // 6. Delete the span from the uprobe_context_map
-#define UPROBE_RETURN(name, event_type, uprobe_context_map, events_map, context_pos, context_offset, passed_as_arg) \
+#define UPROBE_RETURN(name, event_type, uprobe_context_map) \
 SEC("uprobe/##name##")                                                                                              \
 int uprobe_##name##_Returns(struct pt_regs *ctx) {                                                                  \
-    struct go_iface go_context = {0};                                                                               \
-    get_Go_context(ctx, context_pos, context_offset, passed_as_arg, &go_context);                                   \
-    void *key = get_consistent_key(ctx, go_context.data);                                                           \
+    void *key = (void *)GOROUTINE(ctx);                                                                             \
     event_type *event = bpf_map_lookup_elem(&uprobe_context_map, &key);                                             \
     if (event == NULL) {                                                                                            \
         bpf_printk("event is NULL in ret probe");                                                                   \

internal/pkg/inject/consts.go

@@ -29,10 +29,9 @@ var (
 )
 
 const (
-	keyIsRegistersABI = "is_registers_abi"
-	keyTotalCPUs      = "total_cpus"
-	keyStartAddr      = "start_addr"
-	keyEndAddr        = "end_addr"
+	keyTotalCPUs = "total_cpus"
+	keyStartAddr = "start_addr"
+	keyEndAddr   = "end_addr"
 )
 
 func init() {
@@ -108,17 +107,6 @@ func (o errOpt) apply(map[string]interface{}) error {
 	return o.err
 }
 
-// WithRegistersABI returns an option that will set the "is_registers_abi" to
-// value. This information can be determined from the IsRegistersABI method of
-// the TargetDetails in "go.opentelemetry.io/auto/internal/pkg/process".
-//
-// Commonly this is called like the following:
-//
-//	WithRegistersABI(target.IsRegistersABI())
-func WithRegistersABI(value bool) Option {
-	return option{keyIsRegistersABI: value}
-}
-
 // WithAllocationDetails returns an option that will set "total_cpus",
 // "start_addr", and "end_addr".
 func WithAllocationDetails(details process.AllocationDetails) Option {

internal/pkg/inject/consts_test.go

@@ -14,17 +14,6 @@ import (
 	"go.opentelemetry.io/auto/internal/pkg/structfield"
 )
 
-func TestWithRegistersABI(t *testing.T) {
-	opts := []Option{WithRegistersABI(true)}
-	got, err := newConsts(opts)
-	require.NoError(t, err)
-	require.Contains(t, got, keyIsRegistersABI)
-
-	v := got[keyIsRegistersABI]
-	require.IsType(t, *(new(bool)), v)
-	assert.True(t, v.(bool))
-}
-
 func TestWithAllocationDetails(t *testing.T) {
 	const start, end, nCPU uint64 = 1, 2, 3
 	details := process.AllocationDetails{