# ADR-0004 - Introduce a UI architecture module to the core platform

## Date

2024-02-07

## Context

The Gradle core platform provides many services to the Gradle platforms and builds logic. One such group of services allows logic to interact with the build user, to provide diagnostics, progress information, prompt for questions, and so on. Currently, these services are part of the core platform runtime architecture module.

For now we just have this global repository of ADRs.
If we see fit, we can break these out to per-platform ones, or keep a hybrid approach to having global and platform-specific ADSs.

Our aim is to keep the process lightweight and approachable.

Like code, they should be reviewed by any other relevant teams.
The goal is not to *own* a decision, but to *share* it with other teams, and improve the build tool together.

### Format

The format for ADR should follow this template:

```markdown
# ADR-000X - Title

## Date

20YY-MM-DD

## Context

Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna

pkg debug/elf, const R_AARCH64_ADR_GOT_PAGE = 311
pkg debug/elf, const R_AARCH64_ADR_GOT_PAGE R_AARCH64
pkg debug/elf, const R_AARCH64_ADR_PREL_LO21 = 274
pkg debug/elf, const R_AARCH64_ADR_PREL_LO21 R_AARCH64
pkg debug/elf, const R_AARCH64_ADR_PREL_PG_HI21 = 275
pkg debug/elf, const R_AARCH64_ADR_PREL_PG_HI21 R_AARCH64
pkg debug/elf, const R_AARCH64_ADR_PREL_PG_HI21_NC = 276

# ADR-0003 - Avoid introducing Groovy types to public API

## Date

2024-01-12

## Context

Gradle's public API requires equal access from all JVM-based languages.
Kotlin, Groovy, Java, and other JVM-based languages should be able to use the Gradle API without relying on another language's standard library.

Historically, Gradle has shipped with some Groovy types in very prominent APIs.

# ADR-0002 - Avoid using Java serialization

## Date

2012-12-01

## Context

In Gradle we often need to serialize in-memory objects for caching, or to transmit them across process barriers, etc.
Java serialization is one way to implement this, however, despite its simplicity of implementation, it has several drawbacks:

- **Performance:**
Java's built-in serialization mechanism is often slower compared to other serialization solutions.

	BEQ	1(PC)
	BEQ	2(PC)
	TBZ	$1, R1, 2(PC)
	TBNZ	$2, R2, 2(PC)
	JMP	foo(SB)
	CALL	foo(SB)

// ADR
	ADR	next, R11     // ADR R11 // 2b000010
next:
	NOP
	ADR -2(PC), R10    // 0a000010
	ADR 2(PC), R16     // 10000010
	ADR -26(PC), R1    // 01000010
	ADR 12(PC), R2     // 02000010
	ADRP -2(PC), R10   // 0a000090
	ADRP 2(PC), R16    // 10000090
	ADRP -26(PC), R1   // 01000090

	"BLE":   true,
	"CALL":  true,
	"CBZ":   true,
	"CBZW":  true,
	"CBNZ":  true,
	"CBNZW": true,
	"JMP":   true,
	"TBNZ":  true,
	"TBZ":   true,

	// ADR isn't really a jump, but it takes a PC or label reference,
	// which needs to patched like a jump.
	"ADR":  true,
	"ADRP": true,
}

func jumpArm64(word string) bool {
	return arm64Jump[word]
}

var arm64SpecialOperand map[string]arm64.SpecialOperand

pkg debug/elf, const R_AARCH64_TLSGD_ADR_PREL21 = 512
pkg debug/elf, const R_AARCH64_TLSGD_ADR_PREL21 R_AARCH64
pkg debug/elf, const R_AARCH64_TLSGD_MOVW_G0_NC = 516
pkg debug/elf, const R_AARCH64_TLSGD_MOVW_G0_NC R_AARCH64
pkg debug/elf, const R_AARCH64_TLSGD_MOVW_G1 = 515
pkg debug/elf, const R_AARCH64_TLSGD_MOVW_G1 R_AARCH64
pkg debug/elf, const R_AARCH64_TLSLD_ADR_PAGE21 = 518

# ADR-0004 - Use a platform-oriented architecture for Gradle

## Date

2024-02-07

## Context

The Gradle code base is essentially a large monolith, without strong internal boundaries.
This has a number of negative effects on productivity, including:

- Unclear ownership of code.
- Difficult to focus on one particular area.
- Unintended coupling between areas of the code, including tests.

## Decision