[compiler & language] Support builtin constant __COMPILE_FOR_TESTING__.

third_party/move/move-compiler-v2/src/experiments.rs

@@ -286,6 +286,13 @@ pub static EXPERIMENTS: Lazy<BTreeMap<String, Experiment>> = Lazy::new(|| {
                 .to_string(),
             default: Given(false),
         },
+        Experiment {
+            name: Experiment::COMPILE_FOR_TESTING.to_string(),
+            description: "Compile for testing. If set, constant \
+            `__COMPILE_FOR_TESTING__` will be true, otherwise false."
+                .to_string(),
+            default: Given(false),
+        },
     ];
     experiments
         .into_iter()
@@ -305,6 +312,7 @@ impl Experiment {
     pub const CFG_SIMPLIFICATION: &'static str = "cfg-simplification";
     pub const CHECKS: &'static str = "checks";
     pub const CMP_REWRITE: &'static str = "cmp-rewrite";
+    pub const COMPILE_FOR_TESTING: &'static str = "compile-for-testing";
     pub const DEAD_CODE_ELIMINATION: &'static str = "dead-code-elimination";
     pub const DUPLICATE_STRUCT_PARAMS_CHECK: &'static str = "duplicate-struct-params-check";
     pub const FAIL_ON_WARNING: &'static str = "fail-on-warning";

third_party/move/move-compiler-v2/transactional-tests/tests/constants/builtin_constants.exp

@@ -0,0 +1,6 @@
+processed 5 tasks
+task 0 lines 1-30:  publish [module 0x66::m {]
+task 1 lines 32-32:  run 0x66::m::compile_for_testing
+task 2 lines 34-34:  run 0x66::m::min_max
+task 3 lines 36-43:  publish [module 0x66::shadow {]
+task 4 lines 45-45:  run 0x66::shadow::shadowed

third_party/move/move-compiler-v2/transactional-tests/tests/constants/builtin_constants.move

@@ -0,0 +1,45 @@
+//# publish
+module 0x66::m {
+    fun compile_for_testing() {
+        // We are NOT compiling for testing, so expect this to be false. See independent
+        // compile_for_testing test.
+        assert!(!__COMPILE_FOR_TESTING__, 66);
+    }
+
+    fun min_max() {
+        assert!(MAX_U8 == 255, 1);
+        assert!(MAX_U16 == 65535, 1);
+        assert!(MAX_U32 == 4294967295, 1);
+        assert!(MAX_U64 == 18446744073709551615, 1);
+        assert!(MAX_U128 == 340282366920938463463374607431768211455, 1);
+        assert!(MAX_U256 == 115792089237316195423570985008687907853269984665640564039457584007913129639935, 1);
+
+        assert!(MIN_I8 == -128, 1);
+        assert!(MAX_I8 == 127, 1);
+        assert!(MIN_I16 == -32768, 1);
+        assert!(MAX_I16 == 32767, 1);
+        assert!(MIN_I32 == -2147483648, 1);
+        assert!(MAX_I32 == 2147483647, 1);
+        assert!(MIN_I64 == -9223372036854775808, 1);
+        assert!(MAX_I64 == 9223372036854775807, 1);
+        assert!(MIN_I128 == -170141183460469231731687303715884105728, 1);
+        assert!(MAX_I128 == 170141183460469231731687303715884105727, 1);
+        assert!(MIN_I256 == -57896044618658097711785492504343953926634992332820282019728792003956564819968, 1);
+        assert!(MAX_I256 == 57896044618658097711785492504343953926634992332820282019728792003956564819967, 1);
+    }
+}
+
+//# run 0x66::m::compile_for_testing
+
+//# run 0x66::m::min_max
+
+//# publish
+module 0x66::shadow {
+    const MAX_U8: bool = false;
+
+    fun shadowed() {
+        assert!(!MAX_U8, 66);
+    }
+}
+
+//# run 0x66::shadow::shadowed

third_party/move/move-compiler-v2/transactional-tests/tests/constants/round-trip/builtin_constants.decompiled

@@ -0,0 +1,26 @@
+//**** Cross-compiled for `move` syntax from `tests/constants/builtin_constants.move`
+
+//# publish
+module 0x66::m {
+    fun compile_for_testing() {
+        ()
+    }
+    fun min_max() {
+        ()
+    }
+}
+
+
+//# run 0x66::m::compile_for_testing
+
+//# run 0x66::m::min_max
+
+//# publish
+module 0x66::shadow {
+    fun shadowed() {
+        ()
+    }
+}
+
+
+//# run 0x66::shadow::shadowed

third_party/move/move-compiler-v2/transactional-tests/tests/constants/round-trip/builtin_constants.decompiled.baseline.exp

@@ -0,0 +1,6 @@
+processed 5 tasks
+task 0 lines 3-11:  publish [module 0x66::m {]
+task 1 lines 14-14:  run 0x66::m::compile_for_testing
+task 2 lines 16-16:  run 0x66::m::min_max
+task 3 lines 18-23:  publish [module 0x66::shadow {]
+task 4 lines 26-26:  run 0x66::shadow::shadowed

third_party/move/move-compiler-v2/transactional-tests/tests/testing-constant/compile_for_testing.move

@@ -0,0 +1,8 @@
+//# publish --print-bytecode
+module 0x66::m {
+    fun run() {
+        if (__COMPILE_FOR_TESTING__) abort 1 else abort 2
+    }
+}
+
+//#run 0x66::m::run

third_party/move/move-compiler-v2/transactional-tests/tests/testing-constant/compile_for_testing.testing-constant-false.exp

@@ -0,0 +1,24 @@
+processed 2 tasks
+task 0 lines 1-6:  publish --print-bytecode [module 0x66::m {]
+
+== BEGIN Bytecode ==
+// Bytecode version v9
+module 0x66::m
+// Function definition at index 0
+fun run()
+    branch l0
+    ld_u64 1
+    abort
+l0: ld_u64 2
+    abort
+
+
+== END Bytecode ==
+task 1 lines 8-8:  run 0x66::m::run
+Error: Function execution failed with VMError: {
+    major_status: ABORTED,
+    sub_status: Some(2),
+    location: 0x66::m,
+    indices: [],
+    offsets: [(FunctionDefinitionIndex(0), 4)],
+}

third_party/move/move-compiler-v2/transactional-tests/tests/testing-constant/compile_for_testing.testing-constant-true.exp

@@ -0,0 +1,23 @@
+processed 2 tasks
+task 0 lines 1-6:  publish --print-bytecode [module 0x66::m {]
+
+== BEGIN Bytecode ==
+// Bytecode version v9
+module 0x66::m
+// Function definition at index 0
+fun run()
+    ld_u64 1
+    abort
+    ld_u64 2
+    abort
+
+
+== END Bytecode ==
+task 1 lines 8-8:  run 0x66::m::run
+Error: Function execution failed with VMError: {
+    major_status: ABORTED,
+    sub_status: Some(1),
+    location: 0x66::m,
+    indices: [],
+    offsets: [(FunctionDefinitionIndex(0), 1)],
+}

third_party/move/move-compiler-v2/transactional-tests/tests/tests.rs

@@ -39,6 +39,7 @@ const COMMON_EXCLUSIONS: &[&str] = &[
     "/no-recursive-check/",
     "/no-access-check/",
     "/no-recursive-type-check/",
+    "/testing-constant/",
 ];
 
 /// Note that any config which has different output for a test directory
@@ -139,6 +140,24 @@ const TEST_CONFIGS: &[TestConfig] = &[
         exclude: &[],
         cross_compile: false,
     },
+    TestConfig {
+        name: "testing-constant-true",
+        runner: |p| run(p, get_config_by_name("testing-constant-true")),
+        experiments: &[(Experiment::COMPILE_FOR_TESTING, true)],
+        language_version: LanguageVersion::latest(),
+        include: &["/testing-constant/"],
+        exclude: &[],
+        cross_compile: false,
+    },
+    TestConfig {
+        name: "testing-constant-false",
+        runner: |p| run(p, get_config_by_name("testing-constant-false")),
+        experiments: &[(Experiment::COMPILE_FOR_TESTING, false)],
+        language_version: LanguageVersion::latest(),
+        include: &["/testing-constant/"],
+        exclude: &[],
+        cross_compile: false,
+    },
 ];
 
 /// Test files which must use separate baselines because their result
@@ -178,6 +197,8 @@ const SEPARATE_BASELINE: &[&str] = &[
     "misc/bug_14817_extended.move",
     // run in verbose mode to unveil the exact error messages
     "/signed-int/",
+    // different expected result
+    "/testing-constant/",
 ];
 
 fn get_config_by_name(name: &str) -> TestConfig {

third_party/move/move-model/src/ast.rs

@@ -3065,6 +3065,14 @@ impl ModuleName {
         ModuleName(addr, name)
     }
 
+    /// Returns builtin module name.
+    pub fn builtin_module(env: &GlobalEnv) -> Self {
+        Self::new(
+            Address::Numerical(AccountAddress::ZERO),
+            env.symbol_pool().make("$$"),
+        )
+    }
+
     pub fn from_address_bytes_and_name(
         addr: legacy_move_compiler::shared::NumericalAddress,
         name: Symbol,