commit ed1520b659dca8a3d53da5b11bde47557733f8a7 (tree)
parent 53b1108601371e9eda06a884b3ddebb090fb11d4
Author: Motiejus Jakštys <motiejus@jakstys.lt>
Date: Sat, 14 Feb 2026 19:02:57 +0000
astgen: implement unified ptrCastBuiltin with nested cast collapsing
Port the upstream ptrCast() function (AstGen.zig:8969-9087) which handles
nested pointer cast collapsing. All five pointer cast builtins (@ptrCast,
@alignCast, @addrSpaceCast, @constCast, @volatileCast) now route through
a single ptrCastBuiltin() function that:
- Walks inward through nested builtin calls accumulating flags
- Handles @fieldParentPtr nesting (with accumulated outer flags)
- Emits ptr_cast_full, ptr_cast_no_dest, or simple ptr_cast based on
combined flags and whether a result type is needed
This fixes compile errors in field_parent_ptr.zig and switch.zig where
@alignCast(@fieldParentPtr(...)) needed nested cast support.
Also adds @addrSpaceCast support (previously missing).
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Diffstat:
| M | stage0/astgen.c | | | 255 | ++++++++++++++++++++++++++++++++++++++++++++++++++++++++----------------------- |
1 file changed, 181 insertions(+), 74 deletions(-)
diff --git a/stage0/astgen.c b/stage0/astgen.c
@@ -3150,6 +3150,171 @@ static uint32_t simpleCBuiltin(GenZir* gz, Scope* scope, ResultLoc rl,
return rvalue(gz, rl, ZIR_REF_VOID_VALUE, node);
}
+// FullPtrCastFlags bits (Zir.zig:3461).
+#define PTR_CAST_FLAG_PTR_CAST 0x01
+#define PTR_CAST_FLAG_ALIGN_CAST 0x02
+#define PTR_CAST_FLAG_ADDRSPACE 0x04
+#define PTR_CAST_FLAG_CONST_CAST 0x08
+#define PTR_CAST_FLAG_VOLATILE_CAST 0x10
+// Flags that don't need a result type.
+#define PTR_CAST_NO_RESULT_TY_MASK \
+ (PTR_CAST_FLAG_CONST_CAST | PTR_CAST_FLAG_VOLATILE_CAST)
+
+// Mirrors ptrCast (AstGen.zig:8969-9087).
+// Handles nested pointer cast collapsing for @ptrCast, @alignCast,
+// @addrSpaceCast, @constCast, @volatileCast, and nested @fieldParentPtr.
+static uint32_t ptrCastBuiltin(
+ GenZir* gz, Scope* scope, ResultLoc rl, uint32_t root_node) {
+ AstGenCtx* ag = gz->astgen;
+ const Ast* tree = ag->tree;
+
+ uint16_t flags = 0;
+ uint32_t node = root_node;
+
+ // Walk inward through nested builtin calls (AstGen.zig:8984-9047).
+ while (1) {
+ AstNodeTag ntag = tree->nodes.tags[node];
+ if (ntag == AST_NODE_BUILTIN_CALL_TWO
+ || ntag == AST_NODE_BUILTIN_CALL_TWO_COMMA) {
+ // ok
+ } else if (ntag == AST_NODE_GROUPED_EXPRESSION) {
+ // Handle chaining through parentheses (AstGen.zig:8987-8990).
+ node = tree->nodes.datas[node].lhs;
+ continue;
+ } else {
+ break;
+ }
+
+ AstData nd = tree->nodes.datas[node];
+ // Count args: lhs is arg0, rhs is arg1 (0 = absent).
+ uint32_t arg_count = (nd.lhs != 0 ? 1u : 0u) + (nd.rhs != 0 ? 1u : 0u);
+ if (arg_count == 0)
+ break;
+
+ // Get builtin name from source.
+ uint32_t bt = tree->nodes.main_tokens[node];
+ uint32_t bstart = tree->tokens.starts[bt] + 1; // skip '@'
+ uint32_t bend = bstart;
+ while (bend < tree->source_len
+ && ((tree->source[bend] >= 'a' && tree->source[bend] <= 'z')
+ || (tree->source[bend] >= 'A' && tree->source[bend] <= 'Z')
+ || tree->source[bend] == '_'))
+ bend++;
+ uint32_t blen = bend - bstart;
+
+ if (arg_count == 1) {
+ // 1-arg builtin: check if it's a pointer cast.
+ uint16_t flag = 0;
+ if (blen == 7 && memcmp(tree->source + bstart, "ptrCast", 7) == 0)
+ flag = PTR_CAST_FLAG_PTR_CAST;
+ else if (blen == 9
+ && memcmp(tree->source + bstart, "alignCast", 9) == 0)
+ flag = PTR_CAST_FLAG_ALIGN_CAST;
+ else if (blen == 13
+ && memcmp(tree->source + bstart, "addrSpaceCast", 13) == 0)
+ flag = PTR_CAST_FLAG_ADDRSPACE;
+ else if (blen == 9
+ && memcmp(tree->source + bstart, "constCast", 9) == 0)
+ flag = PTR_CAST_FLAG_CONST_CAST;
+ else if (blen == 12
+ && memcmp(tree->source + bstart, "volatileCast", 12) == 0)
+ flag = PTR_CAST_FLAG_VOLATILE_CAST;
+ else
+ break;
+
+ if (flags & flag) {
+ // Redundant cast (AstGen.zig:9015-9016).
+ SET_ERROR(ag);
+ return ZIR_REF_VOID_VALUE;
+ }
+ flags |= flag;
+ node = nd.lhs; // Advance to inner operand.
+ } else {
+ // 2-arg builtin: check for @fieldParentPtr (AstGen.zig:9027-9046).
+ if (blen != 14
+ || memcmp(tree->source + bstart, "fieldParentPtr", 14) != 0)
+ break;
+ if (flags & PTR_CAST_FLAG_PTR_CAST)
+ break;
+
+ // Emit field_parent_ptr with accumulated flags.
+ advanceSourceCursorToMainToken(ag, gz, root_node);
+ uint32_t saved_line = ag->source_line - gz->decl_line;
+ uint32_t saved_col = ag->source_column;
+ uint32_t parent_ptr_type = rlResultTypeForCast(gz, rl, root_node);
+ ResultLoc field_name_rl = { .tag = RL_COERCED_TY,
+ .data = ZIR_REF_SLICE_CONST_U8_TYPE,
+ .src_node = 0,
+ .ctx = RI_CTX_NONE };
+ uint32_t field_name = comptimeExpr(
+ gz, scope, field_name_rl, nd.lhs, COMPTIME_REASON_FIELD_NAME);
+ uint32_t field_ptr = expr(gz, scope, nd.rhs);
+ emitDbgStmt(gz, saved_line, saved_col);
+ ensureExtraCapacity(ag, 4);
+ uint32_t payload_index = ag->extra_len;
+ ag->extra[ag->extra_len++]
+ = (uint32_t)((int32_t)node - (int32_t)gz->decl_node_index);
+ ag->extra[ag->extra_len++] = parent_ptr_type;
+ ag->extra[ag->extra_len++] = field_name;
+ ag->extra[ag->extra_len++] = field_ptr;
+ uint32_t result = addExtendedPayloadSmall(
+ gz, (uint16_t)ZIR_EXT_FIELD_PARENT_PTR, flags, payload_index);
+ return rvalue(gz, rl, result, root_node);
+ }
+ }
+
+ // After loop: flags must be non-zero (AstGen.zig:9051).
+
+ // Path A: pure @ptrCast (AstGen.zig:9053-9056).
+ if (flags == PTR_CAST_FLAG_PTR_CAST) {
+ advanceSourceCursorToMainToken(ag, gz, root_node);
+ uint32_t saved_line = ag->source_line - gz->decl_line;
+ uint32_t saved_col = ag->source_column;
+ uint32_t result_type = rlResultTypeForCast(gz, rl, root_node);
+ uint32_t operand = expr(gz, scope, node);
+ emitDbgStmt(gz, saved_line, saved_col);
+ return rvalue(gz, rl,
+ addPlNodeBin(
+ gz, ZIR_INST_PTR_CAST, root_node, result_type, operand),
+ root_node);
+ }
+
+ // Path B: only const_cast/volatile_cast — no result type needed
+ // (AstGen.zig:9059-9072).
+ if ((flags & ~PTR_CAST_NO_RESULT_TY_MASK) == 0) {
+ advanceSourceCursorToMainToken(ag, gz, root_node);
+ uint32_t saved_line = ag->source_line - gz->decl_line;
+ uint32_t saved_col = ag->source_column;
+ uint32_t operand = expr(gz, scope, node);
+ emitDbgStmt(gz, saved_line, saved_col);
+ ensureExtraCapacity(ag, 2);
+ uint32_t payload_index = ag->extra_len;
+ ag->extra[ag->extra_len++]
+ = (uint32_t)((int32_t)root_node - (int32_t)gz->decl_node_index);
+ ag->extra[ag->extra_len++] = operand;
+ uint32_t result = addExtendedPayloadSmall(
+ gz, (uint16_t)ZIR_EXT_PTR_CAST_NO_DEST, flags, payload_index);
+ return rvalue(gz, rl, result, root_node);
+ }
+
+ // Path C: full cast with result type (AstGen.zig:9077-9086).
+ advanceSourceCursorToMainToken(ag, gz, root_node);
+ uint32_t saved_line = ag->source_line - gz->decl_line;
+ uint32_t saved_col = ag->source_column;
+ uint32_t result_type = rlResultTypeForCast(gz, rl, root_node);
+ uint32_t operand = expr(gz, scope, node);
+ emitDbgStmt(gz, saved_line, saved_col);
+ ensureExtraCapacity(ag, 3);
+ uint32_t payload_index = ag->extra_len;
+ ag->extra[ag->extra_len++]
+ = (uint32_t)((int32_t)root_node - (int32_t)gz->decl_node_index);
+ ag->extra[ag->extra_len++] = result_type;
+ ag->extra[ag->extra_len++] = operand;
+ uint32_t result = addExtendedPayloadSmall(
+ gz, (uint16_t)ZIR_EXT_PTR_CAST_FULL, flags, payload_index);
+ return rvalue(gz, rl, result, root_node);
+}
+
// Mirrors builtinCall (AstGen.zig:9191) dispatch.
static uint32_t builtinCall(
GenZir* gz, Scope* scope, ResultLoc rl, uint32_t node) {
@@ -3244,20 +3409,13 @@ static uint32_t builtinCall(
return rvalue(gz, rl, addPlNodeBin(gz, ZIR_INST_TRUNCATE, node,
result_type, operand), node);
}
- // @ptrCast — typeCast pattern (AstGen.zig:9056, 9807-9826).
- // TODO: Issue 14 — upstream routes through ptrCast() for nested
- // pointer cast collapsing. Currently uses simple typeCast path.
- if (name_len == 7 && memcmp(source + name_start, "ptrCast", 7) == 0) {
- advanceSourceCursorToMainToken(ag, gz, node);
- uint32_t saved_line = ag->source_line - gz->decl_line;
- uint32_t saved_col = ag->source_column;
- uint32_t result_type = rlResultTypeForCast(gz, rl, node);
- AstData nd = tree->nodes.datas[node];
- uint32_t operand = expr(gz, scope, nd.lhs);
- emitDbgStmt(gz, saved_line, saved_col);
- return rvalue(gz, rl, addPlNodeBin(gz, ZIR_INST_PTR_CAST, node,
- result_type, operand), node);
- }
+ // @ptrCast — routes through ptrCastBuiltin (AstGen.zig:9464-9469).
+ if (name_len == 7 && memcmp(source + name_start, "ptrCast", 7) == 0)
+ return ptrCastBuiltin(gz, scope, rl, node);
+ // @addrSpaceCast — routes through ptrCastBuiltin (AstGen.zig:9464-9469).
+ if (name_len == 13
+ && memcmp(source + name_start, "addrSpaceCast", 13) == 0)
+ return ptrCastBuiltin(gz, scope, rl, node);
// @enumFromInt — typeCast pattern (AstGen.zig:9414, 9807-9826).
if (name_len == 11 && memcmp(source + name_start, "enumFromInt", 11) == 0) {
advanceSourceCursorToMainToken(ag, gz, node);
@@ -3518,69 +3676,18 @@ static uint32_t builtinCall(
gz, (uint16_t)ZIR_EXT_SHL_WITH_OVERFLOW, payload_index);
return rvalue(gz, rl, result, node);
}
- // @alignCast — ptrCast family (AstGen.zig:9464-9469, 8969-9087).
- // Simplified: standalone @alignCast uses ptr_cast_full with align_cast flag.
+ // @alignCast — routes through ptrCastBuiltin (AstGen.zig:9464-9469).
if (name_len == 9
- && memcmp(source + name_start, "alignCast", 9) == 0) {
- advanceSourceCursorToMainToken(ag, gz, node);
- uint32_t saved_line = ag->source_line - gz->decl_line;
- uint32_t saved_col = ag->source_column;
- uint32_t result_type = rlResultTypeForCast(gz, rl, node);
- AstData nd = tree->nodes.datas[node];
- uint32_t operand = expr(gz, scope, nd.lhs);
- emitDbgStmt(gz, saved_line, saved_col);
- // align_cast flag = bit 1 (FullPtrCastFlags: ptr_cast=0, align_cast=1)
- uint16_t flags = 0x02;
- ensureExtraCapacity(ag, 3);
- uint32_t payload_index = ag->extra_len;
- ag->extra[ag->extra_len++]
- = (uint32_t)((int32_t)node - (int32_t)gz->decl_node_index);
- ag->extra[ag->extra_len++] = result_type;
- ag->extra[ag->extra_len++] = operand;
- uint32_t result = addExtendedPayloadSmall(
- gz, (uint16_t)ZIR_EXT_PTR_CAST_FULL, flags, payload_index);
- return rvalue(gz, rl, result, node);
- }
- // @constCast (AstGen.zig:9464-9469, 8969-9087).
+ && memcmp(source + name_start, "alignCast", 9) == 0)
+ return ptrCastBuiltin(gz, scope, rl, node);
+ // @constCast — routes through ptrCastBuiltin (AstGen.zig:9464-9469).
if (name_len == 9
- && memcmp(source + name_start, "constCast", 9) == 0) {
- advanceSourceCursorToMainToken(ag, gz, node);
- uint32_t saved_line = ag->source_line - gz->decl_line;
- uint32_t saved_col = ag->source_column;
- AstData nd = tree->nodes.datas[node];
- uint32_t operand = expr(gz, scope, nd.lhs);
- emitDbgStmt(gz, saved_line, saved_col);
- // const_cast flag = bit 3 (FullPtrCastFlags packed u5)
- uint16_t flags = 0x08;
- ensureExtraCapacity(ag, 2);
- uint32_t payload_index = ag->extra_len;
- ag->extra[ag->extra_len++]
- = (uint32_t)((int32_t)node - (int32_t)gz->decl_node_index);
- ag->extra[ag->extra_len++] = operand;
- uint32_t result = addExtendedPayloadSmall(
- gz, (uint16_t)ZIR_EXT_PTR_CAST_NO_DEST, flags, payload_index);
- return rvalue(gz, rl, result, node);
- }
- // @volatileCast (AstGen.zig:9464-9469, 8969-9087).
+ && memcmp(source + name_start, "constCast", 9) == 0)
+ return ptrCastBuiltin(gz, scope, rl, node);
+ // @volatileCast — routes through ptrCastBuiltin (AstGen.zig:9464-9469).
if (name_len == 12
- && memcmp(source + name_start, "volatileCast", 12) == 0) {
- advanceSourceCursorToMainToken(ag, gz, node);
- uint32_t saved_line = ag->source_line - gz->decl_line;
- uint32_t saved_col = ag->source_column;
- AstData nd = tree->nodes.datas[node];
- uint32_t operand = expr(gz, scope, nd.lhs);
- emitDbgStmt(gz, saved_line, saved_col);
- // volatile_cast flag = bit 4 (FullPtrCastFlags packed u5)
- uint16_t flags = 0x10;
- ensureExtraCapacity(ag, 2);
- uint32_t payload_index = ag->extra_len;
- ag->extra[ag->extra_len++]
- = (uint32_t)((int32_t)node - (int32_t)gz->decl_node_index);
- ag->extra[ag->extra_len++] = operand;
- uint32_t result = addExtendedPayloadSmall(
- gz, (uint16_t)ZIR_EXT_PTR_CAST_NO_DEST, flags, payload_index);
- return rvalue(gz, rl, result, node);
- }
+ && memcmp(source + name_start, "volatileCast", 12) == 0)
+ return ptrCastBuiltin(gz, scope, rl, node);
// @Type (reify) (AstGen.zig:9426-9428, 9747-9781).
if (name_len == 4 && memcmp(source + name_start, "Type", 4) == 0) {
AstData nd = tree->nodes.datas[node];
