cgen: fix hash stmt code generation (fix #25184) (#25207)

vlib/v/ast/ast.v

@@ -117,6 +117,8 @@ pub type Stmt = AsmStmt
 	| StructDecl
 	| TypeDecl
 
+pub type HashStmtNode = IfExpr | HashStmt
+
 pub struct EmptyScopeObject {
 pub mut:
 	name string

vlib/v/gen/c/cgen.v

@@ -274,6 +274,11 @@ mut:
 	export_funcs         []string // for .dll export function names
 	//
 	type_default_impl_level int
+	preinclude_nodes        []&ast.HashStmtNode // allows hash stmts to go before `includes`
+	include_nodes           []&ast.HashStmtNode // all hash stmts to go `includes`
+	definition_nodes        []&ast.HashStmtNode // allows hash stmts to go `definitions`
+	postinclude_nodes       []&ast.HashStmtNode // allows hash stmts to go after all the rest of the code generation
+	curr_comptime_node      &ast.Expr = unsafe { nil } // current `$if` expr
 }
 
 @[heap]
@@ -920,6 +925,11 @@ pub fn (mut g Gen) gen_file() {
 		g.inside_ternary = 0
 	}
 	g.stmts(g.file.stmts)
+
+	// after all other stmts executed, we got info about hash stmts in top,
+	// write them to corresponding sections
+	g.gen_hash_stmts_in_top()
+
 	// Transfer embedded files
 	for path in g.file.embedded_files {
 		if path !in g.embedded_files {
@@ -5740,113 +5750,178 @@ fn (mut g Gen) hash_stmt_guarded_include(node ast.HashStmt) string {
 }
 
 fn (mut g Gen) hash_stmt(node ast.HashStmt) {
-	line_nr := node.pos.line_nr + 1
-	mut ct_condition := ''
+	// we only record the hash stmt's node here, send it to corresponding `_nodes`, let `gen_hash_stmts_in_top()` gen the code.
+	the_node := if g.comptime.inside_comptime_if && !isnil(g.curr_comptime_node)
+		&& g.curr_comptime_node is ast.IfExpr {
+		&ast.HashStmtNode(g.curr_comptime_node as ast.IfExpr)
+	} else {
+		&ast.HashStmtNode(&node)
+	}
 
-	if node.ct_conds.len > 0 {
+	match node.kind {
+		'include', 'insert', 'define' {
+			if node.main.contains('.m') {
+				// Objective C code import, include it after V types, so that e.g. `string` is
+				// available there
+				if the_node !in g.definition_nodes {
+					g.definition_nodes << the_node
+				}
+			} else {
+				if the_node !in g.include_nodes {
+					g.include_nodes << the_node
+				}
+			}
+		}
+		'preinclude' {
+			if node.main.contains('.m') {
+				// Objective C code import, include it after V types, so that e.g. `string` is
+				// available there
+				if the_node !in g.definition_nodes {
+					g.definition_nodes << the_node
+				}
+			} else {
+				if the_node !in g.preinclude_nodes {
+					g.preinclude_nodes << the_node
+				}
+			}
+		}
+		'postinclude' {
+			if the_node !in g.postinclude_nodes {
+				g.postinclude_nodes << the_node
+			}
+		}
+		else {}
+	}
+}
+
+fn (mut g Gen) gen_hash_stmts(mut sb strings.Builder, node &ast.HashStmtNode, section string) {
+	match node {
+		ast.IfExpr {
 			mut comptime_branch_context_str := g.gen_branch_context_string()
 			mut is_true := ast.ComptTimeCondResult{}
-		mut sb := strings.new_builder(256)
-		for idx, ct_expr in node.ct_conds {
-			idx_str := comptime_branch_context_str + '|${g.file.path}|${ct_expr.pos()}|'
+			for i, branch in node.branches {
+				idx_str := if branch.cond.pos() == token.Pos{} {
+					comptime_branch_context_str + '|${g.file.path}|${branch.pos}|'
+				} else {
+					comptime_branch_context_str + '|${g.file.path}|${branch.cond.pos()}|'
+				}
 				if comptime_is_true := g.table.comptime_is_true[idx_str] {
 					// `g.table.comptime_is_true` are the branch condition results set by `checker`
 					is_true = comptime_is_true
 				} else {
 					g.error('checker error: condition result idx string not found => [${idx_str}]',
-					ct_expr.pos())
+						node.branches[i].cond.pos())
 					return
 				}
-			sb.write_string(is_true.c_str)
-			if idx < node.ct_conds.len - 1 {
-				sb.write_string(' && ')
+				if !node.has_else || i < node.branches.len - 1 {
+					if i == 0 {
+						sb.write_string('\n#if ')
+					} else {
+						sb.write_string('\n#elif ')
 					}
-		}
-		ct_condition = sb.str()
-	}
-	// #include etc
-	if node.kind == 'include' {
-		guarded_include := g.hash_stmt_guarded_include(node)
-		if node.main.contains('.m') {
-			g.definitions.writeln('')
-			if ct_condition != '' {
-				g.definitions.writeln('#if ${ct_condition}')
-			}
-			// Objective C code import, include it after V types, so that e.g. `string` is
-			// available there
-			g.definitions.writeln('// added by module `${node.mod}`, file: ${os.file_name(node.source_file)}:${line_nr}:')
-			g.definitions.writeln(guarded_include)
-			if ct_condition != '' {
-				g.definitions.writeln('#endif // \$if ${ct_condition}')
+					// directly use `checker` evaluate results
+					// for `cgen`, we can use `is_true.c_str` or `is_true.value` here
+					sb.writeln('${is_true.c_str}')
+					$if debug_comptime_branch_context ? {
+						sb.writeln('/* ${node.branches[i].cond} | generic=[${comptime_branch_context_str}] */')
 					}
 				} else {
-			g.includes.writeln('')
-			if ct_condition != '' {
-				g.includes.writeln('#if ${ct_condition}')
-			}
-			g.includes.writeln('// added by module `${node.mod}`, file: ${os.file_name(node.source_file)}:${line_nr}:')
-			g.includes.writeln(guarded_include)
-			if ct_condition != '' {
-				g.includes.writeln('#endif // \$if ${ct_condition}')
+					sb.writeln('#else')
+					$if debug_comptime_branch_context ? {
+						sb.writeln('/* else | generic=[${comptime_branch_context_str}] */')
 					}
 				}
-	} else if node.kind == 'preinclude' {
-		guarded_include := g.hash_stmt_guarded_include(node)
-		if node.main.contains('.m') {
-			// Might need to support '#preinclude' for .m files as well but for the moment
-			// this does the same as '#include' for them
-			g.definitions.writeln('')
-			if ct_condition != '' {
-				g.definitions.writeln('#if ${ct_condition}')
+				if is_true.val || g.pref.output_cross_c {
+					// check only `IfExpr` and `HashStmt`
+					for stmt in branch.stmts {
+						if stmt is ast.ExprStmt {
+							if stmt.expr is ast.IfExpr && (stmt.expr as ast.IfExpr).is_comptime {
+								g.gen_hash_stmts(mut sb, stmt.expr, section)
 							}
+						} else if stmt is ast.HashStmt {
+							g.gen_hash_stmts(mut sb, stmt, section)
+						}
+					}
+				}
+			}
+			sb.writeln('#endif')
+		}
+		ast.HashStmt {
+			// #preinclude                      => `preincludes` section
+			// #inlude,#define,#insert          => `includes` section
+			// #postinclude                     => `postincludes` section
+			// '*.m' in #include or #preinclude => `definitions` section
+			need_gen_stmt := match section {
+				'preincludes' {
+					if node.kind == 'preinclude' && !node.main.contains('.m') { true } else { false }
+				}
+				'includes' {
+					if node.kind in ['include', 'define', 'insert'] && !node.main.contains('.m') {
+						true
+					} else {
+						false
+					}
+				}
+				'definitions' {
 					// Objective C code import, include it after V types, so that e.g. `string` is
 					// available there
-			g.definitions.writeln('// added by module `${node.mod}`, file: ${os.file_name(node.source_file)}:${line_nr}:')
-			g.definitions.writeln(guarded_include)
-			if ct_condition != '' {
-				g.definitions.writeln('#endif // \$if ${ct_condition}')
-			}
+					if node.kind in ['include', 'preinclude'] && node.main.contains('.m') {
+						true
 					} else {
-			g.preincludes.writeln('')
-			if ct_condition != '' {
-				g.preincludes.writeln('#if ${ct_condition}')
-			}
-			g.preincludes.writeln('// added by module `${node.mod}`, file: ${os.file_name(node.source_file)}:${line_nr}:')
-			g.preincludes.writeln(guarded_include)
-			if ct_condition != '' {
-				g.preincludes.writeln('#endif // \$if ${ct_condition}')
+						false
 					}
 				}
-	} else if node.kind == 'postinclude' {
+				'postincludes' {
+					if node.kind == 'postinclude' { true } else { false }
+				}
+				else {
+					false
+				}
+			}
+			if !need_gen_stmt {
+				return
+			}
+			line_nr := node.pos.line_nr + 1
+			match node.kind {
+				'include', 'preinclude', 'postinclude' {
 					guarded_include := g.hash_stmt_guarded_include(node)
-		g.postincludes.writeln('')
-		if ct_condition != '' {
-			g.postincludes.writeln('#if ${ct_condition}')
+					sb.writeln('')
+					sb.writeln('// added by module `${node.mod}`, file: ${os.file_name(node.source_file)}:${line_nr}:')
+					sb.writeln(guarded_include)
 				}
-		g.postincludes.writeln('// added by module `${node.mod}`, file: ${os.file_name(node.source_file)}:${line_nr}:')
-		g.postincludes.writeln(guarded_include)
-		if ct_condition != '' {
-			g.postincludes.writeln('#endif // \$if ${ct_condition}')
+				'insert' {
+					sb.writeln('')
+					sb.writeln('// inserted by module `${node.mod}`, file: ${os.file_name(node.source_file)}:${line_nr}:')
+					sb.writeln(node.val)
 				}
-	} else if node.kind == 'insert' {
-		if ct_condition != '' {
-			g.includes.writeln('#if ${ct_condition}')
+				'define' {
+					sb.writeln('// defined by module `${node.mod}`')
+					sb.writeln('#define ${node.main}')
 				}
-		g.includes.writeln('// inserted by module `${node.mod}`, file: ${os.file_name(node.source_file)}:${line_nr}:')
-		g.includes.writeln(node.val)
-		if ct_condition != '' {
-			g.includes.writeln('#endif // \$if ${ct_condition}')
-		}
-	} else if node.kind == 'define' {
-		if ct_condition != '' {
-			g.includes.writeln('#if ${ct_condition}')
-		}
-		g.includes.writeln('// defined by module `${node.mod}`')
-		g.includes.writeln('#define ${node.main}')
-		if ct_condition != '' {
-			g.includes.writeln('#endif // \$if ${ct_condition}')
+				else {}
 			}
 		}
+		// TODO: support $match
+	}
+}
+
+fn (mut g Gen) gen_hash_stmts_in_top() {
+	for node in g.preinclude_nodes {
+		g.gen_hash_stmts(mut g.preincludes, node, 'preincludes')
+	}
+	for node in g.include_nodes {
+		g.gen_hash_stmts(mut g.includes, node, 'includes')
+	}
+	for node in g.definition_nodes {
+		g.gen_hash_stmts(mut g.definitions, node, 'definitions')
+	}
+	for node in g.postinclude_nodes {
+		g.gen_hash_stmts(mut g.postincludes, node, 'postincludes')
+	}
+	g.preinclude_nodes.clear()
+	g.include_nodes.clear()
+	g.definition_nodes.clear()
+	g.postinclude_nodes.clear()
 }
 
 fn (mut g Gen) branch_stmt(node ast.BranchStmt) {

vlib/v/gen/c/comptime.v

@@ -401,9 +401,20 @@ fn (mut g Gen) comptime_if(node ast.IfExpr) {
 		''
 	}
 
+	// save node for processing hash stmts
+	// we only save the first node, when there is embedded $if
+	old_curr_comptime_node := g.curr_comptime_node
+	if !g.comptime.inside_comptime_if {
+		g.curr_comptime_node = &node
+	}
+	defer {
+		g.curr_comptime_node = old_curr_comptime_node
+	}
 	mut comptime_branch_context_str := g.gen_branch_context_string()
 	mut is_true := ast.ComptTimeCondResult{}
 	for i, branch in node.branches {
+		g.push_new_comptime_info()
+		g.comptime.inside_comptime_if = true
 		start_pos := g.out.len
 		// `idx_str` is composed of two parts:
 		// The first part represents the current context of the branch statement, `comptime_branch_context_str`, formatted like `T=int,X=string,method.name=json`
@@ -501,6 +512,7 @@ fn (mut g Gen) comptime_if(node ast.IfExpr) {
 				g.writeln('}')
 			}
 		}
+		g.pop_comptime_info()
 	}
 	g.defer_ifdef = ''
 	g.writeln('#endif')
@@ -563,6 +575,7 @@ fn (mut g Gen) push_new_comptime_info() {
 	g.type_resolver.info_stack << type_resolver.ResolverInfo{
 		saved_type_map:               g.type_resolver.type_map.clone()
 		inside_comptime_for:          g.comptime.inside_comptime_for
+		inside_comptime_if:           g.comptime.inside_comptime_if
 		comptime_for_variant_var:     g.comptime.comptime_for_variant_var
 		comptime_for_field_var:       g.comptime.comptime_for_field_var
 		comptime_for_field_type:      g.comptime.comptime_for_field_type
@@ -582,6 +595,7 @@ fn (mut g Gen) pop_comptime_info() {
 	old := g.type_resolver.info_stack.pop()
 	g.type_resolver.type_map = old.saved_type_map.clone()
 	g.comptime.inside_comptime_for = old.inside_comptime_for
+	g.comptime.inside_comptime_if = old.inside_comptime_if
 	g.comptime.comptime_for_variant_var = old.comptime_for_variant_var
 	g.comptime.comptime_for_field_var = old.comptime_for_field_var
 	g.comptime.comptime_for_field_type = old.comptime_for_field_type

vlib/v/gen/c/testdata/comptime_if_top_hash_stmts.c.must_have

@@ -0,0 +1,52 @@
+#if defined(_WIN32)
+#if defined(CUSTOM_DEFINE_user_d1)
+#elif defined(CUSTOM_DEFINE_user_d2)
+#include "pre1.h"
+#elif defined(__linux__)
+#if defined(CUSTOM_DEFINE_user_d3)
+#include "pre2.h"
+#elif defined(CUSTOM_DEFINE_user_d4)
+#if defined(_WIN32)
+#if defined(CUSTOM_DEFINE_user_d1)
+#include "w1.h"
+#define user_d1
+#elif defined(CUSTOM_DEFINE_user_d2)
+#include "w2.h"
+#define user_d2
+#else
+#include "w3.h"
+#define user_not_d1_d2
+#define user_all_windows
+#include "windows.h"
+#elif defined(__linux__)
+#if defined(CUSTOM_DEFINE_user_d3)
+#include "l1.h"
+#define user_d3
+#elif defined(CUSTOM_DEFINE_user_d4)
+#include "l2.h"
+#define user_d4
+#define user_all_linux
+#include "stdio.h"
+#else
+#define user_all_other
+#include "other.h"
+#if defined(_WIN32)
+#if defined(CUSTOM_DEFINE_user_d1)
+#elif defined(CUSTOM_DEFINE_user_d2)
+#else
+#include "macos1.m"
+#elif defined(__linux__)
+#if defined(CUSTOM_DEFINE_user_d3)
+#include "macos2.m"
+#elif defined(CUSTOM_DEFINE_user_d4)
+#endif
+#if defined(_WIN32)
+#if defined(CUSTOM_DEFINE_user_d1)
+#elif defined(CUSTOM_DEFINE_user_d2)
+#include "post1.h"
+#elif defined(__linux__)
+#if defined(CUSTOM_DEFINE_user_d3)
+#elif defined(CUSTOM_DEFINE_user_d4)
+#include "post2.h"
+#else
+#include "post3.h"

vlib/v/gen/c/testdata/comptime_if_top_hash_stmts.vv

@@ -0,0 +1,40 @@
+// vtest vflags: -os cross
+module main
+
+$if windows {
+	$if user_d1 ? {
+		#include "w1.h"
+		#define user_d1
+	} $else $if user_d2 ? {
+		#include "w2.h"
+		#define user_d2
+		#preinclude "pre1.h"
+	} $else {
+		#include "w3.h"
+		#define user_not_d1_d2
+		#include "macos1.m"
+		#postinclude "post1.h"
+	}
+	#define user_all_windows
+	#include "windows.h"
+} $else $if linux {
+	$if user_d3 ? {
+		#include "l1.h"
+		#include "macos2.m"
+		#define user_d3
+		#preinclude "pre2.h"
+	} $else $if user_d4 ? {
+		#include "l2.h"
+		#define user_d4
+		#postinclude "post2.h"
+	}
+	#define user_all_linux
+	#include "stdio.h"
+} $else {
+	#define user_all_other
+	#include "other.h"
+	#postinclude "post3.h"
+}
+
+fn main() {
+}