tests: debug: symtab: add test

Add test for symtab.

Signed-off-by: Yong Cong Sin <ycsin@meta.com>

tests/subsys/debug/symtab/CMakeLists.txt

@@ -0,0 +1,8 @@
+# SPDX-License-Identifier: Apache-2.0
+
+cmake_minimum_required(VERSION 3.20.0)
+find_package(Zephyr REQUIRED HINTS $ENV{ZEPHYR_BASE})
+
+project(symtab)
+
+target_sources(app PRIVATE src/main.c)

tests/subsys/debug/symtab/prj.conf

@@ -0,0 +1,3 @@
+CONFIG_ZTEST=y
+
+CONFIG_SYMTAB=y

tests/subsys/debug/symtab/src/main.c

@@ -0,0 +1,158 @@
+/*
+ * Copyright 2024 Meta Platforms
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <zephyr/debug/symtab.h>
+#include <zephyr/ztest.h>
+
+const struct symtab_info *symtab;
+
+static void *setup(void)
+{
+	symtab = symtab_get();
+
+	return NULL;
+}
+
+ZTEST_SUITE(test_symtab, NULL, setup, NULL, NULL, NULL);
+
+ZTEST(test_symtab, test_size)
+{
+	zassert_true(symtab->length > 0);
+}
+
+ZTEST(test_symtab, test_symtab_find_symbol_name)
+{
+	extern int main(void);
+	const uintptr_t first_addr = symtab->first_addr;
+	const uintptr_t last_addr = first_addr + symtab->entries[symtab->length - 1].offset;
+	uint32_t offset;
+	const char *symbol_name;
+
+	zassert_between_inclusive((uintptr_t)main, first_addr, last_addr,
+				  "No valid address found for `main()`");
+
+	/* Find the name of functions with `symtab_find_symbol_name()` */
+	offset = -1;
+	symbol_name = symtab_find_symbol_name((uintptr_t)main, &offset);
+	zassert_equal(strcmp(symbol_name, "main"), 0);
+	zassert_equal(offset, 0);
+
+	/* Do a few more just for fun */
+	symbol_name = symtab_find_symbol_name((uintptr_t)strcmp, NULL);
+	zassert_equal(strcmp(symbol_name, "strcmp"), 0);
+
+	symbol_name = symtab_find_symbol_name((uintptr_t)symtab_find_symbol_name, NULL);
+	zassert_equal(strcmp(symbol_name, "symtab_find_symbol_name"), 0);
+
+	symbol_name = symtab_find_symbol_name((uintptr_t)test_main, NULL);
+	zassert_equal(strcmp(symbol_name, "test_main"), 0);
+
+	symbol_name = symtab_find_symbol_name((uintptr_t)setup, NULL);
+	zassert_equal(strcmp(symbol_name, "setup"), 0);
+}
+
+/**
+ * This testsuite tests the following position in the symbol table
+ *
+ *
+ *                  [SYMBOL ADDR]       |      Name                   Offset
+ *     before first-->    .             |       "?"          (not found) 0x0
+ *            first-->  0x100           |   <first>                      0x0
+ *                      0x101           |   <first>                      0x1
+ *                        .             |
+ *                        .             |
+ *                        .             |
+ *             last-->  0x300           |    <last>                      0x0
+ *       after last-->  0x301           |    <last>                      0x1
+ *                        .             |
+ *                      0x310 (dummy)   |       "?"          (not found) 0x0
+ *                        .             |
+ *      after dummy-->  0x342           |       "?"          (not found) 0x0
+ */
+
+ZTEST(test_symtab, test_before_first)
+{
+	const uintptr_t first_addr = symtab->first_addr;
+	const char *symbol_name;
+	uint32_t offset;
+
+	/* No symbol should appear before first_addr, but make sure that first_addr != 0 */
+	if (first_addr > 0) {
+		offset = -1;
+		symbol_name = symtab_find_symbol_name(first_addr - 1, &offset);
+		zassert_equal(strcmp(symbol_name, "?"), 0);
+		zassert_equal(offset, 0);
+	} else {
+		ztest_test_skip();
+	}
+}
+
+ZTEST(test_symtab, test_first)
+{
+	const uintptr_t first_addr = symtab->first_addr;
+	const char *symbol_name;
+	uint32_t offset;
+
+	offset = -1;
+	symbol_name = symtab_find_symbol_name(first_addr, &offset);
+	zassert_equal(strcmp(symbol_name, symtab->entries[0].name), 0);
+	zassert_equal(offset, 0);
+
+	if ((symtab->entries[0].offset + 1) != symtab->entries[1].offset) {
+		offset = -1;
+		symbol_name = symtab_find_symbol_name(first_addr + 1, &offset);
+		zassert_equal(strcmp(symbol_name, symtab->entries[0].name), 0);
+		zassert_equal(offset, 1);
+	}
+}
+
+ZTEST(test_symtab, test_last)
+{
+	const uintptr_t first_addr = symtab->first_addr;
+	const int last_idx = symtab->length - 1;
+	const uintptr_t last_addr = first_addr + symtab->entries[last_idx].offset;
+	const char *symbol_name;
+	uint32_t offset;
+
+	offset = -1;
+	symbol_name = symtab_find_symbol_name(last_addr, &offset);
+	zassert_equal(strcmp(symbol_name, symtab->entries[last_idx].name), 0);
+	zassert_equal(offset, 0);
+}
+
+ZTEST(test_symtab, test_after_last)
+{
+	const uintptr_t first_addr = symtab->first_addr;
+	const uintptr_t last_offset = symtab->entries[symtab->length - 1].offset;
+	const uintptr_t last_addr = first_addr + last_offset;
+	const char *symbol_name;
+	uint32_t offset;
+
+	/* Test `offset` output with last symbol */
+	if (last_offset + 0x1 != symtab->entries[symtab->length].offset) {
+		offset = -1;
+		symbol_name = symtab_find_symbol_name(last_addr + 0x1, &offset);
+		zassert_equal(strcmp(symbol_name, symtab->entries[symtab->length - 1].name), 0);
+		zassert_equal(offset, 0x1);
+	} else {
+		ztest_test_skip();
+	}
+}
+
+ZTEST(test_symtab, test_after_dummy)
+{
+	const uintptr_t first_addr = symtab->first_addr;
+	const uintptr_t last_dummy_offset = symtab->entries[symtab->length].offset;
+	const uintptr_t last_dummy_addr = first_addr + last_dummy_offset;
+	const char *symbol_name;
+	uint32_t offset;
+
+	/* Test `offset` output with dummy symbol (after last dymbol) */
+	offset = -1;
+	symbol_name = symtab_find_symbol_name(last_dummy_addr + 0x42, &offset);
+	zassert_equal(strcmp(symbol_name, "?"), 0);
+	zassert_equal(offset, 0);
+}

tests/subsys/debug/symtab/testcase.yaml

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+# SPDX-License-Identifier: Apache-2.0
+common:
+  platform_allow:
+    - qemu_riscv32
+    - qemu_riscv64
+    - qemu_cortex_a53
+    - qemu_cortex_m3
+    - qemu_xtensa
+  tags:
+    - debug
+    - symtab
+
+tests:
+  debug.symtab: {}