commit f490399d20a801a590be8be8d2033ab3bd38f9dd Author: Jeff Epler Date: Sat Jun 21 15:55:26 2025 +0200 Initial commit diff --git a/.clang-format b/.clang-format new file mode 100644 index 0000000..769dd88 --- /dev/null +++ b/.clang-format @@ -0,0 +1,3 @@ +BasedOnStyle: LLVM +IndentWidth: 4 +SortIncludes: false diff --git a/.gitignore b/.gitignore new file mode 100644 index 0000000..7640969 --- /dev/null +++ b/.gitignore @@ -0,0 +1,4 @@ +*.swp +*.swo +*.so +*.o diff --git a/LICENSE b/LICENSE new file mode 100644 index 0000000..ef7e7ef --- /dev/null +++ b/LICENSE @@ -0,0 +1,674 @@ +GNU GENERAL PUBLIC LICENSE + Version 3, 29 June 2007 + + Copyright (C) 2007 Free Software Foundation, Inc. + Everyone is permitted to copy and distribute verbatim copies + of this license document, but changing it is not allowed. + + Preamble + + The GNU General Public License is a free, copyleft license for +software and other kinds of works. + + The licenses for most software and other practical works are designed +to take away your freedom to share and change the works. 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If not, see . + +Also add information on how to contact you by electronic and paper mail. + + If the program does terminal interaction, make it output a short +notice like this when it starts in an interactive mode: + + {project} Copyright (C) {year} {fullname} + This program comes with ABSOLUTELY NO WARRANTY; for details type `show w'. + This is free software, and you are welcome to redistribute it + under certain conditions; type `show c' for details. + +The hypothetical commands `show w' and `show c' should show the appropriate +parts of the General Public License. Of course, your program's commands +might be different; for a GUI interface, you would use an "about box". + + You should also get your employer (if you work as a programmer) or school, +if any, to sign a "copyright disclaimer" for the program, if necessary. +For more information on this, and how to apply and follow the GNU GPL, see +. + + The GNU General Public License does not permit incorporating your program +into proprietary programs. If your program is a subroutine library, you +may consider it more useful to permit linking proprietary applications with +the library. If this is what you want to do, use the GNU Lesser General +Public License instead of this License. But first, please read +. diff --git a/Makefile b/Makefile new file mode 100644 index 0000000..8591bd4 --- /dev/null +++ b/Makefile @@ -0,0 +1,29 @@ + +PLUGIN=micropython_checks.so +SOURCES=micropython_checks.cc + +PLUGINDIR=$(shell $(CC) -print-file-name=plugin) + +CXXFLAGS=-std=gnu++11 -fPIC -Wall -Og -g -fno-rtti -I$(PLUGINDIR)/include +OBJECTS=$(patsubst %.cc,%.o,$(SOURCES)) + +all: $(PLUGIN) + +$(PLUGIN): $(OBJECTS) + $(CXX) $(LDFLAGS) -o $@ -shared $+ $(LDADD) + +%.o: %.cc + $(CXX) -c -o $@ $(CXXFLAGS) $< + +PLUGINFLAG=-fplugin=./$(PLUGIN) + +CCPLUGIN=$(CC) $(PLUGINFLAG) +CXXPLUGIN=$(CXX) $(PLUGINFLAG) + +.PHONY: all clean test +clean: + rm -f $(OBJECTS) $(PLUGIN) + +.PHONY: test +test: $(PLUGIN) test.cc + $(CXXPLUGIN) -Wformat -std=c++11 -c -o /dev/null test.cc diff --git a/README.md b/README.md new file mode 100644 index 0000000..46ce1da --- /dev/null +++ b/README.md @@ -0,0 +1,20 @@ +# Micropython Enhanced Warnings Plugin + +This gcc plugin aims to add diagnostics for Micropython core development. + +In particular, it handles mp\_printf style parameters, finding several apparent +problems in the process. + +To build the plugin (it must match a specific gcc version and target): + * Install packages for gcc plugin development (e.g., gcc-12-plugin-dev on debian) + * Compile it for your specific gcc use case: `make CC=cross-gcc` + * This still builds a plugin to execute on the host system (with CXX), despite how it looks + +To use it during micropython build: + * `make ... CFLAGS_EXTRA=-fplugin=/path/to/micropython_checks.so` + +# License + +GPL-3.0-or-later + +Based on original code from https://github.com/rofirrim/gcc-plugins/ diff --git a/micropython_checks.cc b/micropython_checks.cc new file mode 100644 index 0000000..5149683 --- /dev/null +++ b/micropython_checks.cc @@ -0,0 +1,411 @@ +#include +#include +#include +#include +#include + +// This is the first gcc header to be included +#include "gcc-plugin.h" +#include "plugin-version.h" + +#include "cp/cp-tree.h" +#include "context.h" +#include "function.h" +#include "internal-fn.h" +#include "is-a.h" +#include "predict.h" +#include "basic-block.h" +#include "tree.h" +#include "tree-ssa-alias.h" +#include "gimple-expr.h" +#include "gimple.h" +#include "gimple-ssa.h" +#include "tree-pretty-print.h" +#include "tree-pass.h" +#include "tree-ssa-operands.h" +#include "tree-phinodes.h" +#include "print-tree.h" +#include "stringpool.h" +#include "attribs.h" +#include "gimple-pretty-print.h" +#include "gimple-iterator.h" +#include "gimple-walk.h" +#include "diagnostic.h" +#include "stringpool.h" + +#include "ssa-iterators.h" + +// We must assert that this plugin is GPL compatible +int plugin_is_GPL_compatible; + +static struct plugin_info my_gcc_plugin_info = { + "1.0", "This plugin does nothing useful yet"}; + +namespace { +const pass_data micropython_checks_data = { + GIMPLE_PASS, + "micropython_checks", /* name */ + OPTGROUP_NONE, /* optinfo_flags */ + TV_NONE, /* tv_id */ + PROP_gimple_any, /* properties_required */ + 0, /* properties_provided */ + 0, /* properties_destroyed */ + 0, /* todo_flags_start */ + 0 /* todo_flags_finish */ +}; + +struct micropython_checks : gimple_opt_pass { + micropython_checks(gcc::context *ctx) + : gimple_opt_pass(micropython_checks_data, ctx) {} + + virtual unsigned int execute(function *fun) override { + // This phase has two steps, first we remove redundant LHS from + // GIMPLE_CALLs + walk(fun); + + return 0; + } + + virtual micropython_checks *clone() override { + // We do not clone ourselves + return this; + } + + static bool is_mpprint_call(const tree fn) { + if (!fn) + return false; + if (fn->base.code != ADDR_EXPR) + return false; + if (!fn->base.constant_flag) + return false; + const tree op = fn->exp.operands[0]; + if (op->base.code != FUNCTION_DECL) + return false; + const tree name = op->decl_minimal.name; + if (name->base.code != IDENTIFIER_NODE) + return false; + return strcmp((const char *)name->identifier.id.str, "mp_printf") == 0; + } + + static const char *mpprint_format_arg(gimple *stmt) { + tree fn = gimple_call_fn(stmt); + if (!is_mpprint_call(fn)) + return NULL; + unsigned nargs = gimple_call_num_args(stmt); + if (nargs < 2) + return NULL; + tree arg = gimple_call_arg(stmt, 1); + if (!arg->base.constant_flag) + return NULL; + if (arg->base.code != ADDR_EXPR) + return NULL; + tree op = arg->exp.operands[0]; + if (op->base.code != STRING_CST) + return NULL; + return op->string.str; + } + + void walk(function *fun) { + basic_block bb; + FOR_ALL_BB_FN(bb, fun) { + gimple_stmt_iterator gsi; + for (gsi = gsi_start_bb(bb); !gsi_end_p(gsi); gsi_next(&gsi)) { + gimple *stmt = gsi_stmt(gsi); + + // location_t loc = gimple_location (stmt); + switch (gimple_code(stmt)) { + case GIMPLE_CALL: { + const char *fmt = mpprint_format_arg(stmt); + + if (!fmt) { + break; + } + + unsigned nargs = gimple_call_num_args(stmt); + unsigned argno = 2; + + auto require_float = [stmt](int argno) { + auto arg = gimple_call_arg(stmt, argno); + location_t loc = gimple_location(stmt); + + if (!arg || + arg->exp.typed.type->base.code != REAL_TYPE) { + warning_at( + loc, OPT_Wformat_, + "argument %d: expected a FP argument, not %qE", + argno + 1, arg); + } + }; + + auto require_ptr = [stmt](int argno) { + auto arg = gimple_call_arg(stmt, argno); + + if (!arg || + arg->exp.typed.type->base.code != POINTER_TYPE) { + volatile location_t loc = gimple_location(stmt); + warning_at(loc, OPT_Wformat_, + "argument %d: expected a pointer " + "argument, not %qE", + argno + 1, arg); + } + }; + + auto require_sized_int = [stmt](int argno, tree type1, + tree type2) { + auto arg = gimple_call_arg(stmt, argno); + location_t loc = gimple_location(stmt); + + auto tp = arg ? arg->exp.typed.type : 0; + if (tp) + tp = TYPE_CANONICAL(tp); + if (tp != type1 && tp != type2) { + warning_at( + loc, OPT_Wformat_, + "argument %d: expected %qT or %qT, not %qT", + argno + 1, type1, type2, tp); + } + }; + + auto require_int = [&require_sized_int](int argno) { + require_sized_int(argno, integer_type_node, + unsigned_type_node); + }; + auto require_long = [&require_sized_int](int argno) { + require_sized_int(argno, long_integer_type_node, + long_unsigned_type_node); + }; + auto require_long_long = [&require_sized_int](int argno) { + require_sized_int(argno, long_long_integer_type_node, + long_long_unsigned_type_node); + }; + auto require_qstr = [&require_sized_int](int argno) { + require_sized_int(argno, size_type_node, + signed_size_type_node); + }; + + for (;;) { + while (*fmt != '\0' && *fmt != '%') { + ++fmt; + } + + if (*fmt == '\0') { + break; + } + + // move past % character + ++fmt; + + // parse flags, if they exist + while (*fmt != '\0') { + if (*fmt == '-') { + } else if (*fmt == '+') { + } else if (*fmt == ' ') { + } else if (*fmt == '0') { + } else { + break; + } + ++fmt; + } + + // parse precision, if it exists + int prec = -1; + if (*fmt == '.') { + ++fmt; + if (*fmt == '*') { + ++fmt; + require_int(argno++); + } else { + prec = 0; + for (; '0' <= *fmt && *fmt <= '9'; ++fmt) { + prec = prec * 10 + *fmt - '0'; + } + } + if (prec < 0) { + prec = 0; + } + } + + // parse width, if it exists + int width = 0; + for (; '0' <= *fmt && *fmt <= '9'; ++fmt) { + width = width * 10 + *fmt - '0'; + } + + // parse long specifiers + + bool long_arg = false; + if (*fmt == 'l') { + ++fmt; + long_arg = true; + } + switch (*fmt) { + case 'b': + case 'B': + case 'i': + case 'u': + case 'd': + case 'x': + case 'X': + case 'o': + case 'O': + if (long_arg) + require_long(argno++); + else + require_int(argno++); + break; + + case 'c': + require_int(argno++); + break; + + case 'q': + require_qstr(argno++); + break; + + case 's': + case 'p': + case 'P': + require_ptr(argno++); + break; + + case 'e': + case 'E': + case 'f': + case 'F': + case 'g': + case 'G': + require_float(argno++); + break; + + case 'l': + ++fmt; + if (*fmt != 'u' && *fmt != 'd' && *fmt != 'x') { + location_t loc = gimple_location(stmt); + warning_at(loc, OPT_Wformat_, + "Bad format specification with ll%c", + *fmt); + } + require_long_long(argno++); + break; + default: { + location_t loc = gimple_location(stmt); + warning_at(loc, OPT_Wformat_, + "Bad format specification with %c", + *fmt); + } break; + } + } + if (argno != nargs) { + location_t loc = gimple_location(stmt); + warning_at(loc, OPT_Wformat_, + "Wrong # arguments. Supplied %d, used %d", + nargs, argno); + } + } break; + case GIMPLE_ASSIGN: + case GIMPLE_ASM: + case GIMPLE_COND: + case GIMPLE_GOTO: + case GIMPLE_LABEL: + case GIMPLE_NOP: + case GIMPLE_OMP_ATOMIC_LOAD: + case GIMPLE_OMP_ATOMIC_STORE: + case GIMPLE_OMP_CONTINUE: + case GIMPLE_OMP_CRITICAL: + case GIMPLE_OMP_FOR: + case GIMPLE_OMP_MASTER: + case GIMPLE_OMP_ORDERED: + case GIMPLE_OMP_PARALLEL: + case GIMPLE_OMP_RETURN: + case GIMPLE_OMP_SECTION: + case GIMPLE_OMP_SECTIONS: + case GIMPLE_OMP_SECTIONS_SWITCH: + case GIMPLE_OMP_SINGLE: + case GIMPLE_PHI: + case GIMPLE_RESX: + case GIMPLE_RETURN: + case GIMPLE_SWITCH: + // TODO: complete the remaining trees + break; + default: + // TODO: even more trees in newer gcc versions + break; + gcc_unreachable(); + } + } + } + } + + void micropython_checks_lhs(const std::set &unused_lhs, + function *fun) { + basic_block bb; + FOR_ALL_BB_FN(bb, fun) { + gimple_stmt_iterator gsi; + for (gsi = gsi_start_bb(bb); !gsi_end_p(gsi); gsi_next(&gsi)) { + gimple *stmt = gsi_stmt(gsi); + + switch (gimple_code(stmt)) { + case GIMPLE_CALL: { + tree lhs = gimple_call_lhs(stmt); + if (unused_lhs.find(lhs) != unused_lhs.end()) { + // Deliberately similar to the code in tree-cfg.c + tree fdecl = gimple_call_fndecl(stmt); + tree ftype = gimple_call_fntype(stmt); + + if (lookup_attribute("micropython_checks", + TYPE_ATTRIBUTES(ftype))) { + location_t loc = gimple_location(stmt); + + if (fdecl) + warning_at(loc, OPT_Wunused_result, + "ignoring return value of %qD, " + "declared with attribute warn " + "unused result", + fdecl); + else + warning_at(loc, OPT_Wunused_result, + "ignoring return value of function " + "declared with attribute warn " + "unused result"); + } + } + break; + } + default: + // Do nothing + break; + } + } + } + } +}; +} // namespace + +int plugin_init(struct plugin_name_args *plugin_info, + struct plugin_gcc_version *version) { + // We check the current gcc loading this plugin against the gcc we used to + // created this plugin + if (!plugin_default_version_check(version, &gcc_version)) { + std::cerr << "This GCC plugin is for version " + << GCCPLUGIN_VERSION_MAJOR << "." << GCCPLUGIN_VERSION_MINOR + << "\n"; + return 1; + } + + register_callback(plugin_info->base_name, + /* event */ PLUGIN_INFO, + /* callback */ NULL, /* user_data */ &my_gcc_plugin_info); + + // Register the phase right after cfg + struct register_pass_info pass_info; + + pass_info.pass = new micropython_checks(g); + pass_info.reference_pass_name = "cfg"; + pass_info.ref_pass_instance_number = 1; + pass_info.pos_op = PASS_POS_INSERT_AFTER; + + register_callback(plugin_info->base_name, PLUGIN_PASS_MANAGER_SETUP, NULL, + &pass_info); + + return 0; +} diff --git a/test.cc b/test.cc new file mode 100644 index 0000000..eb82193 --- /dev/null +++ b/test.cc @@ -0,0 +1,31 @@ +typedef struct _mp_print_t mp_print_t; +extern const mp_print_t mp_plat_print; +int mp_printf(const mp_print_t *print, const char *fmt, ...); + +typedef unsigned long long qstr; +extern void abort(); + +int fn() { + short shortarg = 37; + mp_printf(&mp_plat_print, "%q\n", shortarg); + mp_printf(&mp_plat_print, "%q\n", (qstr)shortarg); + mp_printf(&mp_plat_print, "%s\n", 9); + mp_printf(&mp_plat_print, "%s\n", "hi"); + mp_printf(&mp_plat_print, "%s\n", 22 / 7.); + mp_printf(&mp_plat_print, "%p\n", 9); + mp_printf(&mp_plat_print, "%p\n", "hi"); + mp_printf(&mp_plat_print, "%d\n", 9); + mp_printf(&mp_plat_print, "%d\n", "hi"); + mp_printf(&mp_plat_print, "%ld\n", 9); + mp_printf(&mp_plat_print, "%ld\n", (long)9); + mp_printf(&mp_plat_print, "%ld\n", "hi"); + mp_printf(&mp_plat_print, "%lld\n", 9); + mp_printf(&mp_plat_print, "%lld\n", (long long)9); + mp_printf(&mp_plat_print, "%ld\n", "hi"); + mp_printf(&mp_plat_print, "%f\n", 22 / 7.); + mp_printf(&mp_plat_print, "%f\n", "hi"); + mp_printf(&mp_plat_print, "%d %d\n", 7); + mp_printf(&mp_plat_print, "%d %d\n", 7, 7, 7); + abort(); + return 0; +}