Support immediate binding option

[DrXiao]

Since the immediate binding has already been implemented for the x86-64 and AArch64 architectures, the proposed changes extend its use by introducing a new "-z" command-line option, allowing the Arm32 and RV32 targets to also generate dynamically linked executables with immediate binding.

For the two 64-bit targets, immediate binding is always used under the dynamic linking mode as is.

The update usage:

# Support the "-z" option
$ qemu-arm -L /usr/arm-linux-gnueabihf/ out/shecc-stage2.elf
Usage: shecc [-o output] [+m] [--dot] [--dump-ir] [--no-libc] [--dynlink] [-z <lazy | now>] [-E] <input.c>
[Error]: Missing source file

# The build system can use the new 'BINDING' variable to determine whether to use immediate binding.
$ make ARCH=arm DYNLINK=1 BINDING=now

TODO:

• Update the GitHub Actions workflow to validate builds when using immediate binding.

---

Summary by cubic

Adds a -z option to control dynamic binding: lazy (default) or now (immediate). This lets Arm32 and RV32 targets use immediate binding, which was previously hardcoded for x86-64 and AArch64. The Makefile gains a BINDING variable so builds can pass -z now via make DYNLINK=1 BINDING=now.

^{Written for commit 0d1e98b. Summary will update on new commits.}

[cubic-dev-ai]

2 issues found across 7 files

Prompt for AI agents (unresolved issues)

Check if these issues are valid — if so, understand the root cause of each and fix them. If appropriate, use sub-agents to investigate and fix each issue separately.


<file name="Makefile">

<violation number="1" location="Makefile:62">
P2: When a `BINDING=now` build runs `make check`, the test suite still exercises lazy binding. The `check-stage0`/`check-stage2`/`check-abi-*` targets forward only `$(DYNLINK)` to the test drivers, and `tests/driver.sh` compiles its test programs with a plain `--dynlink` (no `-z now`), so on arm/riscv those programs default to lazy binding. With this change `BINDING` becomes a build knob that stage1/stage2 honor, but the tests built by `make check` never verify the immediate-binding path this PR adds. Forward `$(BINDING)` (or a corresponding `-z` flag) to the driver invocations so immediate binding can actually be validated, matching the PR's TODO about CI validation.</violation>
</file>

<file name="src/main.c">

<violation number="1" location="src/main.c:120">
P2: The `-z` handler reads `argv[i + 1]` but never advances `i`, so its value `lazy`/`now` is not consumed and is treated as a positional input on the next loop iteration. Unlike the neighboring `-o` case (which does `i++`), this leaves `argv[i+1]` to hit the trailing `else ... in = argv[i]` branch. As a result, `shecc in.c -z now` first sets `in = "in.c"` and then overwrites it with `"now"`, so the compiler tries to open a file named `now` and fails; and `shecc -z now` with no real input never triggers the "Missing source file" error because `in` is set to `"now"`. Add `i++;` after the value is consumed, matching the `-o` handling.</violation>
</file>

<sub>Reply with feedback, questions, or to request a fix.

Re-trigger cubic</sub>

[cubic-dev-ai]

P2: When a BINDING=now build runs make check, the test suite still exercises lazy binding. The check-stage0/check-stage2/check-abi-* targets forward only $(DYNLINK) to the test drivers, and tests/driver.sh compiles its test programs with a plain --dynlink (no -z now), so on arm/riscv those programs default to lazy binding. With this change BINDING becomes a build knob that stage1/stage2 honor, but the tests built by make check never verify the immediate-binding path this PR adds. Forward $(BINDING) (or a corresponding -z flag) to the driver invocations so immediate binding can actually be validated, matching the PR's TODO about CI validation.

Prompt for AI agents

Check if this issue is valid — if so, understand the root cause and fix it. At Makefile, line 62:

<comment>When a `BINDING=now` build runs `make check`, the test suite still exercises lazy binding. The `check-stage0`/`check-stage2`/`check-abi-*` targets forward only `$(DYNLINK)` to the test drivers, and `tests/driver.sh` compiles its test programs with a plain `--dynlink` (no `-z now`), so on arm/riscv those programs default to lazy binding. With this change `BINDING` becomes a build knob that stage1/stage2 honor, but the tests built by `make check` never verify the immediate-binding path this PR adds. Forward `$(BINDING)` (or a corresponding `-z` flag) to the driver invocations so immediate binding can actually be validated, matching the PR's TODO about CI validation.</comment>

<file context>
@@ -53,12 +53,13 @@ BUILTIN_LIBC_HEADER := c.h
-    STAGE0_FLAGS += --dynlink
-    STAGE1_FLAGS += --dynlink
+    STAGE0_FLAGS += --dynlink -z $(BINDING)
+    STAGE1_FLAGS += --dynlink -z $(BINDING)
 endif
 
</file context>

[cubic-dev-ai]

P2: The -z handler reads argv[i + 1] but never advances i, so its value lazy/now is not consumed and is treated as a positional input on the next loop iteration. Unlike the neighboring -o case (which does i++), this leaves argv[i+1] to hit the trailing else ... in = argv[i] branch. As a result, shecc in.c -z now first sets in = "in.c" and then overwrites it with "now", so the compiler tries to open a file named now and fails; and shecc -z now with no real input never triggers the "Missing source file" error because in is set to "now". Add i++; after the value is consumed, matching the -o handling.

Prompt for AI agents

Check if this issue is valid — if so, understand the root cause and fix it. At src/main.c, line 120:

<comment>The `-z` handler reads `argv[i + 1]` but never advances `i`, so its value `lazy`/`now` is not consumed and is treated as a positional input on the next loop iteration. Unlike the neighboring `-o` case (which does `i++`), this leaves `argv[i+1]` to hit the trailing `else ... in = argv[i]` branch. As a result, `shecc in.c -z now` first sets `in = "in.c"` and then overwrites it with `"now"`, so the compiler tries to open a file named `now` and fails; and `shecc -z now` with no real input never triggers the "Missing source file" error because `in` is set to `"now"`. Add `i++;` after the value is consumed, matching the `-o` handling.</comment>

<file context>
@@ -117,7 +117,17 @@ int main(int argc, char *argv[])
         else if (!strcmp(argv[i], "--dynlink"))
             dynlink = true;
-        else if (!strcmp(argv[i], "-E"))
+        else if (!strcmp(argv[i], "-z")) {
+            if (i + 1 >= argc)
+                usage_error("-z requires \"lazy\" or \"now\"");
</file context>

Suggested change

	else if (!strcmp(argv[i], "-z")) {
	if (i + 1 >= argc)
	usage_error("-z requires \"lazy\" or \"now\"");
	if (!strcmp(argv[i + 1], "lazy"))
	imm_binding = false;
	else if (!strcmp(argv[i + 1], "now"))
	imm_binding = true;
	else
	usage_error("-z requires \"lazy\" or \"now\"");
	} else if (!strcmp(argv[i], "-E"))
	else if (!strcmp(argv[i], "-z")) {
	if (i + 1 >= argc)
	usage_error("-z requires \"lazy\" or \"now\"");
	if (!strcmp(argv[i + 1], "lazy"))
	imm_binding = false;
	else if (!strcmp(argv[i + 1], "now"))
	imm_binding = true;
	else
	usage_error("-z requires \"lazy\" or \"now\"");
	i++;
	}