Add label and opcode parsers

1 files changed, 35 insertions, 0 deletions

diff --git a/newasm/statement.s b/newasm/statement.s
new file mode 100644
index 0000000..83f8d8d
--- /dev/null
+++ b/newasm/statement.s
@@ -0,0 +1,35 @@
+.syntax unified
+.cpu cortex-m0plus
+.thumb
+
+.type statement, %function
+.global statement
+
+// 1 reported an error
+
+// R1 input buffer
+// R2 output buffer
+
+statement:PUSH    {LR}
+          BL      whitespace
+          BL      label
+          CMP     R0, #2        // check for error code 2 (no colon)
+          BNE     1f
+          ADR     R0, no_colon
+          B       err_exit
+1:        BL      whitespace
+          BL      opcode
+          BEQ     2f
+          ADR     R0, no_opcode
+          B       err_exit
+2:        MOVS    R0, #0
+          POP     {PC}
+
+err_exit: BL      putstrln
+          MOVS    R0, #1        // return code 1 (there was an error)
+          POP     {PC}
+
+            .align  4
+no_colon:   .asciz  "Error: Expected colon at end of label"
+            .align  4
+no_opcode:  .asciz  "Error: Expected an opcode"